CA1067483A - Baffle - Google Patents
BaffleInfo
- Publication number
- CA1067483A CA1067483A CA261,774A CA261774A CA1067483A CA 1067483 A CA1067483 A CA 1067483A CA 261774 A CA261774 A CA 261774A CA 1067483 A CA1067483 A CA 1067483A
- Authority
- CA
- Canada
- Prior art keywords
- tube
- tubes
- baffle
- rods
- rows
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
- F28F9/007—Auxiliary supports for elements
- F28F9/013—Auxiliary supports for elements for tubes or tube-assemblies
- F28F9/0132—Auxiliary supports for elements for tubes or tube-assemblies formed by slats, tie-rods, articulated or expandable rods
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
- Supports For Pipes And Cables (AREA)
Abstract
A BAFFLE
Abstract of the Disclosure A plurality of parallel tubes in the form of at least a first plurality of parallel tube rows and a second plurality of parallel tube rows are supported by a baffle comprising an outer ring capable of surrounding the tubes and a plurality of parallel rods which form a plurality of parallel chords with the outer ring wherein the rods are capable of passing in the outer ring the tubes forming adjacent parallel tube rows of one plurality of parallel tube rows and wherein the number of rods in the baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
Abstract of the Disclosure A plurality of parallel tubes in the form of at least a first plurality of parallel tube rows and a second plurality of parallel tube rows are supported by a baffle comprising an outer ring capable of surrounding the tubes and a plurality of parallel rods which form a plurality of parallel chords with the outer ring wherein the rods are capable of passing in the outer ring the tubes forming adjacent parallel tube rows of one plurality of parallel tube rows and wherein the number of rods in the baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
Description
A BAFFLE
Background of the Invention The invention relates to a baffle and a method and appaxatus for supporting a plurality of tubes. In another aspect the invention relates to heat exchangers such as shell and tube heat exchangers and to a method and apparatus to radially support the tubes in such heat exchangers.
Heat transfer is an important part of any process. AB is well known, an indirect transfer of heat from one medium to another is usually accomplished by the use of heat exchangers of which there are many types. For example, there are double pipe, shell and tube, plate heat exchangers and others. Indeed, the art ~f heat exchanger design is developed to a very high degree; however, there is still room for improvement in a number of areas, such as reducing pressure drop, increasing overall heat transfer coeffici-ents, reducing fouling, and in heat exchangers utilizing a tube bundle, such as the shell and tube heat exchangers, improving tube support. In many instances the tubes in a shell and tube heat exchanger prematurely fail because the tubes vibrate or rub against one another or other parts of the heat exchanger, such as for example, a baffle or the shell.
The art has heretofore recognized the need for tube support.
Plate type baffles have been used in heat exchangers for many years. Such baffles provide support for the tubes at least to some degree. The double segmental plate-baffle heat exchanger is well known to those skilled in the art, and although heat exchangers using plate type baffles were a relatively early devel-opment in heat exchanger design, such exchangers are still widely used today. In most plate type baffle heat exchangers the pas-sages in the plate baffles through which the tubes pass are slightly larger in diameter than the outside diameter of the tubes in order to facilitate construction of the exchanger, and AS a ~IQ6'79~
result vibration o~ the tubes can and does occur which ~requently results in premature tube ~ailure.
U. S. 2,018,037, issued to Everett Norman Sieder on October 22, 1935, describes a heat exchanger having a supported tube bundle in which a plurality of bars or rods is dispose~ in the lanes be-tween tube rows. A bar or rod is disposed in each lane and affixed to a ring surrounding the tube bundle so that the bars form a series of parallel chords positioned in a plane perpendicular to the longitudinal axis of the tube bundle. When viewing a cross section of the longitudinal axis of the bundle as shown in Figures
Background of the Invention The invention relates to a baffle and a method and appaxatus for supporting a plurality of tubes. In another aspect the invention relates to heat exchangers such as shell and tube heat exchangers and to a method and apparatus to radially support the tubes in such heat exchangers.
Heat transfer is an important part of any process. AB is well known, an indirect transfer of heat from one medium to another is usually accomplished by the use of heat exchangers of which there are many types. For example, there are double pipe, shell and tube, plate heat exchangers and others. Indeed, the art ~f heat exchanger design is developed to a very high degree; however, there is still room for improvement in a number of areas, such as reducing pressure drop, increasing overall heat transfer coeffici-ents, reducing fouling, and in heat exchangers utilizing a tube bundle, such as the shell and tube heat exchangers, improving tube support. In many instances the tubes in a shell and tube heat exchanger prematurely fail because the tubes vibrate or rub against one another or other parts of the heat exchanger, such as for example, a baffle or the shell.
The art has heretofore recognized the need for tube support.
Plate type baffles have been used in heat exchangers for many years. Such baffles provide support for the tubes at least to some degree. The double segmental plate-baffle heat exchanger is well known to those skilled in the art, and although heat exchangers using plate type baffles were a relatively early devel-opment in heat exchanger design, such exchangers are still widely used today. In most plate type baffle heat exchangers the pas-sages in the plate baffles through which the tubes pass are slightly larger in diameter than the outside diameter of the tubes in order to facilitate construction of the exchanger, and AS a ~IQ6'79~
result vibration o~ the tubes can and does occur which ~requently results in premature tube ~ailure.
U. S. 2,018,037, issued to Everett Norman Sieder on October 22, 1935, describes a heat exchanger having a supported tube bundle in which a plurality of bars or rods is dispose~ in the lanes be-tween tube rows. A bar or rod is disposed in each lane and affixed to a ring surrounding the tube bundle so that the bars form a series of parallel chords positioned in a plane perpendicular to the longitudinal axis of the tube bundle. When viewing a cross section of the longitudinal axis of the bundle as shown in Figures
2, 3 and 6 of the patent, a bar is shown in each and every lane.
Thus, two groups or pluralities of bars provide radial support for each tube in the tube bundle. Although such a structure provides very good support for the tubes in the tube bundle, it incurs the penalty of a relatively large pressure loss which, besides being wasteful of energy, is usually a higher pressure loss than can be tolerated. In fact, even though this patented design is some thirty years old, it is not well accepted by industry as evidenced by the fact that it is rarely if ever used.
A tube support which is used and which does provide a low pressure drop is that described 1n U. S. 3,708,142, issued January 2, 1973 to the same inventor as the inventor of the pre-sent invention. The design of the present invention provides a substantial improvement in heat transfer coefficients and fouling resistance at a relatively small increase in pressure drop as compared to the earlier invention referred to above. Thus, although the pressure drop is generally lower for an e~changer constructed in accordance with U. S. 3,708,142, as compared to an exchanger constructed in accordance with the present invention, the present invention provides a better overall compromi~e when both the pressure drop and the heat transfer coefficient are considered. In addition, tube bundles supported in accordance 1()67~8~
with the present invention are somewhat cheaper to fabricate in some instances as compared to those of the earlier invention.
It is emphasized that the present invention is a very significant breakthrough in heat exchanger d~sign because support-ing a tube bundle in accordance with the present invention limits tube failure due to such things as vibration, improves the overall heat transfer coe~ficient as compared to prior art heat exchangers and at the same time reduces the pressure drop as compared to the plate type baffle heat exchangers well known in the art. Also, heat exchangers employing the inventive baffles and supporting apparatus are economically competitive with heat exchangers of the prior art and at the same time provide better overall performance.
An object of the invention is to support tubes of a tube bundle.
Another object of the invention is to lower the pressure drop on the shell side of a shell and tube heat exchanger and maintain a higher heat transfer coefficient as compared to heat exchangers known in the art.
Another object of the invention is to protect the tubes in a tube bundle from failure due to vibration.
Another object of the invention is to reduce the external ;
fouling of tube~bundles such as the fouling on the shell side of a shell and tube heat exchanger and the consequent loss of heat transfer capability.
Still another object of the invention is to provide a tube support to substantially reduce tube failure in a tube bundle and at the same time improve heat transfer coefficients and reduce the pressure drop on the shell side of a shell and tube heat ex-changer.
Other objects, aspects and advantages of the invention will be apparen-t to those skilled in the art upon a study o~ the specification and drawings.
10~7~33 Summary of the Invention According to the invention a baffle comprises an outer ring suitable for surrounding a plurality of para:Llel tubes which form at least a first plurality of paralleI tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows, and a plurality of parallel rods cooperating with and attached to said outer ring to form a plurality of parallel chords with said outer ring wherein said rods are capable of passing in the spaces between the tubes forming adjacent parallel tube rows of one plurality of parallel tube rows and wherein the number of rods in the baffle is sub-stantially less than the total number of rods which could be posi-tioned in the spaces between the tube rows in the plurality of parallel tube rows.
Further according to the invention a supporting apparatus for a plurality of tubes in the form of a tube bundle wherein the tubes are posltioned to form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces be-tween at least a portion of the adjacent tube rows comprises at least one baffle set providing radial support for each tube and comprising at least three baffles, wherein each baffle is as described above.
Further according to the invention a plurality of tubes is supported by arranging the tubes ln the form of a tube bundle having at least a first plurality of parallel tube rows and a se-cond plurality of parallel tube rows and having spaces between at least a portion of the adjacent tube rows, forming at least one baffle set comprising baffles wherein the number of baffles in each baffle set is sufficient to radially support each tube in the tube bundle, and forming each of said baffles by position-ing an outer ring around the tube bundle and inserting a plurality of rods through a portion of the spaces between adjacent parallel 1~6'7~83 tube rows of one plurality of parallel tube rows to cooperate with the outer ring to form a plurality o~ parallel ahords wherein each such rod is of sufficient size to provide support for the tubes in the tube rows adjacent the rod and wherein the number of such rods inserted to form each baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows of the pluralit~y of parallel tube rows.
