US2554496A

US2554496A - Safety device

Info

Publication number: US2554496A
Application number: US742602A
Authority: US
Inventors: Aylmer H Maude
Original assignee: Hooker Electrochemical Co
Current assignee: Occidental Chemical Corp
Priority date: 1947-04-19
Filing date: 1947-04-19
Publication date: 1951-05-29
Anticipated expiration: 1968-05-29

Description

A. H. MAUDE May 29, 1951 SAFETY DEVICE 5 Sheets-Sheet 1 Filed April 19, 1947 Burner Fig!" H. MAUDE SAFETY DEVICE 5 Sheets-Sheet 2 Filed April 19, 1947 A TTX y a 1951 A. H. MAUDE 2,554,496

SAFETY DEVICE Filed April 19, 1947 I 5 Sheets-Sheet 4 INVA'NTOR ATT).

A. H. MAUDE SAFETY DEVICE May 29, 1951 Filed April 19, 1947 5 Sheets-Sheet 5 Fig. 8

- /NVNTOR A TT).

Patented May 29, 1951 SAFETY DEVICE Aylmer H. Maude, Niagara Falls, N. Y., assignor toHooker Electrochemical Company, Niagara Falls, N. Y., a corporation of New York Application April 19, 1947, Serial No. 742,602

1 Claim.

My invention relates to apparatus for controlling the pressure of gases supplied to reaction chambers, as for example, when they are supplied through calibrated orifices, and it is desirable that the supply should be in accurately controlled proportions; and also for safeguarding reaction chambers or apparatus associated therewith against explosion or other complications in the event of the supply of one of the gases being cut ofi", interrupting the reaction, and the other gas continuing to flow, and supply of the interrupted gas being then resumed, automatically or inadvertently, particularly under reacting conditions.

Examples of gases that are commonly reacted are chlorine with hydrogen, methane, etc. These are burned together in burners located in combustion chambers. Other gas phase reactions are chlorine with carbon monoxide, and hydrogen chloride with acetylene, etc. These are catalytic reactions.

' In each of these cases products of reaction are valuable chemical compounds and either collected or stored or passed immediately to a second reaction. An illustration of a product produced in a burner which may be immediately passed to a second reaction is combustion of chlorim with hydrogen and reaction of the resulting hydrogen chloride with acetylene.

When one of the gases fails, it is practically impossible to shut off the other in less than a fraction of a second, during which time an objectionable and perhaps dangerous quantity of the other gas may have flowed into the reaction chamber. Therefore, rather than try to shut off the other, I have found it better to provide that one of the gases shall always flow for a time after the other, so that there shall be no uncertainty as to which gas shall fill the reaction chamber after any accidental shut-down. Each particular case therefore presents a different safety problem. Thus in the case of the chlorine-hydrogen burner, if the product is to be absorbed in water, it may be desirable to leave the combustion chamber filled with chlorine, which does not form an explosive mixture with air; or on the other hand, if the products of the reaction are to be passed directly to a reaction with acetylene in a closed system, it may be better to leave the combustion chamber filled with hydrogen, which does not react with acetylene.

For purpose of illustration, I will describe my apparatus as applied to the burning of chlorine and hydrogen together, on the assumption that itis desired always to leave the combustion cham 2 ber free from hydrogen, in case of interruption of either gas. 1

In Patent No. 2,295,591, issued to me September 15, 1942, there are illustrated a burner and combustion chamber for burning chlorine and hy-; drogen together, the gases being supplied through calibrated orifices. In Patents Nos. 2,366,669 and 2,366,670, issued to me January 2, 1945, there are illustrated a burner and combustion chamber of an improved type, intended for the same pur pose. In each of these, provision is made for relieving pressure in the combustion chamber in case of explosion therein, and thereby rendering, the explosion relatively harmless. The present invention goes further back, and aims to minimize the likelihood of conditions arising that, could possibly result in explosion.

In carrying out my invention, I utilize a gasometer and calibrated orifice to control the supplv of each gas to the burner. The previously dried gases are supplied to the gasometers, from a source such as a circuit of electrolytic cells, under pressure sufficient to lift the gasometer bell. The pressure in a gasometer bell increases as the gasometer rises from the empty to the full position. Therefore, in order to hold it as nearly as possible constant, I provide a throttling valve in the infeed to each bell and mechanism by which each valve is closed progressively as the bell rises. Thus the travel of the bell is held to narrow limits and the pressure upon its orifice kept nearly constant.

