US2934958A

US2934958A - Gas sampling device

Info

Publication number: US2934958A
Application number: US389520A
Authority: US
Inventors: Gerben R Kingma
Original assignee: Hays Corp
Current assignee: Hays Corp
Priority date: 1953-11-02
Filing date: 1953-11-02
Publication date: 1960-05-03
Anticipated expiration: 1977-05-03

Description

May 3, 1960 G. R. KINGMA A 2,934,958

GAS SAMPLING DEVICE Filed Nov. 2. 1953 2 Sheets-Sheet l INVENTOK @EEBEN E! KO/VM/i G. R. KIN'GMA GAS SAMPLING DEVICE May 3, 1960 2 Sheets-Sheet 2 Filed Nov. 2. 1953 IN VHV TOR.

fix ww a Other objects will be apparent g fication.

GAS SAMPLING DEVICE Gel-hen R. Kingma, Seattle, Wash., assignor to The Hays Corporation, Michigan City, Ind., a corporation of Indiana Application November 2, 1953,'Serial No. 389,520

9 Claims. (CI. 73--421.5)

This invention relates to improvements in gas sampling devices. More particularly, it relates to a device by means of which a sample of gas existing in a furnace, kiln I or any other apparatus or space, may be withdrawn continuously for the purpose of analysis, measurement or testing. Gas analysis apparatus is used extensively in mdustry for the purpose of checking industrial processes, fuel economy, and similar purposesfi Such apparatus may be of the Orsat type or of thermal conductivity type or is, diflieulty is encountered with respect to the withdrawal of a specimen of the gas for purposes of test. The accuracy of the analyzer depends upon the sampling operation and the avoidance of extraneous materials in the system.

Extraneous material, such as foreign matter, dust and dirt, is frequently present in the furnace, kiln 2,934,958 Patented May 3, 1960 Fig. 5 is an axial sectional view of a part of the sampling device with a water cooling system.

Referring to the drawing which illustrates the preferred embodiment of the invention, the numeral 10 designates a wall of a furnace, kiln or other device, apps.- ratus or chamber contain-ing gas to be analyzed. This wall has an opening therein preferably lined by an access tube 12 adapted to be spanned and closed by a closure member 14 detachably secured in place by securing bolts or other securing means 16. As here shown, the closure plate 14 preferably mounts a tube 18 which is welded or otherwise secured thereto and which extends therethrough, said tube being open at both ends thereof.

An adapter tube 20 is mounted within the tube 18 and preferably has a snug fit therein. A conduit 22 is mounted in and extends through the adapter tube 20 with the inner end portion thereof projecting into the furnace or other space containing the gas to, be sampled, the interior surface of the wall 10 being that illustrated at the left in Fig. l.

The conduit 22 mounts a reducer 24 at its inner end, and a coupling tube 26 of larger diameter than the conduit 22 is carried by the reducer. An elongated tube 28 is secured to and projects from the end of the coupling 26. The tube 28 is of substantial length and at its inner end is sealed by a closure plate or plug 30 which preferably is welded in the tube 28. An aperture is formed in the tube 28 intermediate the length thereof, and the same mounts an inlet member 32 which is preferably po-. sitioned parallel to the main gas stream within the furnace or other enclosure. The inlet member 32 is of any type found suitable and preferably constitutes a tubular portion 34 projecting into the tube 28 and an enlarged or other equipment whose operation is being checked by the gas analyzer. Such foreign material may have a deleterious effect upon the analyzer by interfering with its proper operation and by subject-ing the same to clogging. Still another adverse effect upon an analyzer can result in cases where the gas is at high temperature when it passes through the analyzer. This may be particularly true in a thermal conductivity 'type of analyzer.

'tend to affect gas composition, before feeding the same to they gas analyzer. p

, A further object is to provide a device'of this character with novel means for entraining a gas sample in a liquid by an aspirator action and for separating the gas from the solids and liquid of the gas entrained liquid.

f A further object is to provide a device of this cha'racter with novel means for cool-ing'the gas sample.

. Another object is to provide a simple and inexpensive gas sampling device which is capable of operation under conditions of high temperature, corrosive atmospheres,

and in the presence of foreign matter, uniformly, accurately andsuccessfully, for long periods of time without ,danger of clogging or leakage.

from the following speci- In the drawings:

Fig. l is an assembly view illustrating the gas sam- ..pling device and the gas analyzer and the connections therebetween. v

, Fig.- 2 is an enlarged fragmentary detail view ,sh own in section.

