US2379008A - Combustion regulation - Google Patents

Description

June 26, 1945. J. J. KLINKER COMBUSTION REGULATION Filed Dec. 19, 1942, 3 Sheets-Sheet l JOHN J KLINKER Jun 26, 1945. J. J. KLINKER 2,379,008

' COMBUSTION REGULATION 3 Sheets-Sheet 2 Filed Dec., 19, 1942 I JOHN J. lfzuwrzR June :26 1945. J KUNKEfi 2,379,008,

COMBUSTION REGULATION Filed Dec. 19, 1942 :5 Sheets-Sheet s Jpn J KLINKER Patented June 26, 1945 UNITED GOMBUSTION REGULATION John J. Klinker, Decatur, 111., assignor to .A. W. Cash Company, Decatur, 111., a. corporation of Delaware Application December 19, 1942, Serial No. 469,527

2 Claims This invention relates to combustion regulation, and more particularly to the construction and arrangement of apparatus for regulating tlhe combustion of fluent fuels, such as gas or 01 Since these fluent fuels are burned in suspension in a furnace, and the combustion gases travel rather rapidly through the furnace, it is of great importance t maintain at all times the proper relationship between the rate of fuel supply and the rate of air supply. Otherwise there may be periods during which. combustion is proceeding in an ineflicient manner. Particularly, when the supply of fuel is varied frequently to follow an erratic load, it is important that the air supply should be changed promptly and accurately in accordance with the changes in fuel supply.

It is accordingly one object of the inventionto provide a combustion regulating system of a simple and dependable construction which will maintain the correct relationship between the supply of a fluent fuel and the supply of combustion air.

It is a further object of the invention to provide a relatively inexpensive and thoroughly reliabl apparatus for regulating the combustion of fluent fuel and applicable to either natural draft or forced draft furnaces.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is a diagrammatic elevation of a natural draft steam boiler furnace and associated combustion regulating apparatus, certain parts bein shown in section for clearness of illustration;

Fig.2 is a view similar to Fi 1, but showing the furnace supplied with air under forced draft; and

Fig. 3 is a view similar to Fig. 2, but showing a modification of the apparatus.

The embodiment illustrated in Fig. 1 com. prises a furnace ID arranged to form a combustion chamber H; and a steam boiler l2 associated therewith. The boiler is provided with banks of water tubes l4 and a baflie [5 of usual construction. this baffle serving to direct the hot gases from the combustion chamber into proper contact with the water tubes and thence to a gas outlet duct l6, which may lead to a suitable stack up uv.)

or induced draft fan (not shown). The outlet duct H3 is provided with a damper I8 having an operating arm l9. Theboiler I2 'is provided with the usual steam delivery pipe 20.

On the front of the furnace Ill there is mount ed a burner 22 having a central fuel nozzle 23 arranged to direct a stream of fuel rearwardly into the combustion chamber ll through an opening 24 in the furnace wall. A suitable fluent fuel, such as a combustiblegas, is supplied to the nozzle 23 at a pressure above atmospheric through a pipe 26 provided with a valve 21 having an Operating lever 28. The burner 22 is of the natural draft type, the air for combustion being forced therethrough by the pressure of the atmosphere, 2. sub-atmospheric pressure being maintained in the combustion chamber H. The combustion chamber pressure, and hence the rate of air flow through the burner, is controlled by means of the damper I 8. V

The fuel control valve 2'! is regulated in accordance with the demand for heat, and for this purpose I preferably utilize an automatic regulator 30 of the type disclosed in the'Um'ted States patent to Temple No. 2,049,549. This regulator comprises a diaphragm chamber 3| and a'motor 32. Thediaphragm chamber 3| isconnected'by a pipe 3 to the steam delivery pipe 20, and the motor 32 is connected by a rod 35 to the valve lever 28. The regulator thus serves to control the valve 21 in accordance with variations in the pressure of the steam in the pipe 20.

In order to control the damper l8 there is provided a regulator 36 of the type disclosed in the United States patent to Temple No. 1,992,048. This regulator comprises a, pilot valve mechanism 38 supplied with fluid under pressure from a suitable source thr'ough a pipe 39, the valve mechanism being connected by tubes 40 to a hydraulic motor 62 which is connected by a rod 43 to the arm l9,of the damper IS. The pilot valve mechanism is actuated by a lever which in turn is controlled by a flexible diaphragm 45, the diaphragm being loaded by means of a coiled tension spring 41. The upper end of the spring is supported by a, nut 48 mounted on a vertical screw 49 which can be raised and lowered by means of a lever 50. The pressure in the combustion chamber II is transmitted to the upper side of the diaphragm by means of a pipe 52, and the pressure in the gas outlet duct 16 is transmitted to the lower side of the diaphragm by means of a pipe 53. The diaphragm is thus subjected to an effective fluid pressure which is a function of the rat of flow of gases past the boiler l2 and the rate of flow of air into the combustion chamber. Hence the regulator 36 will control the damper l8 and maintain a predetermined rate of air flow corresponding to the loading afiorded by the spring 41. This loading may be adjusted by moving the lever 50 or by manually turning the screw 49.

