US2641923A - Gas gravitometer - Google Patents

Description

Jlm'e 1s, 1953 s. w. BlNCKLEY 2,641,923

. GAS GRAVITOMETER Filed June 18, 1951 3 Sheets-Sheet 41 June 16, 1953 s. wQBlNcKLEY 2,641,923

GAS GRAVITOMETER Filed June 18, 1951 3 Sheets-Sheet 2 S. W. BINCKLEY GAS GRAVITOMETER June 16, 1953 Filed June 18, 1951 3 Sheets-Sheet 5 Z0 Bnveutor,

Patented June 16, 1953 UNITED] STA-[5 P 2 Claims.

The present invention constitutes an improvement upon that type of gas gravitometer clescribed in United States lLetters Patent No. 2,106,966 issued to George S; Binckley on February 1, 1938.

An object of the present invention is to provide a gas gravitorneter of great accuracy, and which in its operation is substantially free from errors due to temperature variations, which corrects for humidity and gives a true specilic gravity of the gas sample. Y

A further object is the provision of a gasgravitorneter adaptable to various ranges of specic gravity.

The present gas gravitometer utilizes two columnsy of equal height, one of which has a continuously iowing sample of the gas passed therethrough, while the other column contains dry air, the diierence of weight between the dry air and the gas in these two columns being measured and recorded in terms of specic gravity. With reference to the foregoing, ordinarly the weight of the gas sample is expressed as a percentage of the weight of the atmosphere as it exists at the time, which includes water vapors which may be present in the atmosphere, Since air containing moisture has less density than dry air at the same barometric pressure, variations in atmospheric humidity above or below that existing at the time the gravitometer is calibrated, will introduce errors in recorded gravity .of the gas samples. The construction and arrangement of the present invention overcomes this error.

Furthermore it has been determined that the effective height of the gas column whoseweight is to be determined may be slightly increased or decreased during operation or" a gas gravitometer, thus introducing an error. k present invention provides means whereby such an error in the determination of gravity is eiectively eliminated. y

A further object of the invention is to provide in a single gas gravitometer means whereby the gas gravitometer may be quickly adapted for use with gases lighter than air, or with gases which have a specific gravity of 2%, times or more than that of air. Y

Other objects of the invention consist in a gas gravitometer which is superior to gas gravitometers now known to the inventor, accurate in operation, easily installed and calibrated and substantially fool-proof in operation.

In the drawing: A Figurey l is a front elevation, partly in fragment and in section, showing the gravitorneter of the invention;

Accordingly, the

. Figure 2 is a side elevation, partly in fragment and in section, of the gravitometer shown in Figure 1 and looking in the direction of the arrow 2 of Figure 1;

Figure 3 is a fragmentary, partially sectional, elevation of the gas and air columns used in the practice of the present invention;

Figure 4 is a perspective view of a weight member utilized when periodic change of the specific gravity range of the invention is desirable;

Figure 5 is a sectional view on the line 5-5 of Figure 4 n Figure 6 is a schematic ilow ,diagram of the gas gravitometer; and

Figure 7 is a front elevation of the gas gravitometer within its case.

Referring now with particularity to the drawings, reference is made to Figure 6. In said figure I have provided two bells, to wit, a Working bell i and a balance bell 2, both of which bells are of identical construction and size and preferably of the sameweight, each bell having a curved or cylindrical side wall 3 and a conical top A, the bell being open at the bottom. y Each bell is adapted to be in part received within sepa- Y rate tanks 5 and E. Each tank has a circular side wall which spacedly surrounds its respective bell and the two tanks communicate at l, to provide a fluid passageway. It is intended that both tanks should be lled to a lcertain level with a liquid, such as a white oil.

Both bells are suspended from a beam 8 and the beam `8 by means of linkage 9 is adapted to actuate a pen arm l0 for movement over a graduated chart at i l, which chart is rotated by ka clock indicated at l2.

A pair of vertical columns are provided at I3 and Ill, the columns being of equal height. The column l3,"ir`1 addition to the vertical portion, has a lateral portion l5 and a further vertical portion at i6, which is central of the tank with its open end positioned above the level of the sealingY liquid IlA in said tank. The column i4 is similarly arranged in that it has a lateral at .I8 and a ,short vertical portion I9 connecting with the lateral, the open end of said vertical portion I9 being above the level of the liquid Il within said tank and bell. The gas sample whose gravity is to be determined is passed through a tubing 20, the said tubing carrying a drop tube 2| extending below the level of a liquid, such as oil 23, contained in bottle 22, so that the rate of flow of gas through orifice plug 28 is constantthat is, fluctuations in pressure of gas in tube 20 result in increase or decrease in rate of dow through tube 2l, but do not affect the rate of 3 gas fiow in tube 28 after the gas has passed the junction of tubes and 2l. Outlet tube 24 functions as a vent to cariy away gas from bottle 22. The tube 23 is bent at an angle to provide a vertical portion 25 and said portion 25 is passed centrally within the portion I6, with the outlet from said tube communicating with the space included between a pair of diffuser plates 25 and 2. An orice plug is included Within the pipe portion 25 at 28. As the specific gravity of the gas is determined with reference to dry air, in other words, the difference in weight between dry air and the gas, I provide a tubing 23, which has two vertical portions as shown at 38 and 3l, with an inter-connecting pipe at 32, the