Brief Description of the Drawings:
FIGURE 1 is an elevational view of a heat exchanger employing an embodiment of the invention;
FIGURE 2 is a cross-sectional view taken substantially on line 2-2 of FIGURE 1 showing a baffle in accordance with the invention;
FIGURE 3 is a cross-sectional view taken substantially on line 3-3 of FIGURE 1 showing another baffle of the invention suitable for use in combination with that of FIGURE 2;
FIGURE 4 is a cross-sectional view taken substantially on line 4-4 of FIGURE 1 showing another baffle of the invention suit-able for use with those of FIGURES 2 and 3;
FIGURE 5 is an elevational view of a plurality of tubes inthe form of a tube bundle employing another embodiment of the invention;
FIGURE 6 is a cross-sectional view taken substantially on line 6-6 of FIGURE 5 showing a baffle of the invention;
FIGURE 7 is a cross-sectional view taken substantially on line 7-7 of FIGURE 5 showing another baffle of the invention suit-able for use with that of FIGURE 6;
FIGURE 8 is a sectional view taken substantially on line 8-8 30 of FIGURE 5 showing another baffle of the invention suitable for use with those of FIGURES 6 and 7;
FIGUR~ 9 is a cross-sectional view taken substantially on 67~33 line 9-9 of FIGURE 5 showing another baffle of the invention suit-able for use with those of FIGURES 6, 7 and 8;
FIGURES 10 to 15 illustrate a baffle set in accordance with another embodiment of the invention comprising six baffles wherein the tubes in the tube bundle are`laid out on a hexagonal pitch.
FIGURE 16 graphically illustrates the overaLl heat transfer coefficient measured as a function of shell side flow rate for a heat exchanger made in accordance with applicant's invention and for two prior art heat exchangers;
FIGURE 17 is a graphical illustration of shell side pressure drop measured as a function of sheIl side flow rate employing the heat exchangers used for determining the values shown in the graph of FIGURE 16;
FIGURE 18 illustrates graphically the ratio of the overall heat transfer coefficient to pressure drop measured as a function of shell side flow rate¢.employing the same heat e~cchangers used for determining the values shown in the gxaphs of FIGURES 16 and 17.
FIGURE 19 is an elevational view of a plurality of tubes in the form of a tube bundle employing another embodiment of the invention;
FIGURE 20 is a cross-sectional view taken substantially on line 20-20 of FIGURE 19 showing a baffle of the invention;
FIGURE 21 is a cross-sectional view taken substantially on line 21-21 of FIGURE 19 showing another baffle of the invention suitable for use with that of FIGURE Z0;
FIGURE 22 is a cross-sectional view taken substantially on line 22-22 of FIGURE 19 showing another baffle of the invention suitable for use with those of FIGURES 20 and 21; and FIGU~E 23 is a cross-sectional view taken substantially on line 23-23 of FIGURE 19 showing another baffle of the invention suitable for use with those of FIGURES 20, 21 and 22.
7~3 Detailed Description of the Prefer_ed Embod ments High'flow rates of the fluids passed through a heat exchanger frequently cause vibration of the tubes in the tube bundle if the tubes are not radially supported which'in turn causes one or more of the tubes to fail prematurely, that is, before the tube or tubes would be expeated to fail based upon the materials used to construct the tubes and the service of the exchanger. Two of the common methods for reducing such vibration are the addition of plate baffles to add additional support to the tubes of the tube bundle and/or the lowering of the velocity of the fluid across the tubes.
~he addition of plate baffles causes a substantial increase in pressure drop through the shell side of the heat exchanger and reduction in the shell side flow rate requires a larger, more expensive exchanger than is otherwise necessary. The present invention solves the vibration problem without substantially increasing the shell side pressure drop or substantially reducing the shell side flow rate. As used herein the terms "pressure drop"
and "pressure loss" are synonymous. It is noted that the heat exchanger and tube bundle designs shown in the drawings are schematic in nature and for purposes of better illustrating the invention. They are not intended as drawings showing thè actual relative size of the exchanger and the component parts of the tube'bundle.
Referring to FIGURE 1, a heat exchanger, denoted generally by reference numeral 10, employing an embodiment of the invention has two tube sheets 17a and 17b and three baf~les 12, 1~ and 16 supporting the tubes 18 which are in the form of a tube bundle 20 positioned inside shell 19. Although each of baffles 12, 14 and 16 is shown lying in a plane which is perpendicular to the longitudinal axis of tube bundle 20, it is possible to use baffles which are not in a plane perpendicular to the longitudinal axis of tube bundle 20; however, baffles lying in the perpendicular ~S~83 plane as shown are easier and cheaper to construct and thus pre-ferred. The tube side of heat exchanger 10 has an inlet nozzle 22 and an outlet nozzle 24 to permit a first fluid to pass over the inside sur~ace of the tubes and the shell. side has an inlet nozzle 26 and an outlet nozzle 28 to permit a second fluid to pass over the outside surface of the tubes when using countercur-rent flow of the heat exchange mediums. The tubes 18 in heat exchanger 10 are laid out on an equilateral triangular pitch as shown clearly in the baffles of FIGURES 2 to 4 and form a first, second and third plurality of parallel tube rows oriented at 60 degrees to one another. Baffle 12 of FIGURE 2 shows the first plurality of parallel tube rows which are positioned parallel to rods 31. Adjacent parallel tube rows form a space through which the rods are positioned. An example of the space formed by adjac-ent tube rows through which a rod is passed is indicated by refer-ence numeral 34. Baffle 14 of FIGURE 3 shows the second plurality of parallel tube rows which are positioned parallel to rods 31.
An example of the space formed by adjacent tube rows through which a rod is passed is indicated by reference numeral 36. Baffle 16 of FIGURE 4 shows the third plurality of parallel tube rows which are positioned parallel to rods 33. An example of the space formed by adjacent tube rows through which a rod is passed is indicated by reference numeral 38. Baffles 12, 14 and 16 constitute a baffle set because all three baffles are required before all the tubes in the tube bundle are radially supported. As used herein a tube is "radially supported" when the tube is restricted from movement in all directions perpendicular to the longitudinal axis of the tube.
Each baffle in FIGURES 2, 3 and 4 is made from an outer ring 30 surrounding the tubes 18 in the tube bundle 20. Rods 31 are positioned within the space between adjacent rows of tubes 34 of FIGURE 2, rods 32 between adjacent rows of tubes 36 of ~ ~G7L~ 3 FIGURE 3/ and rsds 33 between adjacent rows of tubes 38 of FIGURE 4 so as to cooperate with outer ring 30 to form a plurality of parallel chords with outer ring 30. Genexally rods 31, 32 and 33 are affixed to outer ring 30, such as by welding them to the ring or bolting them to the ring using tie down members 40, 41 for baffle 12; 42, 43 for baffle 14 and 44, 45 for baffle 16 along with bolts 46. Rods 31, 32 and 33 must be of sufficient size to provide support for tubes 18 in the tube rows adjacent each rod.
The total number of rods used in each baffle must be;substantially less than the total number of rods which could be positioned in the spaces between the tube rows of the baffle.
Where only three baffles make up a baffle set, three baffles in a baffle set being the least number of baffles that can be used in accordance with the invention where the tubes are laid out on an equilateral triangular pitch, no more rods need be used in each baffle than the number which will provide radial support for each tube in the tube bundleO Generally an equal number of rods are used in each baffle; however, there may be instances where there is some variation in the number of rods used in the individual baffles of a set. At least one baffle set is required in accordance with the invention but baffles over and above those needed to constitute one baffle set can be used including partial baffle sets. For example, where three baffles are necessary for a baffle set, five baffles can be used in accordance with the invention, and if the baffles are equally spaced between the tube sheets, the longest unsupported tube distance is three times the distance between any two of the baffles.
Since one of the more important aspects of the invention is the reduction of tube failure due to vibration, the maximum un-supported tube distance is very important in designing a support-ing apparatus. Since it is desirable to prevent tube collisionsby adjacent tubes between support points, the supporting apparatus ~ 74E~3 is generally designed so that the maximu~ alLowable tube deflec-tion under load is equal to something less than one-half the clearance between adjacent tubes.
FIGURES ~ through 9 illustrate a prefexred embodiment of the invention because the tubes~50 in tube bundle~52 having tube sheets 51a and 51b are laid out in square pitch and generally a s~uare pitch tube layout provides greater surface area for a given shell diameter for an apparatus constructed in accordance with ~ the invention. For example, there are 61 tubes in the embodiment of the invention shown in FIGURES 5 to 9 and only 57 tubes in the embodiment of the invention shown in FIGURES 1 to 4, and both embodiments are drawn to the same scale. The invention as illustrated in FIGURES 5 through 9 shows four baffles 54, 56, 58 and 60 and a supporting apparatus requiring all four baffles to constitute a baffle set. In FIGURES 6 and 7 there is a first plurality of parallel tube rows (the horizontal tube rows~ and~
in FIGURES 8 and 9 there is a second plurality of parallel tube rows (the vertical tube rows). Rods 62 and 62a are positioned in the space between the tube rows in the upper half and the lower haIf of the horizontal tube rows of FIGURE 6 and FIGURE 7 respect-ively and cooperate with outer xings 66 to form a plurality of para*
llel chords with outer rings 66. An example of a space between adjacent tube rows is represented in FIGURE 6 by reference numeral 61a and in FIGURE 7 by reference numeral 61b. Rods 64 and 64a are also positioned in the space between the tube rows in the left half and the right half of the vertîcal tube rows of FIGURE
8 and FIGURE 9 respectively and cooperate with outer rings 66 to form a plurality of parallel chords with outer rin~s 66. An example of a space between adjacent tube rows is represented in FIGURE 8 by reference numeral 63a and in FIGURE 9 by re~erence numeral 63b. Rods 62, 62a, 64 and 64a are of sufficient size to provide support for the tubes in the tube rows adiacent each rod '9L83 and the number of rods in each baffle is substantially less than the total number of rods which could be positioned ln the spaces between the tube rows. The rods in the baffles shown in FIGURES
5 to 9 are held in position by tie down membexs 70 bolted to rings 66 using bolts 80.
