US1775274A

US1775274A - Differential heating system

Info

Publication number: US1775274A
Application number: US243861A
Authority: US
Inventors: Clayton A Dunham
Original assignee: C A DUNHAM CO
Current assignee: C A DUNHAM Co
Priority date: 1924-04-04
Filing date: 1927-12-31
Publication date: 1930-09-09
Anticipated expiration: 1947-09-09

Description

C. A. DUNHAM DIFFERENTIAL lHEATING SYS TEU Original Filed' April 4. 1924 a lala ala aaaa aaa aaa aaa aa a all aalaaaaaaae. Jaaa aaaaaaaaaa aaa aaa, .aaaaaa f aa a |551 a aaafaaauu/aaahaaauaaauaaaaauuuaauauaaaauaralaaaaaaaai l aaaaauaaaaaaaruua/waa .aaaaaraaaaaaaaaaaararlaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaazaaia.

a aaaaaaar: aaalnaaaa aaaaaaaaaaaaaaalaaaraaaa Sept. 9, 1930.

Patented Sept. 9, 1930 uNn-aosTATEs PATENT OFFICE cLAYToN A DUNnAmor GLENcon, ILLINOIS, AssIGNoa To c.'-A. DUNHAII COMPANY,

OF MARSHALLTOWN,

IOWA, A .CORPORATION or IowA DIrnnaENTIAL HEATING SYSTEM l l l Original application led April 4, .1924, Serial No. 704,141.

serial lo. 243,861. Renewed April 22, 1929.

application led Decemberel, 1927,

This invention relates to a steam heating system, comprising separate supply and return mains, and adapted to normally supply steam at sub-atmospheric pressures to the v radiators. 'Means are provided for maintaindraws only L the head of water-n the boiler. This ap parts adapted to carry the return ing the required vacuum or low pressure in main, as Well as a certain pressure differential between the supply and return mains. This exhausting mechanism with- .air and non-condensable gases, the condensate which accumulates in the return main gravitating directly to the boiler or steam generator. According to the presentinvention, a return-trap'is provided in the return main, where steam pressure is automatically provided, if necessary, tol assistp tlie return main in returning the, accumulated liquid condensate to plication is a division of my copending apphcation, Serial No. 7 04,142, filed April v4, 1924.

The principal object of the invention is to provide la newand improvedv combination of out the principles of this invention as briefly outlined hereinabove,

' and as explained in detail in the description which follows.

Other objects andadvanta es of this invention will be more apparent rom the following detailed description of one approved form of the apparatus.

In the accompanying drawings:

Fig. l is a diagrammatic elevation of the assembled apparatus.A Fig. 2 is a vertical section through one of the radiator inlet valves.

Referring to the drawings A designates one of the radiators ,of the heating system,and

B is the steam supply main opening out of the steam'space of thelsteam generator or boiler C and connected by a supply pipe D with radiator A. A manually controlled in let, valve E limits the supply of steam admitted from pi e D to radiator A, and F is a steam trap o preferably of the expansible iiuid-lled disk type, located at the outlet of ,the radiator. This trap is connected by a dpipe 1 with the' return main G.' It is to be un rstood that the radiator A'is Amerely one of .a plurality of v for each of the radiators of any preferred construction,-

