US2269802A - Soot blower - Google Patents

Description

Jan; 13, 1942.

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5 1 Fz gil Fly 14 2 Sheets-Sheet 2 A. M. WILSON sooT- BLOWER Filed Oct. 20, 1938 Jan.

Patented Jan. 13', 1942 SOOT BLOWER Allan Murray Wilson, Clydebank, Dumbartonshire, Scotland Application October 20, 1938, Serial No. 236,004 In Great Britain October 27, 1937 6 Claims.

This invention relates to so-called sootblowers which are used in association with steam-boilers and other heat exchangers for the purpose of periodically ejecting cleaning fluid (usually steam) on tubes and other parts to remove soot, scale and other matter likely to be deposited thereon.

It is known to employ a fluid ejector to which an angular and endwise motion is imparted in the operation of the SOOtrblOWBI', but there are cases in which endwise motion of the fluid ejector is undesirable or unnecessary and this applies especially to soot-blowers in which the fluid ejector is a long conduit usually supported at both ends and having a number of nozzles spaced apart throughout its length, said nozzles being arranged to eject the cleaning fluid at a right angle or other large angle to the axis of the conduit.

An object of the present invention is the provision of a soot-blower in whicha turnable cleaning-fluid ejector is held against endwise motion and in which double control of the cleaning fluid supply and of the ejector are effected by a single control. Another object of the present invention is to make provision whereby the double control involves simply rotational movement, so that the soot-blower is adapted for remote control. Yet another object is to effect control of the supply of cleaning fluid by a valve which is movable endwise to open and close the supply notwithstanding that the ejector itself is held against endwise motion.

The manner in which these and other objects of the present invention are attained will now be described with reference to the accompanying drawings which show one embodiment by way of example only, it being understood that the invention is limited only by the appended claims.

In the drawings:

Figs. 1a and 11) together constitute a sectional elevation of the soot-blower.

Fig. 2 is an elevation of a part of the blower.

Referring to the drawings, the ejector is a long multi-nozzle, or multi-jet, tube This tube is rigidly coupled to a sleeve or tubular member 2 which is journalled in one end of a stationary cylindrical steam chest 3 and which has a collar 4 co-operating with thrust rings 5 and 5 and a cap nut 6 screw to one end of the steam chest, the co-operation being such that the sleeve 2 and the tube I are restrained against endwise motion. The sleeve 2 is associated with a tubular member I constituting a sleeve valve which has, say, three ports 1 adapted to turn more or less in register with, say, four ports 3 in the chest 3, the arrangement being such that in every angular position of the sleeve valve, admission of adequate steam to its ports is assured, provided that the axial position of the sleeve valve is suitable. The valve 1 is adapted to receive both angular motion and axial or endwise motion, this motion being such that at one axial extremity thereof the valve completely closes the ports 3' in the steam chest and at the opposite extremity the ports 1' in the valve register with those in the steam chest, so that steam may pass through the bore of the valve 1 and sleev 2 and thence to the tube 1.

The valve and sleeve interengage by means of a key 8 on the valve, slidable in a key-way 9 in the sleeve, by virtue of which the valve can slide endwise in the sleeve, while the valve and sleeve turn angularly in unison. It will bev apparent that other equivalent means may be used such for example as a pin or pins projecting radially inwards from the sleeve and a slot or slots extending along the valve body.

The valve derives a composite angular and endwise motion from an assembly comprising the combination of a screw device and a cam device.

The screw device comprises a screw follower in the form of a nut l0 secured to the valve and a screwed spindle ll journalled and restrained against endwise thrust in a cylindrical casing l2 which constitutes a structural extension of the steam chest 3, so that said spindle is mounted to rotate in a stationary location. The screw spindle is rotatable through spiral or other gearing l3 by a handwheel (not shown) which may either be arranged at a distance from the sootblower and connected thereto through a rod l4 and. universal joint 14 (as shown), or mounted directly on the soot-blower.

The cam device (Fig. 2) comprises a cam track I5 in the cylindrical casing l2 and a roller or pin 16 on the valve 1. The cam track would preferably have a straight portion at its inner end and a helically or otherwise inclined portion at its outer end, although the form of the track may be varied.

The soot-blower is maintained steam-tight by providing piston rings 11 on the valve and by providing a gland I8 around the valve at the outer end of the steam chest and a gland 19 around the valve at the inner end of the steam chest.

In operation of the blower, the handwheel is rotated first in one direction from its out-.of-use position, indicated by an indicator associated with it. By virtue of the combined action of the screw device It], H, the cam device l5, l6 and the interconnection 8, 9 between valve and sleeve, the valve 1 is slid outwardly and gradually opens the ports 3', I and upon the opening thereof the multi-nozzle tube I starts to turn angularly and play steam over the surfaces to be cleaned. When the axial limit position of the valve is reached, as shown by the indicator, the handwheel is rotated oppositely to an extent insufficient to reduce materially the steam supply through the ports, so that the multi-nozzle tube is merely turned back through its arc of angular displacement. To-and-fro rotation of the handwheel is continued throughout the period desired for conducting the cleaning operation, Thereafter, the handwheel is rotated fully back to its out-of-use position, in which the steam is shutoil by the valve.

