Патент USA US2109239код для вставки
Feb. 22, 1938. - ' c, SCHOLL _ 2,109,239 AIR CONTROL MEANS FOR COMBUSTION APPARATUS Filed Oct. 19, 1935 2 Sheets-Sheet 1 CIWENTOEI CV0»? So?a/2 Feb; 22, ‘1938; C. SCHOLL AfR CONTROL MEANS FOR COMB UTSTION APPARATUS Filed Oct. 19, 1935 2,109,239 2 Sheets-Sheet 2 54 P4 ‘ 35 - #26 29’ 33 36 23v 3/ (ATTOWJ’S ‘ Patented p.512, i938 ' ' ' . , ‘i ‘2,109,239 ' UNITED STATES PATENT OFFICE i .. 2,109,239 Am. common-trams FOR. COMBUSTION ' ' ' APPARATUS Clark Scholl, Springfield, Ohio, assignor to ‘The. ' Steel Products Engineering Company, $pring ?eld, Ohio, a corporation of Ohio . Application October 19, 1935, Serial No. 45,776 13 Claims,‘ (01. 230-114) The present invention relates to improvements thereby permitting the fuel bed to build up to in automatic air control means forv combustion the proper depth, and‘ preventing substantial apparatus, and has particular reference to a combustion losses because of an undue volume ' new and improved automatic damper for control- 5 ling the supply of air ‘under pressure to the fuel bed of a furnace, as for-example in the retort of an underfeed coal stoker. ' ' A more speci?c object resides in the provision 5 in an air blower of a novel rotary inlet damper automatically adjustable in accordance with the It is well recognized that a proper ratio of fuel ,and ?nely dispersed air must be maintained 10 in order to obtain e?icient and satisfactory combustion. Such ratio is di?icult to obtain in stokers with forced draft because of variations in operating conditionsv in?uencing the amount of air supplied to the combustion zone. of excess air. In one 15 common type of .underfeed stoker, fuel is fed through a duct into the bottom of a vretort to varying height of a liquid which is responsive in level to the differential between the static pressure of the air delivered by the blower and 10' the pressure of the atmosphere. A general object resides in the provision of a new and improved damper of the foregoing char acter/which is simple and inexpensive in con- ‘ struction, and sensitive, accurate and reliable in 15 operation. ' ‘ > form a fuel bed, and air for‘ ‘combustion is supFurther objects and advantages vwill become plied under pressure by ayfan or blower through - apparent as the description proceeds. a duct to a plenum chamber, and then through In ‘the accompanying drawings, Figure 1 is a 20 tuyere openings into the bed. When the fuel bed plan view of an underfeed stoker provided with 20 is heavy and dense, the static pressure of the air automatic air supply means embodying the fea will be relatively high, and at times may reach tures of my invention. the maximum that the blower can develop. ConFig. 2 is a fragmentary vertical sectional view . versely, when the fuel bed is thin and porous, its 25 resistance to the passage of air is greatly re- on an enlarged scale taken along line 2-2 of Fig. 1, and illustrating the automatic air supply 25 duced, and hence the static pressure of the air‘ means. may be very low. The volume of air delivered by the blower varies inversely with the static Fig.3 is an axial sectional view of the blower taken along line 3-3 of Fig. 2. ' ‘ " pressure in the air passages. Thus, when the . Fig. 4 is a ‘horizontal sectional view taken 30 fuel bed is heavy, and the volume of air should along line 4-4 of Fig. 2. " . 30 be correspondingly high, the ‘actual volume of air supplied is relatively low. When the fuel bed is light, and a relatively small amount of air is required, the amount of air actually supplied may 35 be considerably in excess of that required for combustion, thus resulting in serious heat losses. v'I'he condition of the fuel bed is determinedyby the kind of fuel that is used, the rate of fuel feed, and the rate of combustion. 40 One of the primary objects of the present invention resides in the provision of novel means for supplying air under pressure automatically in accordance with the conditions of the fuel bed, thereby avoiding the inconvenience of and 45 necessity for manual supervision and adjustment, and the undesirable consequences of failure to make proper adjustments. Another object is to provide an. automatic damper for the air supply means which is respon50 .sive to the static pressure of the air passing tov the fuel bed so that when the static pressure increases, the damper is moved correspondingly toward open position, and when the static presiii Cl sure drops, the damper is moved correspondingly toward closed position to restrict the ?ow of air, Fig. 5 is a vertical sectional view of a modi ?ed form of the invention. Referring more particularly to they drawings, the underfeed stoker disclosed in Fig. 1 has a burner l0 comprising an upwardly opening ?re 35 pot or retort II, a plenum chamber l2 surround ing the pot, and tuyéres i3 opening from the chamber to the top of the pot. Solid fuel, such for example as coal, is fed by a conveyer l4 from a hopper I5 through a duct l6 into the bottom 40 of the ?re pot l l to form a fuel bed. Air under pressure is supplied by a fan or blower I1 through a duct ‘ It to the plenum'chamber l2 for dis charge through the tuyeres 13 into the top por tion of the fuel bed. The conveyer Hand blower 45 I‘! are driven in timed relation through a variable speed mechanism Hi from an electric motor 20. Preferably, the blower H, the variable speed ' mechanism l9, ' and the motor 20 are rigidly mounted on the base of the hopper i5. 