US2633411A - Portable apparatus for analyzing gases - Google Patents

Description

March 31, 1953 J. J. FE'RRAINOLO 2,633,411

PORTABLE APPARATUS FOR ANALYZING GASES Filed Dec. 30,1950 2.$l-1EE'I'SSl-IEET '1 March 31, 1953 J. J. FERRAINOLO PORTABLE APPARATUS FOR ANALYZING GASES 2 SHEETS-SHEET -2 Filed Dec. 30, 1950 attorney Patented Mar. 31, 1953 UNITED STATES PATENT OFFICE PORTABLE APPARATUS FOR ANALYZING GASES Joseph J. 'Ferrainolo, Pittsburgh, Pa. Application December 30, 1'950,Serial No. 203,665

11 Claims.

This invention relates to gas analyzers, and particularly to a portable type of analyzer of simplified construction and operation which is extremely accurate, permits spot analysis, eliminates manifold, does away with the use'of measuring burettes and interconnected absorption bulbs.

There have been many types of apparatus and many methods proposed for the rapid analysis of gases, particularly mine gases where it is important that the composition of thegases in the mine atmosphere be constantly checked to avoid the formation "of dangerous explosive mixture or the failure of the oxygen supply or its replacement by deadly and noxious gases. Typical of the standard apparatus used is the Orsat analyzer in which a measured amount of gas is drawn into a calibrated burette and then passed successively through absorbing solutions for removing each constituent separately. After passing through any one of the absorbing solutions the remaining gas is returned to the burette and measured before being passed to the next absorbing solution. It is at once -apparent that such an apparatus and method requires considerable time in order to make the various passes in the successive absorbing solutions and the necessary measurements after each. The Orsat type of apparatus has been modified in various ways in order to make it portable and to simplify its operation. Such a modification is that shown in the patent to Bailey, Number 2,448,206, issued August 31, 1948. However, these modifications have not done away with the need for a calibrated burette and the successive passes through the absorbing solutions and succeeding returns to the burette for measurement. Moreover, the Orsat type of apparatus by reason of its design requires the use of many stop cocks, which must be greased often to work smoothly.

According to this invention there is provided an apparatus and method of gas analysis by means of which these undesirable characteristics of the present day gas analyzers are avoided. According to the apparatus of this invention the need for a carefully calibrated burette is avoided, the multiplicity of absorbing passes in various solutions and return to the burette for reading are avoided. In addition the need for line cocks is avoided and thereby the concomitant troubles arising therefrom.

The apparatus of the invention comprises genorally at least one measuring compartment, a corresponding absorbing compartment for each measuring compartment connected thereto by a one way valve, said absorbing compartment be- .2 ing open at the top thereof, a separate leveling means connected to the bottom of each absorbing compartment, means in said absorbing compartment for reacting and removing known componentsof the -gas,a piston in each measuring compartment forcing a gas collected in the measuring compartment through the-one way valve into the corresponding absorbing compartment, a similar piston in the'open end of the absorbing compartment retaining the residue-gas in the absorbing compartment, an exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis can be removed, a compensator piston and chamber'of the same size as the measuring compartment, said chamber being closed at the bottom and open at the top, whereby the effects of changes of barometric pressure and temperature can be compensated for, and measuring means adjacent each of theabsorbing chamber and the compensator chamber whereby changes in volume can be measured.

In a preferred form of apparatus there is provided three measuring chambers and three absorbing chambers for determining CH4, CO2, and O2 in the gas being "analyzed. The measuring chamber and absorbing chamber are preferably in a single glass cylinder divided intermediate its ends to form two cylindrical chambers closed at one end.

The operation and. construction of the structure of this invention will be more clearly and easily understood by referring to the drawings in which:

Figure 1 is a'front elevation with the front of the cylinders cut away showing the apparatus of this invention.

Figure 2 is a side elevation of the apparatus of Figure 1.

Figure 3 is an enlarged front elevation of the absorbing chamber piston and measuring means.

Figure 4 is a section on the line 4-4 of Figure 3.

Figure 5 is an enlarged side elevation of the absorbing chamber piston and measuring means.

Figure 6 is an enlarged front elevation of the leveling bottle and bulb used in the preferred form of apparatus.

