US2421941A - Valve mechanism for soot blowers - Google Patents

Description

June 10, 1947.

Filed Nov. l0,

DE LOYS E. HIBNER ET AL.

Y VALVE MECHANISM FOR SOOT BLOVfERS I IHIIIH 'fil June 10, v1947. DE Los E. HIBNER Er AL 2,421,941

v VALVE MECHANISM FOR SCOT BLOWERS s sheets-sheet 2 v Filed Nov. 1o, 1944 ff da 5 Sheets-Sheet 5 Filed Nov. l0, 1944 DE LOSE. HIBNER ET AL.

VALVE MECHANISM FOR SOOT BLOWERS June 10, 1947.

Patented June 10, 1947 UNITED ,STATES PAT ENT orifice vArvnMEoHANislrZ-lii; soo'r nLowEas- VDeLos E. vHibner and Fred C. Arcy, Du` Bois, Pa., assignors `to Vulcan Soot BloweriCorporation,` a vcorporation of Pennsylvania `Appiicauml-rrovimmer 1o, 1944, serial-No. 56232.58

7 Claims. l

:Itis common practice to admit steamto thetubular blowing elements of soot blowers through valvesthat are operated-by steam. Because these valves are large it is usual to employ small pilot valves, that are easily operated, to control the admission of steam to and to exhaust it from the actuators for themain valves. These pilot valves have required rather intricate and delicate mechu anism for their successful operation, adding to the cost of a blower unit and its upkeep.

The primary object of the present invention is to provide a controlling means for themain steam valve that is much simpler and requires less attention than the old type of pilot valve control, while possessing all of the desirable features of the latter.

4In our prior Patent No. 1,995,193 there is disclosed a soot blower head provided with a pilot valve and considerable mechanism that has no other function than to operate or control such valve. In one of its aspects the present invention may be said to have for an object to eliminate such mechanism and substitute therefor and for the valve a simple valve operated by a part or parts that are already serving other purposes.

In the blower unit of the aforesaid patent there are one or two lugs or blocks adjustably mounted on a gear wheel fixed to the tubular blowing element and adapted to strike against a stationarT stop at the end of a predetermined angular movement of saidV element. Incarrying out the present invention a simple valve device may be substituted for the stop and thus serve the double purpose of a pilot valve and stop for the blowing element.

The various features of novelty whereby our invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of the invention and of its objects and advantages, reference may be lfiad to the following detailed description taken in connection with the accompanying drawings, wherein:

Figure lis a View, partly in longitudinal section and partly in side elevation, of a soot blower head equipped in accordance with the present invention; Fig. 2 is a section on line 2 2 of Fig. 4, some parts that would lie in the plane of the section being omitted to expose other parts; Fig. 3 is a view similar to Fig. 2, showing positions of parts when the pilot valve is closed instead of open asin Fig. 2; Fig. 4 is a section on a plane parallel to the axis of the blowing element, illustrating-the pilot valve device and a fragment of the blowing element and' its drive; Fig. 5 is a section on line 5-5 of Fig. 4; and Fig. Gris a-section on line 6*!3-of Fig. 3.

(Cl. 15--104i045) Referring to the drawing, `I` `represents ascot blower head casting, 2a tubular blowing element rotatably supported at one end in the casting, and 3 avalve forcontrolling thepassage of steam from within the head into the tubular blowing element. The valve -is normally held closed by a spring; and, when there is steam `in the head, it must be permittedvto act with the spring as well as against it- The valve is `in the form of a cylindrical cup which fits slidably in aV cylindrical chamber 4, coaxial with the blowing element. The spring 5 is arranged in the -cup and protrudes from the rear end thereof `for engagement with the outer end wall of the Vchamber A. Fixed to the blowing element is a large gear wheel l, with which meshes a pinion 'I on one -end of a driving shaft 8 parallel with the axis of theblowing element. On the outer end oftheshaft 8 is a sprocket wheel!! that may be turned in either direction b y a cooperating chain 1:0; ,The parts just describedare not new but may be said to be typical of soot blower construction.

On the side of the geal` ,casing facing toward the free end of the head is a valve `housing |12, which may conveniently be secured' in place by bolts i3. rIhehousing contains a bore i4 of large diameter, whose axis is parallel to the axis of the blowing element. Midwaybetween the ends of this bore` is a bushing l5 having therein two longitudinalro-ws of ports, [6 and ll,.space d apart from each other in the circumferential direction. These ports communicate, respectively, with exhaust and intake passages land l5. Extending through the bore l 4 andthe bushing isashaft ,20 enlarged between its ends to form a cylindrical valvemember 2l that is a sliding t in the bushing. The member 2l is` attened on one side, as at 22, to provide between it and the surround ing bushing a chamber `24 wide enough to span the distance between ports I6 and I'l .in one angular position of the valv,e while shutting oi communication between such ports when the Valve is turned through a smallangle in either direction from that position. The ends `of bore I4 are closed by heavy discs 215 and 2.61containing openings through whichthe shaft or valve stem extends. In `the annular spaces surrounding the valve stem between the valve and the discs are suitable packings 2l, each` containing a` ring 28, about midway between the ends there of, Vconstructed to permit any steam `that may leak past the Valve and travel along the stem to flow through auxiliary passages 29 tothe exhaust `passage i8.