..lE-i gf3 is another enlarged fragmentary detail view with iparts shown in section. V

Fig. 4 is an axial sectional view of 'a part of the sampling device.

with parts I head portion which bears against the surface plate 36, here illustrated as inset in a recess in the outer wall of the tube 28.

A tube 38 whose outer diameter is less than the inner diameter of the-tube 28 is positioned within the tube 28 'in coaxial parallel relation so as to provide an annular passage 40 therearound for the full length of the tube 38. The inner end portion of the inlet conduit fixture is preferably screw-threaded at 42v and is screw threaded in an aperture in the tube 38 so that the inlet member 32 provides means for positioning the tube 38 within the tube 28. The inner end 44 of the tubular part 34 of the inlet 32 is preferably of concave transverse curvature so as to terminate substantially flush with the inner surface of the tube 38 and thereby provide a streamlined bore within the tube 38. The tube 38 terminates spaced from the end wall 30 of the tube 28. A restriction 46 in the nature of a venturi-defining tubular part is positioned within the tube 38 between the inlet 32' and the end wall 30 of the tube 28. As here shown the bore 48 of the venturi member 46 preferably is of progressively decreasing diameter from each end toward the center thereof. A bushing ring 50 is mounted within the end of the tube 38 at the left of the inlet 32 as viewed in Fig. 4, that is, in the end opposite the 'end portion which mounts the venturi member 46. The screw-threaded shank portion 52 of a nozzle member is detachably mounted-in the tube 38 by means of the bushing 50. The tip portion 54 of the nozzle projects into the aspirator tube 38 in substantially centered relation thereto and adjacent to the inlet 32, so as to discharge a stream in the direction of the venturi 46. The nozzle has a reduced bore portion 56 which bore is enlarged at 58 and terminates in a screw-threaded portion Within which is connected the screw-threaded end portion 60 of a tube 62. The outer diameter of the tube 62 is less than the inner diameter'of the

parts

22, 24, 26 and 28 of the outer tube unit, and said tube 62 extends substantially axially through the parts of said outer tubular unit. v

Referring now to the structure illustrated in Figs. 1 and 3, 2. Compression fitting consisting of parts 70 and 72 is mounted on the outer end of conduit 22, the part 72 projecting beyond the end of tube 22 and having a bore 74 of a diameter greater than the outer diameter of the conduit 62. A T-fitting 76 is mounted upon the fitting part 72, and the conduit 62 extends through the cross-head of the T. A'fitting part '78 is secured to the outer cross-branch of the T-fitting 76, the same having an internally screwthreaded bore portion 80 of larger diameter than the conduit 62 for the major portion of its length and having a reduced bore portion 82 through the remainder of its length, the portion 82 being of a size to receive the conduit 62 snugly. A gasket ring 84 encircles the conduit 62 within the enlarged screw-threaded bore 80 of the fitting 78 and is pressed upon by the inner end of an exteriorly screw-threaded compression member 86 having an enlarged head 88 at its outer end projecting beyond the fitting 78 and preferably of polygonal cross-section to accommodate a tool. Thus the parts 7i-88 define a compression fitting providing a sealed fit on the conduit 62 for mounting the outer

tubular unit

76, 22, 28 on conduit 62. The inner end of the fitting forms a plug for sealing the cross-head of the T-fitting 76 opposite the end of that cross-head at which the fitting 70 is connected.

A filter member Q of any type found suitable is connected to the conduit 62 preferably spaced from the compression fitting 78-88, and the conduit 62 is connected thereto as by means of a compression fitting including the part 92. The part he of the filter member 90 preferably has connection with or accommodates a water supply conduit 96. The arrangement is such that Water from the conduit 96 will pass through the filter 90 and thence through the conduit 62 to the nozzle 54.

The T-fitting 76 has connection through a suitable fitting 100 and a reducer or other fitting 102 with a conduit 104 in the form shown in Fig. 3, although the connection between the fitting 76 and the conduit 104 may be a simple threaded connection as illustrated in Fig. 5. The conduit 164 has connection through suitable fittings 106 and; 108 with a branch or Y-fitting 110, as best illus trated in Fig.2. The

fittings

106 and 108 preferably constitute compression fittings which encircle the conduit 104 and permit the lower portion 112 of the conduit to extend into the body of the branch fitting 110 to at least the level of the branch arm 114 of that fitting, which branch arm is inclined angularly upwardly as seen inFig.

