US2888981A - Automatic gas bleeder igniter - Google Patents

Description

June 2, 1959 l.. M. RIPPLE AUTOMATIC GAS BLEEDER IGNITER 2 Sheets-Sheet 1 Filed March 24, 1954 INVENTOR. Ew/5 M. /Q/ppLE- June 2, 1959 L. M. RIPPLE 2,888,981

AUTOMATIC GAS BLEEDER IGNITER Filed Maron 24, 1954 2 shears-snm 2 Ulf/agr 32 INVENTOR.

Lew/s M. Q/ppLe BY United States Patent C AUTOMATIC GAS BLEEDER IGNITER Lewis M. Ripple, Cleveland, Ohio, assgnor to Republic Steel Corporation, Cleveland, Ohio, a corporation of New `lersey Application March 24, 1954, Serial No. 418,411

2 Claims. (Cl. ISS-123) This invention relates to gas igniters and more particularly to an improved automatic igniter for intermittently igniting Waste gas at the top of a stack In various industrial applications surplus or waste gases are discharged from tall stacks. When these gases are combustible it is a common practice to ignite them and permit them to burn at the top of the stack. Various means, such as spark devices, have been proposed and used for igniting gases at the top of such a stack. However none of these has proved completely satisfactory and reliable and accordingly it is an object of the present invention to provide an improved means for automatically igniting gas at the top of a stack.

Other objects of my invention are the provision of completely automatic mea-ns for igniting gas -which is discharged intermittently frorn a stack, the igniter being controlled so that it is not eiective until the stack is purged of explosive mixtures; the provision of a gas igniter which automatically resets itself after each igniting cycle so that, if the gas supply to the stack is stopped and the ilame goes out, the igniter will automatically be ready to reignite the vgas when it again ilows from the stack; and the provision of an automatic gas bleeder igniter apparatus, particularly adapted for use with gas holders, which is dependable, long-lived, and economical to install and maintain.

The above and other objects of my invention will appear from the following description of one embodiment thereof, reference being had to the accompanying drawings in Which:

Figure 1 is a diagrammatic layout of my igniter apparatus and control hookup associated with a gas holder and bleeder stack therefor.

Figure 2 is a schematic Wiring diagram of the apparatus illustrated in Figure l.

Figure 3 is an enlarged fragmentary -view, taken on -line 3v3 of Fi-gure 4, of the upper portion of a stack illustrating one of the igniter heating elements.

Figure 4 is a plan View, taken substantially on line 4 4 of Figure 3, but drawn on a somewhat larger scale.

Referring to Figure l, a gas holder is generally indicated at G. This is illustrated on a very small scale but is one of the common large tank-like structures comprising a fixed lower vessel 1 and a vertically movable upper portion 2 which telescopes within the vessel 1 and rises and falls depending upon the amount of gas which enters the holder G through the inlet pipe 3. A bleeder outlet pipe 4 extends to the bleeder stack S and is provided with a bleeder valve 5 adapted to open or close the connection from the gas holder G to stack S. Valve 5 is normally held closed as by a weight 5 and may be opened by lifting the arm 5".

The apparatus for opening valve 5 is also diagrammatically illustrated and is not drawn to scale. It includes a exible cable 6 attached to an arm 7 projecting from the top of the movable portion 2 of the Igas holder. This cable 6 passes around fixed pulleys 7 and 8 as indicated and then makes a bend around the floating v e l 1C@ pulley 9 which carries a weight W. From pulley 9 cable 6 extends upwardly and over another fixed pulley 10 and then down to an operating connection to the valve operating arm 5". A fixed stop 11 is disposed in the path of the movable pulley 9 and prevents it from moving to an elevation higher than the stop 11 but does not interfere with rotation of the pulley 9.

When the movable portion 2 of gas holder G rises from the position shown the weight W will be lifted but the portion 6 of cable 6 extending between pulley 10 and valve arm 5" will not move because the force required to lift the weight 5 is greater than that imposed by Weight W. When pulley 9 strikes the fixed stop 11 it cannot go any higher and further upward movement of the portion 2 of gas holder G will pull on the cable 6 and cause corresponding upward movement of the portion 6' of said cable. This will etect opening of the valve 5 and permit gas to bleed from the gas holder G to the stack S.

