US1480673A - Device for regulating the air supply to furnaces of steam boilers - Google Patents

Description

S. DEUTSCH DEVICE FOR REGULATING THE AIR SUPPLY `TO FURNAcEs oF TEAM BILERS Filed June 23 1920 3 Sheets-She'et l ,em/1, mw www@ 1,480,673 Jan" 15 1924.' s. DEUTSCH l DEVICE FOR REGULATING THE AIR'SUPPLY ,TO FURNACES OF STEAM BOILERS Jan. 15 1924. 1,480,657?,

s. br-:UTscH DEVICE FOR REGULATING THE AIR SUPPLY TO FURNACES OF STEAM BOILERS Filed Jun@ 2s. 1920 :s sheets-sheet 5 Patented Jan. 15, 1924.

SIZES-FRIED DEUTSCH,

OFFICE. f

OF VIENNA, AUSTRIA.

L DEVICE FOR REGULATING THE AIR SUPPLYv TO FURNACES 0F `S'LKLTAIYEILOIII'JIERS. r i

Application filed June 2a,

To all whom t may. concern: y Be it known that I, SIEGFRIED DEUTSCH, mech. engineer, citizen of the Republic of Austria, residing at Vienna, Lower Austria, Austria, have invented certain new and useful Improvements in Devices for Regulating the Air Supply to Furnaces of Steam Boilers, of which the following is a specification. This invention relates to devices for regulating the air` supply to furnaces of steam boilers'y the object being to provide an improved device for maintaining a predetermined steam pressure in the boiler.

In the known regulating devices of this kind, a member is provided which is moved to different positionsby and in conformity with the variations of the pressure of the steam in the boiler and varying thereby the cross-section of the air passageleading to the furnace of the steam boiler; these devices have the drawback that the raise and fall of the steam pressure in the boiler are proportionally transmitted to the regulating member, that is to say, a gradually increasing of the boiler pressure causes a gradual movement of the regulating member for closing the air passage and vlce versa. Therefore a slow or lingering opening and closing ofthe airr supply passage is produced, which is practically not very suitable for maintaining a fixed, predetermined pressure in the boiler.L

Bymeans of the present invention the following results are obtained: 1/ the air supply passage to the furnace remains totally open until the desired steam pressure in the boiler is attained, 2/ that the air supply is rapidly stopped, when the steam pressure in the boiler rises above the desired pressure and 3/ that the air supply passage is rapidly ,reopened when the pressure falls below the desired value, so that the steam pressure may be maintained substantially constant.

The. new device is constructed in such a manner that it is adapted to be used also for maintaining various predetermined pressures if adjusted accordingly.

The accompanying drawing illustrates one mode of application of the device according to the invention and the arrangement of its essential kconstituent parts, Figure 1 is a vertical section view of the lower part of the apparatus, and Figure 2 is a vertical section view of the upper part of the apparatus above section AA of Figure 1. Fig. 3 is a` 1920. serai No; 391,249.'

diagrammatical view illustrating the complete apparatus in a simplified manner;

The regulator proper, consists of la con tainer 1 for liquid in which is mounted a cap 2, the lower edge of which is at an angle to the horizontal. Around a'circular opening in the'bottom Aof the container 1 is a tubular piece 3 reaching into the interior of the cap 2 and being provided with lateral openings t. To the lower edge of the tubular piece `3 is connected a tube 5 leading to the furnace of the boiler. The `upper opening of the container 1 may be provided with a rotatable slide valve 6 tor roughly adjusting the entrance of air. The air enters from above into the container 1, flows down around the exterior of the cap 2 and beneath the lower edge into the interior ofthe cap, from there through the openings 4 into the tubular 4piece 3 and through the tube 5 to the furnace. In case ofthe liquid, preferably water, standing only so high in the container l that the edge of the cap `2 is completely free, the cross-sectionof the air passage is a maximum and the maximum quantity of airl may tlowto the furnace.` Thej higher the liquid rises, the smaller becomes the cross-section of the air passagey and in case ofthe cap edge immersing totally into the liquid, the air canv no longer enter into the interior of the bell and the flow of air is interrupted;L

. The container 1 of the regulator communicates'by means of a pipe 7 with a reserve vessel 8 in which normally the level of the liquid is at the same height as itis in the container, viz'at such a height that the cap is out of contact with `the water.` lf the pressure in thereserve vessel 8 increases, the liquid is partly driven out and the level lowers, whereas the liquid in the regulator container thereby rises, so that it is only necessary to make the pressure in the'reserve vessel 8 `depend on the pressure in the boiler for. having theair supply to the furnace controlled by the steam pressure in the boiler. With this object in view the air space of the reserve vessel 8 is connected by means of a -pipe to a vessel 9 having a downwardly extending tube 10, which is open at its lower end and is slidably yinserted in a tube 11,

arrangement being made that the tube 1() fits tightly in the tube 11. .This latter has a branch 12 leading to the water filled part of the steam boiler or to a container, the