2. A conduit 116 is connected to the branch fitting 110 in substantially vertical alignment with the conduit 104 so that liquid discharged from the end portion 112 of that conduit will pass downwardly into and through the conduit 116. A liquid container or bubbler 118'is-inounted by means of a bracket 120 to a suitable support, which is here shown as a part of the wall 10. This support includes a closure plate 122 for the water container 118. The conduit 116 passes through an opening in the top closure 122 and terminates at a level spaced above the bottom wall 124 of the liquid container or trap 118.

Suitable coupling means 126 are connected to the upwmdly inclined branch arm 114 of the branch fitting 110 and provide means for the connection thereto of a conduit 128, which in turn is connected by means. of suitable connectors 130 and fitting 132 with the inlet 134 of .a

gas analyzer 136. The gas analyzer may be of any of "the well known types now on the market and preferably will. be of a type which is adapted for continuous operation.

The gas outlet 138 of the analyzer 136 is connected by means of fitting 140 and coupling members 142 with a discharge conduit 144, which in turn is connected by -.means of couplings 146 and fitting 148 with a tube 150 of the liquid container 118. A discharge conduit 152 has a sealed fit in an aperture in the bottom 124 of the liquid container 118, and the conduit 152 extends upwardly into the liquid container to a level spaced below the top closure 122 of the liquid container and spaced above the level of the lower ends of the

conduits

116 and 150.

Assuming that the device is "mounted on a gas container, such as a kiln, furnace or the like, in the manner illustrated in Fig. 1, with the tube 28 of the aspirator unit within the furnace so that the gas inlet 32 is located within the furnace and is located in a direction parallel to the stream of gas flowing within the furnace, and assuming further that the conduit 96 is connected to a source of water under pressure and that the conduit 104 is operatively connected to the gas analyzer 136 and the water container 118 as shown, the device is in condition for operation.

Water under pressure, and preferably a pressure of at least 20 pounds per square inch, is discharged into the device through the conduit 96, the same passing through the filter and thence through the conduit 62 for discharge at the nozzle 54 into the aspirator unit. The water discharged from the nozzle 54 passes the inner end of the gas inlet'32 and thence passes through the bore 48 of the venturi member 46. As water passes the inner end of the gas inlet 32, an aspirating action occurs, drawing gas through the inlet 32, 34 into the conduit 38 to be entrained in the water being discharged from the nozzle. The water from the nozzle passes through the venturi member and out through the end of the conduit 38, and thence reverses its direction ofrflow to pass through the annular chamber 40 in the return tube 28 and encircling the conduit 38. The water with gas entrained therein thence passes rearwardly around the conduit 62 to the T-fitting 76 where it is discharged into the conduit or drain 104. The water with entrained gas flows by gravity from the elevated end of the inner conduit 38 toward the conduit 104, it being apparent, as seen in Fig. 1, that the inclination of the

various conduits

22 and 28 produces such gravity flow, and, likewise, that the vertical positioning of the conduit 104 will cause the same to drain the tubular unit and conduit 22.

i The liquid with entrained gas is discharged into the branch fitting 110, and the liquid is then free to flow downwardly through the conduit 116 into the liquid container 118. The liquid container forms a liquid trap which resists the admission of some of the gas, and, consequently, a part of the entrained gas is separated from the liquid at the branch fitting 110. This gas is then free to pass through the branch 114 of the fitting into and through the gas feed conduit 128 and associated fittings and couplings for delivery to the gas analyzer 136. The gas which is passed through the analyzer .136, and which is discharged at the outlet 138, then passes through the gas outlet conduit 144 to the conduit for discharge into the liquid container 118. It will be observed that the lower end of the conduit 150 is positioned at a level substantially higher than the lower end of the conduit 116 and only slightly below the level 154 of theliquid in the container 118, so that resistance to discharge of gas from the conduit 150 is small compared to the resistance to the discharge of gas through the conduit 116. Gas bubbles through the liquid in the chamber 118 into the "space above the liquid level 154which is determined by the level of the open upper end of the conduit 152 and thence is discharged through the conduit152 along with the water which overflows from the container 118 incident to the continuous operation of the device. Note that the gas is cooled before being analyzed.

'It will be observed that any impurities, corrosive "ma- -terial or dust which is aspirated in the device is entrained in the'liquid stream and is carried by the liquid into the liquid container 118 and discharged therefrom at 1521f buoyant; otherwise such material is trapped in the liquid rosive material.

assists container 118, and the container 118 is so, constructed that it may be disassembled for cleaning purposes easily and quickly.