In addition to the aforementioned throttling valves, I provide a shut-off valve controlling exit of hydrogen from the hydrogen gasometer to its orifice and another shut-off valve controlling admission of chlorine to the chlorine gasometer. These shut-01f valves are normally locked in wide open position, but when the locking mechanism is tripped, each of these shut-off valves instantly closes tightly. The shut-oil valve controlling exit of hydrogen from the hydrogen gasometer is tripped by mechanism actuated by the chlorine gasometer when the latter is in empty position. The shut-01f valve controlling admission of chlorine to the chlorine gasometer is tripped by mechanism actuated by the hydrogen gasometer when the latter is in empty position. Thus, failure of the chlorine supply to the burner instantly cuts off the hydrogen, but failure of the hydrogen supply permits the contents of the chlorine gasometer to be discharged through the burner into the combustion chamber. Failure of either gas therefore shuts off both, but always leaves the combustion chamber free of hydrogen;

. Referring to the drawings:

i a plan view of the assembly of gasometers, piping, valves, etc.

Fig. 2 is a front elevational view of the same, the burner and combustion chamber being indicated diagrammatically.

Fig. 3 is an elevational view of a portion of the assembly, in section along the line aa and as seen from the top .of Fig. 1.

Fig. 4 is an end elevational View of a portion of the assembly, as seen from the top in Fig. 1 with the portion of the assembly illustrated in Fig. 3 removed, for simplicity, the gasometer be ing shown in section.

Fig. 5 is an elevational View of one of the shutofi valves, with its locking and tripping -r nechanism, to an enlarged scale.

Fig. 6 is a plan view of the same.

Fig. '7 is an elevational detail of the locking mechanism to a still larger scale.

Fig. 8 is an elevational view of the shut-oil valve and trip mechanism to a reduced scale, showing the Valve tripped and closed.

Fig. 9 is a detail to the scale of Figs. 5 and 6, of the sleeve which actuates the arm of the throte tling valve.

Figs. 5 to 9 serve .to illustrate valves associated with'both the hydrogen-and chlorine systems and are therefore provided with a duel set of refer.- ence numerals, those enclosed in parentheses referring to the chlorine system.

Referringto the figures:

I :is the hydrogen gasometerand 2 the chlorine gasometer.

These gasometers comprise respectively tanks 3, -4,-bells iii-adapted to telescope with

tanks

3,4 and suspended from cable '5, 8 which pass over pulleys 9, Iii and ll, 12 respectively.

From cable l is suspended a counterweight comprising bar 13 and sleeve M. Sleeve Hlslides freely upon standpi-pe it, which serves as a guide therefor, as bell =5 rises and falls. Similarly, from cable 8 is suspended a counterweight comprising bar I6, and sleeve 'l "i,- sliding freely on standpipe l8.

For chlorine and hydrogen, the sealing'liquid in thetank may be concentrated sulphuric acid. Its-hould-cf course stand at such a level that-the bottoms of-the bells are always submerged. 'Ihe bells are weighted as indicated at 18 (Figs) and the eounterweights are only sufficient to main The hydrogen and chlorine may be derived froma circuit of electrolytic cells (notshown) subsequently dried and brought under a suitable pressure. Hand operated valves 29 and tfii jfff'lg'. 4) are providedinpipes 2D and YBT respectiVely o s u t n .o th sup l .o t es as s i eme e c ,In the vertical leggof pipezt is provided throa tlingvalve 31, of the plugcock type. llalve fi is t ted. hr ugh. m .32- .Armfiiisilifted, openill JQLY 1, byc l fiin 4 en a ement with. sleeve 33, pivoted upon pin 34,;projectingdromsleeve fl,

' sponding to rising motion of bells I and 2, there- ;iore increases the throttling effect of valves 3| and 353 respectively, and vice versa. The setting of these valves is such that when the bells are in normal position, about three quarters full, they are about half open. As the bells rise, the valves ,are progressively closed, checking further rise.

Conversely, as the bells fall the valves open wider, checking further fall. These throttling valves may be handadjusted by mechanism indicated at ih Fig. 2, to g-i-ve .the desired settling.

I hus the bells are held to a very limitedtravel and the pressure of the gas delivered by them is kept substantially constant. A

However, when the bells reach the empty position, arms 32 37) slip completely out of theiriespective sleeves 33 (-38). Under the act-ion of weights 35 (fill), these arms then instantly fall and shut off pipes 2i! and 2-1, respectively. Thus the throttling valves also become shut-off valves, when their respective bells are'e n-pty. lithe suppiy of gas should thenberesuifnedfnonecanfiow into its bell until the'valve has beenreopried by hand.

-lnthe vertical :legcf pipeg i is provided auto-,

matic shut-off valve 42. Valve retained t ig arm "b Wei ht i 5- j si ii i a ir locked in open position by engagement of lug' fiii, p e iin f m a m is With'i it. .proli. from trigger it, which is pivoted at 8 upon ip 49- T rfll i adapte t tribpe ldy i .rz pi iin immsle r 1.

