US2945627A - Heat transfer apparatus - Google Patents

Description

July 19, 1960 B. L MCDERMOTT HEAT TRANSFER APPARATUS 4 vsheets-sheet 1v Filed Feb. ll, 1957 f||||||llll| July 19, 1960 B. l.. McDERMo-r'r HEAT TRANSFER APPARATUS 4 Sheets-Sheet 2 Filed Feb. 11, 1957 July 19, 1960 B. L. MoDERMoTT 2,945,627

HEAT TRANSFER APPARATUS Filed Feb. l11, 1957 4 sheets-sheer s ATTORNEY July 19, 1950 B. L. MCDERMOTT l 2,945,627

' HEAT TRANSFER APPARATUS Filed Feb. 11, 195'? I fa:

4 Sheets-Sheet 4 74 u] mvENTOR BY l A 1'1 ORNEY United States Patent 'Odice 2,945,627 :Patented JulyA 19, 1960 HEAT TRANSFER APPARATUS Beniamin L. McDermott, 1612 Fargo, Los Angeles, Calif. Filed Feb. 11, 1957, ser. No. 639,340

7 Claims. (Cl. 239-225) This invention relates to a heat transferapparatus of the type commonly known as evaporative condensers employed in the cooling of heaters particularly in refrigeration systems.

Conventional apparatus of the above character commonly embody an arrangement of metallic cooling tubes `for conducting gases to be cooled, together with a means whereby Water and air are directed over the surfaces of tubes in cont-act therewith to effect absorption of heat conducted through and radiating from the tubes `from the warm or hot gases :dowing therethrough and whereby the gases will be reduced in temperature to a pointat or slightly below surrounding air temperature `and whereby such cooling action may cause the gas to condense into liquid within the tubes.

. The eiciency of such apparatus in effecting heat trans- `fer is primarily determined by three factors, namely:

(l) .The -amount of tubing surface available `for heat transfer, its surface condition -and the capacityof the tubing;

(2) YThe amount and temperature of the water to which .the tubing surface is subject and the duration and extent of contact of the water with such surface; and.

(3) The temperature of the air and the volume and rate of. flow thereof. v

. The primary object of the invention is` to provide a construction and arrangement in a heat transfer apparatus of the evaporative condenser type whereby. the several above recited factors may be developed to attain a maximum or at least highly efficient contribution in effecting heat transfer, and wherein the several components Aareso constructed and correlated as to insure a high ratio of heat transfer relative to costs of operation and maintenance.

Another object is to provide mechanismwhereby water and air may be directed onto yan assemblage-of cooling tubes by a fan, pump and moving sprayer actuated collectively by ra single motor driven shaft.

Another object is to provide a water circulating system wherein water is-pumped from a basin and sprayed onto the tubing Iassemblage within la coniining housing and then returned to the basin for recirculation, and in which heat absorbed by the water will be transmitted to abody of air llowing through the apparatus counter to the sprayed water, so as to permit protracted circulation of a charge of water and in which means are provided forautomatically replenishing the charge in vcompensation for loss by evaporation.

Another object is to provide an arrangement in the vwater pumping mechanism whereby the use of packing spraying element land mode of. operation thereof together withV an arrangement of the gas conducting tubing where by cooling water will be thoroughly distributed throughout the outer surfaces of the tubing and under forceable .2 y impact such as to minimize the taccui'nulation of lime deposits on the tubing and to which arrangement is such that the water will be directed throughout the length of the tubing at a uniform temperature so 'as to materially augment heat transfer in comparison with apparatus wherein the water is caused to progressively flow from one heat radiating section of tubing to another such that the temperature of the Water is increased to va .point Where the diiference in rtemperature between the water and gas in portions of the tubing is so reduced as to minimize the heat exchange.

A further object is to provide an evaporative condenser embodying few operatingparts so constructed as to be readily assembled and subject to little wear so as to minimize repairs, which is simple in construction and highly economical in operation, and which is adapted to be designed in various sizes and capacities tomeet various requirements.

