US1974498A - Gas detector - Google Patents

Description

Sept. 25, 1934. C, H.' LEWIS 1,974,498

GAS DETECTOR Filed June 17, 1952 ZSheets-Sheet l 29 y n L i 5 l] 27 5 l] f I E Z1*- Z6 .24 r n l r DE 4 :Il A c n L Lr /j E :l Z0 C 20 j g EE *Z9 Z5 Z4 E )J/s' 7 i -l5/ I f5 1 *1 39 All l J6 39 I 5,4 116 J7 1 J 1 39 2 ai?? 37 l C 49 9 5 ZZ 'f/ w 1 1 I 'H SePt- 25, 1934 c. H. LEwls 1,974,498

GAS DETECTOR Filed June 17. 1932 2 Sheets-Sheet 2 Patented Sept. 25, 1934Y UNITED STATES GAS DETECTOR Clair H. Lewis, Columbus, Ohio, assignor to Columbia Engineering Corporation, New York, N. Y., a corporation of Delaware Application June 17, 1932, Serial No. 617,815

3 Claims. (Cl. .Z3-254) This invention relates to an improved gas detecting lamp and has for an objectto provide a. lamp which is particularly adapted for the use of men engaged in working in underground sewers,

conduits, mains, manholes and the Alike where hydrocarbon gas, or like explosive gases, is often present and explosions likely to occur, whereby, through the use of the lamp, convenient and'careful determinations to reveal the presence of such gases may be made to the end of assuring the safety of the workers and the preservation of property. v

Very little has been done prior to the present invention to provide for the ready and careful ascertainment of the presence of natural gas in such underground atmospheres. VIn fact, the

most often used method has been to submit samples of a given atmosphere to a laboratory equipped to make such determinations or lgas analyses. This however, results in considerable` loss of time and has not been satisfactory, since variationsrmay take place in a given atmosphere between the time when the sample is taken and when the workers actually enter the underground location.

The present invention, therefore, provides a' gas detecting lamp by which the atmosphere of an underground location of the character specified may be aspirated intoV the combustion zone of the lamp and the presence of explosive gases in such atmospheres noted by the changes which take place in the normal character of the flame produced by the lamp. By observing the changes in the physical properties of the flame, such as its elongation, extinguishment,y etc., the percentages of natural gas present in the atmospheres undergoing such tests may be readily determined.

It is another object of the inventionto provide the base of the lamp with a series of lters containing ehemical reagents through which the atmospheres. or gases to be tested under` valve regulation are passed, the said lters functioning to remove from such atmospheres certain undesiredgases which might detrimentally effect or mislead the observer in reading the character of the lamp flame, the filters further serving to permitV of the passage therethrough of naturalgas but to absorb or react with the other undesired gaseous compounds present in the mixture ofY gases undergoing such tests.

It is another object of the invention to provide means whereby gas determination tests maybe made atvarious levels in an Vunderground location. It lis, well known that gaseous atmospheres 'in such locations often stratify with the result that determinations as to the gaseous content of the entire area are misleading if the sample is taken but from a restricted portion of the entire area. The present invention embodiesan aspirating hose line connected with the'fllter cham-r ber of thev lamp, the hose line being of such length that its inlet end may be inserted to draw samples from different levels of the region undergoing testing so that by the provision of quickly made successive tests, the entire atmosphere of a given location as to its explosive gas content maybe readily executed before the region is entered. .I For a further understanding of the invention, reference is to be had to the following description and thev accompanying drawings, wherein: l

Fig.' 1 is a view in side elevation of the improved gas detecting lamp comprising the present invention; j

Fig..2 is a vertical sectional view taken through the lamp on the plane indicated by the line 2 2v of Fig. 1;

vFig. 3 is a horizontal sectional View taken through the base of the lamp on the plane disclosed by the line 3 3 of Fig. 2; i j

Fig. 4 is a similar view on the line 4 4 ofFig. 2; Fig. 5 is a detailvertical sectional view disclosing the valve and orice casing used in admitting filtered gas into the base of the lamp and the view is taken on the line 5 5 'of Fig. 2;

Fig.v 6 is a vertical'sectional view taken on the line 6 6 of Fig. 4; f f y Fig. 'Tris a detail side elevation of a plug member which may be connected withthe lampin lieu of the iiexible hose line; Fig. 8 is a diagrammatic lview disclosing theL various filters and the paths of gas travel therethrough.

