US2367240A - Acetylene generator with vibrating feed valve - Google Patents

Description

Jan. 16, 1945. c. F. SMITH 2,367,240

ACETYLENE GENERATOR WITH VIBRATING FEED VALVE Filed June 27, 1940 3 Sheets-Sheet 1 INVENTOR ATTORNEY.

Jan. 16, 1945. c -F SMITH 2,367,240

ACE TYLENE GENERATOR WITH VIBRATING FEED VALVE Filed June 27, 1940 '3 Sheets-Sheet 2 W. ll

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Patented Jan. 16, 1945 UNITED STATES PATENT OFFICE .ACETYLENE GENERATOR WITH VIBRATING FEED VALVE Carl F. Smith, West Alexandria, Ohio Application June 27, 1940, Serial No. 342,665

Claims. (01. 48-533) This invention relates to acetylene generators, and particularly to mechanism for maintaining a uniform flow of carbide, whereby the service line pressure is kept more uniform.

The improvements are embodied in a generator of the type wherein a carbide feed valve is operated to closed position we rise in generating tank pressure applied to one side of a diaphragm, and to open position by* a spring under stress applied to the opposite side of the diaphragm.

Generators of this class areusually operated with coarse carbide granules of not very uniform size, and one of the obstacles to satisfactory operation is that when the tank pressure falls, allowing the spring to open the feed valve, the coarse granules are usually so stacked around the valve that it must open quite wide before any carbide falls through it, and then, when it does fall, the quantity released is in excess of that desired for uniform gas production.

It is therefore an object of this invention to provide means whereby the feed valve mechanism will be kept in a state of vibration, to the end that the granules in the immediate vicinity of the feed valve will be kept in a loosened state and therefore will be fed more evenly.

The idea of providing more uniform feeding of the carbide, by vibrating the feed valve, is not broadly new, but the mechanism heretofore proposed to achieve this result fails to take advantage of the means available to create a degree of vibra-' tion adequate to produce the best results.

It is therefore another object of this invention to drawthe valve vibrating pressure from the point where vibration is greatest, and apply it to the valve in a more direct and effective manner than has heretofore been known.

That these and other objects and advantages are achieved in the embodiment hereinafter disclosed will be apparent as the invention is further described with reference to the drawings, wherein,

Fig. 1 is an elevational view, partly in vertical section, through a generator embodyingthe improved vibrating mechanism.

Fig. 2 is a view similar to Fig. 1, but showing a slight variant of the mechanism, and

Fig. 3 shows a further modification in the structural details of the device.

Similar numerals refer to I similar parts throughout the drawings.

The generating tank It is conventional having the usual water filler plug l2 located to govern the depth of the water in the tank, the usual drain cock l4, and agitator crank IS. The top of the tank is flanged inward at It and carries the hinge bolts 20 for clamping the carbide hopper 22 in place. A gasket 24 makes a pressure tight joint between the hopper and the tank.

. The hopper 22 comprises a hoppertop 26, a hopper bottom 28 and a cylinder 36 preferably made of Pyrex glass clamped between the top and bottom by the bolts 32. Gaskets 34 make pressure tight joints between the several parts.

The hopper top 26 has a box-like compartment 36 which houses the feed regulating mechanism, the upper side of-the compartment being closed by a cover plate 35 held on by screws 31. A feed regulating spring 38 is contained in a spring housing 40 which is clamped to the underside of the hopper top 26 by screws 42. A feed regulating diaphragm 44 is interposed between hopper top 26 and housing 40, and thus serves also as a gasket between these parts. A hand screw 46 in the bottom of the housing may be operated to regulate the tension of the spring 36. Small holes 45 connect the inside of the housing 40 to the atmosphere.

A post 48, having an integrally extending stem 50, is secured in the center of the feed regulating diaphragm, the diaphragm being held between washers 52 by a nut 54. The stem is vertically slidable in the hand screw 46.

