US2542873A - Multistage deaerating and reheating hot well for steam condensers - Google Patents

Description

Feb. 20, 1951 2,542,873

A. D. KARR MULISTAGE DEAERATING AND REHEATING HOT WELL FOR STEAM CONDENSERS Filed June l8, 1948 HIS ATTORNEY.

Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE MULTISTAGE DEAERATING AND REHEAT- ING HOT WELL FOR STEAM CONDENSERS Alfred D. KarryNewark, N. 1., assignor to Ingersoll-Rand Company, New York, N. Y., a corpo ration of New Jersey Application June 18, 1948, Serial No. 33,868

deliver it to the condensate, to efiect the maximum deaeration of the condensate, and to obtain these advantages without necessitatin the addition of other pieces of equipment to the condensing apparatus;

Other objects will be in part obvious and inpart pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals re-- fer to similar parts,

Figure 1 is an elevation,

denser, and

Figure 2 is a side elevation, partly broken away, taken through Figure l on the line 22. Referring more particularly to the drawings, the condenser, designated 26, comprises a casing 2! having an inlet 22 at its upper end for the entrance of exhaust steam and an outlet 23 at its lower end for the escape of conden-- sate into a hot well 24 extending part way along the lower portion of the casing 2!. The casing 2| contains a group of horizontally disposed cooling water conveying tubes 25 that communicate, in a well known manner, with headers 26 and 2; atthe ends of the casing 2 I. V

As is well known, in surface condensers having tube nests of considerable depth, there is a material drop in pressure between the inlet and outlet openings and consequently a corresponding decrease of temperature in the lower portion of the condenser which results in a lowering of the temperature of the condensate. For example, in the condenser embodying the invention and with an inlet pressure corresponding to 2.90 inches mercury anda temperature of 101.14 F. the pressure at the outlet 23 corresponds to 1.90 inches mercury and a temperature of 99.44" F. This, as will be readily apparent. represents a material lowering of the temperature of the condensate and in order to restore the heat thus lost the casing is provided with a partition 28 shown as cooperating with the ide wall of the casing in section, taken through an intermediate portion of the con- 1 Claim. (01. 257-43) 2| to define a passage 29 which opens at one end into the upper region of the condenser and at its other end into the hot well to convey thereto steam directly from the inlet 22.

In view of the fact that the same differential:

will then exist between the pressures in the hot well and the lower region of the condenser that.

exists between the pressures in the upper and lower portions of the condenser it is essential that means be provided to restrain the steam in the hot well fromflowing through the outlet 23 into the condenser. To this end the casing 2| is provided with a nozzle 30 that depends from the boundin surfaces of the outlet 23 and extends into a trough 3| so that its outlet end portion will be well immersed in the condensate in the trough, and a column of condensate will stand within the nozzle 30 to an elevation corresponding to the difference between the pressures in the not well and at the outlet 23 to assist in maintaining a liquid seal at the nozzle 30.

The trough 3| extends endwise of and is of less width than the hot well so that steam may circulate freely through the hot well and around the trough. In the side walls 32 of the trough,

preferably near their upper edges, are rows of apertures 33 for the flow of condensate from the trough into the hot well in the form of jets so that a maximum area of the condensate will be exposed tothe steam circulating through the hot well. The upper portion of the hot well is vented to the lower zone of the condenser, as through a tube, or tubes, 34 the flow area of which is so chosen that it will provide an outlet for the uncondensible gases liberated from the jets of condensate and for any excess steam in the hot well without lowering the pressure within the hot well below the desired value.

Means are provided for still further increasing the temperature of the condensate and to eifect' its deaeration. To this end the casing is provided with a pair of horizontalwalls 35 to divide the 36 and 31, respectively.

posed edges are suitably spaced with respect to each other to define an outlet 38 for the com- .partment 36 and have walls 89 depending therefrom into a trough 40, in the compartment 31, so that the condensate in the trough and between thewalls 39 will serve as a liquid seal between the compartments. being a replica of the trough 3|. It is preferably supported at it ends by the casing 21, in

The trough 40' is shown as 3 spaced relation with the bottom of the compartment 31, and has the apertures 33 along its sides to cause the condensate to enter the hot well in jet form.

The heating medium serving to thus further increase the temperature of the condensate prior to its p sa e from the'compartment dl, through the usual discharge conduit M, is introducedinto the compartment 3? through a port 42 in the casing 21. It is conveyed to the port 42 by a1. conduit 43 which ma lead. from. a source. of. higher temperature and pressurolasrfor exame ple, an intermediate stage of a turbine discharging into the condenser, or a; heater; the: drip.

from which should be of a greater pressure tham that in the compartment and of a temperature,

and of course of a sufficient c1uantil',y,,to create, a.