In the embodiment of the invention as shown in FIGURES 5 to 9 the baffles are shown in the presently preferred embodiment wher~in rings 66 are simply an annular shape as compared to rings 30 of FIGURES 1 to 4 in which the inside edge of rings 30 is cut to provide partial support for the tubes located adjacent the inside edge of the rings; however, it is difficult to make the aircular cuts for partially supporting the tubes located adjacent the inside edge of the rings 30 so that no radial movement of the tubes is allowed. The design of baffles 54, 56, 58 and 60 of FIGURES S to 9 avoids this problem simply by not making the ring with such cuts and using one additional rod to support the tubes which wouId be otherwise partially supported by the cuts in the ring. The additional rod is shown as 62a in FIGURES 6 and 7 and as 64a in FIGURES 8 and 9. Further, the design of the baffles with annular rings 66 in FIGURES 5 to 9 is preferred because such a design further reduces the pressure lo s through the heat exchang-er since part of the ring which restricted the flow of the shell side fluid is eliminated. Therefore, this design simplifies th~
construction of the baffles and particularly rings 66, helps pre-vent premature tube failure due to the tubes rubbing against the relatively sharp inside edge of the rings, and further reduces the pressure loss across the shell side of the heat exchanger.
In the embodiment of the invention as shown in FIGURES 19 to 23 the baffles are very similar to those shown in FIGURES 5 to 9. In FIGURES l9 to 21 rods 162 are inserted in alternate spaces between adjacent tube rows in each baffle whereas xods 62 in FIGURES 5 to 7 are inserted in adjacent spaces between adjacent ~06'7483 tube rows. In FIGURES 19, 22 and 23 rods 164 are inserted in alternate 5paces between ad~acent tube~ro~s in each baffle as compared to FIGURES 5, 8 and 9 wherein rods 64 are inserted in adjacent spaces between adjacent tube rows. But in any of the embodiments of the invention the rods are only inserted in a por-tion of the spaces between adjacent tube rows. ~IGU~ES 19 to 23 further illustrate rings 166 surrounding tubes 150 which form a tube bundle 152 with the rods passing through tube bundle 152 and attached to rings 166 employing tie down members 170 bolted to rings 166 using bolts 180.
The baffles in FIGURES 19 to 23 are constructed in the same manner as those shown in FIGURES 5 to 9 in that rings 166 of FIGURES 19 to 23 and rings 66 of FIGURES 5 t~ 9 are simply annular rings and not the same type of ring as rings 30 shown in FIGURES
1 to 4 which are cut with an inside edge to fit partially around the tubes to give partial support thereto. Since rings 166 are the annular rings-, use of additional rods 162a in FIGURES 20 and 21 and additional rods 164a in FIGURES 22 and 23 are required.
Rods 162a and 164a are required for the same reason~as rods 62a and 64a in FIGURES 6 to ~ as previously described. Further the baffles in any embodiment of the invention can be positioned in a plane which is not perpendicular to the longitudinal axis of the tubes as well as in a plane which is perpendicular to said axis. It is presently preferred to construct the~support apparatus of the invention using baffles which are positioned in a pIane ;~ perpendicular to the longitudinal axis of the tubes because the ~
rings 166 can be circular in shape as opposed to the more difficult to construct elliptical shape required for baffles positioned in a plane which is not perpendicular to the longitudinal axis of the 3Q tubes. Of course it is understood that baffles positioned in a plane perpendicular to the longitudinal axis of the tubes as well as baffles positioned in a plane not perpendicular to said axis are within the scope of the present invention.
~L~674~33 It is emphasized that a supporting apparatus in accordance with the present invention only requires that the rods in each baffle inserted in the spaces between adjacent tube rows in one plurality of parallel tube rows are inserted into less than the total number of such spaces and further that when the rods are inserted into such spaces in the baffles that at least three baffles are required to radially support each and every tube in the tube bundle. It is immaterial whether the rods are inserted in adjacent spaces, alternate spaces, two adjacent spaces followed by skipping two spaces or any variation desired. The baffles shown in FIGURES
6 to 9 are essentially identical to the baffles shown in FIGURES
20 to 23 for all practical purposes.
The 6 baffles shown in FIGURES 10 to 15, illustrating another embodiment of the invention, are required to make a baffle set using the tube layout there shown. The baffle set provides radial support for each tube and only three rods are tangent to each tube. Three rods positioned around each tube are the mini-`
mum number required to provide radial support for each tube so long as the total spacing between the three rods is in excess of 180 degrees, which is the case in FIGURES 10 to 15.
In FIGURES 10 to 15 baffles 90, 92, 94, 96, 98 and 100 respectively are shown comprising rings 102 surrounding tubes 104 in the form of a tube bundle in which the tubes are laid out on a hexagonal pitch. Rings 102 are the same annular shape as rings 66 shown in FIGURES 5 to 9. In baffles 90 and 92, rods 106 are positioned in the space 108 between parallel tube row~ in a first plurality of parallel tube rows. In baffles 94 and 96 rods 114 are positioned in spaces 116 between parallel tube rows of a second plurality of parallel tube rows. In baffles 98 and 100 rods 118 are positioned in spaces 120 between parallel tube rows of a third plurality of parallel tube rows. The rods of each ~67i~3 : l baffle are held in place by tie down members 110 bolted to rings 102 using bolts 112.
The minimum number of rods in a baffle is the number suffi-cient for the baffle set to provide radial support for each tube forming the tube bundle. It is preferred that this ~unctional limitation also be used to determine the maximum number of rods in a baffle because the pressure drop across the shell side of a shell and tube heat exchanger is the lowest when the least number of rods are used to form the baffles; however, it is essential to use enough rods in each baffle for the baffle set to provide radial support for each tube.
Where a baffle set consists of 4 baffles, the rods in each bafle will be positioned in roughly 50 to 60 percent of the spaces between adjacent tube rows in one plurality of parallel tube rows.
If a baffle set consists of 8 baffles, then roughly 25 to 35 per-cent of the spaces will contain rods. If the tubes of the tube bundle are laid out on a square pitch, then a baffle set must contain at least 4 baffles or a baffle set can contain even num-bers above 4, such as 6, 8, 10, 12 etc. If the tubes of the tube bundle are laid out on triangular pitch, then a baffle set must contain a minimum of 3 baffles; however multiples of 3 can be used to constitute a baffle set, such as 6, 9r etc., although it is also possible to use 4 baffles or an even number of baffles above 4 to constitute a baffle set. If the tubes are laid out on a hexagonal pitch as shown in FIGURES 10 to 15, then at least 6 baffles per baffle set are required to provide radial support for each tube in the tube bundle. The number of baffles consti-tuting a baffle set as described above must not be confused with the total number of baffles used in the tube bundle as thiq latter number can be any number above the minimum number required in a baffle set and the total number of baffles in the tube b~mdle 4~
is otherwise independent of the number of baffLes in a baffle set.
It is apparent from the above description of FIGURES 1 to 15 and FIGURES 19 to 23 that the minimum number of baffles per baffle set is dependent upon the tube layout. Three different tube layouts are shown in the drawings; however, oth~r tube layouts are possible in which the minimum number of baffles in a baffle set may be other than those specifically discussed. But with any tube layout, at least three baffles per baffle set are required to practice the present invention and the specific tube layouts herein discussed are presented for the purposes of illus-tration and are not intended to limit the broad invention.
It is presently believed that the shell side pressure drop for any given e~changer designed in accordance with the invention will be largely localizèd at or near the inlet and outlet regions of the shell, and thus it is recommended to employ inlet and outlet shell side nozzle designs having low turbulence and pressure drop characteristics. For example, diverging nozzles, multiple nozzles and annular distributors provide low pressure drop and low tur-bulence in the shell side inlet and outlet regions. It is impor-tant in designing an apparatus in accordance with the invention to note that the fluid on the shell side of the apparatus flows essentially in the longitudinal direction, that is, essentially parallel to the longitudinal axis of the tubes; therefore it is recommended that longitudinal flow channels or passageways which are relatively large in relation to the clearance between the tubes be minimized either by actual elimination of such passageways or blocking off such passageway using suitable baffles.
Inherent in the design of an apparatus shown in FIGURES 1 to 15 and FIGURES 19 to 23 is the incorporation of a ring baffle and a foundation for the rods forming the rod baffle. The ring 1~ 7a"~
baffle restricts the flow of the shell side fluid between the shelland the tube bundLe and also provides a foundation to attach the rods in order to form the rod ba~fle.
It is appreciated by those skilled in the art that heat exchangers designed in accordance with the invention can be designed incorporating a variety of the configurations known in the art such as U-tubes, multiple tube passes, floating head designs, etc.
As mentioned previously it is preferred to position the outer rings and thus the baffles in a plane perpendicular to the longitudinal axis of the tube bundle because with the outer rings in such position it is generally easier to construct the baffles; however, baffles lying in a plane which is not perpen-dicular to the longitudinal axis of the tube bundle are within the scope of the invention.
In an effort to more fully describe the invention the follow-ing example is provided.
