US1770588A

US1770588A - Pneumatic draft regulator

Info

Publication number: US1770588A
Application number: US290013A
Authority: US
Inventors: Walter J Cook
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-07-02
Filing date: 1928-07-02
Publication date: 1930-07-15
Anticipated expiration: 1947-07-15

Description

July 15, 1930. w. J. cooK PNEUMATIC} DRAFT REGULATOR Filed July 2, 1928 2 Sheets-Sheet l w Qi/A ENTUR v W ATTDAIYE'VE' July 15, 1930. w. J. cooK 1,770,588

PNEUMATI 0 DRAFT REGULATOR Filed July 2, 1928 I 2 Sheets-Sheet 2 W/ TNEss g i A7701? EYS Wwez 1576 Patented July 15, 1930 UNITED STATES WALTER J. COOK, OF GENEVA, NEW YORK Pia-numer c naar'r REGULATOR Application filed July 2,

This invention relates to a new and improved pneumatic draft regulator for use with forced draft systems for boilers and furnaces. p

In order that low grade or finely divided fuel may be used in heating boilers and furnaces it is necessary that some means be provided whereby air ma be fed to the bed of fuel with greater rapi ity and in greater vol ume than would be given by a natural draft.

This result is usually accomplished by providing an electric motor'from which is operated a fan or blower which sends air into the ash pit of the boiler or furnace underneath the bed of fuel. L Such electric motor may be started and stopped manually, if desired, but is usually controlled by thermostatic means. When air under pressure is being sent into the ash pit of a boiler or furnace no opening other than the opening through which the 1 air enters-can be present in the ash pit be cause if it were the air under pressure would expel ashes and embers from the ash pit into the furnace room. This being the case in all of the forced draft systems known to the art it has been customary upon installation to hermetically seal the clean out door and draft door which is usually present in the ash pit of the boiler or furnace. When this is done'the only draft which can ever be furnished for the fire must come from the blower. Under these conditions there can be no draft for the fuel when the blower is not operating. Such an arrangement is uneconomical because of the fact that it does not take advantage of the natural draft when the blower is not operating. In other words, the

bed of fuel is either subjected to a draft under pressure; or it is deprived of any draft at all.

Furthermore in installations of this character there is a strong possibility that unburned gases will accumulate on the surface of the fuel, whichv gases frequently are ignited when the blower is started and the bed of fuel again placed under forced draft; Such ignition of accumulated gases "will 0 cause an explosion which'may and sometimes does cause considerable damage.

1928. Serial No. 290,013.

The main object of my invention is to con struct a means which may be used in con junction with a forced draft system and be operated thereby, which means will insure that the ash pit will be closed while the blower is in operation but which will. cause the'opening of a door into the ash pit when the blower ceases operation so that the bed of fuel may then receive the natural draft which the boiler or furnace itself provides.

Another object is to provide a means whereby the evacuation of unburned gases from the fire pot of the boiler or furnace will be accelerated. 7

Another object is to provide a means for utilizing a portion of the air from the blower to assist in the combustion of the fuel.

Other objects and advantages relate to the size, shape and arrangement of parts all-as will more fully appear from the following description taken in conjunction with the accompanying drawings in which Figure l is an elevation, partially broken away, of a boiler and blower with my apparatus .installed. Figure 2 is a section on line 22 of Figure 1. Y

Figure 3 is a longitudinal vertical section through my device.

Figure 4 is an elevation, partially broken so away, and partially in section 0 my device.

Figure 5 is a section on line 55 of Figure 3. v

Figure 6 is a vertical view, partially in section, of my air jet. M device may be used in conjunction with any iler or furnace with which the forced draft system is'used but for the purpose of explaining the functioning of my device I have here shown a boiler 1 of the type usually called a round boiler having the usual ash pit 2, fire pot 3 and header 4 It is also provided with the usual g clean-out door .-5, draft door 6-, clinker door .7 and fuel door -8 I 5 A blower 9 operated from any convenient source of power, none being here. shown, is located, adjacent the ash pit 2- p with a discharge opening 10 in communication with the ash pit The grates, v 3

not shown, on which the fuel -11' is supported are positioned on the top of the ash pit so that the air from the blower 9 will strike the bottom of the bed of fuel 11. The products of combustion are removed from the boiler through the ordinary smoke stack 12-.

