US2058896A - Apparatus for exploring atmospheres for respiration and explosion hazards - Google Patents

Description

- Oct. 27, 1936. Q U N 2,058,896

APPARATUS FOR EXPLORING' ATMOSPHERES FOR RESPIRATION AND EXPLOSION HAZARDS Filed Alig. 26, 1952 2.Sheets-Sheet 1 Z7 4 mil '9 l m iw 5 I Q L INVENTOR.

UMrZeazYZzUzw .0cx.;21, 1936. c. A. LUNN 2,058,896

APPARATUS FOR EXPLORING ATMOSPHERES FOR RESPIRATION AND EXPLOSION HAZARDS Filed Aug. 26, 1932 2 Sheets-Sheet 2 IN VEN TOR.

BY M .--/ATTORNEY.

Patented Oct. 27, 1936 UNITED STATES APPARATUS FOR EXPLORING ATMOS- PHERES FOR RESPIRATION AND EXPLO- SION HAZARDS Charles A. Lunn, New Caanan, Conn., assignor to Consolidated Edison Company of New York,

Inc., a corporation of New York Application August 26,

9 Claims.

This invention relates to apparatus for exploring atmospheres for respiration and explosion hazards, and is an improvement upon the invention disclosed in the Lunn, Tomkins and Nacovsky application Ser. No. 609,020 filed May 3,

The present improvements provide generally for greater facility and scope in the use of the apparatus disclosed in said application. 7

The present improvements provide for speeding the toxic gas indication, particularly in cold weather, thereby making the device more remje in the hands of the ordinary user. They provide improved means for indicating the n. ation of combustible gas or vapor when .sent above the lower explosive limit, and/or when the atmosphere contains insufficient oxygen to support complete combustion'of the combustible. Other features of improvement will be found set forth in the description which follows.

An embodiment of my present invention is illustrated in the accompanying drawings, .wherein Fig. l is a top plan view of said embodiment which includes the present improvements.

Fig. 2 is a rear elevation.

Fig. 3 is an end elevation.

Fig. 4 is a perspective view of the jacket seen in Figs. 1, 2 and 3.

Fig. 5 is an enlarged detail view, partly in section, of the pipes, etc., seen in Fig. 3.

Only sufficient description of the complete apparatus to understand the present improvements will be herein given, reference being made to said earlier application for a full description of said apparatus and its operation.

Referring to said drawings, numeral ll] designates a means for indicating the presence of a toxic gas, as carbon monoxide, I2 a means for indicating the presence of combustible gases or vapors and of the concentration thereof particularly with relation to the lower explosive limit thereof (inclusive of a toxic combustible gas if present), and M a means for indicating the presence of combustible gases and vapors, and also of deficiency in oxygen, the means l4 preferably comprising a burner for producing a flame. The means or element 14 may be used in conjunction with the element l2, for differentiating between a deficiency in oxygen, and the presence of combustible gases and vapors in concentrations above the lower explosive limit; and for determining whether sumcient oxygen is present in the atmosphere under test to effect 'com- 1932, Serial No. 630,507

plete combustion of its combustible gas or vapor content in element 12.

Numeral l6 designates a pump or aspirator which is preferably arranged so as to supply samples of an atmosphere to be explored or tested to the elements l0, l2 and I4. A sample of the atmosphere tested is an amount of the atmos-' phere to be tested sufficient to fill the chambers of the several elements in combination. The sample fractions may be distributed to said elements in any suitable manner. One mode of distribution is to supply the sample fractions to the elements serially, the elements being connected by serial ducts, as hereinafter more fully described.

The toxic gas indicator preferably comprises a closed chamber 20 having means 2| for giving a chemical indication of the presence of toxic gas in the sample of atmosphere being explored. For testing for carbon monoxide, the means 21 may be a piece of absorbent paper which has been dipped in a water solution of palladium chloride containing an anti-freeze, such as glycerine or ethylene glycol. The toxic gas indicator III for the elements It], I2 and 14 may comprise more than one chamber 20, or more than one means 2| in chamber 20, when, for example, it is desired to test for the presence of more than one toxic gas.