EXAMPLE
Three countercurrent, single pass shell and tube heat ex-changers were constructed and tested. ~ach heat exchanger contalned 137 carbon steel tubest 9.7 feet (2.96 m) long with a 0.5 inch (1.27 cm) outside diameter, laid out on a square pitch of 0.6875 inch (1.7463 cm) and having a shell inside diameter of 10.25 inches t26.04 cm). Each heat exchanger was designed to have the same tube support distance, 9.8 inches (24.89 cm). Both the shell side fluid and the tube side fluid were water with the tube flow rate equal to 4.2 feet per second (1.28 m/sec.), 115,800 pounds per hour. Hot fluid (shell side~ inlet temperatures were generally about 165 F (73.9 C) with the cold fluid (tube side) inlet temperatures employed being appropriate values between 80 F
(26.7 C) and 130 F t54.4 C). Thereby the temperature approach at each end of a tested exchanger was maintained greater than 10 F to provide adequate heat exchange driving force, as known ~1~6/~3 to those skilled in this art, from which consistent test results were calculated. The shell side flow rate, W, was varied from about 2500 to 20,000 pounds per hour (lI34 to 9072 Kg/hr).
FIGURES 16, 17 and 18 graphically illustrate the results of the tests in which the overall heat transfer coeicient, U; pressure drop ~P; and the ratio U//\P were determined as functions o the shell side 1Ow rate, W, by appropriate methods of calculation known to those skilled in this art from data taken during compara-ble test runs. Conversion factors are on each of the drawings for converting the data from English Units to the International System of Units.
One heat exchanger design employed was the double segmental plate baffle type referred to hereinafter as the segmental plate baffle heat exchanger. The baffle cut was 50 percent, that is, the baffle cut was such that it would provide an open area equal to substantially 50 percent of the total cross-sectional area of the shell less the space occupied by the tubes. This type of exchanger is frequently used and considered one of the standard designs in the industry. The tube support distance was 9.8 inches (24.89 cm); thus the baffle spacing was 4.9 inches (12.45 cm).
The second heat exchanger design employed was that described in U.S. Patent 3,708,142, hereinafter referred to as the crisscross rod baffle heat exchanger. In this design each baffle provides radial support for each tube in the tube bundle; thus for a tube support distance of 9.8 inches (24.89 cm) a bafle spacing of 9.8 inches (24.89 cm) was used.
The third heat exchanger design was that of the present invention, referred to hereinafter as the vertical segmental rod baffle heat exchangex constructed in accordance with FIGURES
5 through 9 previously described except that the outer rings were constructed in accordance with the embodiment shown in FIGURES 2 to 4. Four baffles per baffle set were used with a . .' iC~6 7 ~33 baffle spacing of 2.4 inches to provide a tube support distance of 9.8 inches (24.89 cm), the same as used in the other two heat exchangers previously described. The number of rods used in each baffle was ~4 which was the minimum number which prov~ded radial support for each tube in the tube bundle. The rods in each baffle were positioned in approximately 50 percent of the spaces between adjacent tube rows in one plurality of parallel tube rows.
As shown in FIGURE 16, the vertical segmental rod bafEle heat exchanger provided a substantial and unexpected increase in the heat transfer coefficient over that of the other two heat exchangers. Throughout the entire range of flow rates employed the segmental rod baffle heat exchanger of the invention produced heat transfer coefficients ranging from approximately 11 to 14 percent higher than the double segmental plate baffle heat ex-changer, and approximately 50 to 60 percent higher than the -crisscross rod baffle heat exchanger.
FIGURE 17 shows that the shell side pressure loss (in pounds per square foot) of the vertical segmental rod baffle heat exchanger was almost as low as that of the crisscross rod baffle heat exchanger and that ~he pressure drop for either of those two heat exchangers was substantially better than the pressure loss of the double segmental plate baffle heat exchanger. The pressure drop data for the vertical segmental rod baffle exchanger of the invention is particularly surprising since it was this heat ex-changer that provided th~ best heat transfer coefficients~ Heat e~changers employing the tube support apparatus of the present invention are not only capable of operating at a much lower pres-sure drop than that of a double segmental plate baffle exchanger of comparable size but at the same time provide substantially higher heat transfer coefficients as compared to a comparable double segmental plate baffle heat exchanger or a comparable criss-cross rod baffle heat exchanger.
~S~ 3 ~;
FIGURE 18 shows that the ratio of the heat trans~er coeffi-cient to the pressure loss for a given shell side flow rate is substantially higher for the vertical segmental rod baffle heat exchanger as compared to the prior art heat exchangers. This graph, combining the results of FIGURES 16 and 17, provides an overall picture of the exc llent results obtained employing the tube support method and apparatus of the present invention because both the pressure drop and the heat transfer coef~icient are taken into consideration at the same time.
These three graphs and especially FIGURE 18 clearly establish that the present invention definitely provides unexpected results as compared to prior art heat exchangers including one ln which the baffles were constructed with rods.
Thus, two groups or pluralities of bars provide radial support for each tube in the tube bundle. Although such a structure provides very good support for the tubes in the tube bundle, it incurs the penalty of a relatively large pressure loss which, besides being wasteful of energy, is usually a higher pressure loss than can be tolerated. In fact, even though this patented design is some thirty years old, it is not well accepted by industry as evidenced by the fact that it is rarely if ever used.
A tube support which is used and which does provide a low pressure drop is that described 1n U. S. 3,708,142, issued January 2, 1973 to the same inventor as the inventor of the pre-sent invention. The design of the present invention provides a substantial improvement in heat transfer coefficients and fouling resistance at a relatively small increase in pressure drop as compared to the earlier invention referred to above. Thus, although the pressure drop is generally lower for an e~changer constructed in accordance with U. S. 3,708,142, as compared to an exchanger constructed in accordance with the present invention, the present invention provides a better overall compromi~e when both the pressure drop and the heat transfer coefficient are considered. In addition, tube bundles supported in accordance 1()67~8~
with the present invention are somewhat cheaper to fabricate in some instances as compared to those of the earlier invention.
It is emphasized that the present invention is a very significant breakthrough in heat exchanger d~sign because support-ing a tube bundle in accordance with the present invention limits tube failure due to such things as vibration, improves the overall heat transfer coe~ficient as compared to prior art heat exchangers and at the same time reduces the pressure drop as compared to the plate type baffle heat exchangers well known in the art. Also, heat exchangers employing the inventive baffles and supporting apparatus are economically competitive with heat exchangers of the prior art and at the same time provide better overall performance.
An object of the invention is to support tubes of a tube bundle.
Another object of the invention is to lower the pressure drop on the shell side of a shell and tube heat exchanger and maintain a higher heat transfer coefficient as compared to heat exchangers known in the art.
Another object of the invention is to protect the tubes in a tube bundle from failure due to vibration.
Another object of the invention is to reduce the external ;
fouling of tube~bundles such as the fouling on the shell side of a shell and tube heat exchanger and the consequent loss of heat transfer capability.
Still another object of the invention is to provide a tube support to substantially reduce tube failure in a tube bundle and at the same time improve heat transfer coefficients and reduce the pressure drop on the shell side of a shell and tube heat ex-changer.
Other objects, aspects and advantages of the invention will be apparen-t to those skilled in the art upon a study o~ the specification and drawings.
10~7~33 Summary of the Invention According to the invention a baffle comprises an outer ring suitable for surrounding a plurality of para:Llel tubes which form at least a first plurality of paralleI tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows, and a plurality of parallel rods cooperating with and attached to said outer ring to form a plurality of parallel chords with said outer ring wherein said rods are capable of passing in the spaces between the tubes forming adjacent parallel tube rows of one plurality of parallel tube rows and wherein the number of rods in the baffle is sub-stantially less than the total number of rods which could be posi-tioned in the spaces between the tube rows in the plurality of parallel tube rows.
Further according to the invention a supporting apparatus for a plurality of tubes in the form of a tube bundle wherein the tubes are posltioned to form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces be-tween at least a portion of the adjacent tube rows comprises at least one baffle set providing radial support for each tube and comprising at least three baffles, wherein each baffle is as described above.
Further according to the invention a plurality of tubes is supported by arranging the tubes ln the form of a tube bundle having at least a first plurality of parallel tube rows and a se-cond plurality of parallel tube rows and having spaces between at least a portion of the adjacent tube rows, forming at least one baffle set comprising baffles wherein the number of baffles in each baffle set is sufficient to radially support each tube in the tube bundle, and forming each of said baffles by position-ing an outer ring around the tube bundle and inserting a plurality of rods through a portion of the spaces between adjacent parallel 1~6'7~83 tube rows of one plurality of parallel tube rows to cooperate with the outer ring to form a plurality o~ parallel ahords wherein each such rod is of sufficient size to provide support for the tubes in the tube rows adjacent the rod and wherein the number of such rods inserted to form each baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows of the pluralit~y of parallel tube rows.
Brief Description of the Drawings:
FIGURE 1 is an elevational view of a heat exchanger employing an embodiment of the invention;
FIGURE 2 is a cross-sectional view taken substantially on line 2-2 of FIGURE 1 showing a baffle in accordance with the invention;
FIGURE 3 is a cross-sectional view taken substantially on line 3-3 of FIGURE 1 showing another baffle of the invention suitable for use in combination with that of FIGURE 2;
FIGURE 4 is a cross-sectional view taken substantially on line 4-4 of FIGURE 1 showing another baffle of the invention suit-able for use with those of FIGURES 2 and 3;
FIGURE 5 is an elevational view of a plurality of tubes inthe form of a tube bundle employing another embodiment of the invention;
FIGURE 6 is a cross-sectional view taken substantially on line 6-6 of FIGURE 5 showing a baffle of the invention;
FIGURE 7 is a cross-sectional view taken substantially on line 7-7 of FIGURE 5 showing another baffle of the invention suit-able for use with that of FIGURE 6;
FIGURE 8 is a sectional view taken substantially on line 8-8 30 of FIGURE 5 showing another baffle of the invention suitable for use with those of FIGURES 6 and 7;
FIGUR~ 9 is a cross-sectional view taken substantially on 67~33 line 9-9 of FIGURE 5 showing another baffle of the invention suit-able for use with those of FIGURES 6, 7 and 8;
FIGURES 10 to 15 illustrate a baffle set in accordance with another embodiment of the invention comprising six baffles wherein the tubes in the tube bundle are`laid out on a hexagonal pitch.