The fact that the gas passes in an upward direction from V the branch fitting 110 through the branch 114 to and through the conduit 128 in its passage to the gas analyzer 136 insures against passage of solid material or corrosive liquid material from the conduit to the gas analyzer 136. Consequently, the gas which reaches the analyzer is substantially free from dirt and corrosive material. This protects the analyzer against the detrimental action of dust and corrosive material, and also provides the advantage of avoiding errors of analysis and reading and indication or recording of analysis due to dust, dirt or cor- In other words, though the gas of the sample is taken froma location which is very dusty or dirty or corrosive, the analysis of that gas, wholly free from the corrosive and dirt conditions, is made possible by this device.

It will be noted that, in addition to protecting the analyzer 136 from the dust and dirt, the device further protects against discharge of dust, dirt and corrosive material into the atmosphere. Thus the liquid chamber 118 constitutes a liquid trap which serves the dual purpose of closing the system so as to prevent a direct discharge from the interior of the chamber 10 to atmosphere, and further provides protection from access of air to the interior of the analyzer 136. Thus no danger of errors of operation of the analyzer due to access of air thereto is permitted to exist. At the same time a continuous discharge of liquid is made possible so that the operation of sampling and the operation of the analyzer may continue indefinitely, assuming that the trap 118 is not permitted to clog by the accumulation of dirt therein.

may then be separated from the nozzle, and the nozzle may be disconnected from the tube 62. Thus all parts of the sample intake are made readily accessible for cleaning, and all parts of the unit are also readily replaceable if any thereof become damaged.

One of the requirements of the device is that a suflicient amount of water at a sufliciently high pressure be available to insure continuous flow of water through the device. The device operates very well when water is available at a pressure of approximately pounds per square inch and at a rate of flow of one gallon per minute. It will be understood that this flow rate and pressure of water supply are not critical and that the device may operate satisfactorily at rates and pressures either above or below the rates and pressure mentioned. 7

It is frequently necessary for devices of this character to operate in atmospheres subjected to high temperature, and a water cooling system may be provided for such installations of the character illustrated in Fig. 5. In the Fig. 5 construction a compression fitting is mounted upon and encircles the tube 22 adjacent the T-fitting 76. This compression fitting comprises a male part 160 and a female part 162 confining a gasket ring 164 therebetween which is adapted to be compressed by the fitting parts 22 and the parts are substantially concentric so as to provide an annular passage between them which connects with the T-fitting 168. The braush 172 of the T- fitting 168 communicates with an intake conduit-174, Systems of which water for cooling purposes be supplied to the passage between the tubes 1'70 and 22. A reducer 176 is threaded upon the tube 170, and a gasket ring 178 outer diameter of the conduit 170, and the tub parts are substantially concentric so as to define an annular passage between them. The inner diameter of the conduit 182 is preferably substantially equal to the outer diameter of the coupling tube 26 and encircles the same with a snug sealing fit. The tube is of a length to terminate spaced from the reducer 24. When the Fig. 5 water jacket construction is used; th adapter tubes 18, 20 carried by the base plate 14 are preferably of such a size as to receive the conduit 182 with a snug fit. The inlet and

outlet conduits

174 and 186 will preferably be positioned exteriorly of the mounting wall 10 and a part of the tube 182 will extend intotlie test chamber. Water which is supplied at the inlet conduit 174 extends around the tube 22 and passes lengthwise thereof in the space between the tube 22 and the tube 170 until it reaches the outer end of the tube 170. The threetion of flow of the water is then reversed and the water is caused to flow between the tube 170 and thetube 182 back to the branch fitting and the outlet conduit 186. By the use of this apparatus, the extent to which the aspirating water is subjected to the temperature of the heated chamber defined by the wall 10 is reduced to a minimum. As soon as the water passes from the tube 28 and the coupling tube 26 itno the tube 22, it is subjected to the cooling effect of the cooling water flowing from inlet 174 to outlet 186. The path of flow from the nozzle 54 to the tube 22 is comparatively short and, therefore, even though the operating temperature in a furnace may be quite high, the effect of that temperature is rapidly dissipated as far as its action upon the aspirating water is concerned, and no danger exists of the formation of steam and resulting highpressure which might tend to produce danger in the system or shorten the life of the system or apparatus. v

It will be noted that the aspirating water is nevenconimingled with the cooling water, the two flows having their individualand independent paths. 2

While the preferred embodiments of the invention have been illustrated herein, it will be'understood that changes in the construction may be made within the scope of the appended claims without departing from the spirit of the invention.