Samples of atmosphere may be admitted to chamber 20 of element ll] through a duct 21, a fraction of the sample remaining in the chamber 20. A cock 2!] is preferably connected with duct 21, and a sampling tube or hose may have one end connected to the nipple on duct 21, the free end of the hose being introduced into the space or various parts thereof containing the atmosphere to be explored. 33 designates a duct, leading from chamber 20 to element 12, through which, in the illustrated embodiment the sample fractions for elements 12 and I4 pass, which duct 33 is preferably controlled by a three-way cook 35.

The element I2 may be any electrical circuit suitable for measuring a change in the electrical resistance or electrical current in one of its parts, as for example a Wheatstone bridge type of circuit containing a resistance R with which the sample fraction of atmosphere is brought into contact. The resistance R is preferably a hot wire the electrical characteristics of which are changed by a heat change, i. e. by either a loss or gain of heat. In the embodiment chosen for illustration the atmospherein which combustible gas or vapor is present burns around the wire,

the heat of combustion augmenting the heat of the wire, thereby increasing the resistance of the wire, and thereby causing the galvanometer pointer to move to an extent proportional to the concentration of combustible gas in the sample fraction of atmosphere.

The Wheatstone bridge contains the four normally balanced resistances R R R R in the four legs of the circuit, current being supplied in suitable manner, as by a storage battery or by dry-cells S, the circuit being balanced by adjustment of rheostat T. G designates a galvanometer connected in the bridge wire of the circuit. The resistances R may be a platinum wire enclosed in a tube or chamber 36, into which a fraction or fractions of samples of atmosphere may be introduced by means of a tube or duct 31 which may be connected to the outlet duct 33 from chamber 20 as heretofore explained. The fraction or fractions of samples of atmosphere may pass out of tube 36 through a duct 38, which is preferably also connected to a nippled coupling on the receptacle 4|.

The electrical change produced by the burning of a combustible gas around the hot wire in element I2 is indicated and measured by a galvanometer G.

The galvanometer G is preferably equipped with a scale calibrated with reference to the lower explosive limit of mixtures of combustible gases and vapors with air which is undiluted except for the combustible gas therein. For example, the scale shown on G of element I2 may be calibrated in fractions of the lower explosive limit (the lower explosive limit being 10 on the scale illustrated) of mixtures of combustible gases and vapors with air. The position of 10 on the scale designates the least concentration of combustible gas or vapor in air which will explode if ignited.

The numbers below 10 indicate proportionally concentrations of combustible gas and/or vapor in terms of the quantity required to form a lower explosive limit mixture with air.

In the illustrated embodiment, the fraction of sample of atmosphere which is to be tested in element I4 is passed through element I2, passing from element I2 through the nipple 40, to the pump I6 from which it is forced into element I4 through the nipple 55.

The element I4 is preferably an indicator of the flame-type, and comprises a burner for producing a relatively steady flame, as a wick dipping into a combustible liquid contained in a font 41. The burner is contained in a chamber 49 into which sufficient air is normally admitted to maintain a steady flame. The hot gases leave element I4 through openings 18 in a shield 19.

The chamber 49 is preferably made transparent by forming its sides of glass-tubing 53.

The glass tube 53 may be provided with a datum line 8| or a hinged mirror 80 may be provided with 5. datum line etched or scratched thereon, serving as a reference line for adjusting the height of the flame from burner 45 and for assistance in interpreting the effects of the fraction or fractions of samples of atmosphere on the flame.

The pump or aspirator I6 as heretofore stated may be located between elements I2 and I4, being connected to nipples 40 and 55 by means of hose or tubing 85. The pump is conveniently a collapsible rubber bulb having an inwardly-opening valve on its intake side and an outwardly-opening valve on its discharge side.