A second post 56 is secured at its lower end in the floor of the hopper top 26, a lever 58 being fulcrumed to the upper end of the post by a hinge pin 60. The shorter arm of the lever 58is hinged at 62 to the post 48, while the longer arm is arranged to give vertical movement to the stem 64 of the feed valve.

At the lower end, the stem 64 carries the valve heads 66 and 68. A large tube 10 depends from the floor of the hopper top 26 surrounding the stem 64 at some distance therefrom. .The tube 10 is flared at its lower end to deter packing of the carbide about the valve heads. A flexible washer 12 provides a suitable seat for the lower valve head 66. A splash tube 14 is supported on a hub on the underside of the hopper bottom 26 to prevent splashing of water on the valve head and seat when the device is moved.

A screw plug in the wall of the hopper bottom may be removed for filling the hopper with carbide. A safety screw 16 extends through a hub 18 in the cover plate 35 and this screw may be used to forcibly raise the lower valve head 66 against the seat 12 to render thedevice inoperative. The screw 16 extends into a metal bellows 80 which is closed at the bottom and has its open end soldered or similarly secured to the underside of the hub 18, whereby leakage around the screw 16 is prevented.

The parts thus far enumerated and described are substantially the same in Figs. 1, 2 and 3, but the means for vibrating the feed valve stems difler in the several embodiments.

In Fig. 1, the vibrating diaphragm 82 is clamped between the dome 84. and ring 86 by the bolts 88. The dome has an ear 90 by which it is hinged to the end of the lever 58 by the pin 92. At the center, the diaphragm 82 is attached to the valve stem 64 by clamping it between washers 94 by nuts 96, the nuts being threaded onto the valve stem. A tube 98 connects the space within the dome 84 to a source of pulsating pressure. The underside of the vibrating diaphragm 82 is exposed to the gas pressure of the generating tank I0 and hopper 22, and since the tank pressure is usually several ounces higher than the source of pulsating pressure, a light compression spring I00 within the dome 84 compensates for this difference.

In Fig. 2, the vibrating diaphragm 82 is clamped between the dome I02 and ring I 04 by bolts 88. The ring I04 has an ear I08 by which it is hinged to the lever 58 at a point I08. At the center, the

vibrating diaphragm is held on a post I I0 between washers II2 by a nut II4, the nut being threaded onto the post. The lower end of the post H0 is hinged at 6 to the lever 58. The outer end of the lever 58 is hinged to the valve stem 64 by a pin II8. A tube 98 connects the space within the dome I02 to a source of pulsating pressure. The underside of the vibrating diaphragm 82 is exposed to the gas pressure of the generating tank I 0 and hopper 22, and since the tank pressure and pulsating pressure may have a different value a light compression spring I00 is provided.

On Fig. 3, the vibrating diaphragm 82 is clamped between the dome I20 and the ring I22 by screws I 24. The ring is welded or similarly fastened to the tube 10 over an opening I25 in the tube. The center of the vibrating diaphragm is held to a post I26 between washers I28 by a nut I30. A long hub I32 has its outer end closed and its inner open end welded or similarly joined to the wall of the tube 10. The post I28 is slidably fitted to the inside of the hub I32, and, at its middle portion, has a small hub I33 through which the valve stem 84 extends slidably. A tube I 34 connects the space within the dome I20 to a source of pulsating pressure, a portion I35 being flexible. The outer side of the vibrating diaphragm is exposed to the gas pressure of the generating tank I0 and hopper 22 through the opening I25. A light extension spring I36 compensates for the diiference in pressure on the two sides of the diaphragm,

Generators of the class herein shown are usually provided with a flash back arrester which comprises a small tank I38 held to the main tank I0 brackets I40 and containing a lower water compartment I42 the level of which is fixed by the position of a filler plug I44, a middle compartment I48 which carries the bailie plates I48 and an upper or drying compartment which contains the filter material I50. The cap I52 on the top of the flash back tank supports the pressure gauge I54, the safety valve I56 and the service valve I58 from which gas is drawn for use in various applicances such as welding torches, floodlights, and so forth.