Referring more particularly to the drawings, the numeral 1 designates a gas detecting lamp of the s'o-called/Wolf or Davy type, which'comprises a fuel fount or oil receiving base 2, the top of which carries the usual wick 3 and ignitor 4. The upper portion of thebase 2 is annularly shouldered as at 5 and is provided with a ring 6v which is formed with av plurality of ports 7 permitting of the passage of air into the combustion zone 8 of the lamp, the shoulder 5y ofthe ring 6 being provided with a loose annulus 9 also ported as at 10.' The-ports V'7 are closed by means of a screen 11 to prevent explosions taking place in the zone-'8 from transmitting flame backwardly into the base of the detector. 'Controls 12 for actuating the wick 3 and the igntor 4 projectv through the lower portion of therbase 2 where they may be conveniently actuated from a point exteriorly of the lamp proper. The screen 11 is carried by a removable collar 13 which is positoned within the ring 6 and provides a seat for the lower circular edge oi a heavy glass cylinder providing a chimney 14. This cylinder is coated so as to be substantially opaque except ior transparent or translucent regions 15, which are graduated to permit of the ready determination of the height of the flame which obtains in the combustion zone 8. The ring 6 is eteriorly threaded as at 16 for engagement with similar threads formed in an annular securing plate 17 which is adapted to be secured to the detector base 18 of the lamp. Arising -from the plate 17 are spaced vertical rods 19 which have their upper ends connected with a ring 2O arranged above the cylinder 14. The upper end of the cylinder 14 engages with a flanged annulus 21 formed on the lower end of a substantially conical foraminated flame arrester 22, which is formed from iinev wire mesh' and consists of inner and outer members, the construction thereof being such th-at explosions', which occur in thev zone 8 Wilfl not transmit flame to the atmosphere surrounding. the lamp. rlhe upper portion of the annulu's 21 is' provided with a spring 23 which engages with the under side of the ring 20 and provides' for the resilient clamping of the upper portion of the glass cylinder whereby to avoid breakage thereof and yet to maintain the cylinder iirmly on its gasketed base provided by the annulu'sV `13.

Surrounding the conical iiame arrester 22 is a corrugated and perforated casing 24, which protects the flame arrestcrs from injury. Above the casingv 24 is a top plate 25,-. which is secured in place by means of'tie-rodsA 26 extending upwardly from the ring 20, heat dissipating outlets being provided between the upper portions of the casing 24 and plate 25. The center or the plate 25 is provided with a swiveled eye 27 to which is pivotally connected as at 28 a hand-le member 29 by which the lamp may be conveniently carried from place toy place.

the exception of the plate 17', the4 construction so farr described, has been in considerable use heretofore as a gas detecting lamp for us'ef underground mines and other similar locations. Its use, however, in underground sewers, mains', conduits, manholes and the like, of the type found in connection with the properties of public utility companies engaged in distributing gas andL electricity in urban districts, has not been successful, due to the fact that such underground locations of the character last mentioned often contain complex gaseous atmospheres composed of so many or such widely different gases that the name determinations 'of the Wolf lamp .are without meaning, especially in so far as the natural hydrocarbon gas content of such atmospheres is concerned and it is this natural gas content which must be evaluated in determining whether a given atmosphere may be entered with safety.

Therefore, in adapting. the Wolf lamp to this peculiar service and the practical conditions which exist therein, 1 provide in conjunction th'erevrlth the vdetector base 18. rIhis base Ais made up oi three separable sections consisting ofy Likewise the top section 32 is secured to the upper portion of the iilter section 3l by means of a plurality of screws 34 having their headed ends disposed upwardly. Preferably, th.. ined gaskets 35 are disposed between the planer meeting surfaces of the sections 30, 31 32. The upper portion of the top section S2 is provided with laterally directed enlargements 35 in which are pivoted upstanding'screws 3'?, the latter being received within opposed recesses formed in connection with hook like extensions 38 formed with and projecting laterally from the plate 17. The upper ends of the screws c7 receive knurled hand operated nuts 39 by which the Wolf lamp may be securely clamped in connection with the upper portion of the detector base.

In order to control the admission ol gases into the detector, the lter section 31 is provided with a threaded nipple 4G to which is attached one end oi a suitable iength of iiexibie tubing, as indicated at 4l, usually about thirty feet in length. Adjacent to-the nipple, the tubing is provided with a hand operated bulb 42 provided with'suitable check valves (not shown) by which gases may be aspirated into the detector lamp.