A regulator bar --13 is pivotally mounted above the boiler and has depending from one end a chain -11 connected to the draft door 6- so'that the pivoting of the regulator bar 13 about its pivot will open or close the draft door -6. On the opposite end of regulator bar 13- is provided a weight -l5normally holding that end of regulator bar beneath the pivot which will cause the chain 14- to be moved upwardly to hold the draft door 6 in the open position; I also provide a diaphragm 16 in operative contact with the end of the regulator bar 13 from which chain -14 depends. Diaphragm -l6- is connected to the steam chamber, not shown, in header 4 so that when a certain amount of steam is present the diaphragm 16 will be forced downwardly to overcome the action of weight 15 with the result that chain 14 will be lowered and draft door 6 closed.

My draft regulator -17 is positioned between ash pit -2 and blower 9' an consists of an inlet head 18- to which is connected the discharge opening --10 of the blower -9. Inlet head '18- is preferably made of cast iron and carries at its forward'end a gate -19 hook shaped in cross section and being pivotally mounted in the top edge of inlet head 18. Inlet head 18 is provided on its inner end with opposed flanges -20-, one only being shown,

of a size and shape conforming with the size and shape of gate 19 so that when gate 19 is in the down position its edges will contact with flanges -20 to close the opening through inlet head 18-. Gate 19 carries a shaft -21- which is journaled in inlet head 718- and extends outwardly therefrom, shaft 21 being the pivot from which gate 19 is suspended. I also provide on the bottom of inlet head -18 a baflle 22 extending outwardly and upwardly and so ositioned that gate 19 when pivoted wi be moved along the upper A discharge head -23 preferably made On the top of inlet head \,-18 is provided an upwardly extending air tube --26+- carrying a-regulating damper -27-. Air tube -26 has an opening in its bottom end angularly disposed with relation to discharge opening 10 of blower 9 so that when air is being discharged through discharge opening 10 a portion of such air will enter air tube 2( and proceed upwardly therethrough.

In the upper surface of discharge head -'-23 is a second air tube 28 which extends upwardly therefrom and which is provided with a damper -29-. Air tube 28- has a spoon shaped lower end which extends downwardly into the path of the air passing through discharge head 23 so that a portion of such air will enter air tube 28- and proceed upwardly therethrough.

The upper end of air tube 28 is connected to an air jet -30 which is positioned on the inside of smoke stack -12 with its discharge opening pointing upwardly;

Air tube 26 extends laterally into fire pot 3 and carries on its end a discharge nozzle 31 which is positioned above the fuel 11-. Discharge nozzle -31-, as perhaps may best be seen from Figure 2, is preferably formed with a curved forward end 32 in which are provided a plurality, in this case shown as seven, of apertures 33- in spaced relation so that the air passing through air tube -26 into discharge nozzle 31 will be distributed through apertures -33- to different parts of fire pot 3-.

d Air tube 26 is held in position in fire pot -3- by means of lock nuts 34-- and 35, air tube 26 being threaded for such purpose.

As perhaps may best be seen from Figures 4 and 5, shaft 21 carrying gate 19 carries a crank 36- Crank 36-, as perhaps may best be seen from Figure 1, is connected by means of a chain '37 passing through a pulley -38 to the end of regulator bar 13- on which weight 15 is positioned so that the downward movement of crank 36 caused by the rotation of shaft 21- will cause the end of regulator bar 13 to which it is attached to be moved upwardly thereby causing chain -14 to move downwardly and permit draft door -6 to close. Crank -36, as perhaps may best be seen from Figure 4, is so disposed with relation to gate -19 that the upward movement of gate 19 will cause the downward movement of crank 36 due to the rotation of shaft -21- and conversely the downward movement of gate 19 will cause the upward movement of crank 36. In F igure 4 I show in heavy lines gate --19 closed with crank -36 in the up position and I show in dotted lines gate 19 in the raised position and crank -36 in the lowered position.