With the foregoing objects in view, together with such other objects and advantages yas may subsequently appear, the invention resides in the parts `and in the combination, construction and arrangement of parts hereinafter defscribed'and claimed, and'illustrated by way of example in the accompanying drawing, in which:

Fig. l isa side view of the apparatus with parts shown in section and parts shown in elevation;

Fig.' 2V is `an enlarged vdetail in section with parts shown in' elevation as 'seen on the line 2--2 of Figui illustrating the Water spraying element;

Fig. 3 is a view in front elevation 'with Ia portion of the housing removed;

Fig. 4 is la detail depicting a fragmentary portion of the housing in sectiongwith parts in elevation, the view being an enlargement of the housing shown in section .at the left side of Figi with parts of the "apparatusk removed.

yFig. 5 is an enlarged detail in section as seen on the line 5 --5'ofFig.2;

Fig. 6 is an enlarged detail in section taken von the line 6-6 ofFig. 2; Y.

Fig. 7 is a horizontal section and plan fas seen on the line 7%7 of Fig. 3 on'a, reduced scale;

Fig. Brisa plan view of thesuper-structure ramegand Fig. 9 is -a view in cross section and elevationtaken on the line 9 -9 of Fig. 8.

Referringto Vthe drawings more specifically A indicates `genn'ally the casing of thejapparatus which embodies a rectangular main frame B formedV of angle iron members comprising upstanding corner posts a-aa--u .suitably spaced apart withtheir `channeled .inner faces presented inwardly to. form guide. ways... The posts@ are united adjacentthein lowerend portions by aligned angle iron rails b"bbfb arranged interiorlyof thepost s 'with byUaligned angle iron rails ic-c-,ce-. .arrangedfexteriorly of the postswith theirY channeled sides .presented outwardly. and downwardly and .with their upper rmargins flush with the upper ends'of theposts.A

Mounted in and carried on the framejB isjarectangulfar housing C comprising sheet rnetalside walls oi-TnT-d-d unitedat their side marginsin lperpendicular relation tto .eac-h other producing corners whichare slidably engage able with Vthe posts a. The upper margins ofthefwalls d terminate on a common plane rand have outturn'ed, flanges e which seat on the upper rails c whereby/the housing C Iis supported by thev frameA when positioned therein as particularly shown in Fig.' 4.v 1

The iower, ends yof are, side 'walls fd i'erlilinafe'fml 'fa `common planein upwardlyspaced relationltio ,thelQWer railsl b and have thereon, an inwardly. `extendiijlg.dori/.r1- wardly sloping rectangular 'ledge fhaving an psta'xiding ange g extending continuously along three of its four Vposed therebetween and aixed thereto.

inner margins with its fourth inner margin fitted with a downwardly inclined apron h; the ledge f constituting a trough leading to discharge over the apron h.

Mounted on the lower rails b is a basin D comprising a liat rectangular bottom wall and upstanding side walls j which latter terminate on a common plane spaced a short distance below the ledge f. The apron h extends into the basin C a short distance below the upper edge of one of its side walls.

Mounted on the upper end of the main frame B is a superstructure E embodying a canopy supporting framework particularly shown in Figs. 8 and 9 and which includes a rectangular frame F comprising side rails each of which is composed of a pair of parallel lengths of angle-iron members k-l disposed back to back with their channels extended upwardly. The frame F is dimensioned so that its outer member k will conform t the upper rails c fof the main frame B, while its inner member l is disposed so that the inner face of its upstanding web will extend on a vertical plane spaced slightly inward relative to the inner face of the adjacent side wall d of the housing C, for which purpose the members k-l are separated by spacing strips m inter- The opposed inner members I--l of the side rails of the frame F have their horizontal webs cut away or divided mediate their ends and aiiixed to the inner faces of the portions of the vertical webs of each of the members l-l extending along such cut-away portions is a pair of upstandng spaced standards n-n which project both above and below the rails of the frame F. The upper ends of the standards n--n on opposed rails are affixed to and carry a pair of horizontally extending parallel bottom rails oo, while the lower ends of the standards n-n are affixed to and carry a pair of horizontally extending parallel bottom rails r-r. Mounted on the top rails 0 0 intermediate their ends is a base plate s for supporting an upended electric motor G the drive shaft t of which ends downwardly through the plate and is coupled to a vertically extending driving shaft H which leads through a bearing u carried by the bottom rails r; the shaft H being fitted with a spherical element v journalled in the bearing u and `affording a support for the depending shaft on which the latter is revolvable. The shaft H and its mounting are arranged so that the shaft will extend axially of the housing C, the shaft terminating adjacent the lower end of the housing C where it is connected by a coupling w to the upper end of the vertical impeller spindle x of a conventional sump pump J seated on the bottom of the pan D. The pump J has an inlet on its underside, a side outlet connected to a discharge tube y, and the usual bladed rotor z.