'somewhat larger this tube produced by trates from below intofthe tube 10. The

communication between the air space of the reserve vessel` with (the air space of the vesselllhis eiected by means of therefollowing` device :,By akpipe 13 eitendingupwards from ,the bottom o the;` reserve vesvendsF and E,connected at `its lower end Awith a `.pipe14a `fitting 15 anda vertical pipe 16 ,which passes :through thel vessel 9., and has an upper open end, the up'per'part ofthis pipeitlG being surrounded bya tube "of a diameter which yis closed at its ,upperend and s mounted on theL cover Yofthe vessel 18. this way,.the yairspace .of the vesselq9 communicates withthe tube 16, ,by interstices left between this n tube'` 16 and Iits surrounding `ltube 17, this air passage being indicated by arrows.

.When thei furnace is'y kfired, the Ipressure in A,the boilerV increases gradually, thel water in pipe 10 rises without lpractically increasing the ,air pressurein lthe vessel 9`on account oithis pipe being comparatively small 4and .therefore only a small Vquantity of Yairis -,displaced bythe rise of thewater. Consequentlythe liquid in theA reserve vessel 8 isnot exposed to a substantially v.increased pressure andutheregulator is therefore not lappreciablyavactuated. The airsupply pas- `sagesoit` this regulator remain entirely open sotliat ythe intensity of ftlie,iurnace firing is maintained. The rise of lthe'column of water in the tube 10 in cnse'quencek ofthe increase oit 4.the pressure in the boilergis ind dependent of the cross-section of this'tube,

e.; Tol every degree of pressure corresponds .fa.certainheightfofthe column of water, no matter how large be thecross-section .of the yy.tube'communicating' with the boiler. Howeverthe increase of the volume of water in the rise of the column of. water, vwhen the l pressureI increases, :de-

.pen'ds upon the cross-section of the tube. It

it is assumed that the boiler pressure begins toliiicrease at a uniform rate when the level .ot the liquid in tube 10 is below the bottom Y oi vessel 9, the height of the levelo'f the .liquidin `tube 1,0 Vwill increase in proporvtionto the increase in boiler pressure. It

f, .the frictio'nof the,l pipe connectionsbe neg- ,lected, this relation between the height of thelevel of the liquid and the boiler pres- VVsure reniainsbonstant, as the level of the liquid rises-in tube 1Q and in the vessel 9.

a The increase in they height of theV level o the liquidis alwaysproportional to the increase in'boilei` pressure, regardless of the The tube 11u is'of V:the liei'ghtwofthelevel oi the liquid in the cross-section Y of the passage in which the liquid is rising. i 'A deiiitey increaselor decrease in boiler pressure will produce a cor'- res'poiidingly deiinite increase or decrease in regulating device, the change in the height Vofthe level ot the'liquid being proportional to the change inboiler pressure, regardless ot vwhetherthelevel of the liquid is below the bottom of vessel 9 or above this point. It therefore `true that a certain change in the levelot vthe liquidkv whenthis 'level remains below the bottom of yvessel 9` will produce a very small displacenient'otfluid from the top of vessel 9, whilethe 'saine changel inthe level of the liquid, v'when this level ,is above the bottom oitthe vessel 9, will produce aconsiderable'displacement oi the fluid in the top of 'vessel 9.9111' lother words, a given change inboiler pressurewill producev a sliglitdisplacement otthe yfluid in the topv of vessel 9, when the level oi' 'the liquid ilowingiin tube 10 is below ithel bottom of vessel 9; and a considerable displacement of the fluid in the top otvessel 9when the leveloi:p the liquid is abovethe'bottom of vessel 9. "For a given rate of change in boiler pressure, the rateofilow the liquid in tube 10 is much greater of course when the level ci this liquid is above thebottom oi vessel 9than when the level oftliis' liquid is below the bottom of vessel 9. This sudden and large increase of 'volume causes a sudden increase of the air pressure iii the vessel 9 on account oifthe sudden decrease of yvolume of the air space iii thisvessel. 'lhis increased air pressure rapidly forces the liquid in 'the reserve-vessel 8f through the connections 17, 16, 15, 14, 13, thus causing Ia Arapid rise o the liquidv iii the contaiiier 1 of the regulator and simultaneously a rapid closing of the air passageVhen 'the boiler pressure decreases, the decrease ot volume will be'co'nsiderable and cause a rapid opening o'fytheui passage' as long as the water is withinthe vessel 9.: 'n lVh'en the water sinks below the vessel 9, iifurther noticeable change in the regulator will 'take place, because the decrease of volume becomes less on account of Athe smallv crosssection of tube 10. 1n this way ajpredetermined pressure in the boiler .may be pre ci'sely maintained.

