US2085084A - Acetylene generator - Google Patents

Description

June 29, 1937. DEMlNG 2,085,084

ACETYLENE GENERATOR Filed Jan. 12, 1933 4 Sheets-Sheet 95 1 u FILL?! I I Eta 52 g [5'1 (04! G0 i 5? 58 i l J NVENTOR June 29, 1937. G. M. DEMING 2,085,084

ACETYLENE GENERATOR Filed Jan. 12, 1933 4 Sheets-Sheet 2 -ITTO NEV June 29, 1937. G. M. DEMlNG ACETYLENE GENERATOR Filed Jan. 12, 1953 4 Sheets-Sheet 3 m VENTQR l I i J 711 TTORNEy June 29, 1937. DEMlNG 2,085,084

ACETYLENE GENERATOR Filed Jan. 12, 1933 4 Sheets-Sheet 4 Patented June 29, 1937 UNITED STATES PATENT OFFICE ACETYLENE GENERATOR Application January 12, 1933, Serial No. 651,249

8 Claims.

This invention relates to acetylene gas generators of the carbide to water type.

It is necessary to have a number of openings to or from the generator tank, such as an outlet for gas to the delivery line, an entrance for supplying water to the tank, an overflow for the water if it rises above a given level during filling,

a residuum outlet at the bottom of the tank for removing water and sludge, and entrances for filling the carbide hopper. A pressure relief valve for the escape of gas, if the pressure becomes excessive, is necessary.

These openings must be closed at certain times, and each must be open at various times, and it is important to guard against the escape of gas into the generator room as a result of carelessness or mistake in operating the generator.

This invention has for its object to provide an improved acetylene generator of the type described, and comprises novel features and combinations of elements that insure against the escape of gas through improper operation of the generator, and otherwise increase the safety of the generator.

More specificially, the invention comprises certain combinations of connections and interferences between the various manual operating devices to prevent their operation in the Wrong sequence, and to require the operation of the pressure relief valve or valves to exhaust the gas in the generator before opening of the water system valves, or closures of the carbide filling entrances. Interferences are also provided for preventing operation of the carbide feeding mecha- 11ism when the generator is opened to drain or re-charge.

Another safety feature of the invention is a double-acting check valve in the gas delivery line for preventing reverse flow through the line toward the tank and for closing the delivery line to prevent flow from the tank if the outflow becomes excessive or increases very suddenly, as when a line breaks, or is carelessly left without proper fittings, or if an explosion occurs within 5 the generator tank and tends to forcibly eject the gas through the double-acting check valve.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

In the accompanying drawings, forming a part hereof:

Fig. 1 is a side elevation showing an acetylene generator embodying the invention;

Fig. 2 is a top plan view of the generator shown 55 in Fig. 1;

Fig. 3 is an enlarged fragmentary sectional view, taken at the water level of the generator of Fig. 1, and showing the control handle and interference connections in elevation;

Fig. 4 is an enlarged elevation showing the control mechanism for the carbide feed motor;

Fig. 5 is a top plan view of the mechanism shown in Fig. 4;

Fig. 6 is an end elevation of the mechanism shown in Figs. 4 and 5;

Fig. 7 is an enlarged vertical sectional view showing the double-acting check valve of the generator illustrated in Fig, 1;

Fig. 8 is a sectional view on the line 8-8 of Fig. '7 and Fig. 9 is an enlarged vertical sectional view of the shut-off valve shown in Figs. 1 and 2.

A carbide hopper l l is supported in the upper part of a tank l2. Carbide feed mechanism I4 is operated by a feeding shaft I6 to drop particles of carbide into water in the lower part of the tank 12. Such mechanism is well known in the acetylene generator art.

The gas generated by the action of the water on the carbide is stored in the tank l2 above the water and flows out of this space through piping ,I8, which connects with a double-acting check valve 20. This check valve connects with a flash arrester 22. A shut-oil valve 24 on the top of the flash arrester controls the entrance of acetylene into a service line 26.

Pipes 28 and 29 are connected to the piping I8 and flash arrester 22, respectively, and both of these pipes extend outside of the generator room and ordinarily through the roof of the building. A main safety or relief valve 3| and an auxiliary safety or relief valve 32 control the passage of gas through the pipes 28 and 29, respectively. These relief valves prevent the flow of gas through the pipes 28 and 29 when the generator is operating, unless the pressure in the generator becomes excessive, in which case the relief valves are opened by the gas pressure and operate as safety valves. The relief valves can be opened by manual control means, which will be described later. indicates the gas pressure in the generator.

