US2438719A - Automatic control for waste heat utilizers - Google Patents

Description

March 30, 1948- F. sAco, JR., ETA'L I 2,438,719

AUToMATIc CONTROL FOR wAsTE HEAT UTILIZERS Original Filed Jan. 15, 1942 3 Sheets-Sheet 1 3 INVENTOR i9- A Ffl/XJACQM. aw Y MAL/AM A. Wig/$50 ATTORNEYS A March 30, 1943. ESACQJR, ETAL 2,438,719

AUTOMATIC CONTROL FOR WASTE HEAT UTILIZERS Original Filed Jan. 15, 1942 3 Sheets-Sheet 2 ATTORNEYS March 30, 1948. F, s co, JR, AL 2,438,719

AUTOMATIC CONTROL FOR WASTE HEAT UTILIZERS Original Filed Jan. 15, 1942 s Sheets-Shet 3 INVENTOR fZ-Z M 5/1 c0, (/2, 0/70 ATTORNEYS :control system with a 1 tion between the boiler and the drum controlling i the water feed;

\ variety of constructions Patented Mar. 30, 1948 AUTOMATIC CONTROL FOR WASTE HEAT UTILIZERS Felix saco, Jr.-, West Hartford, and William R:

Williamson, Maxim Silencer Hartford, Conn assignors to The Company, Hartford, Conn., a

corporation of Connecticut Continuation of application Serial No. 126,868,

January 15, 1942. This application June 19, 1944, Serial No. 541,036

This invention relates to apparatus for utilizing the waste heat of exhaust gases from internal combustion engines, or other low temperature :gas source, and in particular is concerned with an automatic control for a waste heat boiler system.

This application is a continuation in part of our previously filed case Serial No. 380,022, .Patent No. 2,397,208 for Waste heat utilizer :filed February 21, 1941, and is a continuation of abandoned application Serial No. 426,868 for Automatic control for waste heat utilizer filed January 15, 1942. I

An object of this invention is to reduce the 'heat transfer between the gases and the water in the boiler by varying the amount of contact :sllrface in accordance with the output of steam desired. Other and further objects will appear .from the description and claims.

In this system the heat transfer is controlled 'by varying the contact area between the water and heating surface by means of a pressure reducing valve and drum external to the heating section of the boiler.

The manner in which this is done will be apparent from the following description of the 1 apparatus shown in the accompanying drawings, 1" in which a diagrammatic View of the waste heat preferred form of connec- Fig. 1 is Fig. 2 is a view on line :2-2 of Fig. 1;

Fig. 3 is a diagram of thesystem arranged with the boiler in vertical position, the return line ibeing attached as for a gravity feed system;

.Figs. 4, 5, 6, '7 and 8 show diagrammatically ralternative arrangements for conducting steam through the water control tank; and

Fig. 9 shows a modification in the steam line to the utilizing system.

The waste heat boiler Lshown in outline in Fig. 1, is preferably made according to one of a as detailed generally and specifically in our above-mentioned application Serial No. 380,022, Patent No. 2,397,208, filed February 21, 1941, for Waste heat utilizer" and of which the present application is a continuation in part. A cross section showing the general nature of a boileris shown in Fig. 2. As shown in these views it generally comprises an outer cylindrical shell 2 and an inner cylindrical shell 3 spaced from it and providing between the two shells a water jacket 4 to which water'is fed through an inlet pipe (Fig. 1)

11 Claims. (Cl. 122-456) and from which steamor. a mixture of steam and Water is passed throughoutlet pipefi (Fig; l). The surface area of shell 3 contacting the water in jacket 4 is heated by the exhaust gases entering through a tube l3 into 'a chamber I formed by a partition 8 dividing the inner shell 3 into two chambers l and 9. To permit the gases to pass from chamber 1 to 9 a" metal structure In forming a plurality of conduits H (see Fig. 2) is located around the inner surface of inner shell 3. The gases passing from conduits ll out to chamber 9 are eliminated by passage through exhaust outlet tube 12. The device is a silencer as well as a waste heat boiler, all as disclosed in its various forms in our aforesaid previous application, and dueto'the'low temperature of the exhaust gas will operate as asilencer without' danger even when the water jacket is completely dry.