When the blower 9 is not operated the relation of parts is as shown in Figure 1 with draft door 6 open and with crank 36 in the raised position. When blower 9 is started in operation the air passing through discharge opening and inlet head -18 will strike gate 19- and force it upwardly and the continuing current of air will hold gate -19 in this raised position. The operation of raising gate 19' is facilitated due to the spoon shape of gate -19- and also due to the fact that the baflle 22 is so disposed as to direct the air current against the face of gate -19. When gate 19 has thus been raised crank -36- will have been moved downwardly which will cause regulator bar 13 to be pivoted and draft door 6 closed. 7

When blower 9 is stopped and no air,

is moving through discharge opening 10- and inlet head 18 gate -19 will dro to the closed position which will cause crank -36 to be raised, this in turn will loosen chain -37 and permit weight 15 to 'move downwardly pivoting regulator bar --13 and raising chain -14 which will result in the opening of draft door --6 to permit the fuel -11 to receive the natural draft provided by the boiler 1.

When blower 9 is operating a supply;

of air will be forced through air tube 28 and out through air jet 3() into smoke stack .12. s discharge of air upwardly in smoke stack 12 willfinaterially in-.

crease the suction in smoke stack 12-- and will accelerate the removal of the products of combustion from the fire pot 3 therebypreventing any accumulation of unburned gases in smoke stack 12.

The amount of air which it is desired to send through

air tubes

26 and 28 can be regulated as desired by means of dampers --27- and 29, respectively.

' It will be understood that the size of the different parts of my apparatus may be varied as desired depending upon the type of boiler or furnace with which my device is to be used.

It will also be understood that the opening and closing of draft door --6.- may be accomplished irrespective of any steam regulation by means of a diaphragm --16 as above described, the onlyrequirement being a regulator bar such as 13, a wei ht --15 and

chains

14 and 37, for a though I have shown and described a specific structure and form of part as an exemplification of an embodiment of my invention I do not 'desire'to lation of parts as various changes maybe restrict myself to the exact shape, size or remade the scope of the appended claims.

' I claim:

1. In a fuel burning apparatus, an ash into the ash pit, means for opening such door,- an exhaust flue leading from the fire pot, a' source. of air under pressure, means for introducing such air into the ash pit, means actuated by the air under pressure for closing the draft door, and means for introducing. air under pressure into the fire pot.

2. In a fuel burning apparatus, an ash pit, a bed of fuel above the ash pit, a fire pot above the bed of fuel, a draft door opening into the ash pit, means for opening such door, an exhaust flue leading from the fire pot, a source of air under pressure, means for introducing such air into the ash pit, means actuated by the air under pressure for closing the draft door, means for introducing air under pressure into the fire pot, and additional means for introducing air under pressure into the exhaust flue. v

3. In a fuel burning apparatus having a draft door, means for opening such draft door, a source of air under pressure, means for introducing air under pressure into the fuel burning apparatus, means actuated by the air under pressure for closing the draft door, such means including a, gate pivotally -pit,'a bed of fuel above the ash pit, a fire pot above the bed of fuel, a draft door opening mounted in the path of the air under pressure.

4. In a 'fuel burning apparatus having a draft door, means for-opening such draft a door, a source of air under pressure, means for introduc ng air under pressure into the fuel burningapparatus, means actuated by the ,air under pressure for closing the draft door,

such means including a gate pivotally mounted in the path of the air under pressure, and a bafile for directing the air under pressure against the gate.

' 5; Ina fuelburning apparatus, an ash pit,

a bed of fuel above the ash pit, a fire pot above thebed of fuel, a draft door opening into the. ash pit, means for opening such door, an exhaust flue leading from the fire pot, a source of air under pressure, means for introducing such air into the ash pit, means actuated by the air under-pressure for closing the draft door, and means for introducing air under pressure into'the fire pot, such last named means including a pipe having a portion 7 thereof in the path of the air under pressure.

no l

6. In a fuel burning apparatus, an ash pit,

a bed of fuel above the ash pit, a fire pot above the bed of. fuel, a draft door opening into the ash pit, means for opening such door, an exhaust'flue leading from the fire pot, a. source of air under pressure, means for introducing such air into the ash pit, means actuated bythe air under pressure for closingthe draft door, means for introducing air under pressure into the fire pot, and additional means for introducing air under pressue into the exhaust flue, such last named means in eluding a'pipe having a portion thereof disposed in the path of the air under pressure.

In witness whereof I have hereunto set my hand this 25th day of June, 1928.

WALTER J. COOK.