When the generator is charged, the tank is filled with water up to the level indicated by the dotted line 31 in Fig. 1. The water is supplied to the generator through a filling cup 40, which communicates with the flash arrester 22 through pipe fittings and a valve 42. flash arrester 22 communicates with the generator tank through piping 44 which has a ver- The lower end of the.

A gauge 35, connected to the piping l8,

tically extending end pipe 45 inside the generator tank. The piping 44 includes a valve 41.

The generator tank has an overflow which includes a vertically extending end pipe 449 which connects with fittings 50 at the water level 3?. These fittings 50 extend through the side of the tank and connect with a valve 52. Piping 54, outside of the tank, connects with the valve 52 and extends close to the floor or ground on which the generator is supported. The upper end of the piping 54 is open to the atmosphere to prevent the overflow system from functioning as a siphon.

The relief valves 3i and 32 are operated by links 5! and 58, respectively. Both of these links are connected to a common crank 80 secured to the upper end of a vertical operating shaft 62. This shaft 62 is supported at its upper and lower ends by brackets 8%. A handle 86 is secured to the shaft 62 near its upper end and a handle 67 is secured to the lower end of the shaft. Either of these handles can be operated to rock the shaft 62 and turn the crank 60 to open the relief valves 3i and 32.

The valves 02 and 4'? of the water filling system, and the valve 52 of the water overflow system, are all operated by a main control handle I0. One end of the main control handle I is formed to connect directly to the valves 41 and 52, which are located on a common axis, and a projection of the main control handle is connected to the valve 42 by a. link I2. The main control handle I0 can be oscillated about the common axis of the valves 41 and 52 to open or close all of the water valves at the same time.

A vertical shaft 14 is rigidly secured to the main control handle I0 and extends upwardly along the axis of rotation of the main control handle. The upper bracket 64 serves as a bearing for the upper end of the shaft I4. A crank I is secured to the shaft I4, and a horizontal bar 11 has one end pivotally connected to the crank I5.

The carbide hopper has two filling entrances with closures comprising screw plugs 19 (Fig. 2), which thread into the top wall of the carbide hopper and have square bosses 80 for receiving a wrench. Projections 82 on the bar 11 extend close to a fiat side of each boss 80 and serve as interferences to prevent the bosses from being turned to unscrew the plugs. When the main control handle I0 is moved into position to open the valves of the water system, the vertical shaft I4 moves the crank I5 and shifts the bar 11 longitudinally so that the projections 82 move beyond the plugs I9 and no longer prevent removal of these plugs.

A look or book 85 is integrally connected with the handle 61 and extends downwardly into the path of an extension 81 of the main control handle I0 and serves as an interference to prevent operation of the main control handle when the handle 61 is in the position shown in Fig. 3. When the handle 61 is operated to open the relief valves, the lock or hook 85 is moved into a position in which it does not interfere with the operation of the main control handle. This interference between the handle 61 and the main control handle Ill makes it necessary to operate the relief valves and relieve the pressure in the tank before the valves of the water filling system can be opened. Since the plugs 19 closing the carbide filling entrances can not be opened until after operation of the main control handle 10, the interference between the handle 61 and maincontrol handle also insures that the relief valves have been operated before the carbide filling entrances can be opened.

A drain at the bottom of the tank is controlled by a residuum valve 88, operated by a handle 90. This valve can be opened to drain water and sludge from the tank.

The end pipes 45 and 49 (Fig. 1) extend below the water level 31 far enough so that with the gas pressure in the generator tank as high as the relief valves will permit it is not possible for the lower ends of these pipes to be uncovered until the gas pressure has dropped to substantially atmospheric pressure, or slightly less, during the expulsion of water. For example, if the residuum valve 88 is opened to drain the Water when the gas pressure in the tank is at the maximum value permitted by the relief valves, the expansion of this volume of high pressure gas into the volume of the tank between the water level 31 and the lower ends of the pipes 45 and 49 will so increase the volume of the gas that its pressure drops to substantially atmospheric pressure. This result is obtained by having the ratio of the maximum gas pressure to atmospheric pressure substantially equal to, or less than, the ratio of the volume of the water and gas space above the pipe end to the volume of gas above the water level 31. Thus, it is not possible for gas to be discharged into the generator room through pipes 45 and 49 when handles 61 and are operated during recharging operations following the expulsion of the water and sludge through the valve 88.

The carbide feed mechanism I4 is operated by rotation of the feeding shaft I6 driven by a motor 95 which is supported by a bridge 96 on top of the generator. This motor 95 is operated by a weight 91 hung at the end of a flexible cable 98, Which passes over a sheave 99. The weight 91 moves in a cage I00. Weight motors of this type for the carbide feed mechanism of acetylene generators are well known.