At the top of the stack S are a pair of heating or igniter elements H and H' (one of which is shown in greater detail in Figure 3). These heating elements, as Will be later more fully described, comprise U-shaped electrical conductors, preferably made of corrosion resistant material such as stainless steel. In the operation of my apparatus these heating elements are electrically heated to an incandescent temperature sufficient to ignite ygas emerging from the top of the stack. The means for controlling the heating of the elements H and H' is indicated diagrammatically in Figure l and more in detail in Figure 2. As seen in Figure l, a suitable current supply is conducted to the apparatus through lines 12 and 13 which lead to the primary of a transformer 14. A limit switch L is interposed in the line 15 which leads from one side of the secondary of transformer 14 to the control unit C While line 16 leads from the other side of said secondary to control unit C. The main heating current supply 12-13 is also conducted to the control unit C through suitable conductors 12 and 13'.

The makeup and mode of operation of the control unit C and limit switch L will be fully described later with reference to Figure 2 and it 'will suiice to point out here that limit switch L lis provided with. an operating means, such as arm 19 which, as diagrammatically illustrated, has a forked end extending around the cable 6. A switch actuating block 20 is secured to the cable 6 and, when the portion 6 thereof moves upwardly during or just after opening the valve 5 to the desired degree, the block 20 will engage the end of arm 19 and lift same to effect closing of the limit switch L.

The result of closing the limit switch L upon opening of the bleeder valve 5 `will be to initiate the operation of the control unit C whereby gas is permitted to pass through the bleeder pipe 4 to the stack S for a sulicient time to completely pur-ge the stack S of air and dangerous explosive mixtures and then electrical connections are established from the power source to the resistance heating element H through Wires 21 and 22 and to the resistance heating element H through wires 23 and 24. After the heating elements have reached ignition temperature and been held at that temperature for a period (for example two minutes) sufficient to ignite the gas emerging from the top of the stack, current to the heating elements is automatically shut off. As long as valve 5 is open and gas continues to be bled to the stack S it will burn, but if the supply to the gas holder G is cut ol or diminished and the upper portion 2 thereof moves downwardly the Valve 5 will be closed by Weight 5. Such downward movement of the portion 2 of the gas holder will also permit the limit switch L to open, breaking the circuit to the control unit C and permitting the mechanisms therein automatically to reset.themselvesforan- 'thereto are shown in detail.

other ignition cycle the next time the gas volume in holder G increases suiciently to open valve 5 and close limit switch L.

The electrical connections and control mechanism of my improved automatic gas bleeder ignition apparatus are illustrated in the schematic wiring diagram of Figure 2. In this View the main current supply 12.-13 may be confsidered to be a 440 volt alternating current source. 'The control circuit transformer 14 has its primary connected across lines 12 and'13 and has leads 15 and 16 extending from its secondary. As previously explained, limit switch L is interposed in line 15 and is open (as seen in Figure 2) except when gas holder portion 2 hais risen high enough to open the bleeder valve 5 and close limit switch L. A repeat push button 25, the function of which will be later described, is also disposed in line 15 and is normally in closed position as seen in Figure 2.

The first or circuit making timing relay R is connected across the lines 15 and 16 by lines 15 and 16. It is provided with a normally open contact arm 26 which, when open, breaks the circuit through lines 17, 18 and 18' to the second or circuit breaking timing relay R.

This circuit breaking timing relay R is connected to the secondary of the control circuit transformer 14 on one side through lines 15, 27 and 27 and on the other side through lines 16 and 17, contact arm 26 when closed, and lines 18 and 18. The contact arm 28 of timing relay R is normally closed and completes and connection from line 29 to line 30.

Also incorporated in the control unit C is a contactor generally indicated at M. This contactor M includes `a solenoid 31 which is connected to the secondary of transformer 14 On one side through the lines previously referred to and lines -32 and 32', and on the other side through the lines previously referred to and line 30. It will be understood that solenoid 31 will be energized only when both the contact arm 26 of timing relay R and contact arm 23 of timing relay R are in their closed or circuit making positions. When solenoid 31 is energized it is `adapted to actuate the contact member 33 of contactor M and complete the main heating circuit through lines 12' and 12 to line 34.

The primary 35' of heating element transformer 35 is connected across the main heating current supply lines V34 and 13 by lines 36 and 36 and the primary 37 of a similar heating element transformer 3'7 is connected in parallel bythe lines 38 and 39. Interposed in line 36 is a variable resistance 40 and an ammeter 4l, and a similar variable resistance 42 and ammeter 43 are interposed in line 38. The resistance heating element H is connected to the `secondary 35" of transformer 35 by the lines 21 and 22 and, in similar manner, the secondary 37" of heating element transformer 37 is connected to heating element H by the lines 23 and 24.

