US2303152A - Buffered blower valve - Google Patents

Description

Nbv. 24, 1942. E. G. wEEK BUFFERED BLOWER VALVE I Filed 0ct. 25, 1940 s Sheets-Sheet 1 INVENTOR.

Nov. 24,1942. 5, WEEKS 2,303,152

BUFFERED BLOWER VALVE 3 Sheets-Sheet 2 Filed Oct. 25. 1940 I E Eh-Fm g imn' I I 1 1 INVENTOR.

Patented Nov. 24, 1942 iJNi'iED stares e'-'.rss rf,orrice Edmund George Weeks, London, England, assign. or to Diamond Power Specialty Corporation, Detroit, Miclr, a corporation'of Michigan Application October 25, 1940, Serial No. 362,785 In Great Britain October 25, 1939 2 Claims. (01. 137-139) This invention relates to fluid heater cleaners of the kind comprising a blower tube and a normally closed control valve for-controlling the flow of cleaning fluid to the blower tube, the valve being operable by a piston arranged during service to move the control valve from the open to the closed position when the-pressure onone side of the piston is raised to a sufiicient degree through the leakage of cleaning fluid to that side of the piston while an auxiliary valve for controlling the escape of fluid from the one side of the piston is closed, together with means arranged automatically to open the auxiliary valve when the blower tube is in a predetermined position in order to release'the pressure on the one side of the piston and whereby to efiect opening of the control valve and admission of cleaning fluid to the blower tube. In a fluid heater cleaner of this kind a definite and rapid opening of the valve is obtainable. advantageous it introduces the difficulty that the piston is brought to rest with considerable shock which may cause damage to the parts affected. An object of the invention, therefore, is the provision of simple but eiiective means for overcom- 1 ing this difiiculty. 4

In a fluid heater cleaner of the kind specified in accordance with the presentinvention means are provided'for effecting cushioning of the piston by preventing or limiting escape of fluid from the one side of the piston during the latter part of the opening movement of the control valve.

Thus in one form of cleaner or soot blower in accordance with the invention movement of the piston to open the control valve effects prevention or limitation of the escape of fluid from the one side of the piston.

The cleaner may, for example, be of the kind in which the blower tube simply rotates and is provided with a number of nozzles forthe escape of cleaning fluid or it may be of the type in which theblower tube carries at its end a nozzle which together with the blower tube is retractable to a normalposition.

The invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 shows a longitudinal cross section'of a fluid heater cleaner according to the invention, with parts of the driving gear broken away;

Figure 2 is a plan View of Figure l, also with parts of the driving gear broken away; and

Figures' 3 and-4 are sectional side views of the cover plate and..upper. part of the casing and associated members. to a larger .scale thanliig- Whilst the rapid opening is coincide.

ure 1, respectively showing the upper end of the piston with the plunger half-way and fully home within the port in the cover plate.

The cleaner illustrated is constructed substantially in the manner described in the complete specification of co-pending British patent application No. 21,696/39 and includes a casing. or pressure part I in which is an aperture 2 through. which the blower element including the blower tube 3 extends and in which the element is able to move to and fro, the element being arranged to slide through joints 4 and 5 and provided respectively in the pressure part I and a tubular extension 6 to the pressure part. The pressure part I is also formed with a valve chamber I the longitudinal axis of which is transverse to that of the blower tube 3. Cleaning fluid such as steam'may be admitted to the valve chamber -I through a side opening 8 and the chamber is closed by a sleeve or cylinder 9 and a cover plate I0, the lower end of the cylinder seating upon an annular shoulder I I of the pressure part I and the upper end of the. cylinder engaging the surface of an annular recess I 2 in the cover plate. The cylinder 9 extends above the top of the pressure part I and is formed with an annular projection I3 which by engaging the surface Id of the pressure part ensures that the longitudinal axes of the valve chamber I and cylinder 9 shall The cover plate I9 is located relatively to the cylinder 9 by engagement between the annular projection I5 on the cylinder and the radially outer side of the annular recess I2. The

cylinder 9'is clamped between the pressure part is provided with bushings I9- and 20 through which a piston rod 2! slides. As shown the bushings I9 and 20 and the co-operatingparts of the piston rod are of substantial diameter so that adequate bearing surfaces are provided for accurately locating the longitudinal axis of the piston in coincidence with that of the cylinder. The piston rod 2| is formed in one with'a piston 22 which moves within the cylinder 9, there being a small clearance 23 between the piston and cyl- I inder for the leakage of cleaning fluid. It will be appreciated that upon removal of the cover plate ID the cylinder 9 together with piston 22 and valve lid 24 may be removed as a unit. A fixed valve seat ,25 is screwed into an opening 26 :between thevalve chamber ,1 and the aperture 2 and :the "co-operating; valve lid 24 {is carried by the piston, the valve lid being held to a bolt 21 by a sleeve 28 encircling the bolt, screwed into the valve lid and engaging the head 29 of the bolt. The bolt 21 passes through the hollow piston rod 2| and the shoulder 30 on the bolt is clamped against the end of the piston rod by a nut 3| locked by nut 32, the nuts being accommodated in the recess 33 in the piston and piston rod. The valve lid 24 is biassed to the closed position by gravity and by a compression spring 34 acting between the valve lid and the lower end of cylinder 9 or the associated spider. I g r The upper surface of the piston 22 and the countersunk at 36, coaxial with the piston rod j 2| and bolt 21. The upper end of the bolt 2! extends above the upper surface of the piston 22 and is bevelled to form a plunger 31 arranged to enter the port 35, the arrangement being such that as the plunger 31 moves further into the port 35 the clearance between the plunger and port is progressively reduced, as will be clear from Figures 3 and 4. plunger 31 of greatest diameter of suitable size, the plunger may, if desired, be adapted substantially to prevent escape of fluid through the port 35.