Figure '7 is an enlarged elevation of a piston as used in the measuring, the absorbing and the compensating chambers.

Figure 8 is an enlarged elevation of the one way valve of this invention.

Figure 9 is a section through the exhaustmember showing it in open position.

Figure is a section through the exhaust member showing it in closed position.

Referring to Figure 1 there is illustrated a portable gas analyzer having a frame I 0 upon which are fixed supporting legs H and a carrying handle 12. Mounted on the frame are three cylinders l3, l4, and I5, each one divided into two compartments by a division wall l6 intermediate their ends. These chambers are a measuring chamber '39., Ma, and a. of fixed volume at the bottom and an absorbing chamber i311, Mb, and 85b at the top. A one way valve I1 is provided in the wall It to carry the gas from the measuring chamber to the corresponding absorbing chamber. The valve i! is provided with a screen covering [8, preferably of platinum for breaking up the gas into myriads of small bubbles which pass through the absorbing liquid in the absorbing chamber. A spiral glass baffle .l 9is provided in all absorbing chambers in which combustion does not take place. These are for the purpose of causing the gas bubbles to be in contact with the absorbing liquid for a longer period of time to promote better absorption. A resistance wire or heating element is provided .in the chamber where combustion is to take place; this wire is energized by a battery 2| mounted on the back of the frame it through a switch 22 mounted on the frame It. A piston 23 is provided in each of the measuring chambers to force the gas from that chamber to the absorbing chamber. A second piston 28, made in such form as to reduce its weight, is provided in the open end of the absorbing chamber. Each .of the upper pistons 24 is provided with a knurled handle for ease of handling when operating the device. Each of the absorbing chambers is pro- ;vided with an exhaust outlet made up of a glass side arm 25 fixed to the chamber, a short sec .tion of flexible tube 26 which is adapted to be pinched together by a clamp 21 and a terminal section of glass tubing 28; preferably bent upward at an angle from the line of the side arm 25. A second side arm '29 is provided at the bottom of each absorbing member. To this side arm, which also serves as a bubble trap, due to the downward bend of the outlet to the reservoir, is attached a flexible tube 30 which terminates in a reservoir or leveling bottle 3|. The leveling ,bottle is held to the frame by a clamp 32 from which it may be loosened to raise and lower it. A stopper 33 fitted with a glass tube 34 and a flexible tube 35' and rubber expansion bag 38 is provided in the open end of the leveling bottle 3 I.

At the side of each absorbing chamber there is provided a micrometer measuring scale 31. The bottom nib 38 is used as the base level from which computations are made, and the moving nib 39 (see Figure 4) is adjusted to the upper limit of the gas in the absorbing chamber, both nibs are provided with a fork-like element or marker, as shown.

A compensator 40 is provided to correct for changes in barometric pressure and temperature. The compensator consists of a chamber 4| having the same dimensions as the measuring chamber of the cylnders l3, l4, and I5 and fitted with a piston 24 identical with the upper pistons 24 in the absorbing chamber of cylinder 13. A micrometer scale 31 is provided on the compensator chamber 41 as on the absorbing chamber, the lower nib 38 of the micrometer being set at the level of the bottom of the interior of the com- 'pensator chamber 4 I.

In using the apparatus, it is taken to the spot from which an analysis is desired, the pistons 23 are removed from the measuring chambers I35, its, and l5a. These chambers fill up with the gases from the surrounding atmosphere and the pistons 23 are reinserted trapping a fixed volume of gas in the chambers. The pistons are forced into the measuring chamber thereby forcing the gases through the one Way valves H into the absorbing chamber where they bubble through the solutions maintained therein. In the case of CO2 gas an alkaline solution such as potassium hydroxide is used in the absorbing chamber and in the case of 02 gas a solution of potassium pyrogallate is used. These are well known and recognized absorbents for such gases. When CO2 and O2 bubble through the absorbing solutions they are absorbed and the gas which reaches the top of the solution is free of the gas being absorbed. The gas which reaches the top of the solution forces the pistons 24 at the top of the absorbing chamber to rise. The amount of movement of this piston determines the amount of the gas which has been absorbed in the solution. In the case of either CO2 or 02 the leveling bulb 3! is moved to bring the solution level to the level of the lower nib marker 38 of the micrometer scale. The upper nib marker 33 of the micrometer is next moved to the bottom of the piston 24 and the distance between the nib markers gives the amount of gas unreacted or unabsorbed.