FIGURE 16 graphically illustrates the overaLl heat transfer coefficient measured as a function of shell side flow rate for a heat exchanger made in accordance with applicant's invention and for two prior art heat exchangers;
FIGURE 17 is a graphical illustration of shell side pressure drop measured as a function of sheIl side flow rate employing the heat exchangers used for determining the values shown in the graph of FIGURE 16;
FIGURE 18 illustrates graphically the ratio of the overall heat transfer coefficient to pressure drop measured as a function of shell side flow rate¢.employing the same heat e~cchangers used for determining the values shown in the gxaphs of FIGURES 16 and 17.
FIGURE 19 is an elevational view of a plurality of tubes in the form of a tube bundle employing another embodiment of the invention;
FIGURE 20 is a cross-sectional view taken substantially on line 20-20 of FIGURE 19 showing a baffle of the invention;
FIGURE 21 is a cross-sectional view taken substantially on line 21-21 of FIGURE 19 showing another baffle of the invention suitable for use with that of FIGURE Z0;
FIGURE 22 is a cross-sectional view taken substantially on line 22-22 of FIGURE 19 showing another baffle of the invention suitable for use with those of FIGURES 20 and 21; and FIGU~E 23 is a cross-sectional view taken substantially on line 23-23 of FIGURE 19 showing another baffle of the invention suitable for use with those of FIGURES 20, 21 and 22.
7~3 Detailed Description of the Prefer_ed Embod ments High'flow rates of the fluids passed through a heat exchanger frequently cause vibration of the tubes in the tube bundle if the tubes are not radially supported which'in turn causes one or more of the tubes to fail prematurely, that is, before the tube or tubes would be expeated to fail based upon the materials used to construct the tubes and the service of the exchanger. Two of the common methods for reducing such vibration are the addition of plate baffles to add additional support to the tubes of the tube bundle and/or the lowering of the velocity of the fluid across the tubes.
~he addition of plate baffles causes a substantial increase in pressure drop through the shell side of the heat exchanger and reduction in the shell side flow rate requires a larger, more expensive exchanger than is otherwise necessary. The present invention solves the vibration problem without substantially increasing the shell side pressure drop or substantially reducing the shell side flow rate. As used herein the terms "pressure drop"
and "pressure loss" are synonymous. It is noted that the heat exchanger and tube bundle designs shown in the drawings are schematic in nature and for purposes of better illustrating the invention. They are not intended as drawings showing thè actual relative size of the exchanger and the component parts of the tube'bundle.
Referring to FIGURE 1, a heat exchanger, denoted generally by reference numeral 10, employing an embodiment of the invention has two tube sheets 17a and 17b and three baf~les 12, 1~ and 16 supporting the tubes 18 which are in the form of a tube bundle 20 positioned inside shell 19. Although each of baffles 12, 14 and 16 is shown lying in a plane which is perpendicular to the longitudinal axis of tube bundle 20, it is possible to use baffles which are not in a plane perpendicular to the longitudinal axis of tube bundle 20; however, baffles lying in the perpendicular ~S~83 plane as shown are easier and cheaper to construct and thus pre-ferred. The tube side of heat exchanger 10 has an inlet nozzle 22 and an outlet nozzle 24 to permit a first fluid to pass over the inside sur~ace of the tubes and the shell. side has an inlet nozzle 26 and an outlet nozzle 28 to permit a second fluid to pass over the outside surface of the tubes when using countercur-rent flow of the heat exchange mediums. The tubes 18 in heat exchanger 10 are laid out on an equilateral triangular pitch as shown clearly in the baffles of FIGURES 2 to 4 and form a first, second and third plurality of parallel tube rows oriented at 60 degrees to one another. Baffle 12 of FIGURE 2 shows the first plurality of parallel tube rows which are positioned parallel to rods 31. Adjacent parallel tube rows form a space through which the rods are positioned. An example of the space formed by adjac-ent tube rows through which a rod is passed is indicated by refer-ence numeral 34. Baffle 14 of FIGURE 3 shows the second plurality of parallel tube rows which are positioned parallel to rods 31.
An example of the space formed by adjacent tube rows through which a rod is passed is indicated by reference numeral 36. Baffle 16 of FIGURE 4 shows the third plurality of parallel tube rows which are positioned parallel to rods 33. An example of the space formed by adjacent tube rows through which a rod is passed is indicated by reference numeral 38. Baffles 12, 14 and 16 constitute a baffle set because all three baffles are required before all the tubes in the tube bundle are radially supported. As used herein a tube is "radially supported" when the tube is restricted from movement in all directions perpendicular to the longitudinal axis of the tube.
Each baffle in FIGURES 2, 3 and 4 is made from an outer ring 30 surrounding the tubes 18 in the tube bundle 20. Rods 31 are positioned within the space between adjacent rows of tubes 34 of FIGURE 2, rods 32 between adjacent rows of tubes 36 of ~ ~G7L~ 3 FIGURE 3/ and rsds 33 between adjacent rows of tubes 38 of FIGURE 4 so as to cooperate with outer ring 30 to form a plurality of parallel chords with outer ring 30. Genexally rods 31, 32 and 33 are affixed to outer ring 30, such as by welding them to the ring or bolting them to the ring using tie down members 40, 41 for baffle 12; 42, 43 for baffle 14 and 44, 45 for baffle 16 along with bolts 46. Rods 31, 32 and 33 must be of sufficient size to provide support for tubes 18 in the tube rows adjacent each rod.
The total number of rods used in each baffle must be;substantially less than the total number of rods which could be positioned in the spaces between the tube rows of the baffle.
Where only three baffles make up a baffle set, three baffles in a baffle set being the least number of baffles that can be used in accordance with the invention where the tubes are laid out on an equilateral triangular pitch, no more rods need be used in each baffle than the number which will provide radial support for each tube in the tube bundleO Generally an equal number of rods are used in each baffle; however, there may be instances where there is some variation in the number of rods used in the individual baffles of a set. At least one baffle set is required in accordance with the invention but baffles over and above those needed to constitute one baffle set can be used including partial baffle sets. For example, where three baffles are necessary for a baffle set, five baffles can be used in accordance with the invention, and if the baffles are equally spaced between the tube sheets, the longest unsupported tube distance is three times the distance between any two of the baffles.
Since one of the more important aspects of the invention is the reduction of tube failure due to vibration, the maximum un-supported tube distance is very important in designing a support-ing apparatus. Since it is desirable to prevent tube collisionsby adjacent tubes between support points, the supporting apparatus ~ 74E~3 is generally designed so that the maximu~ alLowable tube deflec-tion under load is equal to something less than one-half the clearance between adjacent tubes.
FIGURES ~ through 9 illustrate a prefexred embodiment of the invention because the tubes~50 in tube bundle~52 having tube sheets 51a and 51b are laid out in square pitch and generally a s~uare pitch tube layout provides greater surface area for a given shell diameter for an apparatus constructed in accordance with ~ the invention. For example, there are 61 tubes in the embodiment of the invention shown in FIGURES 5 to 9 and only 57 tubes in the embodiment of the invention shown in FIGURES 1 to 4, and both embodiments are drawn to the same scale. The invention as illustrated in FIGURES 5 through 9 shows four baffles 54, 56, 58 and 60 and a supporting apparatus requiring all four baffles to constitute a baffle set. In FIGURES 6 and 7 there is a first plurality of parallel tube rows (the horizontal tube rows~ and~
in FIGURES 8 and 9 there is a second plurality of parallel tube rows (the vertical tube rows). Rods 62 and 62a are positioned in the space between the tube rows in the upper half and the lower haIf of the horizontal tube rows of FIGURE 6 and FIGURE 7 respect-ively and cooperate with outer xings 66 to form a plurality of para*
llel chords with outer rings 66. An example of a space between adjacent tube rows is represented in FIGURE 6 by reference numeral 61a and in FIGURE 7 by reference numeral 61b. Rods 64 and 64a are also positioned in the space between the tube rows in the left half and the right half of the vertîcal tube rows of FIGURE
8 and FIGURE 9 respectively and cooperate with outer rings 66 to form a plurality of parallel chords with outer rin~s 66. An example of a space between adjacent tube rows is represented in FIGURE 8 by reference numeral 63a and in FIGURE 9 by re~erence numeral 63b. Rods 62, 62a, 64 and 64a are of sufficient size to provide support for the tubes in the tube rows adiacent each rod '9L83 and the number of rods in each baffle is substantially less than the total number of rods which could be positioned ln the spaces between the tube rows. The rods in the baffles shown in FIGURES
5 to 9 are held in position by tie down membexs 70 bolted to rings 66 using bolts 80.
In the embodiment of the invention as shown in FIGURES 5 to 9 the baffles are shown in the presently preferred embodiment wher~in rings 66 are simply an annular shape as compared to rings 30 of FIGURES 1 to 4 in which the inside edge of rings 30 is cut to provide partial support for the tubes located adjacent the inside edge of the rings; however, it is difficult to make the aircular cuts for partially supporting the tubes located adjacent the inside edge of the rings 30 so that no radial movement of the tubes is allowed. The design of baffles 54, 56, 58 and 60 of FIGURES S to 9 avoids this problem simply by not making the ring with such cuts and using one additional rod to support the tubes which wouId be otherwise partially supported by the cuts in the ring. The additional rod is shown as 62a in FIGURES 6 and 7 and as 64a in FIGURES 8 and 9. Further, the design of the baffles with annular rings 66 in FIGURES 5 to 9 is preferred because such a design further reduces the pressure lo s through the heat exchang-er since part of the ring which restricted the flow of the shell side fluid is eliminated. Therefore, this design simplifies th~
construction of the baffles and particularly rings 66, helps pre-vent premature tube failure due to the tubes rubbing against the relatively sharp inside edge of the rings, and further reduces the pressure loss across the shell side of the heat exchanger.