Seating on the margins of the horizontal webs of the inner member l of the frame F is a horizontally extending rectangular plate K having a central opening L through which the shaft H extends, the plate K covering the upper end of the housing C except as to the opening L and being divided medially thereof into halves so as to permit mounting and removal thereof from opposite sides of the shaft H.

IFixedly mounted on the shaft H above and adjacent the bearing u is a fan M the multi-blades of which are disposed to travel within the opening L and are arranged to induct air from the housing C through the opening L and deliver it to discharge through an outlet N at one side of a sheet metal canopy P carried onthe frame F and extending over the area bounded by the latter and overlying the frame work comprising the standards n and top rails o.

Mounted within the housing C is a heat radiating unit Q here 'shown as comprising a double bank-of lengths of metallic tubes 10 of vertically extending serpentine formation with adjacent tubes of each bank thereof disposed in spaced parallel side'by side relation to each other and with the tubes of one bank slightly'otfset vertically and laterally relative to the tubes of the other bank. Each length of tubing of each bank thereof preferably embodies several spaced apart horizontal leads 11 connected by return bends 12 with the ends of the outermost leads extending in opposite directions and connected with manifolds 13 to which are connected pipes 14 leading exteriorly of the housing C to and from a gas circulating system, not shown, whereby gases t0 be cooled are delivered through the unit Q in the usual manner.

A plurality of the serpentine tubes 10 extend on opposite sides of the shaft H to near opposed side walls d of the housing C while the return bends of the tubes extend adjacent the other opposed side walls of the housing, with the lowermost leads of the tubes spaced upwardly from the lower end of the housing while the uppermost leads are spaced well below the upper end of the housing.

In carrying out the invention the shaft H is equipped with a water distributor R which embodies a tubular cylinder 15 surrounding the shaft H in concentric spaced relation thereto, which cylinder is open at its lower end and is closed at its upper end by a reduction coupling 16 which is fastened to the shaft H a short distance below the bearing u. The cylinder 15 is centered relative to the shaft H by diametrically opposed axially aligned screws 17-17 which are threaded through the cylinder and abut opposite sides of the shaft H.

The cylinder 15 has a series of water discharge orifices 18 formed in the wall thereof in a spiral arrangement leading along the length of `the cylinder whereby on rotation of the latter and the delivery of water thereto as will presently be described, jets of water will be projected laterally of the cylinder in all directions and caused to impinge on the tubes 10 of the heat radiating unit Q.

Aiiixed to the housing of the pump J and encompassing the lower portion of the shaft H and the upper portion of the pump spindle x is a nozzle pipe T the lower end of which is closed and the upper end of which is open and terminates adjacent the open lower end of the cylinder 15 in spaced relation thereto forming a gap 19 between the adjacent ends of the pipe T and cylinder 15 which pipe and cylinder are of corresponding diameters.

As a means for regulating the extent of the gap 19, a sleeve 20 is adjustably mounted on the upper end portion of the pipe T with its upper end presented toward the lower end of the cylinder 15, the sleeve being fitted with a set screw 21 engageable with the pipe T whereby the sleeve may be securely held on the pipe in various adjusted positions longitudinally of the pipe to vary the width of the gap 19 which serves as a relief water outlet to reduce pressure head in the cylinder 15 and also to effect lateral projection of a sheet or film of cold water across the interior of the housing C above the lower lengths of the heat radiating tubes 10. The cylinder 15 has a series of inclined blades 19 on the exterior of its lower end portion immediately above the gap 19 which blades are arranged to deliect such of the water as may be directed upwardly on its discharge from the gap 19 and divert it horizontally. Delivery of water to the pipe T and cylinder 15 is effected by the pump I through the discharge tube y which leads to and connects with the pipe T adjacent the upper end of the latter.

The coupling w uniting the shaft H and spindle x being encompassed by the pipe T, the latter is provided with a side opening 22 opposite the coupling to give access thereto to permit connection and disconnection of the shafts without detaching the pipe T from the pump I, the coupling w being of the slip-on type and secured to the shafts by set screws 23 which may be actuated through the opening 22 to engage or disengage the shafts. A sleeve 24 formed of rubber or the like encompasses the pipe T over the opening 22 to close the latter and is detachably held in place on the pipe by clamps 25.