The lever 50 is moved automatically in accordance with variations in the rate of fuel flow in the pipe 26. For this purpose there is provided a regulator 55 which is similar to the regulator 36 and comprises a pilot valve mechanism 56 sup- 1 plied with fluid under pressure from a suitable Source through a pipe 51. This pilot valve mechanism is actuated by a lever 59 which in turn is controlled by a flexible diaphragm 60, the diaphragm being loaded by means of a coiled tension spring 6|. The upper end of the spring is supported by a nut 63 mounted on a vertical screw 64 which can be raised or lowered by means of a lever 65. This lever is connected to the lever '56 by alink 66. This link is connected by a bar .68 to a hydraulic motor 69 from which tubes "I lead to the pilot valve mechanism .56. A suitable restriction, such a an orifice. plate [2, is provided in the fuel supply pipe 26 to provide a slight pressure differential for regulating purposes. A pipe 13 leads from the pipe .26 anterior to the orifice plate to the space above the. diaphra m 60, an a pipe 74 leads from the pipe 26 p sterior to t orifice plate to the space below the diaphragm 60. Thus the diaphragm is subje ted to an ef c iv fluid pressure which is a function of the rate of flow of fuel to. the furnace.

.The. operation of thi em odiment ll now b apparent from the above discl s re- Fu flow to the burner nozzle 2.3 thro gh th pipe a d the rate of how is controlled by the valve 2 which is actuated y the re ulat r .3 i a dance with the demand-tor st am fr m the boi en'v va iati n, i the r te-o fuel fl will cha e. the pressure d fie ntial trans t throu h the pipes 13*14 to the dia hra m so. The resultant m vement of the diaphr gm il cause the Pil a e. 5. 110 adm t p ss re luid t the m tor 169, whi h wi l the e o adjust the levers 5.0 and .65 to n w posit ns T e m ment of the lever 65 will readjust the tension of the sprin 6 until the t me on the hragm 60 are balanced and the pilot valve 56 has been restored to neutra whereupon the m tor vii! w come to rest. -'I -h e movement of the lever-50 will readjust the tension of; t e sprin which will throw the diaphra m 45 out of balance and cause the pilot valve 58 to admit pressure fluid to the motor 42. This will readjust the damper i8 and change the rate of air flow through the burner 22, thereby changing the pressure difierential which is transmitted through the pipes 521-53 to the diaphragm 45. When the forces on thi diaphragm are again in balance, thepilot valve 36 and even the slightest change in the pressure differential effective on its diaphragm will cause a full stroke of its motor, if such full strokeshould be required to restore the desired rate of air flow. The regulator 55, on the other hand, is of the compensating type, its motor 69 being mechanically connected to it pilot mechanism 56 by means o e ba 68, ever 5, sc t spring 6|, and lever 59 to restore the pilot mechanism to neutral position. Consequently, this regulator has a definite operating range through which the pressure differential efiective on its diaphragm must vary in order to cause full stroke movement of its motor. Within this operating range, the motor 69 will assume and maintain a definite predetermined position for each value of phragm, therebyadjusting the regulator 36 for a will be'restored to neutral and themotor .42 will predetermined rate of air flow for each value of the rate of fuel supply. This rate f air flow will be maintained with great accuracy despite variati n in dra tn Fi there is sh wn a difie f rm of the invention in which the natural draft burner 22 of Fig. 1 has been replaced by a forced draft burner- 22 which is supplied with air under pressure by fa through a duet ll. This duct s prov ded wit an o fice pl e T8 to p o c a s igh pr ssure ifi nt al for regulat n purposes, and with a damper 19 having an op rating arm .80 to control the rate of air flow. This arm il .is connected bya rod 8i to the motor 42. The a r pressure nterior to t e orifice plate I8 is tr nsmitted o he pper s e of the diaph a 4.5 f the re ulato 36- y m ans of a pipe 82, and the air pressure poster or o. the orific plate s tran mitted to th lower side or the diaphragm by means of a pipe 83. The gas outlet damper is nreierahlv ontroll to maintain a sub ta t lly .oo .stant. ressure. slightly be tmo phe ic. the com ust n chamber nd or thi purpose I a regulat r 5 o e yp disol se m th atent to Temp e o 1992,048- This regulator is connected to the combustion chamber by a pipe 66. Pressur fluid is supp ied to the regulator by a pipe 81, and tubes 88 lead rom t e reg la or to a h draulic tor. 89 whi h is connected by a rod 9 0 to the operating arm [9 of the damper la.

