US1751715A - Thermal-conductivity gas-analysis apparatus - Google Patents

Description

J. C. PETERS; JR

March 25, 1930.

THERMAL oonnucnvny GAS ANALYSIS APPARATUS Original Filed Feb. 27,1926

I I I I 1 r,

/ Ai/A A I N VEN TOR 1 A TTORNEY.

Patented Mar. 25, 1930' UNI-TED. STATES PATEN -j OFFICE 31003 O. PETERS, JR, PHIIiADE'LPH IA, PENNSYLVANIA.-

-. mnnnmu-connnc'rrvrry.eas-ananysrsarrmrns Application and February 27, 1926, Serial No. 91,031. Renewed February 4, 1930.-

My invention relates to the art of gas testing or analysis and comprehends a gas analysis unit or structure omprising a chamber, cell or passage whose gas-contacting surface 5 is inactive with respect to gases corrosive In accordance with my invention, the surface of a chamber, as aforesaid, enclosing a body of gas and formed of a material. sub-' ject togaseous corrosion is prevented from contactingwith the gaseous contents of the chamber by an interposed shield inactive and not'subject to corrosion by said gaseous con-' tents.

Further in accordance with my invention, a

chamber or passage enclosing or through which circulate gaseous vapors is lined with a lmaterial, either metallic or non-metallic, in-

chamber, and more particularly, a chamber as aforesaid elongated, and preferably cylindrical, is lined with a supplementary member likewise elongated and preferably cylindrical.

to corrosion by the gaseous contents ofv the chamber. e

Further in accordancewith my a liner member, as aforesaid, of. suitable material as nickel, gold, platinum or glass, preferably theform'er, is suitably maintained in contactin relation with the interior surface of a cham er, and more particularly thcthermal conductivity between the members is maintained at a high value by the interposition of solder, varnish or the like.

My inventionrelates to apparatus or structure of thecharacter hereinafter described andclaimed. j

My present invention is an improvement from a structural viewpoint of the structure" illustrated in my prior Letters Patent N 0.

For an illustration of one of the various to be had to the accompanying drawing, in which:

I Fig. 1 isa vertical sectional view of a' gas analysis unit constructed in accordance with my invention.

with respectto the usual material forming 1 active withv respect to the gases within the of suitable material inactive and not subject 7 invention,

forms my invention may take, reference is Fig. 2 is a horizontal sectional view taken on the line 2-2, of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a perspective view of a liner tube for a gas chamber. 4

Referrin" to thedra-wing, A is a block of metal or otl ier suitable material, usually of a character that is corroded when brought into contacting engagement with some gases, said block having therein thecells or chambers B 00 and C. Or the cells B and C 'maybe in scparate blocks or members. Extending longitudinally of the cells B and O are the resistance-conductors Rand R respectively, of any suitable material havin substantial temperature co-eflicient. Pre erably the conductors R andjR are fine platinum wires, which may havediameters of the order of two mils. .At their upper ends they are soldered at a and b, respectively, to the wires 0 and d, respectiveliv, of gold or other suitable material exten ing through the insulating members e and f, forming gas-tight end closures for the cells B and C, respectively. At their lower ends the conductors R and R are sol'- dered at g and h, respectively, to the metallic springs 'i'and respectively, which are pref-' erably of gold or. othenmaterial vchemically neutral with respect to thegascs involved; The springs a and keep the conductors R and B taut, and are connected to the conductors m and n, of gold or other suitable material, sealed in the end closure members 0 and P, re-

spectively, for the cells B and C. The closure members 0 and 12 maybe of glass or other suitable insulating material, or the lower ends of the springs andj maybe connected to metal end closures of the cells B and C when the block is ofmetaLas indicated. It will be understood that either arrangement bridge or other suitable circuit arrangement,

forexample, as disclosed in my aforesaid Letters Patent No. 1,504,707.. At times, the, mo analysis or testing unit is usedwith gases which fcorrod; the materials usually emthe interior surface thereof, and material inployed in its construction. Ev en slight corrosion of the wall of the chamber B causes a change in the temperature, and therefore, in

the resistanceof wire R, since the amount of heat supplied to the wire is substantlally con accuracy of the observations.

Heretofore, in an attempt to ehmmate corrosion, the interior surface of a gas analysis chamber or cell subject to corrosion by a gas has beenelectroplatgd. Structures of this character yield uns ti factory results, particularly due to the fact that it is impossible or at least extremely diflicult to obtain an impervious surface. I

' In accordance with my' invention, in order to eliminate corrosion of the wall or walls of a gas analysis unit, as chamber B, I utilize a shield of suitable inactive material for preventing contact of the corroslve gases with said wall or walls, such shield being placed in position by any suitable manner other than by electroplating. By preference, I utilize a liner tube T whose outside diameter should substantially conform with the inside diameter of chamber B. Preferably, tube T,

adjacent each end, is provided with a hole.

It is also desirable that there be a good and.

definite thermal contact between liner tube T and the walls of chamber B. To this end,'I may utilize solder, varnish or the like between the exterior surface of said tube and the wall or walls of chamber B.

For the sake of brevity inthe appended claim, it shall be understood that the terms lining, lining member and liner tube do not comprehend a construction wherein the interior surface of a gas analysis unit, chamber, cell or the like of a material corroded by a gas is shielded from contact with the gaseous contents thereof by a coating de posited directly on said surface by an electroplating process.

lVhat I claim is: I Apparatus for testing or analyzing gases comprising an elongated tubular chamber, a resistance conductor disposed therein, a liner tube of material inactive with respect to the gaseous contents of said chamber forming to maintain high, definite,

terposed between said chamber-and liner tube thermal conductivity between them. 7 J ACOB C. 'PETERS,-JR.

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