Means are provided for supplying heat to the chamber 20 of element I0 to hasten, particularly in cold weather, the chemical reaction therein by which the presence of toxic gas is indicated. This heating-means preferably comprises a jacket I00 surrounding jointly the shield I9 of element I4 and the chamber 20, and heating the chamber 20 by the hot gas from the flame of burner 45 which issues through the slots 18 in shield 19. The jacket I00 may comprise two shells or halves IDI, I 02, hinged together, as indicated at I04, and held in closed position by a latch I06 or other suitable means. The shells IOI, I02 may have flanges I08 formed on the upper parts thereof which rest upon the upper parts of chamber 20 and shield 19. The heating means described makes use of the heat already available from the flame of burner 45 and minimizes the chance of a user making an incorrect report as to the presence of toxic gas.

The cock 35 of element I2 has a passage IIO leading directly to the atmosphere, which passage III] is closely controlled by a valve, as the needle-valve H2 illustrated. The three-way cock 35 in conjunction with ducts 33 and H0 may function, therefore, to admit to element I2 (1) a fraction of the sample of atmosphere being explored, without air dilution; (2) a fraction of the sample diluted with air; and (3) air alone.

A pipe II5 (Figs. 3 and 5) is preferably provided which leads from duct 21, at a point ahead of cock 29, (and hence ahead of chamber 20 of element I0) to duct 33 ahead of cock 35, (and hence beyond chamber 20 and ahead of the chamber 36 of element I2), which may serve as a by-pass around element I 0 and a cock I20 is provided in duct 33 for placing element i2 in communication with element I0, or around element I0 through the by-pass provided by pipe IE5. The element I2, provided with means for admitting air simultaneously with air containing combustible gas or vapor, such as tho threc-wa5- cock 35, described, is an improved element per se.

Normally needle-valve H2 is closed, cock 35 in the position to open duct 33 and close duct H0, cock 29 open, and cock I 20 in position to close pipe H5 and open duct 33 through chamber 20 of element I0.

After a fraction sample of the atmosphere to be explored has been supplied to the element I0, it may be trapped in chamber 20 by closing cook 29 and turning cock I20 to close duct 33 to chamber 20 and open it to pipe H5 (position shown in Fig. 5). This will permit tests of the atmosphere being explored to be continued in elements I2 and I4 on other like samples or samplefractions of the same atmosphere being explored While time is provided for insuring completion of the reaction on the sample-fraction in element I0.

As pointed out in said earlier application a position of the pointer of galvanometer G at I0 on the scale (1 on the scale in said earlier application) indicates that the concentration of combustible gas or vapor in the atmosphere being explored, is at the lower explosive limit.

As was also pointed out in said application, the indication of the pointer of galvanometer G may be erroneous, because of insuflicient oxygen in the atmosphere being explored to effect complete combustion of the combustible gas present.

To ascertain the nature and degree of the explosive hazard, and the completeness of the indication of element I2, the three-way cock 35 and valve II 2 are manipulated, and the pumping continued.

If the pointer of galvanometer G stands at or below H] on the scale and upon opening valve l I 2, with cock in the position shown in Fig. 5, and continuing the supply through duct 33 of samplefractions of the same atmosphere being tested (thereby diluting the sample with air) the pointer swings from a position at or below It to a higher part of the scale, this indicates that the atmosphere being explored contains insufficient oxygen to efiect complete combustion of the combustible gas in the atmosphere, that the original indication was erroneous, and that the combustible gas or vapor is present in a higher concentration than shown by the original indication of concentration. By graduating the opening through passage Hi! and continuing the testing on other sample-fractions of the same atmosphere being tested, an indication of the true concentration of combustible gas in the atmosphere being tested can be obtained.

If the flame of burner 35 in element l4 lengthens and extin-guishes, when a fraction sample of the atmosphere being. explored is pumped into chamber 59, this indicates that the atmosphere being tested contains gas or vapor in a concentration above the lower explosive limit.

If under a similar manipulation the flame of burner short-ens and extinguishes, this indicates a deficiency of oxygen in the atmosphere being tested.

To be reliable and comprehensive the indications of element i2 must be taken with the indications of element [4.