portion 3Q being passed centrally of the portion I9 and communicating between the two diffuser plates 33 and 34. The length 3I of the tubing 29 is in direct communication with the case 35, at one end thereof, the case having an intake tube at 36. This case is adapted to hold a material such as a silica gel for the purpose of removing moisture from the air passed through said case and into the tube 29 for reception between the diffuser plates 33 and 34.

The brief rsum of the working elements of the invention has been set forth and it is evident that the owing gas sample passing through the tubing 29 has its pressure regulated by the bottle 22 and that the gas is continuously received within the working bell I above the level of the liquid I'I and that the air is dried prior to said air being received within the balance bell 2 above the surface of the liquid Il. The weight of the gas in bell I and in gas column I3 is balanced against the weight of dry air in bell 2 and dry air in column I4.

Reference will now be made to Figures l, 2 and 3, which specifically show the structure of the invention. It will be noted that I have provided a base 39 upon which the various elements of the invention may be mounted. For instance, the tank members 5 and 6 are provided with depending feet 48, which may be secured by means of bolts or screws 4I to the base. Furthermore, the columns I3 and I4 may be anchored to the base, or secured within sleeve fittings, as shown in Figures 2 and 3, at 42. As the device should stand vertically, with the base horizontal, for best operating characteristics, I may provide a bubble type level, not shown. In addition, levelling screws 43 are passed through the base so that -accurate adjustment of the base and the instruments carried thereon may be obtained. These features are mere refinements and do not constitute a part of the invention.

It will be noted that the tubing 20 for conducting the gas sample to the working bell and thence to the column I3 has a slightly different arrangement from the schematic showing in Figure 6, in that the pressure regulating bottle 22 is held suspended infront of the tanks 5 and 6, the tubing 20 being provided with fittings carried by the cover 44 of said regulating bottle. Also the tubing 20 communicates with a fitting leading to a pipe here designated as 20-a, which pipe has a fitting connecting with a pipe 20-b, which pipe enters an enlargement 45 external the base of the tank 5. The portion I5 for the column I3 likewise has connection with said enlargement 45. Thus in place of the portion I5 being passed through the side wall of the tank 5 as shown schematically in Figure 6, in actual Apractice this portion is below the base of said tank as shown in Figures l and 2. The enlargement 45 carries portions I6 and 25, which portions are central of the tank and extend upwardly therein for communication with the interior of the working bell. The enlargement 45 carries a drain plug 46 which permits drainage of that portion numbered I6, which communicates with the column I3. A like construction is provided for tank 6, wherein the base has an enlargement 41, which communicates with the column I4, which enlargement carries a drain plug 48, with the pipe 32 communicating with the interior of the enlargement and extending centrally of the portion I9 which communicates with part I8. Included within the portion 3! of pipe 29 is a valve49 and the valve in turn is secured to the case 35. This case is cylindrical in form and provided with a screw cap 53. A tube 36 extends from the cap and within the case is placed some air drying medium such as silica gel, as indicated at 5 I.

The beam 8 carries adjacent its ends bearing spools 52 and 53 and links 54 and 55 at one end are provided with knife edges for contact with said spools, the opposite end of each link being received within the slot of a stud carried at the apex of each bell, as shown at 56. A screw 51 is passed through each stud and a link so that each link will suspend a bell when the links are engaging the spools 52 and 53 of the beam. The beam is centrally secured at 58 to a cross head 59 (see Figure 2) the cross head being supported by a pair of fixed fulcrum links 60 and 5I which links depend from portions 62 and 63 of a bracket 64, which bracket is provided with a collar 65 surrounding a portion of the column I3 and held thereto by means of set screws 66. Connection between the fixed links 60 and 6I with the beam 59 is by means of knife edges so that the beam may tip during movement of the bells I and 2.

The cross beam 59 is provided with a cylindrical portion at 61 anda clamp ring 38 surrounds this portion. Depending from the ring is a pendulum rod 69, and diametrically positioned therefrom is a rod I0 carrying -a weight 1I. Secured to the pendulum rod is a thermostatic coil 'I2 adapted to raise or lower the position of a pendulum weight 13. The construction of the elements just referred to is shown in full in the Binckley P-atent No. 2,106,966, heretofore referred to.