"The passage i8 is connectedto the'space in theheadthrough which steam must flow toreach the tubular blowing element after it has passed the main valve, by a pipe 3D; while passage i9 is connected to cylinder or chamber 4 by a pipe 3l. Therefore, when the pilot valve is open, steam can flow from within cylinder 4, behind the main valve, into the blowing element, bypassing the main valve. Such flow can continue after the main valve opens, so that upon the opening of the pilot valve the main valve automatically opens and, as will hereinafter be explained, remains open until the pilot valve is again closed. In order to be certain that pipe 30 will vent properly when the main valve is open, its outlet end may be connected to the annular space surrounding a nozzle 32 that carries the main steam stream into the blowing element in the apparatus shown in our application Serial Number 533,746.

One end of the valve stem projects into theV space within the gear casing and is there provided with a three-armed lever 33 that-lies near the gear wheel 6. The three arms all lie on the same side of the axis of the stem. On the other side of the axis, in what may be termed the hub of the lever, are three notches or seats 34, 35 and 36 arranged in a circumferential row. A spring pressed ball 31 is mounted on a stationary part of the structure in such a position that it may engage any one of the seats, depending on the angular position of the valve, and thus yieldingly hold the valve in any one of three diierent angular positions. The seats are separated from each other by narrow cusp-like parts which, in cooperation with the ball, give to the valve a snap action effect when it is shifted from one position to another.

Figs. 2, 4 and 5 show the parts with the pilot valve in the open position, the ball or latch being in seat 35 and ports I6 and I1 being in open communication with chamber 24 in the valve device. As a result, the space in cylinder 4, behind the main valve, is now connected to an external area of low pressure which, in the particular arrangement illustrated, is the interior of the tubular blowing element. Steam for closing the main Valve can enter cylinder 4 only through a restricted passage 3B which, in the arrangement shown, extends through the cylindrical wall of the main valve at a point such that it is at all times in communication with the main steam space in the head. This restricted inlet passage for the steam is much smaller than the outlet through the pilot valve, so that steam can escape much faster than it can enter the cylinder behind the main valve. Consequently, as soon as the pilot valve opens, the steam pressure behind the main valve drops quickly and the steam in the main chamber in the head is able to open the main Valve in the usual way. The main valve then remains open until the pilot valve again closes and steam pressure can again build up behind the main valve.

The means for rocking the pilot valve will now be described. It will be seen that the middle arm of lever 33 is much thicker than the other two arms. Two stationary stops, 39 and 4U, are disposed on opposite sides of the central arm, out of the plane of the other two arms but in the path of movement of the central arm, for engagement with the latter when it rocks in valve closing directions. The lever actuators are pins 4l and 42, similar to the usual stop pins or lugs, secured to one side of gear wheel B so as to be adjustable independently of each other about the gear wheel axis. These pins cooperate with all of the arms of lever 33. The parts-are so dis- 4 posed and proportioned that when the lever is arranged symmetrically with respect to a plane containing the axes of gear wheel 6 and the valve stem, as in Figs. 2 and 4, the stop pins are able to pass under the free ends oi" the right and left hand lever arms; whereas, after the lever has been rocked into a closed position, the lever arm on the same side as the pin that has done the rocking lies in the path of that pin when the latter starts to retreat.

For the purpose of tracing a cycle of operations it may be assumed that Fig. 2 illustrates the situation in the gear wheel 6 that has just travelled through a small angle in the counter clockwise direction from one limit of its movement; the pilot valve having been in its closed position at the beginning of the movement of the wheel; and that the left hand lever arm was originally lying across the path of such travel of the pin 4I. In reaching the position indicated in Fig. 2, the pin 4I had to rock the left hand lever arm upwardly to get it out of the way; thereby opening the pilot valve. As the gear wheel continues its turning movement the other stop pin, 42, moves toward the lever, finally passing under the right hand lever arm and engaging the central arm which it drives ahead of it until that arm strikes the stop lug 39 and comes to rest, with the pilot valve closed; the conditions now being those illustrated in Fig. 3, with the right hand lever arm projecting across the path which pin 42 must follow in making a sweep in the clockwise direction. If the operator desires to stop at this point he may do so because the pilot valve is` closed and the main steam valve can close and shut off the supply of steam to the blowing element. On the other hand, if the cycle is to include a sweep in one direction and a return, the turning of the gear wheel in the clockwise direction will cause a repetition of the occurrences just described, except that pins 4| and 42 have changed places with respect to work to be done. Fig. 2 may then be said to illustrate conditions just before the return stroke or sweep has been completed.