The invention may receive other embodiments than that herein specifically illustrated and described.

What is claimed is:-

1. Apparatus for exploring atmospheres for respiration and explosion hazards comprising a chamber for containing means chemically reactive to a toxic gas; a chamber and a burner therein for producing a flame, said chamber having a transparent portion through which said flame is visible and a portion through which the heated gases escape, means for pumping a fraction of a sample of atmosphere to be explored to each of said chambers, and means for heating said firstnamed chamber by the heated gases escaping from said chamber containing the burner.

2. Apparatus for exploring atmospheres for respiration and explosion hazards comprising a chamber for containing means chemically reactive to atoxic gas, a chamber and a burner therein for producing a flame, said chamber having a transparent portion through which said flame is visible and a portion through which the heated gases escape, means for pumping a fraction of a sample of atmosphere to be explored to each of said chambers, and a jacket around said first-named chamber and the portion of said other chamber through which the heated gases escape, said first-named chamber being thereby heated by the heated gases from the flame in said other chamber.

3. Apparatus for exploring atmospheres for respiration and explosion hazards comprising a chamber for containing means chemically reactive to a toxic gas; a chamber and a burner therein for producing a flame, said chamber having a transparent portion through which said flame is visible and a portion through which the heated gases escape, means for pumping a fraction of a sample of atmosphere to be explored to each of said chambers, and a jacket around said firstnamed chamber and the portion of said other chamber through which the heated gases escape,

said first-named chamber being thereby heated by the heated gases from the flame in said other chamber, said jacket comprising two hinged parts and means for retaining said hinged parts in closed position.

4. Apparatus for exploring atmospheres for respiration and explosion hazards, comprising a chamber and a wire therein the electrical conductivity of which is sensitive to temperature changes, means for pumping samples of an atmosphere to be explored to said chamber, means for producing combustion in said chamber of combustible gas in said sample, and indicating means responsive to changes of electrical conductivity of said wire, said indicating means comprising a pointer responsive to current-variations and a scale calibrated for positions of said pointer corresponding to the efiect thereon of combustion in said chamber of samples containing combustible gas in amounts at and below the lower explosive limit thereof in the presence of a normal supply of oxygen, an air-duct communicating with said chamber, and a valve for opening and closing said air-duct, whereby observations may be made with and without the simultaneous ad mission of air to said chamber, to thereby check the accuracy of the position of said pointer on said scale.

5. Apparatus for exploring atmospheres for respiration and explosion hazards, comprising a chamber and a wire therein the electrical conductivity of which is sensitive to temperature changes, means for pumping samples of an atmosphere to be explored to said chamber, means for producing combustion in said chamber of combustible gas in said sample, and indicating means responsive to changes of electrical conductivity of said wire, said indicating means comprising a, pointer responsive to current-variations and a. scale calibrated for positions of said pointer corresponding to the effect thereon of combustion in said chamber of samples containing combustible gas in amounts at and below the lower explosive limit thereof in the presence of a normal supply of oxygen, an air-duct communicating with said chamber, and a valve for opening and closing said air-duct, whereby observations may be made with and without the simultaneous admission of air to said chamber, to thereby check the accuracy of the position of said pointer on said scale, and a second valve for regulating the opening in said air-duct.

6. Apparatus for exploring atmospheres for respiration and explosion hazards, comprising a chamber and a wire therein the electrical conductivity of which is sensitive to temperature changes, means for pumping samples of an atmosphere to be explored to said chamber, means for producing combustion in said chamber of combustible gas in said sample, and indicating means responsive to changes of electrical conductivity of said wire, said indicating means comprising a pointer responsive to current-variations and a scale calibrated for positions of said pointer corresponding to the effect thereon of combustion in said chamber of samples containing combustible gas in amounts at and below the lower explosive limit thereof in the presence of a normal supply of oxygen, a duct leading to said chamber through which said samples of atmosphere are introduced, an air-duct leading to said firstnamed duct, and a three-way valve arranged to open said first-named duct and close said airduct, or to open both said ducts, whereby observations may be made with and without the simultaneous admission of air to said chamber to thereby check the accuracy of the position of said pointer on said scale.

