US3382918A - Reinforcing structure for direct flow steam dome for condensers - Google Patents

Description

y 14, 1968 R. J. STOKER ETAL 3,382,918

REINFORCING STRUCTURE FOR DIRECT FLOW STEAM DOME FOR CONDENSERS I5 Sheets-Sheet l Filed Aug.

INVENTORS ROBERT J. STOKE BURTON PAUL ALAN SOLER y 1968 R. J. STOKER ETAL 3,382,918

REINFORCING STRUCTURE FOR DIRECT FLOW STEAM DOME FOR CONDENSERS Filed Aug. 1, 1966 5 Sheets-Sheet 2 INVENTORS ROBERT J. STOKE/i BURTON PAUL ALA/V SOLE/i May 14, 1968 R. J- STOKER ETAL REINFORCING STRUCTURE FOR DIRECT FLOW STEAM DOME FOR CONDENSERS Filed Aug. 1, 1966 Q \F I 6 001:

\\ FIG. 7 [I [I l] [I I] i 42 3 2 l I 4| I05 FIG. 6

INVENTORS ALA/V SOLER 3 Sheets-Sheet 5 United States Patent 3,382,918 REINFURCING STRUCTURE FOR DIRECT FLOW STEAM DOME FOR CONDENSERS Robert J. Stoker, Phillipsburg, Burton Paul, Princeton,

and Alan I. Soler, Cherry Hill, Ni, assignors to IngersolI-Rand Company, New York, N.Y., a corporation of New Jersey Filed Aug. 1, 1966, Ser. No. 569,439 11 Claims. (Cl. 165-67) ABSTRACT OF THE DISCLOSURE This invention relates to a steam dome for use in combination with a surface condenser of generally standard configuration.

It is generally recognized that as the steam flows from the turbine through the steam dome and into the condenser, and as the steam reduces in volume as it condenses into its liquid form, a vacuum is created in the dome. This vacuum causes a great deal of pressure to be applied to the steam dome and without some means of support, the dome will collapse. Prior methods of supporting the steam dome generally comprised internal structural bracing in the form of heavy pipe generally added wherever it was felt necessary, and wherever there was room and most often in a lattice configuration spaced at various levels of the steam dome. These methods of bracing the steam dome provide a structurally sound configuration but steam flow is so adversely affected that condenser performance is reduced.

Therefore, it is the principal object of this invention to provide a dome for use in combination with a condenser which provides good support for the dome but does not interfere with flow of fluid to be condensed.

It is a further object of this invention to provide a steam dome which will increase the efiiciency of a condenser.

In general these objects are carried out by providing a shell having an inlet for receiving fluid to be condensed and an outlet for discharging the fluid into the condenser. First structural means in the form of a closed ring such as a hollow beam is provided at the top of the dome adjacent to and around the inlet to prevent the dome from collapsing around the inlet, and second structural means is provided at the bottom of the dome adjacent the outlet to prevent the dome from collapsing around the outlet. Brace means such as ribs are mounted internally of the shell between the first and second struc tural means and located along the surface of the shell for transferring the load due to the vacuum on the shell from the shell to the top and bottom structural means. These ribs are mounted so that their longitudinal axes extends along the shell in a generally vertical direction and are of such a size that the inside of the dome remains substantially unobstructed thereby permitting free flow of the fluid from the inlet to the outlet. The ribs also direct the flow of steam from the inlet to the outlet and may be placed so that the steam will flow in greater proportion towards the cold end of the condenser.

These and other objects will become apparent from the following description and drawings in which:

3,382,918 Patented May 14, 1968 FIG. 1 is an elevation of the steam dome of this invention connected to a condenser with parts being broken away;

FIG. 2 is a fragmentary detail showing that portion of the steam dome outlined by the circle 2- -2 of FIG. 1;

FIG. 3 is a fragmentary detail of the steam dome outlined by the circle 33 of FIG. 1;

FIG. 4 is a section taken on line 44 of FIG. 1 in the direction of the arrows;

FIG. 5 is a fragmentary detail of a portion of the steam dome outlined by circle 5-5 of FIG. 4;

FIG. 6 is a cross-sectional elevation of a modification of this invention;

FIG. 7 is a top plane view of the steam dome of FIG. 6; and

FIG. 8 is a view similar to FIG. 2 showing another embodiment of this invention.