flow will cause the motor 69 of the compensating regulator 55 to assume a new position, thereby readjusting the non-compensating regulator 36 by means of the lever 50. This will cause the regulator 36 to move the forced draft damper I9 and change the rate of air supply to correspond to the new ;ra-t eo t fuel supply Changes in air flow will varythe'pressure differential transmitted through the pipes 82.83 to the diaphragm 45, so that the regulator 36 'will maintain a predetermined rate of air flow dependent upon the position of the lever 50., Under all conditions the regulator 85 will control the damper 18' to maintain a substantially constant pressure in the combustion chamber II.

in Fig, 3 there is shown a still'further modification of the invention. This embodiment is the same as that shown in Fig. 2 except that the motor 42 of the regulator 36 is connected to the uptake damper 18 instead of to the forced draft damper l9, and the motor 89 of the regulator!!! is connected to the forced draft damper 19 instead of to the uptake damper l 8. With this construction, any change in fuel flow will cause the compensating regulator 55 to adjust the lever 50 on the non-compensating regulator 36, and the motor 42 will thereupon change the position of the uptake damper l8, which will tend to change the pressure within the combustion chamber ll. As soon as the combustion chamber pressure starts to change, the regulator 85 will respond and adjust the forced draft damper 19 until this pressure has been restored to its normal value by the resultant change in air flow. The new rate of air flow will correspond to the new rate of fuel flow, thus ensuring efflcient combustion conditions.

The invention provides a comparatively simple and thoroughly dependable apparatus for controlling the combustion of fluent fuels, and adapted for both natural draft and forced draft installations.

Having thus described my invention, what I claim as new and desire to secure by Letters Patcut is:

1. Control apparatus for a combustion system utilizing a fluent fuel and air as the elements of combustion comprising an adjustable device to control the rate of air flow, a first regulator and a second regulator each including as parts thereof a motor, a pilot mechanism to control the motor and having a neutral position, a fluid pressure responsive device connected to the pilot mechanism to actuate the same, and adjustable loading means for the fluid pressure responsive device to urge the same in opposition to the fluid pressure effective thereon, means connecting the motor of the first regulator to the air flow control device to adjust the same, means to subject the fluid pressure responsive device of the first regulator to an effective fluid pressure which is a function of the rate of air flow and thereby cause the first regulator to control the rate of air flow in accordance with the adjustment of its loading means, means to subject the fluid pressure responsive device of the second regulator to an effective fluid pressure which is a function of the rate of fuel flow, and means connecting the motor of the second regulator to the loading means of both regulators to adjust the same and increase the loading of both regulators upon an increase in the effective fluid pressure on the fluid pressure responsive device of the second regulator, the various parts being so constructed and arranged that any change in the effective fluid pressure on the fluid pressure responsive device of the second regulator will cause the corresponding pilot mechanism to effect movement of the associated motor in such a direction as to adjust the loading means of the second regulator to restore the corresponding pilot mechanism to its neutral position, whereby the first regulator will change the rate of air flow in accordance with changes in the rate of fuel flow.

2. Control apparatus for a combustionsystem utilizing a fluent fuel and air as the elements of combustion comprising an adjustable device to control the rate of air flow, a first regulator and a second regulator each including as parts thereof a hydraulic motor, a pilot valve mechanism to control the motor and having a neutral position, a flexible diaphragm connected to the pilot valve mechanism to actuate the same, and a spring connected to the diaphragm to urge the same in opposition to the fluid pressure effective thereon, means connecting the motor of the first regulator to the air flow control device to adjust the same, means to subject the diaphragm of the first regulator to an effective fluid pressure which is a function of the rate of air flow and thereby cause the first regulator to control the rate of -air flow in accordance with the force provided by its spring; means to subject the diaphragm of the second regulator to an effective fluid pressure which is a function of the rateof fuel flow, and means connecting the motor of the second regulator to the springs of both regulators to adjust the same and increase the force thereof upon an increase in the effective fluid pressure on the diaphragm of the second regulator, the various parts being so constructed and arranged that any change in the effective fluid pressure on the diaphragm of the second regulator will cause the corresponding pilot valve mechanism to effect movement of the associated motor in such a direction as to adjust the spring of the second regulator to restore the corresponding pilot valve mechanism to its neutral position, whereby the first regulator will change the rate of air flow in accordance with changes in the rate of fuel flow.

JOHN J. KLINKER.

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