A collar 'I4 is carried by the column I3, which collar has a lug I5 to which is pivotally secured member 16, the outer end of which member isA bifurcated or slotted so as to receive the pendulum arm and hold the same against movement in what is termed the zero stop position.

The bracket 64 is formed to carry at its forward end the clock I2 and a chart plate 11, the actual chart II being secured to the chart plate by means of a nut 'I8 carried on a hub which is rotated by the clock shaft.

A'collar 'I9 is secured to column I3 and carries a bracket 80, Posts 8| and 82 extend from one side of this bracket. VPosts 8| and 82 both carry adjustable pivot screws 83, with a shaft 84 held therebetween. A lever 85 is secured to shaft 84, the said lever provided with an adjustable weight 86. One end of the link 9 is secured to the lever 85 While the opposite end of said link has a fitting which is pivotally secured to the beam 8 adjacent one end thereof. The pen arm I9 is provided wlth a fitting 81, see Figure 1, which is secured to the shaft 84. The arrangement is such that the pen arm may be swung relative to the fitting from the plane of the chart II. As is usual, the outermost iencl of the pen arm .carries a pen Ill-a. The shaft 84 carries an adjustable balancing weight, designatedr generally as "8.8;

As a device of this character must be carefully calibrated, other balancing weights are provided. F'or instancathe beam 8 carries an adjustable weight 89, actuated by Aa Vernier 90, which aids inbalancingthe beam and its associated parts, such as the working bell, the balance bell, together withlinkage, tol a zero position. yOther weights shown at 9| and 92 are adjustable upon a rod 93 secured to the clamp ring 68. As this clamp ringis associated with the pendulum, it is essential that the pendulum be properly balanced to a zero position. As an aid in this balancing, adjustable weights 94 and 95 are mounted on `a rod `96 extending from the cross head beam 59.

A feature of the present invention resides in the arrangement of the columns vI3 and I4. The

lower ends of the columns I3 and I4 are ntted within members such as shown at 42 in Figure 2 for the gas column and a like member for the .air column, and preferably the gas and air columns are welded to said base ttings. A clamp is secured to both columns, the clamp being held by set screws IDI. The clamp is provided with a lug |02 which has a transverse bore to permit passage therethrough of an elongated screw-threaded rod |03. Lock nuts IIM4 and |05 are carried on the screw threadsY ofA the rod |03 and on each side of the lug. Thelsaid screw-threaded rod carries an adjustable pointer |35 adapted to play over a barometric scale IIi'I secured by clamps |08 and |09 to the column I3. The upper end of said screw-threaded rod |03 is secured to a stud III), which stud extends outwardly from a cap I carried on the c-olumns I3 and I4. This cap is so formed as to provide two annular flanges |I2and |I3. Sleeves |I4 and ||5 surround the upper portions of the respective columns I3 and I4, with the lower ends of said sleeves tted within the flanges I I2 and ||3. The upper end of sleeve I|4 is ins 4ternally screw threaded at IIB and a tubular gas cap ||1 is threaded thereto. A spacer ||8 is provided between the lower end of said cap and the upper end of the sleeve H4. Also to limit the threading between said cap and the vsaid sleeve, the said cap is provided with an internal ring H9. The upper end of the gas cap has an annular top |20. n

The` sleeve |I5 is externally screw threaded for engagement with. the threads of what is termed a lowerV air cap I2I. This cap is threaded to the lower end of an air column casing |22. The lower air cap |2| is provided` with a screen |23, and the top `of said air column casing |22 is provided with a screen |24 and a reduced opening |25. The air column casing houses a material |26 adapted to prevent entry of moist air into the column, which material may be silica gel.

Weights of the character shown in Figure'li may be utilized in the invention to increase the specific gravity range of the instrument. The weights constitute in each instance a disk |21 formed with a central bore |28 and a counter bore |29. The disk is provided with an annular flange |30 and with a radial slot I3I. The

arrangement is such that a weight may be pon sitioned on a stud 5S as shown in Figure 1,-the links 54 and 55 being passed through the radial slot |3I, with the top of the stud tting within the counter bore |29. A radial bore is provided column to dr'y the ambient air.

. vention just described are as follows:

In the adjustable type gas and air columns, air driers are provided for the air column .and for air which enters the tubing 29 to be received within the balance bell. The adjustable air and gas columns have certain advantages over a .column that is not adjustable.. Particularly the adjustment permits compensation for barometric pressure changes. It is evident that the instrument of this invention may be used in different localities and barometric pressure change becomes very important.

The balance bell is used for balancing the weight of the working bell and both 'bells are immersed within the sealing liquid I1, the sealing liquid surrounding both bells and likewise being received within the same as illustrated in Figure 6. Hence surface tension and buoyancy of the sealing liquid is not a factor.