' In Fig. 1, the tube 98 connects the space within the dome-shaped casing 84 to the space in the upper portion of the flash back tank I 38. A small portion of tube 98 as at I60, and a larger portion as at I62, is preferably made of flexible material, the remainder being of metal. The metal part should be welded where it emerges from the tank I0 and where it'enters the tank I38.

Still referring to Fig.1, a large pipe I64 connects the portion of the tank I0 above the water line to the bottom of the tank I38, the gas entering the tank I38 through a check valve I66. Valve I66 comprises a body I68 having a seat I10 wherein a ball I12 rests by gravity, and a perforated cap I14 t limit upward movement of the ball. A drain plug I16 is provided in the bottom of the valve body.

In Fig. 2, a large pipe I18 connects the upper portion of the tank I0 to the bottom of the tank I38. The drain plug I in the bottom of tank I 38 is conventional. A flash back check valve I82 is inserted in the pipe I 18 close to where it emerges from the tank I 0. Valve I 82 comprises a body I84 with a ball I86 on a seat I88 and a guide cap I90 for the ball.

Still referring to Fig. 2, the tube 98 connects the space within the dome-shaped casing I02 into the large pipe I18 near its upper end. A small part I92 and a larger part I94 of the tube 98 should be' of flexible material and the remaining portion preferably of metal. The metal part should be welded where it emerges from the tank l0 and where it enters the pipe I 18.

In Fig. 3, the large pipe I96 which connects the upper portion of tank I0 to the bottom of the flash back arrester tank I38 has interposed therein two valves I66 and I82 which may be like the valves in Figs. 1 and 2, respectively. The tube I 34 which connects the space within the dome-shaped casing I20 to the space within the top of the flash back tank I38 may have the end portions made of metal and the intermediate portion of flexible material. The one end should be welded where it emerges from the tank I0 and where it enters the tank I38.

The check valves I66 and I82 are primarily provided to arrest a flash back from the service line into the generating tank, but incidentally the interrupted opening and closing of the valve causes pulsation of considerable magnitude in the pressure within the flash back arrester. The weight of the ball in the check valve will govern the degree of pulsation, since the pressure in the tank must exceed that in the flash back arrester an amount suiiicient to raise the ball, then when the pressures equalize, the ball drops back onto its seat. It is the rapid repetition of this performance which causes the pulsating pressure. When two valves are used as in Fig. 3, the pulsation is not only more rapid, but, due to the fact that the movement of the two valves will not be synchronized, the vibration is broken up into more uneven pulsations.

It should be noted that while a check valve which is primarily necessary to the flash back arrester is made to serve the additional purpose of an interrupter valve, to cause pulsation of the gas pressure in the line between the interrupter valve and the service valve, one of the valves, as in Fig. 3, may be a check valve and the other may be any sort of a .valve which rapidly interrupts the gas flow from the generating tank. and while the loading of a check valveofthe kind herein shown is inherent in the ball, a valve having a lighter valve head may be used and spring loaded to a degree which will equal the heavier ball.

Operation Theflller plugs I2 and I44 are removed and the tanks fllled with water to the height shown. When the plug I2 is removed all pressure, in the tank I is relieved. This allows thespring 88 to lower the feed valve head 68 until it covers the hopper outlet. 7

The hopper is next removed by loosening the bolts 20, the plug 15 is removed and the hopper filled with granular carbide, and the hopper returned to position with the plug 15 drawn up tight.