rI'he nipple 40 communicates with an L-shaped passage 43, formed in the section 31. The bottom of thepassage 43 terminates inthe center of a laterally directed horizontally disposed passage 44, and the ends of this latter passage communicate with a pair oi vertical passages 45 and 45 formed in the section 31. The upper end of the passage 46 terminates in a socket 47 in which is threaded a bushing 48 provided with a threaded valve stem 49, the bushing surrounding saidV stern being fluid-tight by the provision of a packing nut 50 which engages with. a suitable compr-essibler packing surrounding the stem 49. The outer endof said stem is equipped with an operatingknob 51. The inner end oi the` stem engages With a horizontal port 52 which terminates in a downwardly extending passage 53 communicating with agroove 54 formed in the upper part of the base section 3D. The opposite end of the groove 54' terminates in registration with a vertical socket 55, formed in the section 3l, in whichfispositioned a cartridge 56 provided with removable forarni'nated end caps 57, which cartridges are adapted to receive a suitabley chemical reagent used in the selective treatment and abisorption of conduit or main atmospheres. Usually, Ythecartridge 56 contains calcium chloride or other equivalent deliquescent materials.

After the gases aspirated into the detector pass through the valve 49 and the calcium chloride contained in the cartridgev, the calcium chlollt) ride serving tofremove entrained liquids or water vapor, the gases are V.conducted from top ci the` socket 55 by way ofi `a port 58, formed in the bottom of the top section 32 to a second oartridge 59identical in construction to the cartridge 56 but containing, between the foraminated ends thereof vsoda lime, and from the cartridge, the gases, following reaction with the soda linie, are conducted by way oi a passage 6G, formed in the top surface oi the plate 3c, to third and fourth cartridges 61 and 62 containing activated charcoal, `c-r the equivalent thereof, such as fullers earth or other chemical reagents havingthe ability to selectively remove extraneous compofunds from a mixture gases containing natural hydrocarbon but permitting the latter toi through. unaffected, Xcept for removal Aof Yimpurities therefrom'. Following the passage of the gases through all four of the cartridges-the said gases travel through a passageirs way 63 in which is located a hand operatedvalve 64 corresponding in construction and operation to the Valve 49, and when the valve 64 is open, the purified gase-s pass through a vertically vextending port 65 in which is located a fire screen 66. The gases after traveling through the screen 66 elevate a valve 67 against pressure of a spring 68, permitting said gases to flow under the pressure imparted by the bulb 42 past the valve 67 and thence through a plurality of small oriiices 69 into the chambered area of the top section 32, the gases then passing through the port '7. of the ring 6 into the combustion zone ofA the lamp proper. If desired, the valves 49 and 64 may be closed and a valve 70, corresponding in construction to the valves 49 and 64 opened whereby to allow the direct passage of an vatmosphere undergo-ing testing to the base of the lamp, thereby shunting the cartridges in which the chemical reagents are contained. Normally, however, in theuse of the detector, the valve 70 remains closed, thereby stopping gas flow through its associated passage 71 and compe-lling the atmosphere undergoing testing to pass serially throughsaid cartridges. It is of course within the range of the invention to employ any suitable number of cartridges and to use various chemical reagents, depending upon conditions and the particular gases to be analyzed and for sake of description, it maybe saidthat the detector contains one or more of the sockets or chambers in which chemical reage-nts are positioned.

' If natural or illuminating gas is present in a given atmosphere, the result of the addition of the gas to the combustion zone usually tends to elongate or extinguish the flame of the Wolf lamp, and this elongation or variation in ame propagation from normal may be noted by cornparison of the name determinations with the graduated surfaces appearing Aon the chimney cylinder 14. Combustible compounds present in the atmosphere undergo-ing testing, other than hydrocarbon gas used for illuminating or heating purposes, are absorbed by the chemicals .in said cartridges, but as previously stated, these chemicals do not aiect the hydrocarbon gas.

In the testing of certain types of underground chambers, vthe hose line is not employed but in lieu thereof a plug 72, as shown in Fig. 7, is placed into an opening leading into the chamber. This plug is of tapered hollow form and is provided with a reduced upper end '73, which by the removal of a closure cap 74, may be positioned in the lower end ofV a vertical passage '75 leading directly into the chambered area of the top section 32, the passage '75 being provided with a rey screen 76.

In the operation of the detector, thewick 3 of thelamp is adjusted to produce a flamefheirght equivalent to the graduation .5 .appearing onthe graduated chimney surface, following which, the operator may aspirate an atmosphere sample directly into the ydetector chamber opening. the

valvel and allowing the valves 49 and `64` to remain closed. Approximately 5 bulbs full, (250 cubic. centimeters) of an atmosphere under testV should be sufficient to give rimmediate results. Should an elongation occur, or should the ame be extinguished, accompanied by Van elongationA orv av smothering effect, the next operation tov close the valve 'lo and open the valves 49 and 64, repeating the test at the same level, and if the flame is elongated or extinguished with the valves in this latter position, the operator is informe-d that the sample under test contains naturalvgas.'