50 'The blower H, which constitutes the air sup ply means, may be of any suitable character, and is herein shown as of the rotary type. More par ticularly, the blower l1 comprises a generally cylindrical housing 2| which has a tangential 55 2 2,109,239 outlet 22 connected to the duct i 8, and which is is de?ned by registering openings in the contact formed in one side wall with a circular opening ' ing walls of the duct I8 and the reservoir 40. The chambers 42 .and 43 preferably are disposed in 23. A rotor or fan wheel 24 is ?xed on- a shaft 25 for rotation within the housing 2|, and com ‘ prises a plurality of annularly arranged periph eral vanes 28 de?ning a hollow interior space 21 open at one side and closed at the other side. The shaft 25 is driven by the motor 28. Attached in fixed position to the housing 2| about the front 10 opening 23 is a ring 28 having an inwardly ta pering conical ?ange 28 for directing air_to the interior space of the rotor 24. An important feature of the present invention resides in the provision of novel air control 15 means, preferably in the form of a damper, which ‘ opposite ends of" the reservoir 40, and hence are located side by side with] an interconnecting pas sage 48 beneath the partition wall 4|. The ad justing member 39 is shown in the form of a ?oat in the chamber 43, which is of greater, height and of less horizontal area than the cham ber 42, and has a vertical connecting rod or stem 50 extending upwardly loosely through an open ing 5| in the cover 45. Pivotally connected at one end to the upper end of the rod 50 is a lever 52. The other end of the lever 52 is connected through a swinging link 53 to the damper plate 15 32. Intermediate its ends, the lever 52 is mount serves to control the volume of air supplied through the duct l8 to the fuel bed, and which is ed for pivotal movement on a horizontal axis automatically adjustable in accordance with between two centers 54 adjustably secured in changes in the static pressure of the air. The 20 damper may be of any desired form or type, and may be located in any suitable position of control‘ two upstanding arms 55 of a bifurcated bracket 56 rigidly mounted on one end of the reservoir 40. 20 It will be seen that if the fuel bed is light and in- the air supply system. In the preferred form of the invention, the air supply is controlled at the inlet of the blower I‘! by a damper 30 of the 25 rotary type. Preferably, the damper 33 com prises a ?xed plate 3| integral with the ring 28, porous, the static pressure in the duct I8 will be low. As a result, the ?oat 39 will be'lowered to which constitutes a rim therefor, and a ?at cir cular rotary plate 32 disposed against the outer face ofv the plate.3l. The ?xed plate 3| is formed 30 with an inwardly extending axial hub 33 sup porting a ?xed shaft 34 on the outer end of which the plate 32 is suitably joumaled. Also secured to the shaft 34 within the wheel 24 is a generally conical de?ector 35 for directing the incoming air toward the vanes 26. The ?xed and movable plates 3| and 32 are formed respectively with restrict the flow, of air through the damper 38. Hence, the supply of I air to the fuel bed, al though adequate, will be cut down, thereby giving the fuel bed a ‘chance to build up to the proper depth, and preventing an undue volume of excess air from passing through the fuel bed and di luting the products of combustion. As the fuel 30 bed increases in depth and the holes ?ll up, the static pressure increases, thereby increasing the damper opening. Thus, the correct damper ad justment is automatically maintained at all ' times. The adjustment/is substantially in ac cordance with the condition of the fuel‘bed, and radial uniformly peripherally spaced openings 36 takes, into account the kind‘ of fuel burned, the and 31 adapted to be moved progressively into rate of vfeed and the rate of combustion in so far _ different degrees of communication between zero as these factors effect the condition of the fuel ’ 40 and full registration. bed. ‘The aggregate area of the openings 35, and 40 The damper plate 32 is rotatably adjustable to ’ also of the openings 31, preferably is at