In the embodiment of the invention as shown in FIGURES 19 to 23 the baffles are very similar to those shown in FIGURES 5 to 9. In FIGURES l9 to 21 rods 162 are inserted in alternate spaces between adjacent tube rows in each baffle whereas xods 62 in FIGURES 5 to 7 are inserted in adjacent spaces between adjacent ~06'7483 tube rows. In FIGURES 19, 22 and 23 rods 164 are inserted in alternate 5paces between ad~acent tube~ro~s in each baffle as compared to FIGURES 5, 8 and 9 wherein rods 64 are inserted in adjacent spaces between adjacent tube rows. But in any of the embodiments of the invention the rods are only inserted in a por-tion of the spaces between adjacent tube rows. ~IGU~ES 19 to 23 further illustrate rings 166 surrounding tubes 150 which form a tube bundle 152 with the rods passing through tube bundle 152 and attached to rings 166 employing tie down members 170 bolted to rings 166 using bolts 180.
The baffles in FIGURES 19 to 23 are constructed in the same manner as those shown in FIGURES 5 to 9 in that rings 166 of FIGURES 19 to 23 and rings 66 of FIGURES 5 t~ 9 are simply annular rings and not the same type of ring as rings 30 shown in FIGURES
1 to 4 which are cut with an inside edge to fit partially around the tubes to give partial support thereto. Since rings 166 are the annular rings-, use of additional rods 162a in FIGURES 20 and 21 and additional rods 164a in FIGURES 22 and 23 are required.
Rods 162a and 164a are required for the same reason~as rods 62a and 64a in FIGURES 6 to ~ as previously described. Further the baffles in any embodiment of the invention can be positioned in a plane which is not perpendicular to the longitudinal axis of the tubes as well as in a plane which is perpendicular to said axis. It is presently preferred to construct the~support apparatus of the invention using baffles which are positioned in a pIane ;~ perpendicular to the longitudinal axis of the tubes because the ~
rings 166 can be circular in shape as opposed to the more difficult to construct elliptical shape required for baffles positioned in a plane which is not perpendicular to the longitudinal axis of the 3Q tubes. Of course it is understood that baffles positioned in a plane perpendicular to the longitudinal axis of the tubes as well as baffles positioned in a plane not perpendicular to said axis are within the scope of the present invention.
~L~674~33 It is emphasized that a supporting apparatus in accordance with the present invention only requires that the rods in each baffle inserted in the spaces between adjacent tube rows in one plurality of parallel tube rows are inserted into less than the total number of such spaces and further that when the rods are inserted into such spaces in the baffles that at least three baffles are required to radially support each and every tube in the tube bundle. It is immaterial whether the rods are inserted in adjacent spaces, alternate spaces, two adjacent spaces followed by skipping two spaces or any variation desired. The baffles shown in FIGURES
6 to 9 are essentially identical to the baffles shown in FIGURES
20 to 23 for all practical purposes.
The 6 baffles shown in FIGURES 10 to 15, illustrating another embodiment of the invention, are required to make a baffle set using the tube layout there shown. The baffle set provides radial support for each tube and only three rods are tangent to each tube. Three rods positioned around each tube are the mini-`
mum number required to provide radial support for each tube so long as the total spacing between the three rods is in excess of 180 degrees, which is the case in FIGURES 10 to 15.
In FIGURES 10 to 15 baffles 90, 92, 94, 96, 98 and 100 respectively are shown comprising rings 102 surrounding tubes 104 in the form of a tube bundle in which the tubes are laid out on a hexagonal pitch. Rings 102 are the same annular shape as rings 66 shown in FIGURES 5 to 9. In baffles 90 and 92, rods 106 are positioned in the space 108 between parallel tube row~ in a first plurality of parallel tube rows. In baffles 94 and 96 rods 114 are positioned in spaces 116 between parallel tube rows of a second plurality of parallel tube rows. In baffles 98 and 100 rods 118 are positioned in spaces 120 between parallel tube rows of a third plurality of parallel tube rows. The rods of each ~67i~3 : l baffle are held in place by tie down members 110 bolted to rings 102 using bolts 112.
The minimum number of rods in a baffle is the number suffi-cient for the baffle set to provide radial support for each tube forming the tube bundle. It is preferred that this ~unctional limitation also be used to determine the maximum number of rods in a baffle because the pressure drop across the shell side of a shell and tube heat exchanger is the lowest when the least number of rods are used to form the baffles; however, it is essential to use enough rods in each baffle for the baffle set to provide radial support for each tube.
Where a baffle set consists of 4 baffles, the rods in each bafle will be positioned in roughly 50 to 60 percent of the spaces between adjacent tube rows in one plurality of parallel tube rows.
If a baffle set consists of 8 baffles, then roughly 25 to 35 per-cent of the spaces will contain rods. If the tubes of the tube bundle are laid out on a square pitch, then a baffle set must contain at least 4 baffles or a baffle set can contain even num-bers above 4, such as 6, 8, 10, 12 etc. If the tubes of the tube bundle are laid out on triangular pitch, then a baffle set must contain a minimum of 3 baffles; however multiples of 3 can be used to constitute a baffle set, such as 6, 9r etc., although it is also possible to use 4 baffles or an even number of baffles above 4 to constitute a baffle set. If the tubes are laid out on a hexagonal pitch as shown in FIGURES 10 to 15, then at least 6 baffles per baffle set are required to provide radial support for each tube in the tube bundle. The number of baffles consti-tuting a baffle set as described above must not be confused with the total number of baffles used in the tube bundle as thiq latter number can be any number above the minimum number required in a baffle set and the total number of baffles in the tube b~mdle 4~
is otherwise independent of the number of baffLes in a baffle set.
It is apparent from the above description of FIGURES 1 to 15 and FIGURES 19 to 23 that the minimum number of baffles per baffle set is dependent upon the tube layout. Three different tube layouts are shown in the drawings; however, oth~r tube layouts are possible in which the minimum number of baffles in a baffle set may be other than those specifically discussed. But with any tube layout, at least three baffles per baffle set are required to practice the present invention and the specific tube layouts herein discussed are presented for the purposes of illus-tration and are not intended to limit the broad invention.
It is presently believed that the shell side pressure drop for any given e~changer designed in accordance with the invention will be largely localizèd at or near the inlet and outlet regions of the shell, and thus it is recommended to employ inlet and outlet shell side nozzle designs having low turbulence and pressure drop characteristics. For example, diverging nozzles, multiple nozzles and annular distributors provide low pressure drop and low tur-bulence in the shell side inlet and outlet regions. It is impor-tant in designing an apparatus in accordance with the invention to note that the fluid on the shell side of the apparatus flows essentially in the longitudinal direction, that is, essentially parallel to the longitudinal axis of the tubes; therefore it is recommended that longitudinal flow channels or passageways which are relatively large in relation to the clearance between the tubes be minimized either by actual elimination of such passageways or blocking off such passageway using suitable baffles.
Inherent in the design of an apparatus shown in FIGURES 1 to 15 and FIGURES 19 to 23 is the incorporation of a ring baffle and a foundation for the rods forming the rod baffle. The ring 1~ 7a"~
baffle restricts the flow of the shell side fluid between the shelland the tube bundLe and also provides a foundation to attach the rods in order to form the rod ba~fle.
It is appreciated by those skilled in the art that heat exchangers designed in accordance with the invention can be designed incorporating a variety of the configurations known in the art such as U-tubes, multiple tube passes, floating head designs, etc.
As mentioned previously it is preferred to position the outer rings and thus the baffles in a plane perpendicular to the longitudinal axis of the tube bundle because with the outer rings in such position it is generally easier to construct the baffles; however, baffles lying in a plane which is not perpen-dicular to the longitudinal axis of the tube bundle are within the scope of the invention.
In an effort to more fully describe the invention the follow-ing example is provided.
EXAMPLE
Three countercurrent, single pass shell and tube heat ex-changers were constructed and tested. ~ach heat exchanger contalned 137 carbon steel tubest 9.7 feet (2.96 m) long with a 0.5 inch (1.27 cm) outside diameter, laid out on a square pitch of 0.6875 inch (1.7463 cm) and having a shell inside diameter of 10.25 inches t26.04 cm). Each heat exchanger was designed to have the same tube support distance, 9.8 inches (24.89 cm). Both the shell side fluid and the tube side fluid were water with the tube flow rate equal to 4.2 feet per second (1.28 m/sec.), 115,800 pounds per hour. Hot fluid (shell side~ inlet temperatures were generally about 165 F (73.9 C) with the cold fluid (tube side) inlet temperatures employed being appropriate values between 80 F
(26.7 C) and 130 F t54.4 C). Thereby the temperature approach at each end of a tested exchanger was maintained greater than 10 F to provide adequate heat exchange driving force, as known ~1~6/~3 to those skilled in this art, from which consistent test results were calculated. The shell side flow rate, W, was varied from about 2500 to 20,000 pounds per hour (lI34 to 9072 Kg/hr).
FIGURES 16, 17 and 18 graphically illustrate the results of the tests in which the overall heat transfer coeicient, U; pressure drop ~P; and the ratio U//\P were determined as functions o the shell side 1Ow rate, W, by appropriate methods of calculation known to those skilled in this art from data taken during compara-ble test runs. Conversion factors are on each of the drawings for converting the data from English Units to the International System of Units.