Referring to the drawings, the steam dome of this invention generally indicated at 1 is shown as trapezoid in configuration but may be of any desired shape. It is open at the top to provide an inlet 2 and open at the bottom to provide an outlet 3. The outlet is connected to a surface condenser generally indicated at 4. The condenser includes a plurality of tube bundles such as 5 having an inlet 6 and an outlet 7 for cooling water. In some applications the steam dome may be an integral part of the condenser.

As is conventional with steam domes, there may be a heater pipe 11 with extraction piping (not shown) for removing some of the heat from the steam and preheating feed water for the turbine or for use in other places. Fairing plates 43 serve to make this heater pipe 11 and condenser as a whole more efficient. The extraction piping is taken out through the center of the inlet 2 between fairing plates 43. The center of the inlet is a region of low velocity steam flow, thus, such a placement of these pipes prevents them from interfering with flow into the dome. The fairing plates serve to cut down pressure losses which would result from the friction of steam flowing over the surface of exposed pipes or from steam filling a space normally devoid of flow.

If desired, there may be included baflies 12, FIG. 4, for directing the flow of steam towards the tube bundle 5. These baflles are generally known and may be omitted, if desired, since their function is performed to a great extent by other parts of the steam dome of this invention.

The steam dome is primarily made up of an outer shell 14 of sheet or plate steel. Flow of steam from the turbine is in a downward direction. Plates 42 are mounted in the inlet to form a continuation of the guide and deflector plates in the turbine exhaust hood, and the steam flows into the dome through passages A around the periphery of the inlet. This leaves a center section through which the extraction piping may pass as explained hereinbefore. The flow of steam into the steam dome produces a vacuum which tends to collapse the outer shell. By this invention there is provided an improved structure for supporting the outer shell and preventing its collapse and which leaves the interior of the dome unobstructed thereby providing a better flow path.

This improved supporting structure includes a plurality of supporting ribs 10. These ribs are mounted so that their longitudinal axes are in a generally vertical direction and the width of each rib extends into the cavity of the dome. The thickness of each rib abuts the inside of the shell and is secured thereto by any suitable means such as welding. The ribs extend from a top closed ring or first structural member 20 towards the tube bundles 5, as clearly shown in FIGS. 1 and 4, and a bottom or second structural member 30. The ribs extend into the interior of the shell only a short distance, as is clearly shown in FIGS. 1 and 4.

The top structural member or ring includes a triangular structure along two sides or ends of the dome adjacent the inlet and a channel or boxlike structure along the other two sides of the dome. The triangular portion of the ring 20 includes two side pieces 21 and 22 and the dome shell 14, as clearly shown in FIG. 2. There may also be a top piece 23 to close the structure and provide a firm connection to the side wall of the inlet. The members forming the triangular structure are welded. This triangular section may be made of a single piece either in the form of a triangle with one side secured to the shell or an angle beam with the open side secured to the shell so that the shell closes the triangle.

The channel member along the other two sides of the dome is best shown in FIGS. 4 and 5. This channel is made up of pieces 24, 25 and 26 and closed by the shell 14; all welded together. If desired, the channel may be a single channel with the open side welded to the shell or a box beam with one side welded to the shell.

A lower structural member 30 extends only along the ends of the bottom end of the dome. This triangular member, as best shown in FIG. 3, is made up of the outer shell 14 and two side pieces 31 and 32 which are welded to from the structural member. Again, if desired, this may be made from a one-piece structural member but with the construction shown, the size and shape may be varied more readily for different size and shape domes. For greater strength, the construction shown uses structural members which, when in position and viewed in cross-section, form closed polygons. In some applications, however, it may be desirable to use structural members of other shapes.

Along the ends of the steam dome, the ribs 10 are connected between the triangular portion of the upper structural member 20 and the lower structural member 30, as is clearly shown in FIG. 1. Along the side of the steam dome, the ribs are connected from the upper portion of the dome adjacent the channel 20 down to the supporting structure of the tube bundle 5. Where the ribs 10 abut the hollow beams 20 and 30, these hollow beams may be solid as shown in FIG. 8. This may be done by extending the ribs 10 through the hollow beams or other suitable means for closing that portion of the beam.

The vacuum resulting from steam flowing into the dome causes a pressure to be exerted on the shell 14 when steam enters the dome through the inlet 2. This pressure loading is taken up by the ribs 10 which transfer the bending load to the top structure 20 and bottom structure 30 or to the supporting structure of the tube bundles. The horizontal load component, formerly carried by the lattice work of the prior art, is now carried by axial and bending actions of the ring 20 and bottom member 30. At the exit of the steam dome, the structural member 30 transfers the vertical load component and part of the horizontal load component to the foundation and substructure of the condenser through load transfer members 35.