least as adjust the effective air inlet and hence the air great, if not greater, than the area circumscribed intake of the blower IT in accordance with varia tions in the static. pressure of the air supplied to the fuel bed. by the ?ange 28 so that there will be no restric- I tion in the flow of the air vby the damper 30 when In the preferred embodiment of ' ‘the latter is wide open. the invention, this is accomplished through the medium of a liquid 38 which tends to seek dif ferent levels in accordance with changes in the differential between the static pressure of the air delivered by the blower l1 and atmospheric pressure, and which actuates an adiusting mem ber 38 operatively connected to the damper plate 32. The liquid 38 is placed in a reservoir 40 which is divided by apartition 4! at the top into two chambers 42 and 43 intercom'municating under the liquid level. One chamber 42 is sealed from the atmosphere, and is connected above the liq In the modi?cation shown in Fig. 5, the auto matic' damper controls the ?ow of air from the blower I‘! rather than the air entering the blower. The damper comprises a plate 32“ mounted with in the duct l3 for pivotal movement about a hori zontal axis 34" into different angular positions relative to the path of air ?ow. The operating mechanism for the pivotal damper plate 32*, ex cept for minor di?'erences hereinafter described, is closely similar to that for the rotary damper 55 plate 32, and'hence like parts thereof vare desig nated bythe same reference numerals plus the .uid level through a passage 44 with the interior‘ subscript a. of the duct l8. The other chamber 43, although In this form, the reservoir 40‘ is mounted von substantially closed by a cover 45, is open at the the top of the 'duct l8, and the passage 44* opens 60 top to the atmosphere. When the'stoker is idle, from the duct upwardly through one end‘ of the and atmospheric pressure prevails in the duct i8, chamber 42' to the'top of the liquid 38-. The the liquid 38 will assume the same level in both cover 45' for the chamber 43' has a central cylin drical upstanding dome 51 formed ‘with a series chambers 42 and 43 as indicated at 48. How 65 ever, when the stoker is operating, the static pressure in the duct l8 will exceed atmospheric pressure more or less, and will depress the liq uid in the chamber 42 accordingly. for example to the level 41, and thereby will cause a corre 70 sponding rise of the liquid in the chamber 43 to » the level 48. The adjusting member 39 is mov able in response to the variations in liquid level. In Fig. 2, the reservoir 40 is elongated and rec tangular, and extends along and is directly se 75 cured to one side of the duct II. The passage 44 of peripherally spaced openings 5|,‘ to the atmos 65 phere. The damper plate 32‘ is operable by a rod 58 to which it is pivotally connected at one side of the axis 34', and which extends upwardly from the duct l8 through a vertical tube‘ 59 encircled by the annular ?oat 39-. The lower end of the 70 tube 53 is threaded into a ?anged opening 53 in the bottom of the chamber 43" and in registra~ tion with an opening 5| inthe top wall of the duct l8, and the upper end extends to. above the maximum possible liquid level. ' An inverted cup 75 2,109,239 62, ?xed centrally on the top of the ?oat 39a, and sealed internally from the chamber 43“, is pivotally connected to the upper end of the rod 3 rotary plate to effect a vproportionate adjustment of said inlet area». 5. An automatic damper for forced draft stokers. , > comprising, in combination with a rotary blower having a discharge duct and having an axial tube 59 or into the dome 51. atmospheric air inlet, a ?xed damper plate ex I claim as my invention: 1. An automatic damper for forced-draftstok tending across said inlet, a rotary damper plate ers comprising, in combination with a rotary mounted in cooperative relation against said blower having a discharge duct and an axial - ?xed damper plate, said plates having air inlet ‘ openings movable respectively into di?erent de 10 10 atmospheric air inlet, a ?xed damper plate ex tending across said inlet, a rotary damper plate grees of registration to de?ne the e?ective air mounted in cooperative relation against said ?xed inlet area, means de?ning two chambers con-' taining a liquid in intercommunication below. damper plate, said plates having air inlet open ings movable respectively into different degrees the liquid level, one chamber being closed to the of registration to de?ne the e?ective air inlet atmosphere and being connected above the liquid 15 area, and means located outside of said duct for level to said duct, the other chamber being open above the liquid level to the atmosphere, a float automatically adjusting said rotary plateto in on the liquid in said other chamber, and means crease and decrease said air inlet area respective ly in accordance with increases and decreases in operatively connecting said ?oat to said rotary the static pressure of the air discharged from said plate to control said air inlet area in accordance 20 with changes in the static pressure in said duct blower., , to increase the air ?ow upon an increase in static 2. An automatic damper for forced-draft stok ers comprising, in combination with a rotary pressure and to reduce the air ?ow upon a de blower having a discharge duct and having an crease in static pressure. 