US1926360A - Soot cleaner for air preheaters - Google Patents

Description

SOOT CLEANER FOR AIR PREHEATERS Filed March 2, 1931 5 Sheets-Sheet 1 m Og@ 2 726/672510? Sept. l2 1933. I F. Q AREY 1,926,360

SOOT CLEANER FOR AIR PREHEATERS Filed March 2. 1931 5 Sheets-Shedl 2 @IHM Sept. 12, 1933. F. c. AREY 1,926,360

SOOT CLEANER FOR AIR PREHEATERS Fiied March 2, 1951 5 Sheets-sheet 4 l@ f M Patented Sept. 12, 1933 UNITED STATES sooT CLEANER Fon Am PiniHEA'rEnsl Fred C. Arey, Oak Park, Ill., assigner, by mesne assignments, to Vulcan ySoot Blower Corporation, Du Bois, Pa., a corporation of Pennsyl vania.

Application March 2, 1931. serial No. l519,527

9 Claims; (Cl. 257-1) VSometimes the combustion gases from furnaces are passed through heat interchangers whereby -some of the heat of these gases is transferred to the air entering the furnace .as air of combustion; thus recovering some of the heat that would otherwise escape through the i stack. These air preheaters usually contain a great many vertical tubes through which the combustion gases pass andY around which the air to be heatedvflows. Soot collects in these tubes or ilues, and, unless it is removed,` reduces the eiiiciency of the heat interchanger. It is, therefore, the practice to'blow the soot out of these tubes or ues from time to time. Because there are so many of these tubes, only a few at aj time are blown; the tubes being disposed in parallel rows, and headers having thereon disicharge nozzles extending parallel to andvbeing moved from one row to another, so as to blow entire rows successively. So .far as I amaware,

these blowing headers have heretofore been manipulated manually, the labor involved being considerable, and great care being required to insure that the blowing nozzles will be properly registered with the tubes that are being blown.

The object `of the present invention is to produce a simple-and novel mechanism or apparatus'whereby the headers may beJv moved by power-means which shall shift the headers quickly and position ,them accurately.

Where there Vare many rows of tubes to be blown, it is customary to employtwo headers arranged parallel to yeach other and at a distance apartequal to one-half the distance between the two endmost'rows, so that one-half of the tubes will be `blown by one header and the remaining half by the other header. One4 of the objects of the present invention is to produce a simple .and novel power apparatus or 40 mechanism for operating such double headers.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the claims; but,

for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the .accompanying drawings, wherein:

Figure 1 is a planview of an apparatus arranged inV accordance with my invention, applied to a heat interchanger of which fragments are shown; Fig. 2 is a section on line 2-2 of Fig. l; Fig. 3 is a longitudinalsection through the operating cylinder or engine, the piping thereto and the manual control valve being also shown; Fig. 4 is a section on an enlarged scale on line 4;-4 of Fig. 1; Fig. 5 is a side view of the engine; Fig. 6 is a section on line 6-6 of Fig. 5; Fig. 7 is a section on line 7 7 of Fig. 4; Figs. `8y and 9 are sections, on a larger scale,

col

taken on lines 8-8 and 9 9, respectively, of

Fig. 6; and Figs. 10`and 11 are views similar to Fig. 9, showing different positions of the parts,

'and a fragment of the ratchet wheel being shown in dotted lines instead ofY in full lines.

v Referring to Figs. 1 andZ of the drawings, A represents the casing or housing of a heat interchanger lled with numerous parallel rows of tubes or fiues B of which only a few are shown. In the particular arrangement shown, the tubes in adjacent rows are staggered so as to permit a partial nesting of the tubes and an efcient utilization of the space within the casing or' housing. The lower vends of the tubes or flues are open and are located at some distance above the bottom of the casing, so as to provide, below the tubes, a space or chamber in which'the blowing headers may be disposed. There are two'headers, 1 and 2,.each as long. as one of the rows, and each provided with two sets of nozzles 3 and 4, so placed thateach header will blow two rows of tubes or ilues ata time. I'he header 1 is fixed upon the end of a large tubular member or pipe 5. The header 2 is xed upon the end of a Atubular member or pipe 6, confl siderably smaller in diameter than the member 5 andextending through and fixed to the latter eol so thatthe two pipes act as asingle memberor unit. The pipe 6 projects from the header end of the pipe 5 Va distance equal to one-half the lengthA of the heat interchanger-so that; whenr either header is registering with two extreme rows of iiues. the other header isregister-- ingwith two rows along the middle ofthe heat interchanger. Steam, air, or other fluid under pressure is deliveredI into the outer end ofthe pipe 5 from a supply pipe 7 through aflexible connection 8. In the same way, blowing fluids may be suppliedtothe outer end of the pipe 6 which projects beyond the pipe 5, from a supply pipeV 9 through a suitable exibleconnection 10. The supply pipes '7 and 9 are provided'with manual controlling valves `11 and 12, respec tively. When the valve v11 is opened, blowing fluids will be supplied to the header 1, so that,

if the headersare moved vinwardly` from the headerwill be at the rear end, so that, if the valve 11 is'closed and the valve 12 opened, the rear header will become the active one by moving the headers forward again, step by step, the rear half ,of the flues will be blown, two rows at `a time.