lenewed November 9, 1927. Divided and this similar radiators that may be utilized in the which has threaded engagement with an internally threaded sleeve 32 adapted to be rotated by a handle 33, the' sleeve and handle being supported by the bonnet `34 of the valve casing. 'The stem 47 is non-circular in crosssection and extends through' an opening of similar shape in a guide plate) 35 which is in terposed between the ,upper edge'of the casing and the bonnet. Consequently when the handle 33 is turned, nut 3l is forced downwardly so as to seat the valve over port 44. The outlet port of the valve casing is through a boss 36 securedby union 37 to a nipple 38, which is screwed lnto radiator A. A plate or disc 39 formed with an orifice 40 is arrangedin the boss 36 andis held against a shoulder 41 by ansplit ring 42. The orifice plate 39 is removable so that the valve the heatingsystem may be fitted with a plate having an orifice of the proper size to provide forthe admission to the radiator of the proper amount of steam. The orifices are of such size that when the system is filled with steam, they will admit enough steam to the radiators to make up for condensation. That is, the pressure in the radiators will substantial- 1y equal the supply pipe pressure. The orifice valve 2 and the boiler. At I is shown a thermostatic trap positioned in a pipe 3 between the drip pipe H and the return main G for venting air from the drip pipe into the return i main. At J i's an air eliminator connected by pipe 4 withthe return main, and having an air outlet pipe 5 provided withan outwardly opening check valve 6. At K is shown Aa thermostat, preferably, but not necessarily, employed for controlling the dampers 7 and 8 of the steam generator through the instrumentality of a damper operating motor 9 of common construction.

Liquid condensate is returned to the boiler from return main G and drip pipe H b y gravity, as hereinafter described. The air and non-condensable gases are withdrawn.

from the return main G'through a pipe 10 leading to any suitable type of exhausting paratus, the one here indicated being closed and described more in detail in my parent application Serial= No. 704,142, hereinabove referred to; At L is indicated a hurling water tank connected by pipe 11 with 25 the drip pipe H. The water level in drip pipe H will normally extend above the pipe 11, so

I that a constant supply of'water 1s main-v tained in the tank L. However, the same water is used over and over again in this pumpin system, bein withdrawn from and returne to. the tank so. that there is normally the pipell.. The centrifugal pump M receives water from tank L and forces the' same through ajet exhauster N, to the suction space 'of which is connected the pipe 10, leading from the return main G, this pipe being provided with a check valve 12 opening .toward the jet'exhauster. Water from the jet ex- 40 hauster passes into an air separating tank O and thence back to the water tank L. The air and gases are discharged to the 'atmosphere from tank O through a iioat-controlled valve, the'outlet also being provided with an outwardly opening check-valve. All of this is disclosed more in detail in my co-pending application, Serial No. 704,142, above referred to. This formof lpumping or exhaustingmechanism is here s own merely by way of example, and many other forms. of motordriven or other suitable exhausting mechanism could be substituted for the one here illustrated diagrammatically. v

The pump M is preferably driven by an electric motor P, the controlling switch of which is' governed byv a diierential pressure device R, the low pressure chamber of which Ais connected by pipe 19.with pipe 10 leading from the return main G, and the high pressure chamber of the4 controller is connected b means of e 20 with some por'- tion of t e system w ich is substantially at boiler pressure. 'As here shown,'ppe 20 connects into the hurling watercircuit. The exhausting I mechanism operates to l switch Q to shut no appreciable flow of liquid through return main of the heating system, and tol vent this air. The control mechanism is so adjusted that the exhausting means will continue to operate until a predetermineddifference inpressure tween the return main G and the supply main B (that is all parts of the System which are at substantially boiler pressure), after which the differential controller R willoperate the off motor P thus stopping the pumping system. When this pressure differential has fallen below the desired minimum the exhausting mechanism will again be automatically started to renew the with-` drawal of gases from the return main G.

The horizontal leg 21 of the return main G is considerably above the water line'of the boiler so that waterof condensation .from the heating system will flow into the boiler of the generator-by gravity drostatic head of water collecting in the vertical leg or standppe 22 of the 4return main above the boiler water level, so long, that is, as the boiler pressure is effectively less than the force exerted by such water col-` has been established b ey due to the hyumn. The return main is shut olf from boiler pressure by check valve 2. The accumulation of water in the drip pipe H will continue until this'water ba ances the boiler pressure, after whichthe excess water accumulation will flow by gravity into the boiler.