At the time the measuring chambers are filled. the compensator chamber il may also be filled by removing the piston 24 and replacing it. When the micrometer reading of the absorbing chamber is taken, a like reading of the compensator chamber is taken. This reading corrects for any changes in the barometric pressure or temperature since it is of fixed volume. The reading from the absorption chamber is subtracted from the compensator chamber reading to give the amount of gas absorbed. The result is then divided by the total compensator reading and multiplied by hundred. In the case of CO2 this gives the percentage of CO2 in the gas. In the case of 02 the percent of CO2 must be subtracted from the final result since alkaline pyrogallate absorbs both 02 and CO2.

Where an analysis of the methane (CH4) content of the gas is desired, the gas is forced above the solution in absorbing chamber l5b as in the case-of CO2 and Oz. The solution level is lowered by means of the leveling bottle until the burning wire or ignitor 2%! is exposed. The current is turned on and the wire becomes hot causing the methane to burn. The solution is raised and lowered below the wire several times in order to assure complete combustion. The current is turned on and the reading made as in the case of CO2 and C2. The resulting percentage must be divided by two to get the percent of methane. This is because two volumes of gas are destroyed for each volume of methane according to the following reaction:

CH4+2O2=CO2+2H2O (gas) (gas) (gas) (liquid) When the analysis is completed the absorbing chambers are cleared of remaining gases by first lowering the level of the liquid below the exhaust outlet by lowering the reservoir, after which the clamp 21 is opened thereby permitting the gas to escape from the side arm or exhaust outlet 25, flexible tube 26 and elbow 28. Any gas between the level of the liquid and the bottom of the piston is forced through the exhaust outlet 25 by manually pressing the piston 24 downwardly.

The simplicity and ease of operation of the apparatus of this invention is believed to be readily apparent and the many advantages to be gained by its use need not be outlined here. It should be noted, however, that by using this apparatus it is possible to analyze gases rapidly at the point where they are taken without elaborate equipment and loss of time.

It will be understood that the apparatus of this invention may take different forms depending upon the conditions under which it is to be used within the terms of the following claims.

I claim:

"1. A portable apparatus for analyzing gases comprising at least one measuring compartment, a corresponding absorbing compartment for each measuring compartment, said measuring compartment-and absorbing compartment being=connected by a one way valve, said absorbing compartment being open at the top thereof, a separate leveling means connected to the bottom of each absorbing compartment, said absorbing compartment being adapted to contain aselective liquid absorbent removing known components of a gas, a piston in each measuring compartment forcing a gas collected in the measuring compartment through the one way valve into the corresponding absorbing compartment, a second piston in the open end of the absorbing compartment retaining the residue gas in the absorbing compartment, an exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis can be removed, a compensator piston and chamber of the same size as the measuring compartment, said chamber being closed at the bottom and open at the top whereby the effects of barometric pressure and temperature can be compensated for, and measuring means adjacent each of the absorbing chamber and the compensator chamber whereby changes in volume can be measured.

2. A portable apparatus for analyzing gases comprising at least one r neasuring compartment, a corresponding absorbing compartment for each measuring compartment, said measuring compartment and absorbing compartment being connected by a one way valve, a screen mesh covering the discharge end of said valve whereby the gases passing therethrough are broken up into smaller bubbles, said absorbing chamber being open at the top thereof and fitted with a movable piston, said measuring compartment being open at the end opposite its connection with the absorbing compartment and fitted with a movable piston, a separate leveling means connected to the bottom of each absorbing compartment, said absorbing compartment being adapted to contain a selective liquid absorbent removing known components of a gas, an exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis can be removed, a compensator piston and chamber having the same size as the measuring compartment, said chamber being closed at the bottom and open at the top whereby the efiects of barometric pressure and temperature can be evaluated, and measuring means adjacent each of the absorbing chamber and the compensator chamber whereby changes in volume can be measured.