pressure within the compartment 3'1 corresponding to say, 2.20 inches of mercury and a temperaa ture of 104.34 R, so that a higher pressure and temperature. will exist. in. the.- oompartment: 31 than the, compartment 36. If, .onthe; other hand; steam serves.- as. the; heating mediuma it must en er the. compartment, 31. at. avpressurea cr'at; least. the same value as: that .in the said compartment and: in sufiicient. quantity to heat thecondensate-spilling from, the. trough; 461th the desired'temperature;

- Thfi uncondgensiblei gases. thus liberated from the condensate, in: the; compartment. 3.1 may escapepthrouglr a,tube; ole-tubes, inte -the com partment 3,6; whencee tl iey'will.- passthrough the; tubes. 34 into the condenser. toilovv over thezlower most tubes: 255 and be withdrawn. welllmown: evacuating means (notv shown) throughpassages 45' opening into the nozzle 311i and communicate ing- Witha aadischarge conduit 46; In'th-isconnection, it should. be; understoodthat the tube- 44. is; also of. suchflaw area that, in operation, it, will. provide an. ample outlet 1 for the; uncondensible $3 .68;. and excess steam fromthe; compart' ment; 31. and ,Will; at,-the;same time, maintain the desired-.1 differential between the pressures; in; the r compartments 36. and 31..

In th operation-.ofithe; condenser, the-steam; entering: theinlet opening, 2 2;- and. passing 5 down-- wardly over the cool surf aces of. the. tube 2 5 will: he condensed, and the condensate thus formed: will-pass, through the nozzle 31L into-the. trough. 3;! ,thence throuslithe-apcrtures 33: into thecompartment. 3,6. in thezform. of; jets. At the-same? time steam at discharge temperature and pres-.- sure, will flow through theipassage, 29- intothecompartment; 3.5 into intimate contact. with: thejetsof condensateissu-ing from the trough 3 l-- and is-condensed-by audits: heat. is transferred. tor-the;

condensate. I

The gases liberated by; this increase inthetemperatureof itheacondensate will-escape through the -tubes 34: intothe' condenser for removal by the; evacuating apparatus, and the heated condensatez-will-flow along-qthe-walls 35anol through the-outlet 3.8.;intolthe. trou h, thencethroughthe apertures 3,3 into-theg compartment 31 asqjetsiort exposure to'theheat of. the fluidamedium enter-- ing. the compartment 31- through the port-42;. The exposure; of the. condensatev to, this. hot ,me-' dium. will; cause: the: further. degasification and heating of; the condensate prior: to its passage through the. discharge conduit.- 4 I. toaboiler... The

uncondensible' gases, released. by thus further heatingthe condensate willescape from thecom.

partment- 3T throughthe tubes 44.; into the, com,-

' claims.

partment 36 and pass therefrom through the channels connecting the compartment 36 with the evacuating apparatus.

From the foregoing description, it will be obvious to those skilled in th art that, by subjecting the condensate repeatedly to a heating medium capable of bringingiit'to aboiling point, the condensate may be substantially freed of dissolved gases found to have a corrosive effect upon the surfaces of boiler tubes and the like.

While. I. have. shown my invention in a form capahleoi' subjecting. the condensate to only two steps of heating and deaeration, it is to be understood thatlidoanot intend it to be so limited, a-nd that the invention is susceptible of further modification; as for example by the addition of one. or. more. deaeration compartments, without departing from its spirit or the scope of the I claim:

In an; apparatus of the; character described; a condensen,;, a hot; well. forv the condenser. having.

amuppen compartment and alower compartment,-

walls-insaidwell for. dividingthe well into;- said-1 compartments, a trough in the upper compartment, an outlet: for. the condenser to allow the flow. of: condensaterto-th hot well" said. out-lethaving a side depending; from. the.- condenser into the; trough in, the. upperv compartment below the overflow-point. so. asrto for-m aliquid seal between.

the condense-r. andthe; upper compartment, a trough. in thelower compartment, an outlet for the-upper: compartment to allow the flow of con-- 7 densate tothe lower compartment said' outlet. having sides,v depending; from said walls and ex tendinginto, the; trough; in. the lower comparta ment below the overflow point seas. to= formv a:

liquidseal between the upper v and. lower. compartments, a plurality ofapertures. in the-troughs toallowthe.condensaterinthe liquid: seals to flow into the-respectivecompartments an-inletzin one: side of the upper compartment-for introducing? steamzfrom: the condenser to increasewthetemperaturenf the condensate, anoutlet in theoppo- I site side of the upper compartment to'allow un.

comlensih-le,v gasesto; escape irom the upper; compartment tor the condenser, an. inlet opening;

one side-of the lower compartmentfor the-introduction of a. hot fluid mediumfrom. anextern-ali source-to further. increase thetemperature Qfithfi: condensate, and anoutletinthe oppositeside-of." ther-lower compartment to allow uncondensible: gases. toescape. from the lower compartment-totheupper: compartment.

ALFREDD. KARE;

REFERENCES. CITED:

The following references are of record in the file of this patent:

V UNITED STATES.. PATENTS Number:

Germany Feb. 3; I933

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