At the top of the vertical leg 22 of return main G is positioned areturn trap T, into which the horizontal leg 21. of the return main discharges. with a one-way check valve 23, opening toward the trap T, and preferably the pipe 21 is provided with a downwardly bent portion 24 to overcome the resistance of valve 23 to the water accumulation behind the valve. The trap is ,in open communication with the vertical leg 22 of return main G. The return trap T is of a type in common use, the one here shown by way of example being disclosed in the patent to "Johnson, 1,509,299, granted )September 23, 1 924. Any other trap of this trap and the pipes 25 and 27 are provided with valves under control of a pivoted float 28. When the float is down, that is when there is no material accumula-tion of water in the tank T, the steam pipe 27 will be closed and the air vent pipe 25 will be open. Wheny suiicient water has accumulated Ain the trap -to raise the float a predetermined distance,

the valve. controlling the air vent-pipe is f closed and the valve controlling the steam The return pipe 21 is provided i system since the traps hausting mechanism will function since there will be no pressure dierential between the supply and 4return mains at this time. Air

l will be exhausted fromthe return main G,

and also through main G from the entire F are open, and the lowered pressure in the b'oiler will cause steam to be supplied to the radiators at a lower temperature than if the boiler were subject to atmospheric pressure. When the radiators A have lled with steam, the traps F will close. The exhausting mechanism will continue to o crate until the return main G (now shut 0E fiiom the supply side of the system) is further exhausted and the desired pressure differential has been established between the supply and return sides of the system, whereupon the differential controller R will function to sto the exhausting mechanism. As

the steam 1n the radiators A condenses, the water will'flow into the traps F thus causing these traps to open and permit the water to iiow through pipes 1 to the return main G, the trap F immediately closing as soon as steamattempts to pass therethrough. The vacuum created by the condensing steam in the radiators will act to maintain a sub-atmospheric pressure in the radiators, and by suitably controlling the lires in steam generator C any desired sub-atmospheric pressure of the steam Within the radiators may be maintained, thus varying the heat given out bythe radiators in accordance with temperature requirements.

The water of condensation will gravitate into the vertical leg 22 of the return main G and will accumulate until the column of water in pipe 22 stands above the water level inthe boiler to an extent suiiicientvto overbalance thc boiler pressure, whereupon the excesshead of water will open the one-way valve 2 and gravitate into the boiler. Water of condensation will also accumulate in the drip pipe H (which is at boiler pressure) until the head of water in this pipe is sufficient to force the excess water into the boiler against the boiler pressure. Water will accumulate to a height slightly above the pipe 1l, so that the exhausting mechanism will always be primed.

Any air accumulating in drip pipe H will be vented through pipe 3 and trap I into the return main G, so that it will be Withdrawn and vented, along with the air and non-condensi- 4ble gases in return main y Water in tank T as exists in the return main G, vso that water will iow freely thru horizontal leg 2l of return main G into the trap T. As long as the pressure differential between the supply and return mains is at or less than normal, that is represents a pressure equal to or less than the hydrostatic head of the water column in pipe 22, the condensate will gravitate into the boiler. Under these conditions the trap T does not function as such but is merely a part of the return conduit. If, however, due to excess of steam generated over condensation the normal dil"- ferential is exceeded, and this condition persists, the liquid condensate will accumulate in the pipe 22 and trap T since the water column in the trap will be insuiiicient to balance theA increased boiler pressure. This causes the lioat 28 to rise, closing the vent pipe 25 and opening the trap to the steam pipe 27 so that steam at boiler pressure enters the trap. Since boiler pressure is now exerted on the accumulated condensate, the water will gravitate into the boiler. During this operation, any condensate accumulating in the return main G above the trap T is prevented from escaping through the air vent of aireliminator J -by the float controlled valve of said eliminator (which is of the usual construction). Check valve 30 prevents water from flowing out through pipe 29 from the eliminator J. Y

When the tra T has been discharged into the boiler, the iibat 28 willbe lowered, thus closing steam pipe 27 and opening the vent pipe 25. The trap T is vented of excess pressure through pipe 25 and valve 26 to the atmosphere', the further reduced to that of the return main through equalizing pipe29 and valve 30 leading to the air eliminator J..