The function of lthe variable resistanceis 4th and 42 is to permit adjustment of the heating current applied to the heating elements H and H to the lowest value which will heat these elements to a ytemperature suicient dependably to ignite the gas at the top of the stock. ln order to increase the life of the heating elements H and vH it is desirable to operate them at the lowest temperature which will achieve the desired results and it is for this reason that the variable resistances 4@ and 42 and ammeters 41 and 43 are provided. By arranging the heatving elements H and H in parallel one may burn out, or otherwise fail, without interfering with the operation of the other. The transformers 35 and 37 are provided to furnish the desired low voltage, high amperage current to the heating elements H and H.

In Figure 3 and 4 the heating element H', its mounting on `the stack S, and the electrical connections leading As explained above, the `element H is of generally hairpin or loop shape having its .closed upper end 45 bent outwardly to overhang the Ledge of the `stack S. The lower ends of element H are secured, as by welding, to supporting brackets 46 and 47. Bolts 48 and 49 extend through the stack S and serve to clamp -the brackets 46 and 47 respectively in position. This clamping action is effected by Athe nuts 50 and 51 and insulating washers 52 and 53, and insulating bushings 54, electrically insulate these parts from the metal stack S. Current is conducted to thetbolts 48 and 49 by bus bars 55 and 56, which are secured on the outerends of bolts 4S and 49 by nuts 57 and 58. As indicated in Figure '3 these nuts may be welded to the adjacent bolt and bus bar and the heads of the bolts 48 and 49 may be welded to the brackets 46 and 47 in order to insure proper electrical connection and to prevent loosening of the parts.

The sequence of operation of the entire mechanism described above will now be explained:

When the movable portion 2 of the gas holder G rises to a predetermined value:the valve 5 will be opened and the limit switch L will be closed. When this occurs the first timing relay R will be activated or set into action. This relay may be any one of several well known types and accordingly its detailed mechanical structure will not be described. It is so arranged that when energized by the closing of switch L a time delay mechanism starts to function and the Contact arm 26 will not be moved from its open position (seen in Figure 2) to closed position until after a predetermined time delay, for example three minutes, has occurred. This time delay is adjusted to be such that the gas entering the stack S through the bleeder pipe 4 will have completely purged the stack of air before contact arm 26 is closed.

When the time delay period of relay R ends the contact arm 26 will be closed, completing the control circuit to the second timing relay R and also to the contactor M because the arm 28 of relay R is normally closed. As soon as contactor M is energized the contact member 33 is moved to complete the circuit in line 1212 and the main current supply will then be connected to the transformers 35 and 37 and the heating or igniter elements H and H will immediately start to warm up.

As it takessome time, for example about seconds, for the heating elements H and H to reach gas ignition temperature, and as it is desired to leave the heating elef ments Hand H at their igniting temperature for period suicient to insure ignition of the gas emerging from the stack S, the second timing relay R is so arranged that its contact arm 2S remains in closed or circuit making position (as seen in Figure 2) until suflicient time has elapsed to insure ignition of the gas. This may be, for example, three and one half minutes. At the end of this time the timing relay R operates to move the contact arm Z8 out of its circuit making position and to break the circuit between lines 29 and 30. This results in the immediate de-energizing of the contactor M and the immediate movement of its contact member 33 into open position. When this occurs the main heating circuit to the heating elements H and H' is broken and they immediately cool down to normal temperature.

After the above described cycle and for so long as the limit switch L is held closed and the valve 5 is open and discharging gas into the stack S, the first timing relay R will be energized and its contaotor 26 held closed. This will result in the second timing relay R also being energized and its contact arm 28 held open. However, when the supply of gas in the gas holder diminishes and the upper movable portion 2 moves downwardly, the limit switch L will open and the valve 5 will close at a pre-determined point. When the valve 5 closes the gas supply to the stack is shut oif and the llame at the top goes out. When limit switch L is opened relay R is deenergized and the Contact arm 26 immediately moves to its open position. The second timing relay R is also immediately de-energized when the limit switch L is opened and its contact arm moves immediately from open posif assaasr tion back into its normal closed position as seen in Figure 2.