Thus, in operation of the soot-blower, the act of turning the handwheel to-and-fro automatically opens the steam supply to the steam ejector, effects simple turning motion of the ejector and automatically shuts oil" the steam supply,

Various modifications may be made without departing from the scope of the invention. For example, in an alternative valve arrangement, the valve is a screw-and-cam operated piston valve which works inside a sleeve secured to the multi-nozzle ejector tube. The sleeve and tube as a unit are turnable but axially immovable, the sleeve having ports controlled by the valve and arranged in permanent axial register with the ports in the chest. A pin-and-slot, or key-andkeyway connection is provided between the valve and sleeve, by virtue of which connection the toand-fro combined turning and endwise motion of the valve effects to-and-fro turning motion of the sleeve and ejector tube.

In a power operated soot-blower, for example one operated by a fluid-pressure cylinder-andpiston assembly, the combined screw device It), II and cam device l5, l6 may be dispensed with, and the operative connection between the valve and the sleeve may be so devised as to convert a purely endwise motion of the valve into turning motion of the ejector. For example, the constructional example according to the drawings could be so modified that in place of the sleeve valve, a piston valve is provided which is non-rotationally reciprocable inside the sleeve by the cylinder-and-piston assembly, and the slot of a pin-and-slot connection between the piston valve and the sleeve is formed wholly or partially at a helical or other inclination to effect the requisite to-and-fro turning of the sleeve and multi-nozzle tube.

An advantage of a blower according to the invention is that it is well adapted to deal with cleaning fluid supplied at very high pressure, for example steam at 750 lbs. per square inch, whereas multi-nozzle blowers heretofore in use have been unable to deal with pressures exceeding about 250 lbs. per square inch, so that when such blowers were installed on high pressure boilers reducing valves were necessary.

I claim:

1. A soot blower which comprises a steam chest, a tubular member mounted in the chest for turning motion, means on said chest to restrain said tubular member against endwise motion relative to said chest, a cleaning-fluid ejector secured to said tubular member, said ejector consisting of a conduit having a number of discharge nozzles spaced apart lengthwise of the conduit, a ported sleeve valve mounted in the chest for both turning and endwise motion, means for actuating said valve including co-operating screw and cam devices for moving said valve turnably and endwise, and means on the valve and tubular member for transmitting turning motion to the tubular member and ejector, said last-mentioned means comprising an interengaging keyway and a key slidable in the keyway.

2. A sootblower comprising a steam chest, an inlet in the chest connectible to a. source of cleaning fluid supply, an outlet communicating with the inlet, an ejector mounted in the outlet for rotary displacement only, said ejector consisting of a conduit having a number of discharge nozzles spaced apart lengthwise of the conduit, a valve member mounted for endwise and rotary movement in said chest and adapted upon such movement to control the supply of cleaning fluid from the inlet to the outlet, co-operating screw and cam means, means for actuating said valve member including devices for imparting endwise and rotary movement to the valve member, and a driving connection between said valve member and ejector, said connection transmitting only rotary movement from the valve member to the ejector.

3. A soot-blower comprising a steam chest, an inlet in the chest connectible to a source of cleaning fluid supply, an outlet communicating with the inlet, an ejector mounted in the outlet for rotary displacement only, said ejector consisting of a conduit having a number of discharge nozzles spaced apart lengthwise of the conduit, a valv member mounted for endwise and rotary movement in said chest and adapted by such movement to control the supply of cleaning fluid from the inlet to the outlet, means for imparting endwise and rotary movement to the valve member, said means including a rotatable element restrained to rotation in a stationary location, and a driving connection comprising a key and keyway between said valve member and ejector, said connection transmitting only rotary displacement from the valve member to the ejector during endwise movement of said member.

4. A soot-blower comprising a steam chest, an inlet in the chest connectible to a source of cleaning fluid supply, an outlet communicating with the inlet, an ejector mounted in the outlet for rotary displacement only, said ejector consisting of a conduit having a number of discharge nozzles spaced apart lengthwise of the conduit, a valve member mounted for endwise and rotary movement in said, chest and adapted by such movement to control the supply of cleaning fluid from the inlet to the outlet, means for actuating said valve member including a combinedscrew and cam device adapted to impart endwise and rotary movement to the valve member, and a driving connection comprising a key and keyway between said valve member and ejector, said connection transmitting only rotary displacement from the valve member to the ejector.

5. A soot-blower comprising a turnable cleaning-fluid ejector, means holding said ejector against endwise motion, a ported sleeve valve for controlling the supply of cleaning fiuid to the ejector, a rotatable blower-operating screw for moving the valve to-and-fro endwise so as firstly to open and lastly to close the supply, a cam device for superposing a turning motion on the valve as and when the valve moves endwise,

means restraining said screw to rotation in a stationary location, and a key-and-keyway connection between the valve and ejector, said connection transmitting turning motion from the valve to the endwise immobile ejector.

6. A soot-blower comprising achest, a turnable cleaning-fluid ejector extending from said chest, means holding said ejector against endwise motion, a valve in said chest for controlling the supply of cleaning fluid to the ejector, means for moving the valve to-and-fro endwise so as firstly to open and lastly to close the supply, a cam device acting between said chest and valve to superpose a to-and-fro turning motion on the valve as the valve moves to-and-fro endwise, and a key-and-keyway connection between the valve and ejector, said connection transmitting turning motion from the valve to the endwise immobile ejector.

A. M, WILSON.

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