US2848197A

US2848197A - Condenser

Info

Publication number: US2848197A
Application number: US532176A
Authority: US
Inventors: Jr George W Evans; George A Worn
Original assignee: Lummus Co
Current assignee: CB&I Technology Inc
Priority date: 1955-09-02
Filing date: 1955-09-02
Publication date: 1958-08-19
Anticipated expiration: 1975-08-19

Description

Aug.- 19, 1958 GJw. EVANS, JR, ET AL ,1

CONDENSER Filed Sept. 2, 1955 2 Sheets-Sheet 2 INVENTORS Gram-EA Wo/ew BY GEORGE/(14AM J/e. 49. M AGE T CONDENSER George W. Evans, Jr., Teaneck, N. J., and George A. Worn, Greenwich, Conn, assignors to The Lurnmus Company, New York, N. Y., a corporation of Delaware This invention relates to improvements in steam power plant equipment and more particularly to improved condensing apparatus for such a plant. A steam power plant employing a turbine normally includes, in addition to a boiler or steam generator, a series of feed water heaters and a surface condenser for the exhaust steam from the turbine. Steam is condensed in the condenser and the condensate'is conducted from the hot well ofthe condenser through the feed water heaters in series and returnstothe boiler. Within the heaters, the condensate is-heated by steam which may be bled from one or more stages of the turbine. Such steam is condensed in its passage through the heaters and the condensate is also returned'to the boiler. This condensate, together with'make-up water, as required for the-boiler, should be deaerated beforeintroduction to the boiler and it is customary to provide a separate deaerator unit for that purpose. The deaerated water is then pumped from such unit through one or more heaters to the boiler.

An object of our invention is to provide a combined steam condensing and deaerating apparatus devised to obtain advantageous cooperation of condenser features with deaerating means.

A further object of our invention is to provide aconstructionof, high vacuum, surface condenser adapted especially for large sizes in which each condenser-tube contributes the maximum area possible to active condensation of steam.

A stillfurther object ofour invention is to provide an improved condensing unit wherein exhaust steam from a side exhaust or end'exhaust turbine may be conveniently introduced through a side inlet in the unit with a resultant substantial saving in supporting structure and head' room and wherein the inlet area of the nest of condensing tubes is at a maximum so that the velocity of the-steam entering the nest of tubes is materially reduced and the paths of steam flow converge toward points of complete condensation.

Further objects and advantages of our invention will appear from the following description taken in connection with the accompanying drawings.

In the drawings:

Figure 1 is a vertical sectional view of a condenser unit embodying the invention, the section being on'the line 11 of Figure 3;

Figure 2 is a diagrammatic top view of a portion of a steam power system embodying a side exhaust turbine and the invention; and

Figure 3 is a vertical section on the line 3-3 of Figure l, partly broken away.

The structure of the condensing unit shown in Figs. 1 and 3 includes a shell 10 horizontally disposed and formed atone side with a portion 11, which provides an inlet passage for exhaust steam from the turbine. The steam inlet 12 in portion 11 may be rectangular in vertical section having. opposite walls 13, which converge outwardly from theshell to the steam inlet and terminate in horizontal portions 13w. Opposite walls 14 may United States Patent a IC 2 converge outwardly from the shell to the steam inlet and terminate in vertical portions 14a, similar to portions 13a of -the walls 13, and form therewith a frame for connectionwith the exhaust opening of the turbine.

The opposite ends of the shell are provided with flanges and have secured thereto respectively

tube sheets

15 and 16 and water boxes 17 and 18. Tubes 19 connect to the tube sheets and are ranged in a nest comprising two or more

equal banks

20 and 21 formed one above the other and spaced to define therebetween a horizontal central lane or lanes 23; Water box 18 has a horizontally, diametrically disposed pass partition 24v and two

nozzles

25 and 26. Referring to Fig. l, the nozzle 25 admits cooling water to the compartment below the pass partition for flow through the tubes of the lower tube bank 20 to, the water box 17 and thence in reverse direction through. the tubes of the upper bank 21 to the water box compartment above the partition and out through the nozzle 26. Thus, the condenser as illustrated is a two-passunit but the number of passes may be varied by appropriate arrangements of pass partitions and nozzles.

Each tube bank has an air oiftake bafile structure which includes walls 27; 28 and 29 and 30, 31 and 32 respectively; the ends of each bafile structure being open so that non-condensible gases may be withdrawn from bothbanks through nozzles 33'and .34. Within each bafile structure is a portion of "the tubes off the respective bank which act as an air cooler section. Also Within eachbafiie structure are transversely disposed'interleaving baflie plates-35 and36', which are spaced *to provide a tortuous path of flow forthe non-condensible gases. A steam jet ejector, not'shown, may. be connected to nozzles 33 and 34m maintain .a desired vacuum. Such an ejector may deliver to the usual inter-and-aftercondenser combination, not shown.