T s m hanismi r cl a illus ra ed gs- 5 to ,8.- ihii shu -O va v ii, in .ths ezi f hrdres r r mhe .Lis .t i ned and th -sapp 9 hydro en to th burner Ins an l @1 1 f as i u trated i i --8. w e pin .55 liit an But sleeve l7 and pin Stlare,unglercontroliof bell 2; henc -flQ of h drogen .f om hel is t burneris cut ofi when chlorineibell 2' reaches wh the t l -Q instantly cutoff, when pin 5 !5 lifts triggerLE BJ-But' sleeve lfi and pin 59 are under control of Joel bell i he it low-crap r si 9aj. -.s hen, Any

the hydrqgen s re 9 th bii ee fail residual chlorine in bell z is, hpw everynotp e vented from-flowing to the,burner untilbellz is likewise empty.

The burner and combustion chamberare indicated at-60 and t J-Fie f enesi rsi rfillqlih calibrated orifices at 62;}13.

It should be noted'that s hut-oii valve}; is. located in the outlet-from bell [to -the-burner,

whereas shut-off valve 5| is located in the inlet from the source of chlorine to bell 2. There is no shut-off valve in the outlet from bell 2 to the burner. Hence, the hydrogen flow to the burner is always out off before the chlorine flow is cut off, and when the hydrogen is cut off the chlorine continues to flow long enough to consume any hydrogen in the pipe leading to the burner. The combustion chamber can therefore never be left filled with hydrogen or an explosive mixture of hydrogen and chlorine, but is always left filled with chlorine or hydrogen chloride.

It should also be noted that when the chlorine bell has emptied itself it trips the hydrogen shut-off valve. Failure of either gas, which of course extinguishes the burner flame, therefore leaves both shut-off valves closed, as well as both throttling valves, and resumption of normal operation is under full manual control. This involves first seeing that both gasometers are supplied with gas, opening the throttling valves, opening the chlorine shut-off valve and looking it in open position, and finally, with an ignition torch playing upon the burner, opening the hydrogen shut-off valve and looking it open. ,7

In like manner, if preferred, the apparatus may be constructed so that in the event of failure of either gas the combustion chamber will always be left filled with hydrogen, or a mixtureof hydrogen and hydrogen chloride, and substantially free from chlorine.

In the combining of hydrogen chlo ide with acetylene to produce vinyl chloride, it isgenerally preferred to adapt the apparatus to prevent the reactor from becoming filled with acetylene. On the other hand, in burning chlorine with'r'nethane, or combining it with carbon monoxide, it is generally preferred to leave the chamber filled with chlorine rather than with the other gas.

I claim as my invention:

In apparatus for supplying two eactable gases A and B to a reaction chamber, which apparatus includes a pressure control chamber for each gas, an inlet conduit for each gas to its respective pressure control chamber andian out let conduit for each gas from its respective pressure control chamber to said reaction chamber, a vertically movable bell in each pressure control chamber and a counterweight therefor, and throt tling valves controlling the admission of gas into said pressure chambers and proportioning means maintaining them in predetermined proportions so long as the supply of each gas remains unimpaired, the improvement in safety shut-01f means therefor comprising: a shut-off valve in the inlet conduit for gas A; a shut-off valve in the outlet conduit of gas B; a weighted arm affixed to each of said valves in such position that movement thereof in response to said weights will no 2,295,591

fully and immediately close said respective valves a sidewardly extending lug on each of said arms; support means adjacent each counterweight; a trigger on each support means, each trigger having two legs perpendicularly with respect to each other and positioned with one arm substantially vertically arranged and the other substantially horizontal, said triggers each being pivotally mounted at the lower extremity of its vertically positioned leg on said support means and having a lug at the intersection of each of said legs normally engaging the lugs on each of said respective arms for holding same in raised, or valve-open, position against said weights, and having their respective horizontal legs extending adjacent each of said counterweights; pins extending from each of said counterweights engageable with said horizontal trigger legs when the counterweights are raised beyond certain predetermined positions by which to move said horizontal legs on their respective pivot points and disengage said respective lugs and release said arms, the arms controlling gas A being associated with the counterweight of the gas B pressure chamber and the arm controlling gas B being associated with the counter-weight of the gas A pressure chamber; and said proportioning means comprising means constantly urging said throttling valves to fully closed position, releasable means connected with said counterweights normally holding each of said valves independently open and movable with movement of said counterweights and each released when the counterweight to which it is connected moves past said certain predetermined positions, whereby to close substantially instantaneously the throttle valve associated with Whichever gas is controlled by the pressure control chamber Whose counterweight has so moved past such predetermined position; whereby falling of gas pressure in the pressure chamber for either gas and the consequent raising of the corresponding counterweight beyond a predetermined point will effect substantially instantaneous closing of the shut-oil valve controllin the other gas and the reaction chamber will, regardless of which gas source has failed, to be left with a concentration of gas A substantially in excess of the concentration utilized for reaction purposes.

AYLMER H. MAUDE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 431,961 Barrow July 8, 1890 550,162 Dickerson Nov. 19, 1895 Maude Sept. 15, 1942