Attached to saidboiler'outlet pipe 6 is a crossover pipe l4 (Fig.1) leading to'the-upper portion of a drum I5. In this pipe M is a pressure reducing valve I0 of'any suitable construction. The top of drum It is provided with a steam outlet I! which is connected by the drum to pipe [4 and which leads to any suitable mechanism provided to utilize the steam supplied. Drum l5 also has a safety valve 2i 'set in the top thereof. The bottom of the drum connects with the inlet pipe 5 by conduit IS. A blow-off valve i9 is provided at the end of conduit l8 beyond its connection with inlet 5. The return of steam condensate from the system supplied, if the apparatus is adapted (as in Fig. 1) for a pump return'system, is by return line 26 tothe lower portion of drum I5 through a water feed device 23, preferably of the usual float chambered construction, which maintains the water in the drum 5 at a minimum'level (line A-e-A). If the apparatus were joined to a gravity return system then return line would be coupled to the system at the elbow connection of conduit l8 and inlet pipe 5. This type of connection has been illustrated in the modification of Fig. 3 where return line 20 is joined to the elbow of pipe 5 and conduit l8.

It will be understood that there are also various possibilities with'respect to the relative arrangement of the drum,. the reducing valve control and the boiler. v The arrangementseen in Fig. 3 shows different changes whichcan be made to vary the structure of Fig. 1. The waste heat boiler is here arranged in a vertical position and the drum I5 is located so that its water line is below the top of the boiler; In. addition the in operating the apparatus for a particular' j ft.e i i -2 V g ferred to the water and, t erefore-no more steam is generated. The pressure then'in' the jacket,

3 Y 7 pressure reducing valve I6 is made responsive to conditions somewhere in the line H, as'by a thermostatic device located in any desiredplace, as at 25;;in's'tehld@fjinfthe topjoidrum 15 as in Fig. 1. I'oc atioh'bf the thermostat control is particularly adaptable to the de-superheating arrangements discussed below. The use of any i' I -It will be noted that the reducing valve I 6 one or more of the variations enumerated is} guided largely by considerations "of "convenience" pose or in a particular place. I

Referring now to the operatiomof the'device, the automatic control apparatus "is-designate utilize only so much of the heat from the exhaust gases as is convenient for ithe;necessities of the system to which it is coupledthroughljoutletH;

The drum l contains the water supply fed to the jacket} of the boiler through inlet 5. Water in jacket 4 is heated by contact with the outer -.s urfac .e

1 5 rrzed into steam which rises gfh p pe? to the u'p'per portion of [5 and-outifil ifdilgihconduitfll. When the stegffifprssur up ,in'druin I 5to anamount Ernie reducingvalve l6 and.

inan'd'foi steam, thepresset begin closing ofi'the the'cros over pipe'ld. Steam WWW 'ted in the ja'cket"4 4 M c6nini'encestorise 1: res ureincreases' it causes the water in the jacket 4"t,o 'be forced back through pipe 5 and condlfitninto 'thedrum 1'5.

in ane gift. ie ais eamh ,iwea c i d h arent thatthe pressure in 'ja'cket that an eixc'ess amoiihtcannot enter to 'createex- 7 plosivc-r pressures-by fiasljiingto "steam. "When r thereis a complete siiiitiofi with no dinand for steain any greases messagin thefirum caused -by -the waterbaoliing up iiito'it maybere1revea' by t safety valve"? l. iwhe enough water is foiced out'o he acket"td uncoverf-all'nf the shell '3, no 'n'i'orefh'eat "is'ftrans h s reached it which 'is "the closing pres'surecr the *redu cing valve" 16 plus" the total h i t dm 'As the pressure drops-in the-drunf below the closing point, or V the valve. due; to an increase "in Q 7 steam demand, the pressure reducing" valve opens, renewin steam l 9tscap fromthe" heating" "sect'ign 4 to supplylthe" demand; As. steamleaves the heating sction throiigh pipe '6', the'pressure V 7 my the uppe1 -part ofth d-r-urn. NInZ Figm the-spresa )3 jacket Twill allowing the'w'ater torise and tent iri c'oiitlact' with'rnfore" heating surface and;therebygenerateniore' steam to meet them-- -'dste an'i,de'iifand.

drum l5 h s afieapaity above'theminiessary to hold the entire water'content of th boiler under the condition where no steam is needed. This excess capacity is provided to assure "that the water in thiegdrum willat no time 5 interferawith the connection between steam outlet I? and the cross-over pipe I 4, nor obstruct the 1 safety valve connection in the top of the drum.

lt may 'b'e reg-u ted rnanuall or automatically by steam ressure ed'rrom the drum [5 through a '-'cionr'iecftion' Fig. 1),. or from a thermostatic "device "located whereverthetemperature control is desired.