Water is supplied to the basin D through a pipe 26 fitted with a discharge valve 27 opening to the basin, which valve is automatically controlled by a iioat 28 on geh-tess in arm connected to the valve in a usual manner, the oat being Iactuated by the fall and rise of water level in the .basin to open and close the valve and thereby maintain a substantially uniform volume of water in the basin thus compensating for loss of water as is occasioned by evaporation. The float 28 is arranged beneath the ledge f rearward of the apron h to shield it against direct impact of water flowing from the housing C into the basin D. The basin D is equipped with an upstanding drain pipe 29 leading to a suitable point of discharge for preventing accidental overflow of the basin.

The pump J is submerged in the water contained in the basin D with its impeller spindle x leading upwardly with a sliding lit through a sleeve x in the hub z on the pump housing to which the pipe T is connected, which sleeve constitutes a tubular bearing for the spindle x as well as for the shaft H since -the-latter is rigidly connected to the spindle x in continuation thereof. 'Ihe bearing thus `formed is submerged in water contained in the pipe T whereby packing of the spindle x in its bearing and consequent friction is obviated as well as oil lubrication of the bearing rendered unnecessary since water in the bearing will afford adequate protection against excessive wear. Any leakage of water through the bearing as may occur. will be unobjectionable since the leakage will be maintained in the water circulating system thereby causing no damage as might occur if it were outside the system.

Mounted in the upper portion of the housing C and extending thereacross adjacent the underside of the top plate K is a vapor collecting and condensing screen U comprising a pair of parallel horizontally extending panels each of which comprises a rectangular frame 30 fitted with a series of inclined closely spaced sheet metal louvers 31 having inturned upper margins 32, the louvered panels being positioned with the louvers therein oppositely in' clined relative to each other to form angular passages between adjacent louvers. The frames 30 are seated on a rectangular sill 33 supported on hangers 34 demountably attached to opposed side walls d of the housing C by screws 35.

By mounting the blower fan M, water distributor R and pump I on a single shaft these elements are c01- lectively operated directly from a single source of power, and by suspending the actuating shaft H from a single overhead bearing u as herein set forth, power consuming friction due to a plurality of bearings is eliminated thereby affording economy of operation of the apparatus.

In the operation of the invention hot gases to be cooled and condensed are caused to flow through the tubes 10, water is supplied in the basin D, and shaft H is rotated by the motor G. Rotation of the shaft H drives the pump I, water distributor R and fan M. Actuation of the pump J delivers water from the basin through the discharge tube y into the pipe T filling the latter and effecting discharge of water from the open upper end of the pipe T both laterally through the gap 19 and into and through the then rotating cylinder 15 from whence jets of water are ejected through the orifices 13, the water thus being directly sprayed onto the elements of the heat radiating unit Q and against the side walls d of the housing C from whence a portion of the water rebounds and again impacts on portions of the unit Q. The margins of some of the orifices 18 may be inclined upwardly from the interior of the cylinder so as to direct jets of water discharging therethrough at an upward inclination. Subsequently the discharged water returns to the basin D, a portion of the water raining directly into the basin and another portion being caught by the ledge f and directed therefrom over the apron h into the basin. The sprayed water absorbs heat from the elements of the unit Q.

During the above recited operation the fan M acts to induct air into the lower end of the housing C and upwardly through the latter to discharge through the opening L in the top plate K and through the outlet N in the Ycanopy lP, the incomingar flowing inwardly over the margin of the basin D beneath the ledge f and moving upwardly through the falling rain of water in the housing C. The ascending column of air within the housing C absorbs heat .from the water being sprayed in the latter and effects cooling thereof.

Water vapors rising with the air column are collected and condensed by the screen U and returned to the basin D together with the sprayed water. l

VAs before stated the float controlled feed valve 27 will act to maintain the water supply in the basin D at a substantially uniform level.

While a specific embodiment of the invention has been shown and described, the invention is not limited to the exact details of construction set forth, and the invention embraces such changes, modifications and equivalents of the parts and their formation and arrangement as come within the purview of the appended claims.

I claim:

l. In a water distributing mechanism for heat exchange apparatus the combination of a vertically extending rotatable shaft, having a lower end, a tubular cylinder encompassing said shaft in spaced relation thereto and aflxed thereon, said cylinder being closed at its upper end and having an open lower end spaced above the lower end of said shaft and having a series of discharge orifices spaced apart along its length; a rotary pump spaced below the lower Vend of said shaft having an upright impeller spindle connected to andY driven by said shaft, said pump having an inlet and an outlet, a pipe encompassing said spindle in spaced relation thereto having a lower end connected to said pump and having an open upper end encompassing and spaced from the lower end of said shaft and terminating in spaced relationto the open lo'wer end of said cylinder; a sleeve bearing in said pump encompassing said spindle co-operating with the connection between said pump and the lower end of said pipe to close the latter to said pump; and a tube leading from said pump outlet to the interior of said pipe.