Beneath the shell 10 there is a hot well 37, which ex.- tends along the major portionofthe shell length and is of quite substantial-depthand'width, to give it relatively-large storage capacity. Within the upper portion of the hot well, there are deaerating means, for the condensate drained from the tube bank. Such means includes perforated shower trays 38' and 39 with upturned outer edges. These trays extend horizontally the full length of the hot well but do not individually span the full width of the hot'well. All of the shower trays are welded or otherwise suitably secured. to the. adjacent walls of the hot well. Airofitake pipes, not shown, may-leadfromopposite sides of the hot well, at points between trays 38 and39, to the air'oiitake baffle structures; The hot well has a condensate discharge nozzle 40 leading from its lower portion.

Incorporated and coacting with the. condenser tube banks' 20 and 21*are'condensateshower trays 41 and42 for-deaeratingcondensate from therespective tube banks. Tray 42", which is positioned within the horizontal central lane 23 receives most of the condensate from the tube bank-21 and showers suchcondensate to an underlying iinperforat'e plate 43; which is shaped to direct the condensate to the rearsideof the'condenser shell where it falls to a point below the lower tube bank and is thereafter directed to the hot well. In showering from tray 42to plate43, the condensate from the upper tube bank is substantially reheated and deaerated. A weir 44 at-the top of the hot well 37 and within shelllt) is provided with notched end portions 45 whereby condensate from plate 43.is directed toward the ends of the hot Well and'discharges in divided streams to tray 38." Final deaeration ofthe upper tube bank' condensate occurs asit showers from trays 38 and 39 'to' the hot'wellwith condensate from' the lowertube bank; Tray 41-, which underlies tube bank 20, receives most of the condensate from such lower tube bank and showers such condensate 4 to the

trays

38 and 39 in the hot well. In showering from the tray 41 to trays 38 and 39, the condensate from the lower tube bank is substantially reheated and deaerated. Final deaeration of the lower bank condensate occurs as it showers from

trays

38 and 39 to the hot well with condensate from the upper tube bank.

All of the shower trays have their free edges turned up so that the condensate will collect sufiiciently on the trays for passage through the perforations rather than spill ineffectually from one edge. The upper edge of the upturned tray portion is notched so that in the event of tray flooding, condensate pouring over a tray edge will fall in a plurality of streams.

In the operation of the apparatus, exhaust steam passes from the turbine T (Fig. 2) into the condenser, and condensate is withdrawn from the hot well 37 through a pipe 46 and passed in succession through the tube side of a drain cooler C and a plurality of feed water heaters H, on routeto the boiler, not shown. Steam is bled from one or more stages of the turbine through pipes P and P and passed to the shell side of heaters 1-! respectively, to heat the water flowing through the tube side of the heaters by indirect heat exchange. Condensate of the steam within the heaters may be passed through pipe 47 from one heater to another, and through a pipe 48 to the drain cooler C and thence through deaerating means before joining the condenser condensate in the hot well 37. Make-up water may be supplied, as needed, to the system at any suitable point.

Usually a vacuum ranging from 26 to 29 inches will be maintained within the condenser and this vacuum will exist within each deaerator.

It is known that in order to obtain the necessary condensing surface without unduly increasing the size of the condenser, the'tube spacing adjacent the steam inlet perimeter of the nest of tubes must of necessity be such as to occasion no objectional loss in vacuum between the point or points of complete condensation within the tube nest and the steam inlet to the condenser. To overcome objectionable losses of vacuum, the cooling tubes 19 are distributed so as to increase the inlet area of the nest of tubes so that the velocity of steam flow entering the nest of tubes is materially reduced below that employed in ordinary condensers. Likewise the condensing surface is so distributed that the paths of steam flow converge toward the air ofitake bathe structures.

To accomplish the above and primarily to eliminate the massive structure generally required to support the turbine above the condensing unit, the present invention utilizes a side inlet to the condenser with the tubes divided into separate independent groups having separate primary condensate deaerating means and separate air offtake structures. With such an arrangement the condenser may be positioned adjacent to the turbine affording better maintenance opportunity and substantially less support: ing structure. The tubes are arranged for maximum inlet area for the steam with the condenser steam inlet facing directly into the turbine exhaust. The tubes of each group are distributed to obtain the advantage gained by having the condensing surface so distributed that the areas of steam fiow diminish from the steam space toward the air otftakes in substantially direct proportion to the decrease in condensation taking place along the paths of steam flow, or in direct proportion to the decrease in volume of uncondensed vapor along the path of flow.