7. Apparatus for exploring atmospheres for respiration and explosion hazards, comprising a chamber and-a wire therein the electrical conductivity of which is sensitive to temperature changes, means for pumping samples of an atmosphere to be explored to said chamber, means for producing combustion in said chamber of combustible gas in said sample, and indicating means responsive to changes of electrical conductivity of said wire, said indicating means comprising a pointer responsive to current variations and a scale calibrated for positions of said pointer corresponding to the effect thereon of combustion in said chamber of samples containing combustible gas in amounts at and below the lower explosive limit thereof in the presence of a normal supply of oxygen, a duct leading to said chamber through which said samples of atmosphere are introduced, an air-duct leading to said first-named duct, and a three-way valve arranged to open said firstnamed duct and close said air-duct, or to open both said ducts, whereby observations may be made with and without the simultaneous admission of air to said chamber to thereby check the accuracy of the position of said pointer on said scale, and a second valve for regulating the opening in said air-duct.

8. Apparatus for exploring atmospheres for respiration and explosion hazards, comprising a chamber for containing means chemically reactive to a toxic gas, means for heating said chamher; and a chamber and a wire therein the electrical conductivity of which is sensitive to temperature changes; a duct connecting said firstnamed chamber serially with said chamber containing said conducting wire, another duct from a point ahead of said first named chamber to a point beyond it and ahead of said chamber containing said wire, passing around said firstnamed duct, and means controlling the passage through said duct so that fractions of samples of atmosphere may pass from said first-named chamber to said chamber containing said wire, or to said chamber containing said wire through said duct which passes around said first-named chamber, and said chamber containing said wire thereby receive fractions of samples of atmosphere which have not been affected by the heat of said first-named chamber and also successive fractions for successive tests therein, and means for pumping fractions of samples of an atmosphere to be explored to each of said chambers.

9. Apparatus for exploring atmospheres for respiration and explosion hazards, comprising a chamber for containing means chemically reactive to a toxic gas, a, chamber and a burner therein for producing a flame, said chamber having a transparent portion through which said flame is visible and a portion through which the heated gases escape; and a chamber and a wire therein the electrical conductivity of which is sensitive to temperature changes, means for heating said first-named chamber by the heated gases escaping from said chamber containing the burner: a duct connecting said first-named chamber serially with said chamber containing said conducting wire, another duct passing around said firstnamed duct from a point ahead of said first named chamber to a point beyond it and ahead of said chamber containing said wire, and means controlling the passage through said duct so that fractions of samples of atmosphere may pass from said first-named chamber to said chamber containing said wire, or to said chamber containing said wire through said duct which passes around said first-named chamber, and said chamber containing said wire thereby receives fractions of samples of atmosphere which have not been affected by the heat of said first-named chamber, and also successive fractions for successive tests therein; and means for pumping fractions of samples of an atmosphere to be explored to each of said chambers.

CHARLES A. LUNN.

CERTIFICATE OF CORRECTION.

Patent n 2,058,896. I o October 27, 1936.

CHARLES A. LUNN.

It is hereby certified that error appears in the printed specification or the above numbered patent requiring correction as follows: Page 1, second column, line 25, strike out the words "'for the elements 10, 12 and 14" and insert the same after "atmosphere" in line 30; page 2, first column, line 45, before "sample" insert the; same page, second column, line 48, and page 3, first column, line 21-22, for "fraction sample" read sample fraction; page 4,

--first column, beginning with the word "from" in line 39, claim 8, strike out all to and including the word "duct" in line 43, same claim, and insert instead the words passing around said first-named duct from'a point ahead of" said first named chamber to a point beyond it and ahead of said chamber containing said wire; and second column, line 36, claim 9, for "receives" read receive; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

- Signed and sealed this 19th day of January, A. D. 1937.

"" enry Van Arsdale Acting Commissioner of Patents.

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