As the contacter M has previously been de-energized and has opened the circuit in lines 12' and 12, all three units R, R and M are now again ready for another gas igniting cycle. This will occur in the manner described above as soon as the upper portion 2 of the gas holder G again moves upwardly suciently to open the valve 5 and close the limit switch L.

From the above it will be observed that my improved gas igniting mechanism is entirely automatic in its operation and will effectively and safely ignite gas at the top of a stack each time that gas is discharged into the stack.

A repeat push button 25 is provided in the line 15 in order that the gas may be reignited if, due to extremely high winds or other unusual circumstances, the flame at the top of the stack is extinguished while gas is still owing into the stack. In such event it is only necessary to operate the push button 25 to break the control circuit through line 15. This will result in the same sequence of events as happens when the limit switch L is opened upon downward movement of the gas holder. After the control circuit has been broken by manually moving the push button 25 the units R, R and M will all immediately be reset and then, upon release of push button 25 and cornpletion of the control circuit through line 1S, the elements H and H' will be heated to ignition temperature and the gas will be lit again. Push button 25 is also available for testing when desired.

Although I have described the illustrated embodiment of my invention in considerable detail it will be understood that variations and modications may be made in the form and arrangement of the various elements making up my improved apparatus. For example, the timing relays shown and described in the control circuit are of the type which are set into action or activated when the control circuit to them is closed to energize the relay mechanism. As is well understood in the art, timing relays, contactors, etc., may be arranged to be set into action or activated when the control circuit thereto is broken to de-energize the mechanism. Accordingly, the terms activate and de-activate as used in the speciiication and claims are intended to include both closing and opening of the circuit in question. Accordingly, I do not wish to be limited to the exact equipment herein shown and described but claim as my invention all embodiments thereof coming within the scope of the appended claims.

I claim:

1. In gas igniter apparatus, a stack having an open discharge end and an imperforate wall adjacent said open discharge end, an electrical resistance heating element having spaced ends and a closed loop portion therebetween, spaced supports for said ends of said element on the inside of said stack adjacent said open discharge end, and conductors extending through the wall of said stack from said supports, the spaced ends of said heating element being entirely within and closely adjacent to the inner surface of said imperforate wall and the closed loop portion of said heating element extending outwardly beyond said open discharge end of said stack and being bent outwardly into vertically over-hanging relation to the periphery of said discharge end of said stack.

2. Gas bleeder igniter apparatus for purging a stack of air and then igniting gas discharged at the top of the stack comprising, a stack having a top end opening to the atmosphere, a valve for controlling the ow of gas to the stack, means for opening said valve, an electrical resistance igniter element of loop form disposed at and having its closed end extending above the top end of the stack adjacent and in overhanging relation to the periphery thereof, said igniter element having spaced end portions entirely within and closely adjacent to the inner surface of said stack, said stack being imperforate adjacent said Vigniter element, electrical connections from a main current supply to said igniter element, an electrically operated contacter having an open position and a closed position and adapted when closed to complete said electrical connections from said main current supply to said igniter element, a control circuit including a source of control current and said contacter, main switch means in said control circuit, means actuated by said valve opening means for closing said main switch means when said valve is opened, a time delay relay connected in said control circuit to be energized upon closing said switch means, said time delay relay being adapted to close said control circuit and energize said electrically operated contactor at a predetermined time after said relay is closed, said contacter being adapted when energized to close and cornplete said connections from said main current supply to said igniter element, a second time delay relay connected in said control circuit to be energized upon closing of said control circuit by said first named time delay relay, said second time delay relay being adapted to open said control circuit and de-energize said electrically operated contactor at a predetermined time after said contacter has been energized, and manually operable switch means for temporarily opening and then closing said control circuit independently of said main switch means in order to effect repeat operation of the igniter cycle when said main switch is closed.

References Cited in the le of this patent UNITED STATES PATENTS 629,462 Old July 25, 1899 749,769 Wilson Ian. 19, 1904 1,473,716 Willcox Nov. 13, 1923 1,834,289 McCabe Dec. 1, 1931 2,041,014 Norton May 19, 1936 2,229,717 Brace et al. Ian. 28, 1941 2,249,489 Noack July 15, 1941 2,525,314 Rial Oct. 10, 1950 2,596,729 See May 13, 1952 2,656,008 Engle Oct. 20, 1953 2,734,562 Haberle et al Feb. 14, 1956 FOREIGN PATENTS 454,868 Canada Mar. 1, 1949 2,986 Great Britain Mar. 6, 1885 295,827 Switzerland Jan. 15, 19'54

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