6. An automatic damper for forced draft stok 25 air inlet, a ?xed damper member extending ers comprising, in combination with a blower across said inlet, a rotary damper member mount ed in cooperative relation against‘ said ?xed having a discharge duct and having an air inlet, damper member, said members being ?at and a ?xed damper member for said inlet, a rotary Y58, and is adapted to telescope loosely onto the having air inlet openings movable respectively into di?erent degrees of registration to de?ne the e?ective air inlet area, a stationary reservoir adapted to contain a liquid varying in level in accordance with changes in the static pressure of the air ?owing through said duct, and means operable in response to variations in the level of said liquid for automatically adjusting said ro tary member. , I 3. An automatic damper for forced draft stok ers comprising, in combination with a rotary blower having a peripheral discharge duct and having an‘ air inlet in one side, a ?xed damper member for said inlet, a rotary damper member mounted in cooperative relation with said ?xed damper member, said members having air inlet openings movable respectively into di?erent'de damper member mountedin cooperative relation with said ?xed damper member, said members 30 having air inlet openings movable respectively into di?erent degrees of registration to de?ne the effective air inlet area, means de?ning two chambers containing a liquid in intercommuni cation below the liquid level, one chamber being 35 relatively large and shallow, being closed to the atmosphere and being connected above the liq uid level to said duct, the other chamber being relatively small and deep and being under a substantially constant pressure above the liquid 40 level, a ?oat on the liquid in said other chamber and spaced from the walls thereof, and move ment multiplying means operatively connecting said ?oat to said rotary member to control said air inlet area in accordance with changes in the 45 static pressure in said duct. 7. An automatic damper for forced-draft stok inlet area, a stationary reservoir having two liq- Y uid chambers in intercommunication below the ers comprising, in combination with a forced liquid level, one of said chambers being closed draft supply means having a discharge air-?ow to the atmosphere and being in communication duct and an air inlet, a rotary damper for ad above the liquid level with said duct, the other of justing the effective area of the air inlet, a liquid said chambers being open to the atmosphere, reservoir having a partition de?ning two liquid and means operable in response to variations in chambers intercommunicating below the liquid liquid level in one of said chambers for adjusting level, one of said chambers being closed to the said damper automatically in accordance with atmosphere and in communication above the 55 variations in the static pressure of the air in said liquid level with said duct, the other of said cham bers being open above the liquid level to the duct. atmosphere, a ?oat in said other chamber, a lever 4. An automatic damper for forced draft stok ers comprising, in combination with a rotary pivotally mounted intermediate its ends on said blower having a hollow propeller and having a reservoir and having a link connection at one 60 Ci) casing with a peripheral discharge duct and an end with said ?oat and a link connection at the air inlet opening in one side, a ?xed damper other end with said damper, whereby vertical plate secured to said casing across said inlet and movement of said ?oat will e?ect a proportion having a conical ?ange for directing air into ate angular adjustment of said damper. 