(llo bev more specific, the oiliera'tion of the device is as follows 1' )assume that the 4apparatus is adjus'tedto yregulate toi' agiven pressure. li pressure in the boiler is below this value the level ot the liquid in `themtubes lOand 11"'will besoiiiewhat'below `the' bottoni of the vessel 9, andthe cross sectionl of theair passage in the regulator proper` will beM a maximum. Villienthepres sure has increased to the vOi'veii value' Vthe level ot the liquid iny tube10 willbe even with the bottom of the vessel 9, and the air" passage will still be wide open. As the pressure increases beyond the given value, the height of the liquid will increase correspondingly. This increase in height causes a large volume of the liquid to enter the vessel 9, due to its large cross section. This sudden change forces the fluid from the upper part of the vessel 9 through the communicating connections 17, 16, 15, 14 and 13 into the container 8. This causes an increase in pressure in this container 8, thus forcing the liquid therein through the pipe 7 into the regulator; and as the liquid rises in the regulator, the air passage is rapidly closed. This shutting otl' of the air supply lessens the rate of combustion, and the pressure in the boiler decreases accordingly until the given value is reached.

In order to adapt the device for maing taining different degrees of pressure in the boiler, the vessel 9 may be adjusted to difilerent heights. For this purpose the vessel 9 is guided along the pipe 16 which passes through it and is surrounded by a chamber 18 having at its upper end a tubular extension 19 closed at the top. The pipe 10 is slidably mounted in the tube 1l, and passes through a packing 20 in the bottom or chamber 18.` When the vessel 9 is adjusted to a higher level, the pressure in the boiler must become correspondingly higher before the water will enter the vessel 9. When the vessel provided with an indicator movable along a vertical scale ixed on the outward side ot chamber 18 and indicating the boiler pressure tobe maintained, it is possible to so adjust the height of the vessel 9 that the regulating device will regulate for any desired boiler pressure.

In order to obviate the loss of the liquid by evaporation a film of oil 21 may be put on the surtace ot the liquid in the regulator vessel l.

It is understood that I do not limit myself to the described details of construction which might be modified in various ways without departing from the spirit oi: the present invention. l

IV hat I do claim as my invention and desire to secure by Letters atent is,

l. In a device of the character described having an air passage, the combination of a regulator proper -for varying the crosssection of the air passage, and fluid pressure means for actuating the regulator proper, said means comprising a reserve vessel for holding a liquid, a pipe connection between the lower part of said reserve vessel and said regulator proper7 a vessel of relatively large cross-section, a pipe connection between the upper part ofsaid reserve vessel and the upper part of said vessel ot large cross-section, a pipe connection of rela-tively small cross-section between the lower part of said vessel of large cross-section, and the boiler, said pipe connection being normally lilled with a liquid upto the bottom of said vessel of large cross-section.

2. In a device of the character described having an air passage, the combination of a regulator proper for varying the crosssection of the air passage, and Huid pressure means for actuating the regulator proper, said means comprising a reserve vessel for holding a liquid, a pipe connection between the lower part of said reserve vessel and said regulator proper, a vessel of relatively large cross-section, a piper connection between the upper part or said reverse vessel and the upper part of said vessel of large cross-section, a pipe connection of relatively small cross-section between the lower part of said vessel of large cross-section and the boiler, said pipe connection being normally filled with a liquid up to the bottom of said vessel of large cross-section, and said vessel of large cross-section being adjustable to any desired height.

3. In a device of the character described having an air passage, the combination of a regulator proper for Varying the crosssection of the air passage, and iuid pressurek means for actuating the regulator proper, said means comprising a reserve vessel or holding a liquid, a pipe connection between the lower part of said reserve vessel and said regulator proper, a vessel of relatively large cross-section, a pipe connection between the upper part of said reserve vessel and the upper part of Said vessel of large cross-section, a pipe connection of relatively small cross-section between the lower part of said vessel of large cross-section and the boiler, said pipe connection being normally lilled with a liquid up to the bottom oit' said vessel of large cross-section, and said pipe connection between the lower part ot' said vessel of large cross-section and the boiler being adapted to permit adjustment of said vessel at any desired height.

4. In a device of the character described, a regulator proper for controlling the supply of air to the furnace, a pipe of relatively small cross-section communicating with the boiler, a vessel of relatively large cross-section communicating with said pipe, and a reserve vessel forpholding a liquid, communicating with said vessel of large cross-section and with said regulator proper, said lvessels and pipe being arranged so that changes in boiler pressure near a predetermined value will produce a rapid flow of the liquid between the reserve vessel and regulator proper, while corresponding changes in boiler 'pressure considerably below the predetermined value will produce only slight flow of the liquid.

In testimony whereof I affix my sign'ature.`

ING. siEGFRiED DEUTSCH?

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