If no lelongation occurs or if the flame is not. extinguished with the valve 70 closed, a sample is aspirated with valves 49 and 64 open, the sample" under.` test should be considered free from natural gas, and the next series of tests should be made at'various depths by lowering the inlet endof the flexible tubing 41 to different levels in,` for instance, the manhole or sewer.

'l If .tests made at the top of sewers, conduits, etc., as well as at the various depths, show no combustibles or leffects thereof when samples are discharged into the detector, it is not necessary touse the absorbers, thereby prolonging the life of the several reagents, and using the absorbers only when indications of combustibles are evident as arresult of the initial tests. Y When the detector is to be used for testing so-called bar holes, curb boxes, etc., valves 49, 64and 70 are closed, and the closure 74 removed from the bottom of the detector, permitting the upper enld ofthe plug 72 to be connected with the passage'l for the purpose of conducting a sample to the detector. This is a direct connection to the detector chamber andldoes not result in the passage of the lsamples through the absorbers. If, at any time, doubt as to contents so secured is entertained, samples may be aspirated through the absorbers by connecting the sampling line to the reduced end 73 of the plug 72. The aspiration of samples of various contents of sewers, conduits, etc. through the. herein dev scribed detector effectively removes the following gaseous chemical compounds from samples tested giving direct results and percentages of natural gas contained in the sample:-

Acetic acid, acetaldehyde, acetone, acrolein, alcohol (ethyl and wood), aldehydes, amylacetate (banana oil), aniline, benzine, benzyl chloride, benzyl bromide, bromine, butyl alcohol, butyl acetate, camphor, carbon bisulphide, carbon dioxide, carbon tetrachloride, chloracetone, chloracetophenone, chloracetyl chloride, chlorine, chloroform, chlo'ropierin, collodion, creosote, cyanogen chloride, dimethyl sulphate, esters, ether, ethyl acetate, ethyl chloride, ethyl gasoline, ethylene dichloride, ethylene, fluorine, formaldehyde, furfural, hexane, hydrogen bromide, hydrogen chloride, hydrogen cyanide, hydrogen sulphide, japan, kerosene, lacquer, naphtha, natural gasoline, nitric acid, nitric oxide, nitrobenzene, nitrogen peroxide, pentane, phenol, phosgene, phosphorous pentachloride, phosphorus trichloride, propane,xsilicon tetrachloride, sulphur chloride, sulphur dichloride, sulphur dioxide, sulphuric acid, sulphur trioxi-de, straight run gasoline, tar, thiophosgene, tin tetrachloride, titanium tetrachloride, toluidine, toluene, turpentine. 1

In View of the foregoing, it will be seenthat apparatus is provided in which the objects of the invention and other advantages are obtained. In the detector, readings are direct and results obtained are immediate in terms of percentages of natural gas, mixed gas, coke oven gas and blast furnace gaspresent in 'all samples tested; The calibration of the scale on the chimney 14 is preferably in tenths of inches, permitting readings to be made to the nearest hundredth of an inch.- This scale is etched on the front and rear ofthe chimney toY avoid parallax. 'Ihe detector eliminates the necessity of taking and analyzing gas samples with remotely disposed apparatus and also the necessity of lowering the detector into sewers, conduits, etc., rwhich is an added safety factor and a time saver. The aspiration of vsam- CII ples permits the latter to be taken from any desired depth, eliminating the possibility of errors in reporting existing conditions due to stratified atmospheres of manholes, sewers and the like. The aspiration of samples permits the detector to be used when openings are too small to allow a detector to be introduced directly into the suspected area, as samples may be aspirated into the detector or the detector set immediately over the suspected area. All of the passages of the detector are protected by means of thirty-two mesh wire gauge preventing flash-back of flame should an exposion occur in the detector chamber, which would never permit flame propagation into the sampling line. These safety features permit this detector to be used Where gaseous samples may contain high percentages of hydrogen. Among other advantages, the detector provides for simplicity in construction, convenience in main-l tenance and use and also low initial cost.

The following table sets forth the results of tests made in connection with various types of gases and/or fluids encountered in sewer and conduit atmospheres:

Samples aspirated Samples aspirated directly absglgrs 20 bulbs Reagents into detector chamber (approx. 1000 cc.)

lame elongated .1; 20

Carbonv tetrachloride.

No elect.

No eiect.

No effect.

No elect.

No effect.

Benzine Straight run gasoline.

Wood alcohol Toluene Ethylene dichloride- N atural gasoline No eil'ect.

No effect.

No effect.

No elect.

No effect.