While the invention is disclosed as employed in power plant service, it may be employed advantageously in other services requiring surface condenser equipment where it is particularly desirable to support the prime mover on the same level with such condenser. It is, of course, to be understood that the present disclosure of the invention is merely illustrative and in no wise limiting and that the invention comprehends such modifications as will fall within the scope of the following claims.

In the claims, the words steam, except where identified with a steam power system, is intended to comprehend other vapors also, and the word air, wherever it occurs, is intended to comprehend also other non-condensible gaseous media.

We claim:

1. The combination of a surface condenser unit including a shell, a nest of substantially horizontal condensing tubes Within the shell, means for circulating cool. ing water through the tubes, the shell having a side steam inlet passage for conducting steam in a substantially horizontal direction to the tube .nest for condensation, a hot well positioned below the tube nest to receive partially deaerated steam condensate from said tubes, a substantially horizontal baflie plate located within the shell and dividing the nest into separate groups of tubes, one above the other, said baffle plate being so disposed as to collect condensate from the upper group of tubes and direct such condensate in a separate path away from said inlet passage for discharge into said hot well, a horizontally disposed perforated tray located below said upper group of tubes and above said battle plate to intercept condensate from said upper group of tubes and shower it in divided streams to said plate whereby said condensate is substantially reheated and partially deaerated by steam passing between said groups of tubes, a second horizontally disposed perforated tray located beneath the lower group of tubes and above said hot well to collect condensate from said tubes and shower it in divided streams downwardly for discharge into said hot well whereby said condensate is substantially reheated and partially deaerated by steam passing under said lower group of tubes, a deaerating device'within said but well to complete deaeration of condensate from the separate discharge paths, and air off-take means leading from a relatively cool portion of each group of tubes and spaced from said side steam inlet passage for removing non-condensable vapors.

2. The combination of a surface condenser unit including a shell, a nest of substantially horizontal condensing tubes within the shell, a steam inlet passage in one side of the shell for conducting steam in a substantially horizontal direction to the tube nest for condensation, means for circulating cooling water within the tubes, a hot well positioned below the tube nest to receive partially deaerated steam condensate therefrom, a substantially horizontal baffle plate located within the shell and dividing the tube nest into separate groups of tubes, one above the other, said baffle plate being so disposed as to collect condensate from the upper group of tubes and direct said condensate along said plate away from said inlet passage for discharge downwardly in a separate path to said hot well, a horizontally disposed perforated tray located below said upper group of tubes and above said bafiie plate to intercept condensate from said upper group of tubes and shower it in divided streams to said plate whereby said condensate is substantially reheated and partially deaerated by steam passing between said groups of tubes, a second horizontally disposed perforated tray located beneath the lower group of tubes and above said hot well to collect condensate from said tubes and shower it in divided streams downwardly for discharge into said hot well whereby said condensate is substantially reheated and partially deaerated by steam passing under said lower groups of tubes, a deaerating device within the hot well to complete deaeration of condensate from the separate discharge paths, and air elf-take means leading from a relatively cool portion of each group of tubes for removing non-condensable vapors, said off-take means being spaced from said side stream inlet and including a portion of the tubes of each group.

3. The combination of a surface condenser unit including a shell, a nest of substantially horizontal condensing tubes within the shell, said nest comprising at least two separate groups of tubes, one above the other, a steam inlet passage in one side of the shell for conducting steam in a substantially horizontal direction to the tube nest for condensation, means for circulating cooling water through the tubes, a hot well positioned below the tube nest to receive partially deaerated steam condensate from separate condensate discharge paths, substantially horizontal bafile plates locatedwithin the shell and between adjacent groups of tubes, each of said plates being so disposed as to collect condensate from the next upper group of tubes and direct such condensate along said plate away from said inlet passage for discharge downwardly in a separate path to said hot well, a horizontally disposed perforated tray located above each of said bafiie plates to intercept condensate from the group of tubes next above each plate and shower it in divided streams to said plate whereby condensate from each upper group of tubes is substantially reheated and partially deaerated by steam passing between said adjacent groups of tubes, a horizontally disposed perforated tray located beneath the lower group of tubes and above said hot well to collect condensate from said tubes and shower it in divided streams downwardly for discharge into said hot well whereby said condensate is substantially reheated and partially deaerated by steam passing under said lower group of tubes, 21 deaerating device within the hot well to complete deaeration of condensate from the separate discharge paths, and air off-take means leading from a relatively cool portion of each group of tubes and spaced from said side steam inlet passage for removing noncondensable vapors.

References Cited in the file of this patent UNITED STATES PATENTS