2. The structure called for in claim l together with a sleeve adjustably mounted on the upper end portion of said pipe having an upper end presented toward the lower end of said cylinder, and means for holding said sleeve in various adjusted positions longitudinally of sa-id pipe to vary the relation of its upper end to the open lower end of said cylinder.

3. The structure called for in claim 1 together with a sleeve adjustably mounted on the upper end portion of said pipe having an upper end presented toward the lower end of said cylinder, means for holding said sleeve in various adjusted positions longitudinally of said pipe to vary the relation of its upper end to the open lower end of said cylinder, and a series of inclined deilecting blades on the exterior of said cylinder adjacent the open lower end thereof.

4. In a heat exchange apparatus, a water distributing mechanism comprising a vertically extending rotatable shaft, a tubular cylinder encompassing and affixed to said shaft open at its lower end and closed at its upper end, said cylinder having a series of discharge orifices along the length thereof; a rotary pump having an upright impeller spindle connected to and driven by said shaft; a sleeve bearing in said pump through which said spindle extends; a pipe encompassing said spindle and the lower end of said shaft in circumferentially spaced relation thereto, said pipe having its lower end connected to said pump around said bearing and closed thereby and having its upper end opening to the lower end of said cylinder; and a discharge tube leading from said pump and connecting with said pipe; the open end of said pipe being spaced from the lower open end of said cylinder to form a discharge gap between said pipe and cylinder.

5. In a heat exchange apparatus, a water distributing mechanism comprising a vertically extending rotatable shaft, a tubular cylinder encompassing and aliixed to said shaft open at its lower end and closed at its upper end, said cylinder having a series of discharge orifices along the length thereof; a rotary pump having an upright impeller spindle connected to and driven by said shaft;

a sleeve bearing in said pump through which said spindle extends; a pipe encompassing said spindle and the lower able means on said pipe for varying the extent of said gap.

6. In a heat exchange apparatus, a water distributing mechanism comprising a vertically extending rotatable shaft, a tubular cylinder encompassing and afxed to said shaft open at its lower end and closed at its upper end, said cylinder having a series of discharge orifices along the length thereof; a rotary pump having an upright impeller spindle connected to andl driven by said shaft; a sleeve bearing in said pump through which said spindle extends; a pipe encompassing said spindle and the lower end of said shaft in circumferentially spaced relation thereto said pipe having its lower end connected to said pump around said bearing and closed thereby and having its upper end opening to the lower end of said cylinder; a discharge tube leading from said pump and connecting with said pipe the open end of said pipe being spaced from the lower open end of said cylinder to form a discharge gap between said pipe and cylinder,

and detlector blades projecting laterally from said cylinder adjacent said gap.

7. In a heat exchange apparatus, a water distributing mechanism comprising a vertically extending rotatable shaft, a tubular cylinder encompassing and affixed to said shaft open at its lower end and closed at its upper end, said cylinder having a series of discharge orices Y along the length thereof; a rotary pump having an upright impeller spindle connected to and driven by said shaft;

' a sleeve bearing in said pump through which said spindle extends; a pipe encompassing said spindle and the lower end of said shaft in circumferentially spaced relation thereto said pipe having its lower end connected to said pump around said bearing and closed thereby and having its upper end opening to the lower end of said cylinder; a discharge tube leading from said pump and connecting with said pipe, the connection between said shaft and spindle comprising a set screw carrying slip-on coupling VVarranged within said pipe, and wherein the pipe has a side opposite said coupling to give access thereto; and means on said pipe for covering said side opening adapted to be positioned to expose said opening.

References Cited in the le of this 'patent UNITED STATES PATENTS 2,117,411 Erbach May 17, 1938 2,570,247 Kals Oct. 9, 1951 2,602,002 Schutt July 1, 1952 2,709,110 Schmidt May 24, 1955 2,720,085 Boyle Oct. 11, 1955 2,752,124 Nofziger June 26, 1956 2,771,283 Eranosian Nov. 20, 1956 2,780,306 Boyle et al Feb. 5, 1957 2,783,088 Butler Feb. 26, 1957 2,817,960 Lustwerk et al Dec. 31, 1957

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