. I claim:

1. A gas sampling device, comprising a water supply conduit, a nozzle on said conduit, an aspirator tube mounted on said nozzle and projecting therefrom, a return tube encircling said aspirator tube, nozzle and conduit with clearance, means mounting said return tube on said conduit, a drain communicating with said return tube adjacent said mounting, the free end of said return tube projecting spaced from the end of said aspirator tube and being closed, and a tubular fitting mounted in said tubes adjacent the discharge end of said nozzle to admit gas into said aspirator tube.

2. A gas sampling device comprising an inclined outer tube having its upper end closed, a water supply conduit extending through the lower portion of the tube with clearance, sealing means at the lower end of said tube and encircling said conduit, outlet means communicating with the lower portion of said outer tube, a nozzle connected to said water supply conduit, an aspirator tube into which said nozzle discharges, said aspirator tube being mounted in said outer .tube with clearance and terminating spaced from" the closedend of said outer tube, and gas inlet means communicating with said aspirator tube.

3. A gas sampling device comprising an inclined outer tube closed at its upper end, an aspirator tube mounted in said outer tube with clearance and terminating spaced from the closed end of the outer tube, gas inlet means communicating with said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, the lower end of said aspirator tube being closed, and outlet means at the lower end of said outer tube.

41 A gas sampling device comprising an inclined outer tube closed at its upper end, an aspirator tube mounted insaid-outer tube with clearance and terminating spaced from the closed end of the outer tube, gas .inlet means communicating with said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, the lower end of said aspirator tube being closed, and outlet means at the lower end of said outer tube, said aspirator tube having a venturi restriction therein, said gas inlet means being located between said nozzle and venturi.

5. A gas sampling device comprising an inclined outer -tube closed at its upper end, an aspirator tube mounted in said outer tube with clearanceand terminating spaced tirom the closed end of the outer tube, gas inlet means communicatingwith said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, the lower end of said aspirator tube being closed, and outlet vmeans at the lower end of said outer tube, said gas inletmeans constituting an open ended tubular fitting passing through the walls of both tubes. 6 Ages sampling device comprising an outer tubular unit closed at one end, an aspirator tube mounted in said outer unit with clearance and terminating spaced from {the closed end of said outer unit, gas inlet means cm .municating with said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, said aspirator tube being closed adjacent to said nozzle, means connected to said tubular unit intermediate municating with said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, said aspirator tube being closed adjacent to said nozzle, means connected to said tubular unit intermediate its ends and spaced from said inlet means for mounting said unit in sample taking position, outlet means from 7 said tubular unit located at the end portion thereof opposite that at which said gas inlet means islocated, and a water jacket encircling a portion of said tubular unit.

8. A gas samplingdevice comprising an outer tubular unit closed at one end, an aspirator tube mounted in said outer unit with clearance and terminating spaced from the closed end of said outer unit, gas inlet means communicating with said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, said aspirator tube being closed adjacent to said nozzle, 'meansconnected to said tubular unit intermediate its ends and spaced from said inlet means for mounting said unit in sample taking position, outlet means from said tubular unit located at the end portion thereof opposite that at which said gas inlet means is located, and a water jacket encircling a portion of said tubular unit and including two annular passages communicating at one end thereof, water supply means connected to one passage and water outlet means communicating with the other passage.

9. A gas sampling device comprising an outer tubular unit closed at one end, an aspirator tube mounted in said outer unit'with clearance and terminating spaced from the closed end of said outer unit, gas inlet means coinmunicating with said aspirator tube, water inlet means communicating with said aspirator tube and including a nozzle, said aspirator tube being closed adjacent to said nozzle, means connecting said tubular unit intermediate its ends and spaced from said inlet means for mounting said unit in sample taking position, outlet means from said tubular unit located at the end portion thereof opposite that at which said gas inlet means is located, and a water jacket encircling a portion of said tubular unit and including two annular passages communicating at one end thereof, water supply means connected to one passage and water outlet means communicating with the other passage, said water supply and Water outlet means being located adjacent to said first outlet means and said annular passages extending longitudinally therefrom toward said gas inlet means.

References Cited inthe file of this patent UNITED STATES PATENTS McEvoy May 1, 1951