With the exhausting mechanism out of action, and the system operating at normal or By means of the equalizing connecpressure in the trap being super-atmospheric pressures, the action of Y steam heating systems, for forcing liquid condensable gases from the return main, .a

iconnections herein disclosed, the trap condensate back I believe that I am the first in the -manner hereinabove set forth in a system ,op-

erating under sub-atmospheric pressures. By means of the pressure equalizing and venting T may be utilized to return liquid condensate to the boiler under boiler pressure; ing the low pressure conditions maintained in the return side of the heating system.

l. In a steam heating apparatus, a steam generator including a boiler, a radiating system, means comprising an exhausting :apparatus for Vmaintaining a pressure below atmospheric in the radiating system and a difference of pressurev between the inlet and outlet ends thereof lsullicient to-move the heating medium through the system, said exhausting apparatus operating to withdraw gaseous fluids only,

anda conduit for liquid condensate through which water from the radiating system will gravitate tothe boiler, a return trap in this conduit above the normal-water level therein, and connections with this trap whereby steam at boiler pressure is utilized to return. liquid to the boiler when this liquid accumulates in the trap.

2. In a steam heating apparatus, a steam generator including a boiler, a radiating system, means comprising an exhausting apparatus for maintaining a pressure below atmospheric in the radiating system and a difference of pressure between the inlet and outlet ends thereof sufficient to move the heating medium through apparatus operating to withdraw gaseous 'fluids only, and densate through which water from the radiating system will gravitate t the boiler, a return trap in this conduit above 'the normal waterV level therein, and valved connections leading from the trap to the boiler `and return main for alternatively admitting steam at boiler pressure to the trap or pressure inthe trap to that of the low pressure side of the system; l

3. In a steam heating apparatus, a steam generator including a boiler, a radiator. a supply main, a return main, exhausting means for withdrawing only air and nonregulator for said exhausting means which tends to 'maintain a constant minimum pressure differential as between thesupply and return mains, said return main ycomprising-a standpipe connected with the lower portion of the boiler which extends above' the water level of the boiler so as to provide for a watercolumn of a height to overbalance the boiler pressureV when thediflerence in the pressures in the supply and return mains corresponds toor is less than the aforesaid differential,

a return trap` in the standpipe above the norto the boiler by steam pres-- without disturbthe system, said vexhausting a conduit for liquid conlowering the above the normal mal water level therein, and valved connections leading from the trap to the supply and return mains for alternatively admitting steam at boiler pressure to the trap ing the pressurein the trap to that existing in the return main.-

4, In a steam heating apparatus, a steamy generator including a boiler, a radiator, a supply main, a return main, exhausting means for withdrawing only air-and noncondensable gases from the return main, a regulator for said exhausting means which tends to maintain a constant minimum pressure diiierential as between the supply and return mains, said return main comprising a standpipe connected with the lowerportion of the boiler which extends above the water level of the boiler so as to provide fory a water-column of a height to overbalance the boiler pressure when the difference in the pressures in the supply and ret-urn mains corresponds to or is less than the aforesaid differential, a'check-valve opening toward the boiler in the connection between the standpipe and the boiler, a return trap in the standpipe above the normal water level therein, and valved connections leading l'from the trap to the supply and return mains for alternatively admitting steam at boiler pressure to the trap or lowering the pressure in the trap to that existing in the return main.

5. In a steam heating system, a steam generator, pipes connecting the generator and radiator for respectively delivering steam to the radiator and returning liquid condensate to the generator, exhausting means connected with the return pipe for withdrawing airand noncondensable gases from' the system and for maintaining a pressure differential between the supply and return sides 'of the system, a return trap positioned in the return pipe above the normal water level therein, and

-va1ved connections leading from the trap to the sup ly and return mains for alternatively admitting steam at boiler pressure to the trap, or lowering the pressure therein to the pressure existing in' the'return side of the system.- 6. Ina steam heating' system, a steam generator, a radiator, supply andreturn pipes connecting the generator and radiator for respectively deliverin steam to the radiator and returning .liqui condensate to the generator, exhausting means connected with the .return pipe for withdrawing airV and noncondensable gasesrom the system and for maintaining a pressure differential between the supply and .return sides of the system, a return trap-,positiened in the return pi water level therein, a. chec or lower- 'l a radiator, supply and return valve in the upper'portion 'of' thereturn pi j e 'il opening towar ne trap, mea-ns forprovi in boilerressure inthe trapfwhen ,water ac umulates therein, and means for venting excess pressure from the trap when the water has been forced therefrom, said latter means mcluding an equalizing pipe connecting the trap with the return main valve.