One heat exchanger design employed was the double segmental plate baffle type referred to hereinafter as the segmental plate baffle heat exchanger. The baffle cut was 50 percent, that is, the baffle cut was such that it would provide an open area equal to substantially 50 percent of the total cross-sectional area of the shell less the space occupied by the tubes. This type of exchanger is frequently used and considered one of the standard designs in the industry. The tube support distance was 9.8 inches (24.89 cm); thus the baffle spacing was 4.9 inches (12.45 cm).
The second heat exchanger design employed was that described in U.S. Patent 3,708,142, hereinafter referred to as the crisscross rod baffle heat exchanger. In this design each baffle provides radial support for each tube in the tube bundle; thus for a tube support distance of 9.8 inches (24.89 cm) a bafle spacing of 9.8 inches (24.89 cm) was used.
The third heat exchanger design was that of the present invention, referred to hereinafter as the vertical segmental rod baffle heat exchangex constructed in accordance with FIGURES
5 through 9 previously described except that the outer rings were constructed in accordance with the embodiment shown in FIGURES 2 to 4. Four baffles per baffle set were used with a . .' iC~6 7 ~33 baffle spacing of 2.4 inches to provide a tube support distance of 9.8 inches (24.89 cm), the same as used in the other two heat exchangers previously described. The number of rods used in each baffle was ~4 which was the minimum number which prov~ded radial support for each tube in the tube bundle. The rods in each baffle were positioned in approximately 50 percent of the spaces between adjacent tube rows in one plurality of parallel tube rows.
As shown in FIGURE 16, the vertical segmental rod bafEle heat exchanger provided a substantial and unexpected increase in the heat transfer coefficient over that of the other two heat exchangers. Throughout the entire range of flow rates employed the segmental rod baffle heat exchanger of the invention produced heat transfer coefficients ranging from approximately 11 to 14 percent higher than the double segmental plate baffle heat ex-changer, and approximately 50 to 60 percent higher than the -crisscross rod baffle heat exchanger.
FIGURE 17 shows that the shell side pressure loss (in pounds per square foot) of the vertical segmental rod baffle heat exchanger was almost as low as that of the crisscross rod baffle heat exchanger and that ~he pressure drop for either of those two heat exchangers was substantially better than the pressure loss of the double segmental plate baffle heat exchanger. The pressure drop data for the vertical segmental rod baffle exchanger of the invention is particularly surprising since it was this heat ex-changer that provided th~ best heat transfer coefficients~ Heat e~changers employing the tube support apparatus of the present invention are not only capable of operating at a much lower pres-sure drop than that of a double segmental plate baffle exchanger of comparable size but at the same time provide substantially higher heat transfer coefficients as compared to a comparable double segmental plate baffle heat exchanger or a comparable criss-cross rod baffle heat exchanger.
~S~ 3 ~;
FIGURE 18 shows that the ratio of the heat trans~er coeffi-cient to the pressure loss for a given shell side flow rate is substantially higher for the vertical segmental rod baffle heat exchanger as compared to the prior art heat exchangers. This graph, combining the results of FIGURES 16 and 17, provides an overall picture of the exc llent results obtained employing the tube support method and apparatus of the present invention because both the pressure drop and the heat transfer coef~icient are taken into consideration at the same time.
These three graphs and especially FIGURE 18 clearly establish that the present invention definitely provides unexpected results as compared to prior art heat exchangers including one ln which the baffles were constructed with rods.
Claims (34)
1. Supporting apparatus for a plurality of tubes in the form of a tube bundle, said tubes positioned to form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows comprising:
at least one baffle set providing radial support for each tube and comprising at least three baffles, wherein each baffle comprises an outer ring surrounding said tube bundle; and a plurality of rods positioned in a portion of the spaces between adjacent tube rows in one plurality of parallel tube rows and cooperating with said outer ring to form a plurality of paral-lel chords with said outer ring, each said rod being of sufficient size to provide support for the tubes in the tube rows adjacent said rod, and the number of rods in each such baffle being sub-stantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
at least one baffle set providing radial support for each tube and comprising at least three baffles, wherein each baffle comprises an outer ring surrounding said tube bundle; and a plurality of rods positioned in a portion of the spaces between adjacent tube rows in one plurality of parallel tube rows and cooperating with said outer ring to form a plurality of paral-lel chords with said outer ring, each said rod being of sufficient size to provide support for the tubes in the tube rows adjacent said rod, and the number of rods in each such baffle being sub-stantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
2. The apparatus of claim 1 wherein the tubes are laid out on a square pitch and each baffle set comprises at least four baf-fles.
3. The apparatus of claim 2 wherein the number of rods in a baffle is the number sufficient for the baffle set to provide radial support for each tube in the tube bundle.
4. The apparatus of claim 1 wherein the plurality of rods is positioned in alternate spaces between adjacent tube rows in one plurality of parallel tube rows.
5. The apparatus of claim 1 comprising a plurality of baffle sets.
6. The apparatus of claim 1 wherein the outer ring surround-ing the tube bundle is positioned in a plane perpendicular to the longitudinal axis of said tube bundle.
7. The apparatus of claim 1 wherein the outer ring surround-ing the tube bundle is positioned in a plane which is not per-pendicular to the longitudinal axis of said tube bundle.
8. The apparatus of claim 2 wherein the number of baffles in a baffle set is eight.
9. The apparatus of claim 1 wherein the tubes are laid out on a triangular pitch.
10. The apparatus of claim 9 wherein each baffle set com-prises at least four baffles.
11. The apparatus of claim 10 wherein the number of rods in a baffle is no more than the number sufficient for the baffle set to provide radial support for each tube in the tube bundle.
12. The apparatus of claim 10 wherein the outer ring sur-rounding the tube bundle is positioned in a plane perpendicular to the longitudinal axis of said tube bundle.
13. The apparatus of claim 10 wherein the outer ring sur-rounding the tube bundle is positioned in a plane which is not perpendicular to the longitudinal axis of said tube bundle.
14. The apparatus of claim 1 wherein the tubes are laid out on a hexagonal pitch and each baffle set comprises six baffles.
15. The apparatus of claim 1 wherein the tubes are laid out on a square pitch and each baffle set comprises four baffles, wherein the outer ring surrounding the tube bundle is positioned in a plane which is not perpendicular to the longitudinal axis of said tube bundle, and wherein the plurality of rods is positioned in alternate spaces between adjacent tube rows in one plurality of parallel tube rows.
16. The apparatus of claim 1 wherein all the rods of each baffle are positioned in the spaces between adjacent tube rows in one plurality of parallel tube rows.
17. Apparatus comprising:
a plurality of tubes forming a tube bundle, said tubes positioned to form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows;
means supporting the ends of said tube bundle; and means supporting the tubes in the tube bundle intermediate their ends, said intermediate supporting means comprising at least one baffle set, each baffle set providing radial support for each tube and comprising at least four baffles wherein each baffle comprises an outer ring surrounding said tube bundle and positioned in a plane perpendicular to the longitudinal axis of said tube bundle;
a plurality of rods positioned in a portion of the spaces between adjacent tube rows in one plurality of parallel tube rows, attached to said outer ring and forming a series of parallel chords with said outer ring, said rods of sufficient size to provide support for the tubes in the tube rows adjacent each rod, and the number of rods used in each such baffle being substantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
a plurality of tubes forming a tube bundle, said tubes positioned to form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows;
means supporting the ends of said tube bundle; and means supporting the tubes in the tube bundle intermediate their ends, said intermediate supporting means comprising at least one baffle set, each baffle set providing radial support for each tube and comprising at least four baffles wherein each baffle comprises an outer ring surrounding said tube bundle and positioned in a plane perpendicular to the longitudinal axis of said tube bundle;
a plurality of rods positioned in a portion of the spaces between adjacent tube rows in one plurality of parallel tube rows, attached to said outer ring and forming a series of parallel chords with said outer ring, said rods of sufficient size to provide support for the tubes in the tube rows adjacent each rod, and the number of rods used in each such baffle being substantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
18. The apparatus of claim 17 further comprising a shell surrounding said tube bundle isolating the outside surface of the tubes from the inside surface of the tubes, said shell having an inlet and an outlet for a first fluid to pass over the inside surface of the tubes and an inlet and an outlet for a second fluid to pass over the outside surface of the tubes.
19. The apparatus of claim 18 wherein the inlet and outlet for the second fluid to pass over the outside surface of the tubes are nozzles of a design which minimize the pressure drop and turbu-lence at or near these regions of the apparatus.
20. A method for supporting a plurality of tubes comprising:
arranging the tubes in the form of a tube bundle having at least a first plurality of parallel tube rows and a second plural-ity of parallel tube rows and having spaces between at least a portion of the adjacent tube rows;
forming at least one baffle set comprising baffles wherein the number of baffles in each baffle set is sufficient to radially support each tube in the tube bundle; and forming each of said baffles by (A) positioning an outer ring around said tube bundle and (B) inserting a plurality of rods through a portion of the spaces between adjacent parallel tube rows of one plurality of parallel tube rows to cooperate with the outer ring to form a plurality of parallel chords wherein each such rod is of sufficient size to provide support for the tubes in the tube rows adjacent said rod and wherein the number of such rods inserted to form in each baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows of said plurality of parallel tube rows.
arranging the tubes in the form of a tube bundle having at least a first plurality of parallel tube rows and a second plural-ity of parallel tube rows and having spaces between at least a portion of the adjacent tube rows;
forming at least one baffle set comprising baffles wherein the number of baffles in each baffle set is sufficient to radially support each tube in the tube bundle; and forming each of said baffles by (A) positioning an outer ring around said tube bundle and (B) inserting a plurality of rods through a portion of the spaces between adjacent parallel tube rows of one plurality of parallel tube rows to cooperate with the outer ring to form a plurality of parallel chords wherein each such rod is of sufficient size to provide support for the tubes in the tube rows adjacent said rod and wherein the number of such rods inserted to form in each baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows of said plurality of parallel tube rows.