8. An automatic ‘damper for forced draft stok "105 said “propeller, a rotary damper plate mounted in cooperative relation against said ?xed damper . ,ers comprising, in combination with a blower ‘having a discharge duct and an air inlet, a plate, said plates having air inlet openings mov damper for adjusting the effective area of the able respectively into different degrees of reg istration‘ to de?ne the e?ective air inlet area, air inlet, a liquid reservoir having a partition de the aggregate area of the openings in each ?ning two rectangular liquid chambers juxta 70 posed end to end and intercommunicating below damper plate being no less than the area cir cumscribed by said ?ange, and means out of the the liquid level, one of said chambers being rela grees of registration to de?ne the e?’ective air path of air ?ow through said duct and adjust able in response to variations solely in the static pressure of the air in said duct for adjusting said tively large and closed to the atmosphere and in communication above the liquid level with said duct at the discharge side of said damper, a ?oat - 75/ 4 _ 2,109,239 in the other chamber which is relatively small and open above the liquid level to the atmosphere, and movement multiplying means operatively connecting said damper and said ?oat for syn chronous movement, whereby vertical movement of said?oat in response to varying liquid levels will e?ecta proportionate adjustment of said damper. 9. An automatic damper comprising, in com 10 bination with an air-?ow passage, an adjustable damper for controlling the volume oi’ air ?owing through said passage, a liquid reservoir having two liquid chambers inte'rcommunicating below the liquid level, one of said chambers being closed 15 to the atmosphere and in communication above the liquid level with said passage at the outlet side of ‘said damper, the other of said chambers being open above the liquid level‘ to the atmos phere, a ?oat in one of said chambers, a lever '20 having a ?xed fulcrum and having pivotal con 25 ' - 40 multiplying means to said damper to effect a proportionate variation in the air inlet area. 12. An automatic damper comprising, in com bination with an air duct and means for supply ing air under pressure to said duct, a damper pivotally mounted in said duct, a liquid reservoir mounted on said duct and having a partition de ?ning two liquid chambers in intercommunica tion below the liquid level, one of said chambers being closed to the atmosphere and being in com munication above the liquid level with the in terior of said duct at the discharge side of said damper, the other or said chambers being open to the atmosphere, a tube communicating with 10 said duct and extending outwardly into said 15 other chamber to a point above the liquid level, an annular ?oat mounted on the liquid in said other chamber and encircling said tube, a cap on said ?oat telescoping with and substantially sealing said tube fromv the atmosphere, and a 20' nections with said ?oat and said damper whereby pivotal link connection between said cap and said movement of said ?oat in response to varying; damper extending through said tube, whereby liquid levels will e?'ect ,a proportionate adjust said damper will be moved toward open position ment of said damper. as said ?oat rises in response to an increase in 10. An automatic damper comprising, in com static pressure in said duct. bination with an air ?ow passage, an adjustable 13. An automatic damper comprising, in com damper for controlling the volume of air ?owing bination with an air duct and means for supply throughsaid passage, a reservoir having two liq— I ing air under pressure to said duct, an adjust uid chambers of unequal height and of unequal able damper in said duct, a liquid reservoir horizontal areas in intercommunication below the mounted over said duct and having two liquid 30 liquid level, the chamber or larger area being chambers in intercommunication below the liquid closed to_the atmosphere and in communication level, one of said chambers being closedto the above the liquid level with said passage at the atmosphere and being in communication above outlet side of said damper, and a ?oat in the the liquid level with the interior of said duct, the chamber of smaller area operable in response to other of said chambers being vopen to the at variations in liquid level for adjusting said damp mosphere, a tube communicating with said duct er automatically in accordance with variations in and extending into said otherv chamber to a the static pressure of the air in said passage. point above the liquid level, an annular ?oat 11. An automatic damper for forced-draft mounted in said other chamber and encircling stokers comprising, in combination with a rotary said tube, and a connection between said damper 40 blower having an air inlet and a discharge duct, a low pressurevair damper in control of all or the air passing to said duct and adjustable to vary the effective area 01’ said air inlet-from zero to maximum, and means including a ?oat movable in response to variations 'in the pressure of the air in said duct and connected by a movement and said ?oat extending through said tube, whereby said damper will be adjusted synchro nously with the vertical movement of said ?oat in response to variations in the static pressure in said duct. ' CLARK SCHOLL.