7. In a steam heating system,

erator, a radiator, supply and eyond the checka steam genreturn pipes connecting the generator and radiator-for re-y return pipe for withdrawing -air and noncondensable gases from the system and for maintaining a pressure diierential between the supply and return sides of the system, a return trap positioned in the return pipe above the normal water level therein, a vent pipe leading from the trap, an 'outwardly opening check-valve in the vent pipe, a steam pipe connecting the trap with the supply pipe, float-operated valves connecting the steam and vent pipes vwith the interior of the trap whereby the vent pipe will normally be open and the steam pipe closed, butthe vent will be closed and the steam pipe opened when liquid accumulates in the trap, a checkvalve in the return pipe opening toward the trap, an equalizing pipe connecting the vent pipe with the return pipe beyond the check valve therein, and a check-valve in the equalizing pipe opening toward the return pipe.

8. In a steam heating system, a steam generator, a radiator, supply and return pipes connecting the generator and radiator for respectively delivering steam to the radiator and returning liquid condensate to the gen- `erator, exhausting means connected with the greturn pipe for withdrawing air and non- 4condensable gases from the system and for maintaining a pressure differential between the supply and return sides of the system, a return trap positioned in the return pipe above the normal water level therein, a vent pipe leading from the trap, an outwardly opening check-valve in the vent pipe, a'steam pipe connecting the trap with the supply pipe, float-operated valves connecting the steam and vent pipes with the interior of the trap whereby the vent pipe will normally be open and the steam pipe closed, but the vent will be closed and the steam pipe opened when liquid accumulates in the trap, an aireliminator connected with check-valve inthe return pipe between the air eliminator and trap and opening toward-the trap, an equalizing pipe connecting the vent pipe with the air-eliminator, and a checkvalve in the equalizing pipe opening toward the air-eliminator.

9. In a steam heating apparatus, a steam generator, a radiating system, means for maintaining a pressure below atmospheric in the radiating system and a determined difference of pressure between the inlet and outlet ends thereof, and a return conduit the return pipe, a

the radiating system will gravitate to the generator, a return trap in this conduit above the normal water level therein, and means including a f1pipe connection with the generator and a oatcontrolled valve in the trap whereby `steam at boiler pressure is utilized to return Water to the generator when this water accumulates in the trap.

10. In a steam heating apparatus, a steam generator, maintaining a pressure below atmos heric in the radiating system and a determined difference of pressure between the inlet and outlet ends thereof, 4and a return conduit through which water from the radiating system will gravitate to the generator, a return through which water from trap in this' conduit above the normal water level therein, and means comprising pipe connections with the generator and return conduit' and float-controlled valves in the trap for alternatively boiler pressure to the trap or lowering the pressure in the trap to that of the low pressure side of the system.

11. In a steam heating apparatus, a steam generator, a radiator, supply and return pipes connected to the generator and radiator for respectively delivering steam to the radiator and returning condensate to the enerator, means for maintaining a determlned pressure differential between the supply and return sides of the system, a return trap positioned in the' return Vpipe above the normal water level therein, and means comprising pipe connections with the generator and return conduit and float-controlled valves in the trap for alternatively admitting steam at boiler pressure to the trap, or lowering the pressure therein to the pressure existing in the return side of the system.

12. In a steam heating apparatus, a steam generator, a radiator, supply and ieturn pipes connected to the generator and radiator for respectively delivering steam to the radiator and returning condensate to the generator, means for maintaining a determmed pressure diiierential between-the supply and return sides of the system, a return trap positioned in the return pipe above the normal water level' therein, a check-valve in the upper portion of the return pipe opening toward the trap, means including a pipe connection with the generator anda float-controlled valve in the trap for providing boilerpressure in the trap when water accumulates therein, and means for venting excess pressure from thetrap when tht water has been forced therefrom, said latter means including anvequalizing pipe connecting the trap with the return main beyond the check-valve.