21. The method of claim 20 wherein a baffle set comprises three baffles and the tubes in the tube bundle are laid out on a triangular pitch.
22. The method of claim 20 wherein a baffle set comprises four baffles and the tubes in the tube bundle are laid out on a square pitch.
23. The method of claim 20 wherein a baffle set comprises six baffles and the tubes in the tube bundle are laid out on a hexagonal pitch.
24. The method of claim 20 wherein the outer ring is posi-tioned in a plane perpendicular to the longitudinal axis of the tube bundle.
25. The method of claim 20 wherein the outer ring is posi-tioned in a plane which is not perpendicular to the longitudinal axis of the tube bundle.
26. The method of claim 20 wherein the number of rods in a baffle is the number sufficient for the baffle set to provide radial support for each tube forming the tube bundle.
27. The method of claim 20 wherein the plurality of rods is inserted into alternate spaces between adjacent parallel tube rows of one plurality of parallel tube rows.
28. The method of claim 20 wherein a baffle set comprises four baffles and the tubes in the tube bundle are laid out on a square pitch, wherein the outer ring is positioned in a plane which is not perpendicular to the longitudinal axis of the tube bundle and wherein the plurality of rods is inserted into alternate spaces between adjacent parallel tube rows of one plurality of parallel tube rows.
29. The method of claim 20 wherein all of the rods of each baffle are inserted in the spaces between adjacent tube rows in one plurality of parallel tube rows.
30. A baffle comprising:
An outer ring suitable for surrounding a plurality of paral-lel tubes which form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows, and a plurality of parallel rods cooperating with and attached to said outer ring to form a plurality of parallel chords with said outer ring wherein said rods are capable of passing in the space between the tubes forming adjacent parallel tube rows of one plurality of parallel tube rows and wherein the number of rods in the baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
An outer ring suitable for surrounding a plurality of paral-lel tubes which form at least a first plurality of parallel tube rows and a second plurality of parallel tube rows and spaces between at least a portion of the adjacent tube rows, and a plurality of parallel rods cooperating with and attached to said outer ring to form a plurality of parallel chords with said outer ring wherein said rods are capable of passing in the space between the tubes forming adjacent parallel tube rows of one plurality of parallel tube rows and wherein the number of rods in the baffle is substantially less than the total number of rods which could be positioned in the spaces between the tube rows in the plurality of parallel tube rows.
31. The apparatus of claim 30 in which the maximum and the minimum number of rods employed is the number required to provide support for the tubes in the tube rows adjacent the rod.
32. The apparatus of claim 31 wherein the tubes are laid out on a square pitch and at least four baffles are required to provide radial support for each tube surrounded by the outer ring.
33. The apparatus of claim 31 wherein the tubes are laid out on a triangular pitch and at least three baffles are required to provide radial support for each tube surrounded by the outer ring.
34. The apparatus of claim 31 wherein the tubes are laid out on a hexagonal pitch and at least six baffles are required to provide radial support fox each tube surrounded by the outer ring.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US68167076A | 1976-04-29 | 1976-04-29 | |
| US05/715,704 US4136736A (en) | 1976-04-29 | 1976-08-20 | Baffle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1067483A true CA1067483A (en) | 1979-12-04 |
Family
ID=27102703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA261,774A Expired CA1067483A (en) | 1976-04-29 | 1976-09-22 | Baffle |
Country Status (17)
| Country | Link |
|---|---|
| JP (1) | JPS52133159A (en) |
| AU (1) | AU497197B2 (en) |
| BR (1) | BR7608437A (en) |
| CA (1) | CA1067483A (en) |
| DD (1) | DD128941A5 (en) |
| DE (1) | DE2706049C2 (en) |
| ES (1) | ES456346A1 (en) |
| FR (1) | FR2357852A1 (en) |
| GB (1) | GB1562662A (en) |
| IT (1) | IT1085928B (en) |
| MX (1) | MX144609A (en) |
| NL (1) | NL164658C (en) |
| NO (1) | NO142415C (en) |
| PL (1) | PL112917B1 (en) |
| SE (1) | SE423647C (en) |
| SU (1) | SU919610A3 (en) |
| YU (1) | YU39672B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ZA786655B (en) * | 1977-12-23 | 1979-10-31 | Phillips Petroleum Co | Tube bundles for heat exchanges and methods of assembling such tube bundles |
| US4311187A (en) * | 1979-11-29 | 1982-01-19 | Phillips Petroleum Company | Vortex generators |
| US4299276A (en) * | 1980-04-21 | 1981-11-10 | Phillips Petroleum Company | Heat exchanger having radial support |
| CH659884A5 (en) * | 1982-04-30 | 1987-02-27 | Bbc Brown Boveri & Cie | HEAT EXCHANGER WITH A TUBE BAND FLOWED IN THE LENGTH DIRECTION. |
| US5005637A (en) * | 1986-11-05 | 1991-04-09 | Phillips Petroleum Company | Heat exchanger U-bend tube support |
| US4823866A (en) * | 1987-11-09 | 1989-04-25 | Phillips Petroleum Company | Tube support for heat exchanger |
| GB2409825B (en) * | 2004-01-08 | 2007-06-13 | Statoil Asa | Heat exchange system for a slurry bubble column reactor |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1790817A (en) * | 1931-02-03 | jacobus | ||
| US2018037A (en) * | 1933-09-29 | 1935-10-22 | Foster Wheeler Corp | Heat exchanger |
| US2581121A (en) * | 1947-12-23 | 1952-01-01 | Standard Oil Dev Co | Means for changing baffle pitch in a heat exchanger |
| US3495556A (en) * | 1968-07-03 | 1970-02-17 | Dorr Oliver Inc | Heat exchanger of the tube bundle type |
| US3708142A (en) * | 1971-01-11 | 1973-01-02 | Phillips Petroleum Co | Tube supports |
| CA921020A (en) * | 1971-03-19 | 1973-02-13 | Her Majesty In Right Of Canada As Represented By Atomic Energy Of Canada Limited | Tube bundle assembly |
| DE2262621C3 (en) * | 1972-12-21 | 1982-11-11 | M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 4200 Oberhausen | Spacer for the tubes of a tube apparatus, in particular a steam generator, having a tube bundle of straight or U-shaped tubes, and a method for piping it |
| DE2313438B2 (en) * | 1973-03-17 | 1978-07-20 | Gutehoffnungshuette Sterkrade | Tubular apparatus, in particular steam generators |
| NO132704C (en) * | 1973-04-10 | 1975-12-17 | Norsk Hydro As | |
| US3967677A (en) * | 1975-05-28 | 1976-07-06 | Mobil Oil Corporation | Heat exchanger baffles |
-
1976
- 1976-09-22 CA CA261,774A patent/CA1067483A/en not_active Expired
- 1976-11-22 AU AU19850/76A patent/AU497197B2/en not_active Expired
- 1976-11-29 MX MX167192A patent/MX144609A/en unknown
- 1976-12-16 JP JP15144776A patent/JPS52133159A/en active Granted
- 1976-12-16 BR BR7608437A patent/BR7608437A/en unknown
-
1977
- 1977-02-04 NO NO770388A patent/NO142415C/en unknown
- 1977-02-07 GB GB4921/77A patent/GB1562662A/en not_active Expired
- 1977-02-07 SE SE7701291A patent/SE423647C/en not_active IP Right Cessation
- 1977-02-08 NL NL7701310.A patent/NL164658C/en not_active IP Right Cessation
- 1977-02-12 DE DE2706049A patent/DE2706049C2/en not_active Expired
- 1977-02-21 YU YU473/77A patent/YU39672B/en unknown
- 1977-02-28 ES ES456346A patent/ES456346A1/en not_active Expired
- 1977-03-08 IT IT21058/77A patent/IT1085928B/en active
- 1977-03-09 SU SU772456033A patent/SU919610A3/en active
- 1977-03-10 PL PL1977196561A patent/PL112917B1/en unknown
- 1977-03-11 DD DD7700197808A patent/DD128941A5/en unknown
- 1977-03-17 FR FR7708052A patent/FR2357852A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| NL164658C (en) | 1981-01-15 |
| ES456346A1 (en) | 1978-02-16 |
| MX144609A (en) | 1981-10-30 |
| FR2357852A1 (en) | 1978-02-03 |
| FR2357852B1 (en) | 1982-02-26 |
| YU47377A (en) | 1982-05-31 |
| SE423647B (en) | 1982-05-17 |
| IT1085928B (en) | 1985-05-28 |
| SE423647C (en) | 1984-04-09 |
| DD128941A5 (en) | 1977-12-21 |
| NO142415C (en) | 1982-12-01 |
| YU39672B (en) | 1985-03-20 |
| NO142415B (en) | 1980-05-05 |
| SU919610A3 (en) | 1982-04-07 |
| GB1562662A (en) | 1980-03-12 |
| NO770388L (en) | 1977-11-01 |
| AU497197B2 (en) | 1978-12-07 |
| NL164658B (en) | 1980-08-15 |
| BR7608437A (en) | 1977-12-13 |
| DE2706049A1 (en) | 1977-11-10 |
| JPS52133159A (en) | 1977-11-08 |
| JPS5421579B2 (en) | 1979-07-31 |
| AU1985076A (en) | 1978-06-01 |
| DE2706049C2 (en) | 1983-04-07 |
| NL7701310A (en) | 1977-11-01 |
| SE7701291L (en) | 1977-10-30 |
| PL112917B1 (en) | 1980-11-29 |
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