Figs. 4-6 show a brake wheel I02 on a shaft I04 of a governor I06. The brake wheel I02 has pins I08 extending from one side. An arm III] has a pivotal connection II2 to the motor h0using II3, and has a hook H4 at one end for catching the pins I08 to stop rotation of the brake wheel I02.

An arm II6 has a pivotal connection H8 to the bridge 96. A bar I20 is attached at its lower end to the arm I I8, and at its upper end has a pin and slot connection I22 to the arm Ilil. A tension spring I24 urges one end of the arm II6 downwardly and holds the bar I20 down so that the hook H4 is raised out of the path of the pins I08.

The arm II 6 is also connected to a bar I26, which has a reduced lower end I28 extending through an opening in the horizontal bar 11. The bar I26 extends at an angle to the horizontal, as shown in Fig. 6, and when the horizontal bar 11 moves to the left (in Fig. 6) it exerts an upward thrust on the arm II6. Referring to Fig. 4, this upward thrust of the bar I26 rocks the arm II6 counterclockwise, stretches the spring I24, and lifts the bar I20. The lifting of the bar I20 permits the hook end of the arm IIO to drop by gravity, catch one of the pins I08, and stop rotation of the governor shaft.

This movement of the horizontal bar 11, to the left in Fig. 6, occurs whenever the main control handle I0 (Fig. 2) is operated to open the valves of the water filling system. Thus, the operation of the carbide feeding motor is prevented whenever the main control handle is in position to open the valves of the water supply system.

A cable I30, shown in Fig. 1, connects the handle 90 of the residuum valve with one end of the arm II6 so that movement of the handle to open the residuum valve rocks the arm H6 and lifts the bar I20 (Fig. 4), to cause the hook II4 on the arm IIO to catch one of the pins I08 and stop the motor. Thus, opening of the residuum valve to drain the generator tank automatically stops operation of the carbide feed mechanism. The residuum valve is connected to the motor interference independently of the interference between the main control handle and the motor. This independence makes it possible to expel the water from the generator under gas pressure, and at the same time stop the motor.

The operation of the carbide feed mechanism is further controlled by a regulator I35 (Fi 4), which is of conventional design and contains diaphragms or other pressure operated means which move a rod I31 outwardly as the gas pressure in the regular increases. The regulator is in communication with the interior of the tank and therefore subject to the gas pressure in the generator.

The rod I31 is pivotally connected to a lever I39 which is fulcrumed on a supporting bracket I40. The lever I39 has a looped end I42 surrounding the feeding shaft I6. A collar I44 is secured to the feeding shaft below the looped end I42, and pins I46 extend upwardly from the top face of the collar. If the gas pressure in the generator reaches an excessive value, the rod I31 will move the lever I39 sufficiently to bring the looped end I42 into the path of the pins I46 and stop rotation of the feeding shaft. The looped end I42, collar I44, and pins I46 constitute a lock for stopping the operation of the feeding mechanism. During the ordinary operation of the generator, the pressure does not rise high enough tocause the lever I39 to stop the rotation of the feeding shaft by contact with the pins I46.

The regulator I35 controls the speed of the motor, and consequently the rate at which the carbide feed mechanism operates, through a. brake comprising a three-arm brake lever I50, a rod I52 pivotally connected at its upper end to the brake lever I50 and having its lower end extending through an opening in the lever I39, a coil spring I53 surrounding the rod I52 between the lever I39 and a collar I54 secured to the rod I52. The spring I53 between the lever I39 and collar I54 provides a semi-rigid connection through which movement of the rod I31 and lever I39 is transmitted to the rod I52 and brake lever I50.

The brake lever I50 is pivotally supported by a shaft I58. Two arms I6I and I62 of the brake lever extend close to the brake wheel I02, as shown in Fig. 4, and comprise a double brake. When pressure in the regulator I35 lifts the rod I31 and moves the lever I39 to raise the rod I52, the brake lever I50 is rocked counterclockwise and the upper arm I6I presses its braking surface against the wheel I02 and stops the rotation of the governor shaft.

If pressure in the generator continues to increase, the rod I31 is moved outward further and lowers the left-hand end of the lever I39 so as to. cause it to engage the pins I46 and stop the feeding of carbide, as previously described. This further motion is permitted by the spring I53.