The headers may be provided at their ends with wheels 13 running on suitable stationary tracks 14 which, therefore, support the weight.

of the headers.

The pipes 5 and 6 may be held in fixed telescoped relation to each other in any suitable manner. Thus, the pipe 5 may be made sectional and have therein a suitablev coupling, such as indicated at 15, Fig. 7; one member of the coupling having an internal spider 16 provided with a central hub or sleeve 17 into which meeting sections of the inner pipe 6 may be screwed. This particular' coupling is placed close to the header 1. At the Yforward or outer end of the pipe' 5 there is a suitable head 18 closing thek pipe 15 and centering the pipe 6 therein. l In order to move the headers back and forth n through the heat interchanger, I provide -the mechanism to cooperate with the rack bar.

pipe5 with rack Vteeth 20 distributed from one end 'thereof to the other so as to transform the pipe into a rack bar,.and also 'provide power In theV arrangement shown, the motor or engine comprises a vertical cylinder 22 containing va reciprocable piston 23 having a rod 24 extending down through the bottom end of the cylinder.

The piston rod is connected to the upper head I I of a vertical rack( bar 25 meshing witha toothed segment 26 loose on a transverse shaft 27 underlying the pipe 5 adjacent to, the heat interchanger. Fixed to the shaft 27 is a ratchet wheel 28 havingfour teeth 29." On the toothed segment is a pawl 3() cooperating with the ratchet wheel. The parts are so proportioned that, during a stroke of the piston in one direction, it will cause the pawl to drive the ratchet double-ended, so that it may be utilized `to turn the ratchet wheel, step by step, in either direction. In the arrangement shown, as best illustrated in Fig. S,there is a tension spring 31, connected at one end tothe pawl and at the otherend .to the toothed'segment; vthe points `of connection of-thespring being so disposed in relation to the axis v32, about which the pawl "swings,` that the spring will serve to hold down either end of the pawl.

are fconnected to the pawl.

Two cords 33y and 34 When one end of the pawl is in operative relation to the ratchet wheel, a pull on the corresponding cord will move that end of the pawl into* an idle vposition andthe other end into its working position. -On the shaft l27,'and rctatable'therewith,

is a pinion 35 that meshes with the rack teeth 2Q on theblower pipe. Therefore, during one stroke lofi each cycle of the engine, vthe headers will be moved "adistance corresponding to a quarter turn of the pinion. The partsfare so proportioned that this distance isjust equal to twice the Vspace between successive rows of flues in the heat interchanger; whereby the headers will be moved back or forward, Vtwo rows at a time, during each cycle Vof the engine. In other words; when the-pawll is in one'of ,itsv working positions, Vand the engine is operated, the headers will be movedbackward, whereas, when the v pawl' is shifted, as heretofore explained, the

Athe sleeve.

The pawl is `I do not mount the pinion 35 directly on the shaft 27, but support it on a sleeve 37 that is fixed to the shaft; the pinion being rotatable on The Y'sleeve has thereon two separated radial lugs 38 and 39, and the pinion 35 has a finger or pin 40 extending between these lugs. There is a set screw 41 passing through each lug into engagement withrthe projection oriinge'r 40. By adjusting the set screws 41, the ypinion may be shifted slightly angularly of the shaft so as to make a nal neadjustment to bring the nozzles on the-headers 4into exact registration with the flues. l Y