the steam= dmand "decreases less water is carried over bythe steam until a pointis reached where 1 only dry saturated steam is delivered, Frnmtrfis point ontoa no demand condition,

' callyi possible thatat ver y' low load :the steam can reducing?itssuper'heat. ,Itiisi desirableflto include a trap "'27 "in thef'cross-over M 'gtogprevent water backing into the steam generator. iflfhe crossable ft'o fhave'ithe'cr0ss=over' drain to the "drum, 7

' the arrangement of Fig," 4' is; preferable. 111' the "arrangement of theilattei'f fi ure the; pressurere- I ducing valve ,1 6imaifiif desiredbeinstalled in the 40 "in"Fig'."6.. Fig. 4 'alsojshows'a modificationof the rt'urndine of value-in reducingrhe:tendencr.of large quantities of water 7 to enter the 'boiler., s,ud- --dently, which'tif the water-is .coolwould cause a '-wateris hot: might cause, undesirable; flashinginto steam. A check valve 35, permitting-.freerflow away from the-boiler, is placed'in: line; 5;:While a check valve of standard type will perform the same junction. :1 Flow from:th'e?bni1errtoidlzum '15 :Zis :unrestrictedwwhileaiwatergcanitfiow into'gthe throttlei31. :.-1Additiona1= reduction oft-the :superheat may be se-cured:by -:causingthe fsteamzrtot ztrayelxthrough g i a section o1-'=colleiitpipeesubmerged imtheiwater coir iin is iconnected to the':steam 7 leadin'g to'.itheesteamwutilizing -'-system In the rran'gement ofFig'..8:the:-crossever l 4- onnects directlyhwitha the upperi iehdl-of surereducing valve FB {is placedin pipe: 31?. :Z'Since the conditions tending to superheatingziof the- 'I steam; occur when' th'e water3-leve1 in 5 the druiniis rising-,*- the lerigth jo'f submerged travel 101?? the steam in the arrangements ofi Figa 4 .to 8tin- Q 'either in line I 7 (Fig. 3) or superheated steam will come over: It is theoreti-' "pe *superheatedto a. ftemperature very close-to 'that of the exhaust-gases. Highly superheated l drum at the "end of extension 26 .as sho wnat zfl' lag' in the-supply lofi'steam demandedor ifithe "aximum wateiwlevei: in" theidrn'm.

a ieavie creases as the degree of superheat tends to increase.

Preferably, and as shown in the several arrangements disclosed in Figs. 1 to 8 inclusive, the steam line from the boiler to the steam utilizin system includes both the valve l5 and the drum i5, that is, the steam going to the utilizing system passes through cross-over l4 reducing valve i6 and drum l5 on its way to the supply pipe IT. This arrangement has the advantage that the steam separation takes place in the drum and permits the use of the water in the drum for reducing the degree of superheating of the steam, in the manner above described. Another arrangement is shown in Fig. 9 in which drum l5 serves only as a water control space and the steam separation takes place only in the boiler jacket. The steam supply pipe Il may be connected directly to the boiler as shown in Fig. 9.

We claim:

1. A waste heat utilizer having a water jacketed shell and conduits for conducting exhaust gases in heat transferring contact with the shell, and an automatic control for regulating the amount of heat utilized, said control comprising a water drum connected at its bottom to a low point of said jacket and near its top to a high point of the jacket, said latter connection having a pressure reducing valve therein responsive to steam pressure in the top of the drum, and means to conduct steam from the drum.

2. A waste heat utllizer having a boiler and conduits for conducting exhaust gases in heat transferring contact therewith and an automatic control for regulating the amount of heat utilized, said control comprising a water drum connected to a low point of said boiler and also having a connection to a high point of the boiler, said latter connection having a pressure reducing valve therein responsive to steam pressure in the top of the drum, and means to conduct steam from the drum.

3. Means for controlling the steam output of a waste heat boiler which comprises a chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, the chamber having a capacity in excess of the water capacity of the boiler, a steam supply line from the boiler for connection to a steam utilizing system to be served by the boiler and including said chamber, a pressure reducing valve in the steam supply line located between the boiler and the part of the steam supply line leading to the utilizing system, and means responsive to a variation in the steam r of the boiler, a steam supply line from the boiler pressure in the steam supply line to adjustthe opening in said pressure reducing valve.