Generation may now be started by turning down the safety screw 16 until the valve heads 66 and 68 are approximately in the position shown in the drawings, whereupon carbide will fall from the hopper into the tank, gas will be generated, and when the generated pressure, bearing on the upper side of the regulating diaphragm 44, overbalances the force to which the spring 38 is adjusted, the valve head 66' will be drawn against the flexible seat 12 and generation will for the moment cease. I

During this period of generation, the service valve I58 may have been closed. If now the gauge I54 does not show vthe desired pressure, the regulating screw 46 may be turned until the desired pressure is obtained. The screw 16 should now be raised at least as high as the position shown in the drawings, and left there for all operating conditions. If, however, it becomes desirable to lock the device against carbide flow, while the generator is being moved, or while it is to be out of use for a period of time, this may be done without relieving the pressure in tank I0 by turning the hand 'screw 16 downward far enough to hold the valve head 66' up against the flexible seat 12.

Referring particularly to Fig. 1, the pressure in tank I0 is transmitted through pipe I64 and check valve I66, through the water compartment I42, baflle plates I48, and filter I50, to the top of the flash back tank I38.

The check valve I66 should be so proportioned and the ball I12 should be of such weight that it will require an excess pressure in the tank I0,

over that in the top of tank I38, of several ounces before the ball will be raised to allow a bubble of gas to pass. Since the space for gas in the tank I38 is limited, a small volume only need be transferred thereinto to make several ounces difierence in pressure. It follows that, with a normal flow of gas out of the service valve I58 the rise and fall of the ball I12 is as rapid as gravity will return it to its seat after the gas pressure raises it. This rapid pressure pulsation is transferred through the tube I62, I60, 96 into the domeshaped casing 84, where, acting on diaphragm 82 it vibrates the feed valve stem 64 vertically.

It should be noted that pulsation of the vibrating diaphragm 82 is applied directly to the feed valve stem 64, and that the pressure regulating diaphragm 44 has no part in creating feed valve vibration, while, in devices heretofore proposed, the pulsations of the vibrating diaphragm are transferred pneumatically to pulsate the feed regulating diaphragm which in turn vibrates the 4 feed valve. The loss of vibrating force through several transfers, when it is only several ounces to begin with, is a serious objection to the present state of the art.

As the valve head 66 moves away from and back to the seat 12, in response to a drop and subsequent rise in pressure in tank I0 due to gas consumption and regeneration, the continuous vertical vibration oi the feed valve head 68 keeps the granular. carbide loosened and flowing freely and uniformly through the valve seat washer 12. The lower flared end of the large tube 10 prevents too great a weight of carbide settling on the valve head 68.

In Fig. 2, the pressure in tank I0 is transferred to the top of tank I38, first through the check valve I82 then through the pipe I18. In this embodiment of the invention, the pulsating pressure is taken from the top of the pipe I18 instead of the top of the tank I38, and transferred through tubing I94, I92, 98 into the dome-shaped casing I02. As the space within the dome-shaped casing alternately increases and decreases, the casing must move rapidly up and down with respect to the lever 58. This vibrates the lever which in turn vibrates the valve stem 64, but in doing so; it must also slightly vibrate the regulating diaphragm 44, although the regulating diaphragm in no sense supplies or transfers a motive force for vibrating the valve.

In Fig. 3, the pulsating pressure is again taken from the top of the flash back tank I38 and conveyed to the dome-shaped casing I20 through tubing I35, I34, but in this case the pulsation in the casing I20 creates a lateral vibration of the feed valve stem 64 as it is moved vertically by the regulating diaphragm.

It should be noted that, in each of the several embodiments shown, the pulsating pressure within the dome, acting on one side of the vibrating diaphragm, is directly opposed by the slightly higher pressure in the generating tank I0 acting directly on the other side of the vibrating diaphragm. An advantage of this arrangement results for the reason that when a volume of as is passed by a check valve ball, the pressure'is considerably increased in the dome-shaped, casing on one'side of the vibrating diaphragm but is also somewhat decreased on the opposite side of the diaphragm whereby the vibrating effect of such transfer is the algebraic sum of the two pressure changes. This effect has not heretofore been obtained.