It is essential, in order to insure accurate registration of the nozzles with the nues, that the ratchet wheel be brought to rest at the end of 'f the working stroke of the engine and does not 10 loverrun more or less. To this' end Iy have provided novel stopmeans that positively stops the ratchet Wheel whenever it has made a quarter turn. This feature is best shown in Figs. 9,v 10 andll'. On a stationary part 43 of the'casting 105 44, that supports the'engine and the operating mechanism, is mounted a double-ended pawl 45 lying in the planer of the ratchet wheel. Hung l on the same Yshaft 46 that supports the pawl 45 is a dog 47 lying in the plane'of a hub 48 on 110 one side of the toothedV segment. The dog'has a roller v49 that'rdes on the periphery of this hub, and it carries two compression springs 50 A 'The parts are so-proportioned that, when the 120 roller is out ofw the notch and `resting on the periphery of the hub,A one of the'springs 50`and 51 will be compressed, whereas the other spring will be in its normal expandedv condition. With the parts in the positionsV shown in Fig. 9, a downward, movement of the rack bar 25 will cause the pawl 30 to turn the'ratchet wheel in a counter-clockwise direction. The end 45a of the pawl 45 stands'clear of the tooth that must pass this pawl, and the notch 54 is at some dis- 130 tance from thel roller on the lholding dog. As the ratchet wheel and the toothed segment continue to turn, the notch willapproach thevdog and the roller on the-'dog will drop into the same, as indicatedrin Fig. 10. yThe spring 51,135 which was originally underl compression,^and has, therefore, held thev nose 45a of the holding pawl up; expands as the dog drops into the notch and the spring 50, which originally stood away from the lug 52, is brought' into engagement with 140 thisv lug, so that the holding pawl becomes bal-l anced on these springs, and both'ends stand clear ofthe ratchet wheel. Then, during the further movement of the toothed segment and ratchet wheel, the notch'passe's out from under 145 the dog, causing the dog to be swung into the position shown in Fig. 11, releasing the spring 51 and compressing the spring'50,` The spring 50, therefore,y rocks the holding pawl in the directionv to bring the nose 45a of the holding pawl 150 down into the path of the teeth on the ratchet wheel. This action occurs before the endy of the stroke of the engine and, therefore, before the ratchet wheel has completed its intended movement, so that, when the ratchet wheel has made a quarter of a turn, the holding pawl will lie in the path of a tooth, and will, therefore,` prevent overrunning of the ratchet wheel.

p ing the return stroke of the rack 25 and the toothed segment, the actions just described are performed in reverse order; the notch moving in the clockwise directionin Fig. ll to the position shown in Fig. 10, causing the holding pawl to assume a neutral-position; and, iinally; the positions shown in Fig. 9 being reached, and the holdingpawl being so placed that the ratchet wheel may be turned upon the next working stroke of the operating pawl.

It will be seen that .the holding pawl is effective to stop the ratchet wheel, regardless of the direction in which the ratchet wheel., is turning because, assuming that the operating pawl is reversed in Fig. 9, the down stroke of the-rack 25 will be ank idle stroke during Which the movement of the toothed segmentwill bring the holding pawl into the position shown in Fig. l1. Consequently, on the up stroke of the rack, the ratchet wheel will turn in the clockwise direction without being interfered with by the holding pawl until, toward the end of the stroke, the holding pawl has been brought into the position shown in Fig. 9, and,vtherefore, serves to arrest further clockwise movement of the ratchet wheel until after the next down stroke of the rack.

It will, therefore, be seen that, after having opened the supply valve 11, the operator need onlyl cause the engine piston to reciprocate, in

order to move the headers and cause the forward half of the flues to be blown; and then, after shutting the valve 1l and opening the valve 12, and reversing the actuating pawl 30, set the engine in motion again so as to move the headers forward and blow the rear half of The engine itself contains some novel features.

The main ports 61 and 62, leading from the pipes 57 and 58, respectively, to the interior of the cylinder, are at some distance from the ends of the cylinder so that each will be covered by the piston when the latter is in the correspending end of the cylinder. Each port is connected to the extreme end of the cylinder byl means of a passage 63 containing a spring-held check valve 64 that opens inwardly toward the cylinder. Therefore, when, for example, the pist0n is up, as shown in Fig. 3, and air or steam is admitted to pipe 57, it flows in the port 61 and from there past the check valve into the upper end of the cylinder. The passage 63 yis restricted, so that the motive fluid entering the cylinder through the same will move the piston slowly until the upper edge of the piston passes the main supply port 61; whereupon the piston moves rapidly on its downward stroke until the lower edge covers the port 62 which has been racting as the eXhaust port. When the port 62 is covered, the fluid beneath the piston is confined and forms a cushion to check the downward movement ,ofV the piston. I have, however, provided each en d of the cylinder with a small by-passage 65 extending around the check valve so that the air or steam pocketed between the piston and the adjacent cylinder head may escape very slowly through this small by-passage. In other words, the piston is vnot suddenly stopped, nor is the pocketed fluid confined further than to compel it to leak out slowly and thus permit thepiston to come gradually to a position of rest. By this arrangement, I am able to produce a rapid movement of the piston during the time the blowing nozzles are out of registration with the ilues, during the shifting of the headers, and .thus avoidloss of the blowing medium; the slowl movement at the beginning of.

the stroke, and again at the end, occurring while the nozzles are still vblowing into` the flues.