4. Means for controlling the steam output of a waste heat boiler which comprises a chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, means maintaining a, minimum water level in the chamber, the chamber having a capacity above said minimum water level in excess of the water capacity of the boiler, a steam supply line irom the boiler to the chamber, a steam supply line from the chamber for connection to a steam utilizing system to be served by the boiler, a pressure reducing valve in the steam supply line from the boiler to the chamber and located between the boiler and the steam supply line to the steam utilizing system, and means responsive to a predetermined steam pressure in the chamber and steam supply 6 a line t the utilizing system to close said reducing valve;

5. Means for controlling the steam output of a waste heat boiler which comprises a chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, means maintaining a minimum water level in the chamber, the chamber having a capacity above said minimum water level in excess of the water capacity to the chamber, said steam supply line opening below the minimum water level of the chamber, a steam supply line from the chamber for connection to a steam utilizing system to be served. by the boiler, and a pressure reducing valve in the steam supply line from the boiler to the chamber.

6. Means for controlling the steam output of a 'waste' heat boiler which comprises a, chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, means maintaining a minimum water level in the chamber, the chamber having a capacity above said minimum water level in excess of the water capacity of the boiler, a steam supply line from the boiler to the chamber, a portion of said supply line being submerged below the minimum water level in the chamber, a steam supply line from the chamber for connection to a steam utilizing system to be served by the boiler, and a pressure reducing valve in the steam supply line from the boiler to the chamber.

'7. Means for controlling the steam output of a waste heat boiler which comprises a chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, means maintaining a minimum water level in the chamber, the chamber having a capacity above said minimum water level in excess of the water capacity of the boiler, a steam supply line from the boiler to the chamber said supply line having a portion submerged below the minimum water level in the chamber, a steam supply line from the chamber for connection to a steam utilizing system to be served by the boiler, and a pressure reducing valve in the steam line from the boiler to the chamber and located below said minimum water level.

8. Means for controlling the steam output of a waste heat boiler which comprises a. chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, means maintaining a minimum Water levelin the chamber, the chamber having a capacity above said minimum water level in excess of the water capacity of the boiler, a steam supply line from the boiler to the chamber, a steam supply line from the chamber for connection to a steam utilizing system to be served by the boiler, a portion of said last named line being submerged below the minimum water level in the chamber, and a pressure reducing valve in the steam line from the boiler to the chamber.

9. Means for controlling the steam output of a Waste heat boiler which comprises a chamber located externally of the boiler, a water line connecting the lower portion of the chamber and the lower portion of the boiler, the chamber having a capacity in excess of the water capacity of the boiler, a steam supply line from the boiler for connection to a steam utilizing system and including sa d chamber, a Emi iei i: valve in said supply line between the boileg my; the chamber and xeepeneive to aincrease or eeereese in nie'ssn eiheeieameum ply line; Qn that side of t is: iiieeeuie reslneins valve tow rds the ne ler to reset: i ely de rees? or increase th openi "thm glfl Q hi:

M ns er eont ellln the l iim fiqfimii of e waste h a bo er l amenities e ene a-e? located exter lly Qf impeller. e weter'liee necting the lower noniiee 9f ihe ehem eee and lewerr p rtmn w? the hQil.h fi min 13%? g a capacity n exce s 9f i ls: QWZEQBQQZEX if E??? boiler, a steam s nelyliii Hem 132$ b9il connection :to a steam in; lame y i one 12 e udin said chamber. a'ieres iire eeiiein YEW? in said steam. suPPWliil hW??? ilie eel-lee @116 said chamber, and means responsive g in: crease or decrease in rnre ir in ikie'eieemi Sli ply line on that side of the nmsu e'reueine valve remote from the boiler to game ,igia ely 421g: crease or increase the QRBI' ing bliroi gk sgig vglye,

11. Means for controlling the steam 29 2mm; 9? a Waste *heat boiler which comprises apQgmlggg located externally of the boiler, a wage; lingggn;

neetiee lmver ez qn Qt th eiaambev the lower portion of the boiler, the chamber hav ng e eeeeei y i .exeeewi the-W l ie? em 9 W 95 hee-@3 32 e sieeen ine we! the b art? the ehmben a ereseuee'eeq ieinewlv In eieain enemy 1. 1 e s ee eve-P y iee we i bell ier ee iae ii i 'ie a, e f em u ili ine ys sACQ, 'Ja.

mrmmces we!) mow n ieferenees van; of eeex the fi e of t s Pa ient: 7

UNITED STATES PATENTS Name Dat g g V Jagoblls 1.932 ';;989,5, 1 9 H att Jen- 28, 1935 'ZQgQlfilB La Mont .e-e'--- M 2 41949

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