13. In a. steam Vheating apparatus, a steam a radiator, supply and return pipes to the generator and radiator for generator, connected respectively delivering steam to the radiator a radiating system, means fory admitting steam at and returning condensate to the generator,

means Jfor maintaining a determined pres-4 sure differential between the supply and return sides of the system, a return trap pov sitioned in the return pipe above the normal Y and the steam pipe opened when liquid ac- 'lates in the trap. v y

heating system, a steam gencumulates in the trap, a check-valve in the return pipe opening toward the trap, an equalizing pipe connecting the vent pipe with the return pipe beyond the check-valve therein, and a check-valve in the equalizing pipe opening toward the return pipe,

14. In a steam heating` system, a steam generator, a radiating system, means for controlling the flow of steam through the radiata determined ing lsystem and maintaining diierence of pressure between the inlet and outlet ends thereof, and a return conduit through which water from the radiating system will gravitate to the generator, a return trap in this conduit above the normal water level therein, and means including', a pipe connection with the generator and a ioatcontrolled valve in the tra whereby steam at boiler pressure is utilize to return water to the generator when this water accumu- 15.` In a steam erator, a radiating system, means for controlling the flow of steam through the radiating system and maintaining a determined difference of pressure between the inlet and outletfends thereof, and a return conduit through which water from the radiating system will'gravitate tothe generator, a return trap in this conduit'above the normal'water level therein, and means including pipe connections with the generator and return conduit and float-controlled valves in the trap for alternatively admitting steam at boilerv pressure to the trap or lowering the pressure in the trap to that of the low pressure side.

ofv the system.

' 16. In a steam heating system, a steam generator, connected to the generator and radiator or res ectively delivering steam to the radiator an returning condensate to the generator,

a radiator, 'supply' and return p1 s for alternatively admitting steam at boiler pressure to the trap, or lowering the pressure therein to the pressure existing in the return side of the system.

17. In a steam heating system, a steam generator, a radiator, supply and return pipes connected to the generator and radiator for respectively delivering steam to the radiator and returning condensate tothe generator, means in the supply pipe for controllably restricting the flow of steam to the radiator,

means for maintaining a determined pressure differential between the supply and return sides of the system, a return trap`positioned in the return pipe above the normal water level therein, a check-valve in the upper portion of the return pipe opening toward the trap, means ,includinga pipe connect-ion with the generator and afloat-controlled valve in the trap for providing boilerpressure in the trap when water accumulates therein, and means yor'venting excess pressure from the trap when the water has been forced therefrom, said latter means including a ioat-controlled valve in the trap and an equalizing pipe connecting the trap with the return main beyond the check-valve.

A18. In a steamheating system, aKL steam generator, a radiator, supply and return pipes connected to the generator and radiator for respectively delivering steam to the radiator and returning condensate to the generator, means in the supplypipe for restricting the flow of steam to the radiator, means for main- Y steam-pipe connecting the trap'with the supply pipe, ioat-operated valves connecting the steam and vent pipes \With the interior of the trap whereby 4the vent pipe will normally be open and the steam pipe closed, but the vent will be closed and .the steam pipe opened when liquid accumulates in the trap, a check- ,n valve in the return pipe opening toward the trap,

an equalizing' pipe connecting the vent pipe with the return pipe bevond the checkvalve therein, and a check-valve in the equalizing pipe opening towardthe return pipe.

CLAYTON A.- DUNHAM.

means in the supply pipe for controllably re-v l stricting the flow of steam to the' radiator,

' means for maintaining a' determined pressure differential between the supply and return .sides of the system, a return trap posi'- tioned in the return pipe above the normal water level therein, and means including pipecqnnections with the generator and the return P1Pe l0()l sides of the an outwardand float-controlled valves in the trap A