The spring I53 is maintained in a state of compression by means of the limiting pin I66 in the rod I52. The initial compression of this spring is sufficient to permit the brake arm I6I to apply a braking force to the wheel I02 that is great enough to stop the motor even with a very slight rise of pressure within the generator shell and without involving an appreciable amount of rubbing between the brake and the brake wheel at slightly lower pressure levels. At the same time a very soft spring is employed that yields readily enough so that the loop I42 may be caused to engage with-the pins I 46 without an unreasonable further use of pressure above the level that will cause the brake to engage the brake wheel.

When the pressure in the generator is very low, as when the generator is opened for recharging, the rod I31 moves down and lowers the right-hand arm of the lever I39 and the rod I52 to such an extent that the lower arm I62 of the brake lever I50 holds the brake wheel against rotation. When operation of the generator is first started, the rod I52 is held up by hand to move the arm I62 away from the brake wheel I02 until after the generator has built up enough pressure so that the regulator I35 will keep this lower arm I62 away from the brake wheel.

Figs. 7 and 8 show the construction of the double-acting check valve 20. The valve includes a housing comprising a body portion I10 and upper and lower covers I12 clamped to the body portion by bolts I14. A partition I15 divides the interior of the housing into an upper chamber I16 and a lower chamber I18. Gas enters the lower chamber through an inlet I80, and the upper chamber has a threaded outlet I82 through which gas flows from the valve housing to the flash arrester.

The partition I15 has. an opening I84 with lips I85 and I86 at its upper and lower ends, respectively. An upper valve element I88 includes a disk I89 which clamps a seat I90, of soft rubber or other suitable material, against a casting I92 which is of square cross-section and has studs I94 in sliding contact with the side of the opening I84. The valve element I88 has a central stud I95. The disk I89 and seat I are of greater diameter than the opening I84, so that the seat contacts with the lip I85 when the valve element I88 is in closed position.

A lower valve element I98 is of similar construction to the upper valve element I88 and has a seat 200 which contacts with the lip I86 when this lower valve element is in closed position. The lower valve element has a central stud 202 and the length of the central studs I95 and 202 is such that it is impossible for both of the valve elements I88 and I98 to be seated at the same time. In Fig. 7, the upper valve element I88 is shown in closed position and the lower valve element in open position. If the lower valve element moves upward into closed position, its central stud 202 will strike the central stud I95 of the upper valve element and move the upper valve element into open position. Thus, the central studs prevent the two valve elements from being accidentally closed against the lips and the lower one failing to drop open, under the influence of gravity, because of no vent to the space between the valve elements.

The opening of the valve elements I88 and I98 is limited by stops 205 carried by the covers I12. Both of the covers I12 are of identical construction to facilitate manufacturing procedure, but the exact shape is determined by the require ments of the lower cover. There is considerable space under the lower valve element I98 so that lime sludge which sometimes gets into the casing does not interfere with the operation of the lower valve element. The lower stop 205 limits the opening movement of the valve element I98 so that a sudden increase in the flow of gas around this lower valve element, or a gas fiow of very high velocity, will cause the lower valve element I98 to close against the lip I86 and stop further fiow of gas. Thus, the outflow of gas from the generator is automatically cut off if it becomes excessive as the result of a broken line, or one which has been carelessly left without proper fittings, or if an explosion occurs within the generator.

The particular gas flow necessary to cause the lower valve element I98 to close is determined by the weight of the valve elements, by the crosssectional area of the opening I88 in which the valve elements slide, and by the degree of displacement of the seat 288 from the lip I86. The design of the check valve depends on the service for which the generator is intended and the quantity of gas which it is designed to deliver.

When the shut-off valve 2 3 is opened to supply gas to the service line 28, the initial gas flow will be very rapid if the service line is empty. The shut-off valve 24 is provided with means for preventing this initial gas fiow from closing the lower valve element I98 of the doublet-acting check valve.

Fig 9 shows the construction of the shut-off valve 24. A valve body 2I0 is connected to the flash arrester by a fitting 2I2, and the service line 26 is connected to the upper end of the valve body. A partition 2I5 inside the valve body has an opening 2i! with a lip 220 at one side. A valve element 222 having a seat 224 is movable into closed position against the lip 220, or into open position away from the lip 22!), by a hand-wheel 225 at the end of a threaded valve operating stem 226. A throttling block 228 is attached to the valve element 222 and partially fills the opening 2|! to prevent a sudden fiow of gas as the shut-off valve 24 is opened. As the seat 224 is moved away from the lip 220, the throttling block 228 obstructs the fiow of gas through the opening 2 I! so that the service line 26 fills slowly and there is no sudden flow through the double acting check valve, such as would cause the lower valve element to close. When the shut-off valve 24 is fully opened, the throttling block 228 is completely withdrawn from the opening 2 I l.