Additional support against a horizontal force may be provided by cross bracing such as shown in FIG. 6. This cross bracing or gridwork acts as a system of compression members and is similar to that used in prior art devices in that it includes structural member 42 and cross braces 41. These cross braces are arranged so that extraction piping may be located in central section F, G, H, I. Cross braces 41, FIG. 7, may be at an angle other than 90 with respect to members 42 in order to conform to similar vane configurations in the turbine exhaust and eliminate interference with steam flow. Although this cross bracing is best shown in the alternative embodiments of FIGS. 6 and 7, this bracing may also be used in the embodiments of FIGS. 1 -5.

If desired, the ribs which support the steam dome may be placed so that the steam is directed in greater amounts towards the cold end of the tubes and less amount towards the warm end of the tubes. This configuration is clearly shown in the modification of FIGS. 6 and 7. It can be seen that the ribs are placed farther apart at the inlet 2 towards the cold end of the tube bundles than at the warm end of the tube bundles. This enables more steam to be directed towards the cold end creating a more effective steam dome and condenser. If desired, the ribs 100 may be spaced equally at the inlet and unequally at the exit towards the tube bundle. The same results will occur by more steam flowing towards the cold end of the tube bundles than towards the Warm end. The structural members 20 and 30 of FIGS. 1-5 and 8 have been omitted from FIGS. 6 and 7 for purposes of clarity but in actual construction are included.

In construction, the size of the dome and amount of steam flow are considered to determine the amount of pressure which will be exerted on the shell. From this it can readily be determined how much load will have to be absorbed by the structural members 20 and 30 and how far apart and what size ribs must be used.

It is essential that wherever there is a break in the structural members 20 and 30 or the ribs 10, such as where the heater pipe 11 is located, some means such as the heater pipe itself must be included to transfer the load around this break. This is to guard against weak areas.

From the foregoing description it can be seen that a novel steam dome is provided which has greater strength and allows an open area for easy flow of steam from the turbine towards the condenser. It is not necessary to lace the heater pipes through the supporting structure as all the supporting structure is located adjacent the shell wall. Additionally, the flow is directed by the supporting ribs rather than hindered by the supporting structure.

It is intended that the foregoing description be merely that of a preferred embodiment, and that the invention not be limited in any way except by that which is within the scope of the appended claims.

We claim: 1. A dome for use in combination with a condenser comprising:

a shell having an inlet for receiving fluid to be condensed and an outlet for discharging said fluid into a condenser;

first structural means mounted internally on said shell and circling said inlet for supporting said shell and preventing said shell from collapsing inwardly around said inlet;

second structural means mounted internally on said shell adjacent said outlet for supporting said shell and preventing said shell from collapsing inwardly around said outlet; and

brace means mounted internally of said shell interconnecting said first and second structural means for transferring a load on said shell to said first and second structural means and being dimensioned for guiding the flow of fluid between said inlet and said outlet and located along the surface of said shell and adapted to leave the inside of said shell substantially unobstructed.

2. The dome of claim 1 wherein said first structural means includes a ring extending completely around said inlet.

3. The dome of claim 2 wherein said ring includes side portions of generally channel shape and end portions of generally triangular shape.

4. The dome of claim 1 wherein said first structural means is a substantially hollow beam.

5. The dome of claim 1 wherein said second structural means includes a generally triangular shaped member along the ends of the dome adjacent the outlet.

6. -The dome of claim 1 wherein said brace means includes a plurality of ribs mounted so that their longitudinal axes extend along said shell in a generally vertical direction.

7. The dome of claim 6 wherein said first structural means is a closed ring extending completely around said inlet and said second structural means is a generally triangular shaped member along the ends of said dome adjacent said outlet.

8. The dome of claim 6 further including cross bracing in the upper portion of the dome in said inlet.

9. The dome of claim 6 further including means to transfer the load on said dome to the lower substructure of said condenser.

10. The dome of claim 6 wherein said ribs are joined to the supporting structure of the tube bundles of the condenser.

11. The dome of claim 10 wherein said ribs are spaced and located for directing a greater proportion of said fluid towards the cold end of said tube bundles than towards the warm end.

References Cited UNITED STATES PATENTS 1,923,274 8/1933- Miller et al. 165-159 2,111,240 3/1938 Grace 165-161 X 2,453,662 11/1948 Graham 165-114 3,139,926 7/1964 Tinker 165-111 FOREIGN PATENTS 651,246 3/1951 Great Britain.

r ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner.

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