Since the nozzles are ordinarily permitted to blow into the same-nues for ten or twelve sec? onds, ample time is given the operator to cause the-piston a make itsreturn stroke before another working stroke is neededto advance the headers through the neXt step.

, It will thus be,` seen that I have produced a simple and rugged mechanism whereby aprogressive blowing of a large number of ilues'may be carried out efficiently and expeditiously, without requiring any further care or attention of the operator than to open and close the controlling valves (when the Valves are all controlled manually as shown), and shift the operating pawl when one half of the flues have been blown. It will also be seen that I haveproduced a simple and novel stop to prevent overrunning of a ratchet wheel that may be turnedstepby step in either direction; together with'a simpley and novel reciprocatingnengine in which the piston is effectively combined, and in which rapid acceleration at the beginning of each stroke and deceleration atthe end of each stroke is rapid,-

so that high-speed in operation is secured.

While I have illustrated and described with particularity only a single preferred form of my invention, I do not desire to be limited to the exact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the denitions of my invention constituting the appended claims.

I claim: f

1. The combination with tubes arranged in parallel, equally-spaced rows, a blowing .header device parallel to said rows andmovable past the ends of the tubes, a pipe Vfoi` supplying fluid under pressure to such header. of a reciprocating engine, and driving connections between said Vpipe and said engine to 'cause said header to move from one row to another during one stroke of the engine and to remain stationary during the other stroke.

2. The combination with tubes arranged in parallel, equally-spaced rows, a blowing header device parallel to said rows and movable past the ends of the tubes, a pipe for supplying fluid under pressure to such header, of a reciprocating engine, and positive driving connections between said engine and said pipe to cause said header device to move through a distance equal to that between two rows of tubes to be blown during each cycle of engine operation.

3. The combinaton with tubes arranged in parallel, equally-spacedv rows-,- and utwo blowing` headers in fixed relation to each other at a` distance apart equal to the total spacing between one half of the rows, the headers being parallel to said rows and movable Atransversely of the latter, of means to move said headers step by stepfrom one row to another through a distance equal to the spacing between one half of said rows and then back to the starting point, means to arrest the headers in registration with rows of Vtubesat the end of each step, and. means to admit uid under pressure into either header whereby one-half of the rows of tubes may be blown while the headers are moved step by step in one direction and-the other half be blown while the headers are moved step by step lin the opposite direction.

4. In an apparatus rof the character described,

ltwo blowing headers spacedl apart from and in two blowing headers spaced apart from and in parallel relationto each other, fa pipe xed' to .one of the headers, a second pipe extending through the first pipe and past the header connected to that pipe to the other header, the rstmentioned pipe having a row of rack teeth extending along the same on the outside thereof, a pinion engaged with said rack teeth, and means to turn said pinion step by step.

6. A soot blower` comprising a blowing header, a rack fixed thereto and projecting therefrom, a pinion meshing with the rack, a ratchet wheel fixed to thepinion, a pawl cooperating with the ratchet wheel, the pawl being reversible and the teeth on the ratchet wheel being shaped to permit the wheel to be turned in either direction by the pawl, a reciprocable power'device, and

erating pawl, and means controlled by said.

actuator to maintain the holding pawl in an idle position at the beginning of a working stroke of. the operating pawl and thereafter carry it into a position to stop the ratchet wheel at the end of the working stroke of the operating pawl.

18. In combination, a soot blower comprising a header, a rack iixed thereto and projecting therefrom, a pinion meshing with the rack, a ratchet wheel fixed to said pinion, a double-ended holding pawl mounted adjacent to said wheel and adapted in one working position to serve as a stop to limit rotation of the ratchet wheel in one direction'and in its other position to limit rotation of the wheel in the opposite direction, a doubleended operating pawl, an actuator for the operating pawl, and means controlled by the actuator to shift the holding pawl to cause it to prevent overrunning of the ratchet wheel when moved step by step in either direction by the operating pawl.

9. A soot blower comprising a blowing header,

a rack fixed thereto and projecting therefrom,

a pinion meshing with said rack, a power cylinder, a piston in said cylinder, means for admitting to the cylinder and controlling'motive uids to cause the piston to move very slowly at the beginning and end of each stroke and rapidly during the remainder of the stroke, and means controlled by saidV piston to turn `said pinion step by step.

- FRED C. AREY.v

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