In the type of instrument shown, two columns are used, one column for the flowing gas sample whose speciiic gravity is to be determined with relation to dry air, and a second column having means both'at the entrance and exit for said Movement of the two columns is simultaneousas both columns are of the same length and such movement is indicated on the barometric scale |01, movement occurring when the nuts |04, |05 are loosened on the threaded rod |03 to raise or lower both said columns and to lock them in a specific position. Obviously, the columns are adjustable in height to compensate for barometric pressure changes. As shown, the columns extend within the sleeves IIII and IIE for a con- "siderable distance so that the columns have quite -a range of movement. The present two column arrangement with adjustability for height of both columns simultaneously provides a means which allows the columns to be moved easily and without'the necessity of changing iixed lengthl columns.

To change-the range ofthe gravitometer for different specific gravities, the weights shown in Figure 4 may be utilized to raise or lower the speciiic gravity range of the instrument. Thus, assuming that both columns have been iixed as to height, the weight shown in Figure 4 may be placed over the stud of the working bell. Thus, with a range of weights, the instrument may be made to record from zero to .5 or by `changing the weights from .5 to 1.0; 1.0 to 1.5;

1.5 to 2.0 to 2.5.

yThe Vernier type weight provided for the beam 0 at 89 and 90 is important, in that air balance or zero setting is made by adjusting the position of said weight, to the end that the beam is in equilibrium with the pen which plays'over the chart at point 1.0.

We will not attempt here, in the statement of operation, to go into calibration ofthe instrument, although it is evident that the same may be calibrated quite easily by adjusting the weights connected with the various parts which include, of course, the pendulum and its thermostatically controlled weight.

In operation this instrument utilizes, as before stated, the difference in weight between a column of gas and a column of dry air of equal height. The entire interior of the gas column and the working bell I is filledl with gas while the dry air column and the balance bell are lled with dry air. These tWo columns are of exact height and the bells are of exact diameters. Therefore, the difference in weight of the two volumes is a major force acting on the Working bell and tending to raise or depress it, as the gas is heavier or lighter than dry air. This force is resisted bythe Weight of the pendulum which moves and allows the pen mechanism to move in direct ratio to the specic gravity of the gas sample. The rate of flow through the gravitometer is approximately 2 cubic feet per hour. Thus, the gas Within the instrument, theoretically, is completely changed about 19 times every hour, or about once every 3 minutes. Thus the time `lag is short and complete purging is rapid.

In order thatno error be introduced by temperature variations, the pendulum Weight is mounted on an arm which in turn is attached to one end of the thermostatic coil, at I2 and 73. This coil and assembly is so calibrated that the center of gravity of the `weight is raised or lowered in direct proportion to the change in the air-gas diierential, due to a given temperature variation. VEven under extreme conditions of temperature change, the record made by this instrument is that due to the working force acting on the head of the Working bell, which would exist if the temperature were constant at 60 Fahrenheit. The pendulum weight alone, and not the entire assembly of its supporting elements, resists forces acting on the working bell. The working bell and the balance bell, of course, are placed at equal distances from the fulcrum of the beam from which they are suspended. The balance bell functions to balance the weights of the working bell and also functions to compensate the eiect of the buoyant force and surfaceV tension of the sealing liquid Il. As the bells 'are of the same diameter, the surface tension of the liquid may vary to any extent Without having any elect whatsoever upon the calibration. narily extreme changes in humidity would have a definite bearing on the recorded gravity on the chart. However, the present invention in utilizing a double column With dry air is not affected in any manner by changes in Ordii humidity and the record as recorded on the chart is the true specific gravity of the gas corrected for temperature and humidity.

I claim:

1. A gravitometer, including a tank holding a sealing liquid, a working bell and a balance bell immersed in part in said sealing liquid to provide an enclosed space in each bell, a balance beam supporting said bells, means for directing a flowing gas sample within the venclosed space of the working bell, means for directing dry air into the enclosed space of the balance bell, a pair of elongated columns the tops of which are above the level'of the sealing liquid, one of which communicates with the enclosed space within the Working bell and the other of which communicates with the enclosed space Within the balance bell, and compensating means comprising means for simultaneously varying the length of each column.

2. A gravitometer including a tank provided with a sealing liquid, a balance bell and a working bell immersed in part Within the said sealing liquid to provide an enclosed space above said liquid in said working bell and in said balance bell, means for directing air Within the balance bell into the enclosed space and means for preventing the entrance of moist air within the balance bell, means for directing a gas sample Within the enclosed space of the working bell, a pair of columns, 'the tops of which are above the level of the sealing liquid, one columnV of which communicates with the enclosed space in the working bell and the other column of which communicates with the enclosed space in the balance bell, and means in the column communicating with the balance bell for preventing the entrance of moist air within said column.

SYDNEY WILLIAM BINCKLEY.

References Cited in the le of this patent UNITED STATES PATENTS France Nov. 9, 1921 Australia June 15, 1934:

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