No effect.

bulbs (approx. 1000 cc). Flame elongated .l; 40 bulbs (approx. 2000 ce). Flame elongated .5 and remains at this height and smoking.

The following table discloses observed actions of gaseous mixtures following passage through the absorbers of the detector:

Atmospheres deficient in oxygen Observed llame action:

1.. Flame recedes from tip to wick, 2. `Flame smothered out slowly at mixtures of approximately 16 per cent oxygen. Note: Results the same when aspirated directly into detector.

Small percentages of natural gas and air-Deftczent in oxygen Observed flame action:

l l. Slight elongation of flame.

2. Yellow tip of flame disappeared accompanied by a recession of the blue inner cone and yellow outer cone 'from tip to wick.

3. Flame lifted off wick.

Note: Results the same when aspirated directly into detector.

` Small percentages of natural gas and air Observed name action:

l. Flame elongated up to a point where the l mixtures became explosive, then the name was snapped out accompanied by a swirl or a wavering back and forth before being extinguished. Note: Results the same when aspirated directly into detector.

Atmospheres deficient in oxygen and carbon dioxide pressure Small percentage of natural gas, atmosphere deficient in oxygen and carbon dioxide present Observed ilame action:

1. Slight elongation. 2. Yellow tip of flame disappeared accompanied. by a recession of the blue inner'cone and yellow outer cone from tip to wick.

3. Flame lifted off wick.

Note: Results the same as samples containing a; small percentage of natural gas and atmos; pheres deficient in oxygen, due to CO2 being removed by soda lime.

4. When sample is aspirated directly into detector chamber, (not thru the absorbers) the lifting off elect is more pronounced and more rapid.

AtmasplteresY deficient in oxygen-carbon monoxide, carbon dioxide and natural gas present Observed flame action:

1. Slight elongation7 or no elongation (dependent upon proportions of various gases in the mixture) 2. Yellow tip of fiame disappeared accompanied by a recession of the blue inner cone and yellow outer cone from tip to wick.

3. Flame lifted off wick.

4. When sample is aspirated directly into detector chamber (not thru absorbers) the lifting ofl eect is more pronounced and more rapid.

Note: Results the same as samples containing a small percentage of natural gas and atmosphere decient in oxygen, due to CO2 being removed by soda lime, and the carbon monoxide being present in small percentages does not change results of fiame action.

When the flame of the detector is elongated and is not extinguished, a plotted curve may be pro,- vided with each detector for the purpose of determining the approximate percentage of natural or mixed gas present in any sample aspirated through the absorbers.

Where the flame of the detector is elongated and extinguished, accompanied by a, swirl, or the name is snapped out, and the sample has been aspirated through the absorbers, the sample is above six per cent. gas when working in natural, coke oven, blast furnace or mixed gases.

Also, in gases Where the name of the detector is slightly elongated, and the inner and outer cone of the name recedes slowly from the tip to the wick, accompanied by a lifting-off eiect of the blue inner cone and a disappearing eiiect of the yellow outer cone, the sample under test contains natural or mixed gas.

What is claimed is:

1. Apparatus for detecting the presence of eX- plosive hydrocarbon gases in underground sewers, conduits and the like, comprising a lamp structure including a fuel fount, a wick, a graduated name measuring chimney and a screened outlet for said chimney, in combination with a base receptacle detachably connected with the fount of said lamp and provided with a chamber in which said fount is positioned, said chamber being in communication with the combustion Zone of the lamp, said receptacle being provided With a gas inlet having a pair of branched passages leading to said chamber, one of said passages being provided with a multiplicity of serially connected compartments adapted for the reception of chemical reagents capable of selectively extracting from the gases passing through the apparatus undesired gaseous compounds, and manually operated valve means for governing selectively the travel of gases through said passages.

2. The structure as specied in claim 1 in combination with a flexible aspirating hose line connected at one end with said inlet and adapted to have its other end positioned in an atmosphere to be tested.

3. Apparatus for detecting the presence of combustible matter in a gaseous iiuid comprising a safety lamp provided with a screened combustion Zone having means for burning fuel therein with a controlled visible flame, a base receptacle in which the lower portion of said lampris detachably connected, the upper portion oi said receptacle being provided with a chamber communicating with the combustion zone of the lamp, an atmospheric inlet formed with said base receptacle, a duct leading from said inlet directly to the chamber of said base receptacle, a valve for controlling gas ow through said duct, a second duct leading from said inlet to said chamber, a plurality of serially related chemical containers disposed in said second-named duct for selectively absorbing a constituent gas from fluids passed through said second-named duct, and valve means for regulating the passage of gases through

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