It will thus be seen that we have produced a pilot valve device of extreme simplicity, which is rugged and not likely to get out of order, and which is a single unitary structure that may be secured in place as a whole by a few bolts or other ordinary fastening means after having been completely assembled and adjusted. If repairs should be needed, the complete unit may be detached, repaired and then reinstalled/without requiring any adjustment during this last step. An additional advantage ofour new construction is that the pilot valve is positively operated, both to open and close it, so that it cannot fail to close at the end of each cycle and to be open as the blowing element is moving from one limit to the other. Along with these accomplishments we have succeeded in eliminating all parts not required for turning and controlling the movements of the blowing element heretofore employed for operating a pilot valve in similar situations.

While we have illustrated and described with particularity only a single preferredr form of our invention, we do not desire to be limited to the exact details thus illustrated and described; but intend to cover all forms and arrangements coming within the denitions of our invention constituting the appended claims.

We claim:

l. The combination with a soot blower in which the main valve for admitting cleaning fluid to a movable blowing element that moves back and forth is caused to close when the pressure of fluid behind it attains a predetermined value and is caused to open when the pressure drops below that value, of means for constantly delivering cleaning fluid under pressure behind said main valve, other means including a control valve to cause fluid from behind the main valve to escape faster, when the control valve is open, than it is delivered by the irst means, said control valve being limited to movements between two extreme positions in which it is closed and through an intermediate position in which it is open, an actuating member for said element, stop pieces adjustably mounted on said member to determine the limits of movements of the element, and

means on the control valve to be engaged by the stop pieces to open the latter at the beginning of each movement of the blowing element in either direction and to close it again at the end of that movement.

2. The combination with a soot blower in which a main valve for admitting cleaning fluid to an oscillatory blowing element is caused to close when the pressure of the fluid behind it attains a predetermined value and is caused to open when the pressure drops below said value, and in which there is a gear wheel on the blowing element through which it is driven, together with stop pieces adjustably mounted on .the gear wheel: of means for constantly delivering cleaning uid under pressure behind the main valve, and a controlling valve to cause fluid behind the main valve to escape faster than it is delivered by the aforesaid means mounted near said gear wheel in position to be actuated by said stop pieces lto open and close it and to serve as a stop to arrest the stop pieces at each of the desired limits of movements of the blowing element.

3. The combination with a'soot blower in which the main valve for admitting cleaning fluid to a movable blowing element is caused to close when the pressure of fluid behind it reaches a predetermined value and is caused to open when the pressure drops below that value, and in which there are stop pieces movable in unison with the blowing element: of means for constantly delivering fluid under pressure behind the main valve, and a control valve for allowing the escape of Huid from behind the main valve faster than it can be delivered by the aforesaid means, the

control valve being mounted in the path of move` ment of the stop pieces for oscillation between two closed positions and an intermediate open position, and the par-ts being so constructed that a stop piece approaching the valve from either direction closes it and, upon retreating, again opens it.

4. An apparatus such as described in claim 2, wherein the controlling valve has a three-armed lever all of the arms of which are in the paths of the stop pieces on the gear wheel and are so shaped that when the controlling valve is open a stop piece can pass from either direction under an outer arm and engage the intermediate arm to shift the latter valve into the closed position.

5. An apparatus such as described in claim 2, wherein the controlling valve is oscillating and has a three armed lever all of the arms of which are in the paths of the stop pieces on the gear wheel and are so shaped that when the controlling valve is open a stop piece can pass from either direction under an outer arm of the lever and engage the intermediate arm to shift such Valve into the closed position, and the parts being so constructed that when a stop piece is moving the intermediate arm into the valve-closed position the outer lever arm under which the piece has just passed swings down behind such piece in position to be actuated thereby when the direction of travel of the latter is reversed.

6. An apparatus such as described in claim 3, wherein a latch is provided for yieldingly holding the controlling valve in any of the three positions into which it may be brought.

7. The combination with a soot blower having a blowing element that moves back and forth and a main valve to admit cleaning fluid to such element, of a control valve for the main valve limited to movements between two extreme positions in which it is closed and through an intermediate position in which it is open, an actuating member for said element, stop pieces adjustably mounted on said member to determine the limits of movement of the element, and means on the control valve to be engaged by said stop pieces to open the latter at the beginning of each movement of the blowing element in either direction and to close it again at the end of that movement.

DE LOS E. I-lIBNER. FRED C. AREY.

REFERENCES CTED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,491,248 Schur Apr. 22, 1924 1,954,018 Miller Apr. 10, 1934 2,122,560 De Florez July 5, 1938 1,995,198 Arey et al Mar. 19, 1935 2,350,202 Thomas May 30, 1944 2,110,534 Snow et al Mar. 8, 1938 FOREIGN PATENTS Number Country Date 145,233 Great Britain July 2, 1920

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