A relay valve 38 includes a spindle 39 the axisof which is disposed in a plane parallel to the axis of the blower tube and a cam 40 on the blower element is arranged to transmit movement to the spindle 39 through a tappet 4| transverse to the blower tube and a lever 42 inter mediate the spindle and tappet. In the arrange: ment shown the spindle 39 is parallel to the axis of the blower tube, the relay valve 38 being arranged as a removable unit secured ina recess 43 in the cover plate II], which recess is in communication with the cylinder '9 through the port 35.

The spindle 39 of the relay valve slides through a sleeve 44, the inner end of which is clamped against a shoulder 45 in the recess 43 by a threaddle 39 is of reduced diameter so that when the movable valve ,face 49 formed near the inner end of the spindle is moved from the valve seat 50 on the sleeve, fluid is able to pass into the annular space :51, and through'the ports 48 into the annular space 52 and thence to a duct 53 in the cover plate. The spindle 39 is biassed to the closed position by a spring 54 which acts between seatings on the ferrule 45 and a collar 55 secured to the spindle and the lever 42 operates the relay valve by pressing against the outer end I of the spindle. 39. The lever 42 is pivoted to,

By making the part of the and the tappet 4| is arranged to slide in a bracket 56 secured to the pressure part 4- by studs and nuts 5'! and the length of the tappet 41 is adjustable, whilst a pin and slot arrangement 58 prevents rotation of the tappet 4| and thus maintains proper orientation of a roller 59 at the low er end of the tappet 4| in relation to the cam 40.

The relay valve 38 is arranged to exhaust pressure fluid acting on the upper side of piston 22 to the inner side of a wall 60 of the fluid heater. Thus a tube 6| is arranged to conduct the fluid from the duct 53 in cover plate ID to a duct 52 leading to the interior of a wall box 63 clamped by screws 64 to the front side of the pressure part I, the tube being readily disconnectable from the cover plate ID by means of the joint 65.

The blower tube 3 is provided with ports 56 and carries a nozzle 51 and is formed in one with a spindle 68. The ports 66 lie always between the joints 4 and -5 in the annular space 69 between the blower element and aperture 2 and tubular extension 6 so that when the valve lid 24 is lifted cleaning fluid is able to flow from the valve chamber 1 through opening 26 into annular space '69 and through ports 65 blower tube -3 and nozzle 61. The spindle 68 carries the cam 40 for operating the tappet 4! when the nozzle 1 61 has been projected from the retracted position and forms part of suitable operating means including a driving shaft I0 for moving the blower tube 3 and nozzle 61 axially and efiecting the requisite rotation of the latter.

When pressure fluid is admitted to the valve chamber 1 with the blower tube 3 in its normal or retracted position and the relay valve 3'8 closed, pressure fluid leaks past the piston 22 through clearance 23 and raises the pressure in the space H between the piston 22 and cover plate ID so that, notwithstanding the pressure exerted by the cleaning fluid on the underside of the piston, the force of gravity and the biassing spring 34 are effective in pressing the valve lid 24 against its fixed seating 25. If, however, the blower tube 3 is advanced, the associated cam 40, when the nozzle 61 reaches an operative position, through operation of tappet 4I-and lever 42 effects opening of the relay valve 38 and thereby vents fluid from space H through port 35, duct 53 and tube Bl. The cleaning fluid below the piston, therefore, moves the latter rapidly upward and quickly lifts the valve lid 24 thereby admitting cleaning fluid to the aperture 2 in the pressure part! and thence by way of ports 66 to the blower tube. As the piston 22 moves towards its uppermost position the plunger 31 on the bolt 21 by entering the port 35 for the escape of fluid exerts a throttling eflfectwhich increases as the movement proceeds, so that the escape of fluid is restricted. The fluid thus retained in the space 1| is compressed and serves as a cushion for the piston. Notwithstanding the rapid opening of the valve, therefore, the piston and valve are brought to rest gradually and without shock.

When the cam 40 allows the relay valve 38 to reclose, cleaning fluid leaking through the clearance 23. by raising the pressure in space 1|, effects movement of the valve lid 24 to the closed position.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. A fluid control comprising a spring pressed valve having a valve seat guarding a main fluid entry, said valve having an enlarged end at a distance from said valve seat, a cylinder surrounding said enlarged end and having slight normal clearance therewith whereby fluid inletted between said valve seat and said enlarged end may leak past said end, a head for said cylinder and a relief valve operable by outside influence to vent the pressure between said cylinder head and said enlarged end whereby said valve is opened to permit the passage of fluid into said main fluid entry, said cylinder head having a passageway leading to said relief valve, saidenlarged end having a conical valve atop thereof for seating in the entry to said passageway, said conical valve passageway leading to said relief valve and terminating at its inlet end in a valve seat, said enlarged end portion having a conical extension thereon arranged for seating in said valve seat upon opening of said relief valve, said conical valve having a smaller diameter than that of said passageway whereby a restricted flow through said passageway is permitted.

EDMUND GEORGE WEEK'S.

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