The preferred embodiment of the invention has been described, but changes and modifications can be made, and various features of the invention can be used alone or in combination with other features, without departing from the invention as defined in the claims.

I claim:

1. In an acetylene generator, a tank; a flash arrester; a relief valve for controlling the escape of gas from the tank; another relief valve for controlling the escape of gas from the flash arrester; a carbide hopper having a filling entrance; a closure for said filling entrance; interference means to prevent opening of said closure; a water filling system including a valve; interference means for preventing opening of said valve; control means for operating both of the relief valves in unison, said control means including a connection for moving the water valve interference means into an inoperative position when the relief valves are opened; and control means for operating the water valve, including a connection which moves the closure interference means into an inoperative position when the control means for the watervalve is operated to open the water valve.

2. An acetylene generator comprising a tank; a gas delivery line leading from the upper part of the tank; a flash arrester in the delivery line; a pressure relief valve on the delivery line between the tank and fiash arrester; another pressure relief valve on the flash arrester; common manual control means for opening both of the relief valves in unison to effect the escape of gas from the tank and flash arrester; a carbide hopper at the top of the tank; a closure for a filling entrance in the carbide hopper; a water filling and overflow system for the tank including valved piping for filling and valved overflow piping; a main control handle for operating the water system valves in unison; interference means operated by the main control handle for preventing opening of the carbide filling entrance closure except when the main control handle is in position to open the valves of the water system; other interference means for preventing operation of the main control handle; and a connection between the relief valve manual control means and said other interference means for shifting the latter into an inoperative position when the relief valve manual control means is operated to open said relief valves.

3. An acetylene generator including a tank; a water filling pipe for supplying water to the lower part of the tank; a valve in said water filling pipe; a main control handle for operating the valve; a carbide hopper at the top of the tank; feed mechanism including a motor for feeding carbide from the hopper into the water in the tank; a residuum valve at the bottom of the tank for draining water and sludge from the tank; means directly connecting said feed mechanism with the residuum valve for preventing operation of said feed mechanism when the residuum valve is open; and other means operatably connected with the feed mechanism and the main control handle for preventing operation of said feed mechanism when the main control handle is in position to open the water valve.

4. In an acetylene generator, a tank in which acetylene gas is generated under pressure; carbide feeding mechanism; a brake for controlling the operation of said feeding mechanism; a lock for stopping the operation of the feeding mechanism; regulator means operated by gas pressure in the generator; means connecting the regulator with the brake for operating the brake as the gas pressure increases; and means between the regulator means and lock whereby the regulator means operates the look when the gas pressure in the generator increases above a given value.

5. In an acetylene generator, a tank in which acetylene gas is generated under pressure; carbide feeding mechanism; a friction brake for controlling the operation of the feeding mechanism; regulator means operated by gas pressure in the generator; and motion transmitting means between the regulator and brake for applying the brake as the pressure in the generator increases; a yielding connection in said motion transmitting means allowing further movement of the regulator means after the brake reaches the limit of its travel, and alock operated by said further movement of the regulator means.

6. In an acetylene generator, in combination with a generator tank having a relief valve for the escape of gas from the tank; a water filling system including a valve; overflow piping communicating directly with the interior of the generator for draining off water which is above the working level of the generator; and a valve in the overflow piping; of manual control means for operating the relief valve; a common control handle for opening and closing the valves in the filling system and overflow piping; aninterference which prevents operation of the common control handle to openthe valves; and means, operated by movement of said manual control means to open the relief valve, for causing the interference 5 to be withdrawn from said control handle.

7. In an acetylene generator, in combination with a generator tank having a carbide hopper; mechanism including a motor for feeding carbide from the hopper into water in the tank; and a 2 residuumvalve atthe bottomof the tank for draining water and sludge from the tank; of brake means for preventing operation of the motor; motion-transmitting means, operatively connecting the residuum valve with the motor brake means, and adapted to transmit motion of the residuum valve, as it moves into open position, to the brake means to cause the brake means to stop the motor and prevent it from operating until the motion-transmitting means is moved the other way as the residuum valve is closed; and means to release the brake means as the residuum valve is closed.

8. In an acetylene generator, in combination with a generator tank having a carbide hopper; mechanism including a motor for feeding carbide from the hopper into water in the tank; a water filling system including a valve; and a main control handle for operating the water filling valve; of brake means for preventing operation of the motor, and means operatably connecting the main control handle with the brake means to prevent operation of the carbide feed mechanism when the main control handle is in position to open the water filling valve. I

GEORGE M. DEMJNG.

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