3. A portable apparatus for analyzing gases comprising a frame, at least one cylindrical tube Cit open at both ends mounted on saidframe in a vertical position, a wall intermediate the ends of said tube containing a "one way valve, said wall and tube defining a lower measuring com-- partment and an upper "absorbing compartment, leveling means connected to the absorbing compartment adjacent the wall, said absorbing compartment being adapted to contain a selective liquid absorbent removing known components of a gas therein, a piston in each measuring com partment forcing a gascollected therein through the one way valve into the absorbing compart ment, a piston slidable in the 'open end "of the absorbing compartment retaining the gas which enters the absorbing compartment, exhaust means intermediate the ends of the absorbin compartment through which the gas remaining at the end of an analysis can be removed, a compensator piston and chamber of the same size as the 'measuringcompartment, said chamber being closed at the bottom and open at the top whereby the efiects of barometric pressure and temperature can be compensated for, and measuring means adjacent each of the absorbing compartment and the compensator chamber whereby changes in volume can be measured.

4. A portable apparatus for analyzing gases as claimed in claim 3 in which the measuring means include a hired base point adjacent to and intermediate the ends of the absorbing compartment, a movable index member slidable vertically along the absorbing compartment above the base point and micrometer screw means attached to the inde'ii member for moving it -'along the wail of the absorbing compartment.

5. A portable apparatus for analyzing gases as claimed in claim 3 in which the one way valve is provided with a screen mesh covering the outlet end thereof whereby the gasses passing through the valve are broken up into a large number of small bubbles. v

6. A portable apparatus for analyzing gases comprising a frame, a plurality of cylindrical tubes open at both ends thereof mounted vertically on the frame at spaced apart positions, a wall intermediate the ends of each of said tubes containing a one way valve, said wall and tube defining a lower measuring compartment and an upper absorbing compartment, leveling means connected to the absorbing compartment adjacent the wall, a manually operable piston in each measuring compartment forcing a gas collected therein through the one way valve into the absorbing compartment, 3, piston slidable in the open end of the absorbing compartment retaining the gas which enters the absorbing compartment, exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis may be removed, electrical ignition means in one absorbing compartment of said plurality of tubes, connections from the ignition means to a source of electrical energy for actuating the ignition means, the remaining absorbing compartments of said plurality of tubes being adapted -to contain a selective liquid absorbent removing known components of gas therein, a compensator piston of the same size as the piston in each absorbing compartment, a compensator chamber of the same size as the measuring compartment receiving said compensator piston, said-chamber being closed at the bottom and open'at the topwhereb'y the effects of barometric pressure and temperature can be compensated for, and measuring means adjacent each of the absorbing compartment and the compensator chamber whereby changes in volume can be measured. 7. A portable apparatus for analyzing gases as claimed in claim 6 in which the absorbing chambers other than that one provided with the ignition means are provided with a glass vertical spiral extending from a point above the intermediate wall but below the exhaust means. 8. A portable apparatus for analyzing gases comprising at least one measuring compartment, a corresponding absorbin compartment for each measuring compartment, said measuring compartment and absorbing compartment being con nected by a one way valve, 2, screen mesh covering the discharge end of said valve whereby the gases passingv therethrough are broken up into smaller bubbles, said absorbing chamber being open at the top thereof and fitted with a movable piston, said measuring compartment being open at the end opposite its connection with the absorbing compartment and fitted with a movable piston, a separate leveling means connected to the bottom of each absorbing compartment, said leveling means includin a downwardly bent side arm at the bottom of the absorbing compartment adapted to serve as a bubble trap, a flexible tube connected to said side arm, and a reservoir bottle connected to the flexible tube, said reservoir bottle adapted to maintain the liquid at the surrounding atmospheric pressure, said absorbing compartment being adapted to contain a selective liquid absorbent removing known components of a gas, an exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis can be removed, a oom pensator piston and chamber having the same size as the measuring compartment, said chamber being closed at the bottom and open at the top whereby the effects of barometric pressure and temperature can be evaluated, and measurin means adjacent each of the absorbing chamber and the compensator chamber whereby changes in volume can be measured.