Having described several embodiments of the invention and the manner in which they operate, I claim:

1. In an acetylene gas generator having a generating tank of relatively large capacity, a hopper for receiving carbide, a carbide feed valve movable for controlling the delivery of carbide from said hopper to said tank, and regulating means including a diaphragm one side of which is responsive to the pressure of the gas generated in said tank for controlling the feed valve to effect regulation of the pressure of the generated gas, the combination of a liquid trap flash back arrester, an open conduit for delivering the generated gas from said tank into said arrester where it escapes in 'bubbles passing upwardly through the liquid into a space of relatively small capacity above such liquid resulting in variations and pulsations in the gas pressure therein, and a conduit extending from said space above thc liquid to the opposite side of said diaphragm to make said varying and pulsating pressure eifective upon able for controlling the delivery of carbide from said hopper to said tank, and regulating means including a diaphragm one side of which is responsive to the pressure of the gas generated in said tank for controlling the feed valve to effect regulation of the pressure of the generated gas, the combination 01' a liquid trap flash back arrester incorporating a check valve therein, an open conduit for delivering the generated gas from said tank into said arrester where it escapes in bubbles passing upwardly through the liquid into a space of relatively small capacity above such liquid resulting in variations and pulsations in the gas pressure therein, and a conduit extending from said space above the liquid to the opposite sideof said diaphragm to make said varying and pulsating pressure effective upon said diaphragm with resultant vibration of said diaphragm and of said feed valve.

3. In an acetylene gas generator having a generating tank, a hopper for receiving the carbide, a carbide feed valve movable for controlling the delivery of carbide from said hopper to said tank and regulating means including a diaphragm one side of which is responsive to the pressure of the as generated in said tank for controlling the movement of said feed valve to eil'ect regulation of the pressure of the generated gas, the combination of means for delivering the gas generated in said tank to a point of discharge, means in the path of discharge of said gas to produce a pulsating pressure in the discharged gas with respect to the pressure within said tank, means cornmunicating with said pulsating source of gas pressure and with the opposite side of said diaphragm to effect a vibrating movement thereof, and means for mechanically connecting said diaphragm to said feed valve to cause a sidewise vibratory motion thereof.

4. In an acetylene gas generator having a generating tank, a hopper for receiving canbide, a

carbide feed valve movable for controlling the delivery of carbide from said hopper to said tank, and regulating means including a diaphragm one side of which is responsive to the pressure of the gas generated in said tank for controlling the position of said feed valve to eflect regulation of the pressure of the generated gas, the combination of adjustable means for yieldably applying force to said diaphragm to predetermine the pressure at which said pressure regulating means operates, means extending into the pressure zone and having a positive operative connection with said carbide feed valve for locking said carbide teed valve in closed position, and a flexible bellows enclosing said last mentioned means and eilectively' sealing the same against escape of pressure from said pressure zone.

5. In an acetylene gas generator having a generating tank and adapted to handle carbide in granular form, the combination of a hopper for receiving the granular carbide, said hopper having a valve seat defining a feeding opening, a diaphragm one side of which is responsive to the pressure of gas generated in said tank to regulate the supply of carbide thereto, a valve rod operably connected with said diaphragm for movement in response to the generated gas pressure, adjustable spring means for moving said valve and opposing the pressure of the gas on said diaphragm to regulate the gas pressure developed by said generator, a valve member carried on said rodand movable away from said seat to enlarge said feeding opening in response to a reduction in gas pressure, and a second valve member carried by said rod in spaced relation with the first said valve member leaving a free feeding space be tween said valves for normal regulated operation, said second valve member being movable to a closed position against said seat under the action of said spring mean throughout the normal regulating range of adjustment thereof in response to abnormal loss of gas pressure from said tank to shut off further feeding of carbide into said hopper.

CARL F. SMITH.

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