9. A portable apparatus for analyzing ases comprising a frame, at least one cylindrical tube open at both ends mounted on said frame in a vertical position, a wall intermediate the ends of said tube containing a one way valve, said wall and tube defining a lower measuring compartment and an upper absorbing compartment, leveling means connected to the absorbing compartment adjacent the wall, said leveling means including a downwardly bent side arm at the bottom of the absorbing compartment adapted to serve as a bubble trap, a flexible tube connected to said side arm and a reservoir bottle connected to the flexible tube, :said reservoir bottle adapted to maintain the liquid at the surrounding atmospheric pressure, said absorbing compartment being adapted to contain a selective liquid absorbent removing known components of a gas therein, a piston in each measuring compartment forcing a gas collected therein through the one way valve into the absorbing compartment, a piston slidable in the open end of the absorbing compartment retaining the gas which enters the absorbing compartment, exhaust means intermediate the end of the absorbing compartment through which the gas remaining at the end of an analysis can be removed, a compensator piston and chamber of the same size as the measuring compartment,

said chamber being closed at the bottom and open at the top whereby the effect of barometric pressure and temperature can be compensated for, and measuring means adjacent each of the absorbing compartment and the compensator chamber whereby changes in volume can be measured.

10. In portable apparatus for analyzing gases a measuring and absorbing device comprising a measuring compartment, a corresponding absorbing compartment, said measuring compartment and absorbing compartment being connected by a one way valve, a screen mesh covering the discharge end of said valve whereby the gases passing therethrough are broken up into smaller bubbles, said absorbing chamber being open at the top thereof and fitted with a movable piston, said measuring compartment being open at the end opposite its connection with the absorbing compartment and fitted with a movable piston, leveling means connected to the bottom of the absorbin compartment, said absorbing compartment being adapted to contain a selective liquid absorbent removing known components of a gas and exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis can be removed. 11. In portable apparatus for analyzing gases a measuring and absorbing device comprising a measuring compartment, a corresponding absorb.. ing compartment, said measuring compartment and absorbing compartment bein connected by a one way valve, a screen mesh covering the discharge end of said valve whereby the gases passing therethrough are broken up into smaller bubbles, said absorbing chamber being open at the top thereof and fitted with a movable piston, said measuring compartment being open at its end opposite its connection with the absorbing compartment and fitted with a movable piston, leveling means connected to the bottom of the absorbing compartment, said leveling means including a downwardly bent side arm at the bottom of the absorbing compartment adapted to serve as a bubble trap, a flexible tube connected to said side arm, and a reservoir bottle connected to the flexible tube, said reservoir bottle adapted to maintain the liquid at the surrounding atmospheric pressure, said absorbing compartment being adapted to contain a selective liquid absorbent removing known components of a gas and exhaust means intermediate the ends of the absorbing compartment through which the gas remaining at the end of an analysis can be removed.

JOSEPH J. FERRAINOLO.

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

UNITED STATES PATENTS 489,117 Great Britain July 10, 1938

Claims (1)

10. IN PORTABLE APPARATUS FOR ANALYZING GASES A MEASURING AND ABSORBING DEVICE COMPRISING A MEASURING COMPARTMENT, A CORRESPONDING ABSORBING COMPARTMENT, SAID MEASURING COMPARTMENT AND ABSORBING COMPARTMENT BEING CONNECTED BY A ONE WAY VALVE, A SCREEN MESH COVERING THE DISCHARGE END OF SAID VALVE WHEREBY THE GASES PASSING THERETHROUGH ARE BROKEN UP INTO SMALLER BUBBLES, SAID ABSORBING CHAMBER BEING OPEN AT THE TOP THEREOF AND FITTED WITH A MOVABLE PISTON, SAID MEASURING COMPARTMENT BEING OPEN AT THE END OPPOSITE ITS CONNECTION WITH THE ABSORBING COMPARTMENT AND FITTED WITH A MOVABLE PISTON, LEVELING MEANS CONNECTED TO THE BOTTOM OF THE ABSORBING COMPARTMENT, SAID ABSORBING COMPARTMENT BEING ADAPTED TO CONTAIN A SELECTIVE LIQUID ABSORBENT REMOVING KNOWN COMPONENTS OF A GAS AND EXHAUST MEANS INTERMEDIATE THE ENDS OF THE ABSORBING COMPARTMENT THROUGH WHICH THE GAS REMAINING AT THE END OF AN ANALYSIS CAN BE REMOVED.

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