US2029231A - Sampling device - Google Patents

Description

Patented Jan. 28, 1936 PATENT OFFICE SAMPLING DEVICE Augustus W. Gleason and Ernest L. Moyer, El Segundo, Calif.

' Application October 29, 1934, Serial No. 750,558

10 Claims.

This invention relates to devices for sampling the liquid contents of a tank, and particularly to one which will take a true average sample and will maintain said sample in an original and uncontaminated or undepleted condition.

It is well known that petroleum and its derivatives which are stored in large tanks may not be of, uniform composition throughout, but may remain in a stratified state, depending upon the nature of the various sources from which a given tankful is drawn and the rate and time of its introduction into .the tank. This is particularly true of very light and volatile oils, in which various blends are made. The once common practice in obtaining samples to determine the characteristics of a tank of oil was to take such samples at intervals vertically throughout the tank and mix them for inspection and testing, but this was found to lead to grave errors, due to such mixture not truly representing the average of the tank contents.

Devices have been constructed which will ob- 'tain a truly proportional and continuous vertical sample in a tank, usually by means of a small pump cylinder and piston adapted to be passed vertically through the liquid in a tank, and at the same time, actuated to cause a sample of the liquid to be drawn into the said cylinder at a rate proportional to the said vertical movement. An example of this type is described in United States Patent No. 1,767,301, dated June 24, 1930.

It has been found, however, that in certain circumstances, particularly with very volatile liq- ,35 uids, the loss of vapor when transferring the relatively small samples from certain prior art devices into a conventional sample bottle for transportation or storage, causes serious errors in subsequent analyses and tests, such as vapor 40 pressure determinations, accurate fractional distillations and the like. In consequence this invention is an improvement over those samplers heretofore used, as it provides means for taking .average samples from the tank directly into the 45 sample bottle. In addition, it may provide means for pumping the liquid to be sampled into a bottle already full of water or other immiscible liquid, displacing the latter, and preventing any contamination or loss of vapors, as occurs when air '50 is displaced, due to the turbulence which may occur during the pumping, which promotes vaporization and depletion of the sample.

In addition to the objects just enumerated, it is an object of this invention to provide an average sampling device into which a sample bottle tanks of various heights without extensive may be readily installed and a proportional sample obtained.

Another object is to provide an average sampling device which will be adapted to be used in changes or adjustments to the actuating mechanism.

These and other objects and advantages will become further apparent from the following description and from the accompanying drawing, 10 which forms a part of this specification and illustrates a preferred embodiment of this invention, together with an alternative form.

In the drawing:

Figure 1 is a vertical and part sectional view of an average sampling device embodying this invention.

Figure 2 is a vertical and part sectional view on plane 11-11 of Figure 1, which plane is substantially at right angles to the plane of Figure 1.

Figure 3 is a vertical sectional view of an alternative formof the device shown in Figures 1 and 2, to a reduced scale, and shows the modification of the pump discharge and sample bottle vent tubes for water displacement operation.

Referring to the drawing and particularly to Figures 1 and 2, the reference numeral l0 indicates generally the frame of the device, which comprises a central transverse plate II, from which a plurality of bars l2 extend downwardly to spacing ring l3. Bottle support cup I4 is adapted to be detachably secured to ring 13, as by the bayonet joint formed by pins l5 and. slots 16. The sample bottle I! is adapted to rest on spring [8 in perforated cup l4, and to be urged upwardly thereby so that the top of the bottle neck will be pressed against annular gasket I9, retained in flange 20 on the lower side of plate I l, to form a fluid tight joint therewith.

The pumping mechanism is preferably mounted on top of plate II, and may be of any convenient type. In this example it is a conventional double acting reciprocating piston pump and comprises cylinder 2|, fitted at both ends with inlet valve chambers or pots 22, and outlet valve pots 23, in which are ball valves 24. In the preferred embodiment shown in Figures 1 and 2, the pump discharge tube 25 extends downwardly from upper and lower outlet valve pots 23 and connects with a transverse passage 26 in plate II. The opposite or inner end of passage 26 communicates with a second or continuing discharge tube 21 which extends downwardly from plate II into sample bottle ll, terminating at a point near the bottom. A small spring loaded ball check valve 28 is fitted to the end of discharge tube 21 to prevent accidental withdrawal or leakage of the liquid sample in bottle I1, and

- spillage of liquid in tube 21 when the bottle I1 is removed from frame Ill.

The inlet tube 29 for upper and lower inlet valve pots 22 is best shown in Figure 2 and extends downwardly through plate ll to a point near the bottom of frame I0, so that a sample may be withdrawn from the tank at that level. A riser 30 also extends upwardly for a short distance at the top of tube 29 so that samples may alternatively be drawn at that level. A small spring loaded ball check valve .3I is threaded onto either 29 or 30 to prevent ingress of liquid except while the pump is operated. Threaded cap 3 la (Figure 2) serves to close that inlet which is not in use.

In the embodiment of Figures 1 and 2, Where the sample bottle 11 originaly .full of air, a vent tube 32 extends from a transverse passage 33 in plate I l, downwardly .for a short distance into bottle H. The outer end of passage 33 terminates in an air vent valve 34 on top of plate H. Valve 34 is also of the ball check type, similar to valve 28, and permits air to escape from bottle 11 as the latter is filled with liquid by the pump, while it prevents undesired admission of the said liquid into the bottle through passage 33 and tube 32.

The preferredarrangement of the pump mechanism is bestshown in Figure 1. Inside cylinder 2| is a piston 35 which may be of alternate discs of hard and soft material, as shown. Piston rod 136 extends through a stufiing box :31 at the top of cylinder 2| and thence through a rigidly secured :crosshead 38 and an end guide 39. Guide 3 9 is preferably bifurcated, as shown in Figure 2 and extends upwardly from each side of cylinder 2|. A bifurcated connecting rod 40 straddles guide 39, is pivoted on crosshead 38 (Figure 1), and is journaled at its upper endnon crank 4| in shaft 42. Shaft '42 is journaled on each end in bearings 43 at the top of brackets 44, which extend upwardly from each side of plate 1 l.

Pulleys 45 and 4t are secured to shaft 42, as at one side of crank '41, and are adapted to be rotated by a flexible suspension means 41 such as a cordQbelt :or the like. The diameters of pulleys 45 and '45 are so related to the depths of liquid in the tanks in which the device is to be used, the capacity of the sample bottle l1, and the bore and stroke of the pump mechanism, that as the device is moved vertically through the tank and is actuated by cord 41, the bottle I? will be either partially or completely filled with liqu'id. Obviously, if too much liquid were "pumped, so that the bottle I! were filled before the tank had been traversed completely, the excess would be pumped out through vent 34 and a truly average sample -would not be obtained.

The'usual mode of operation of this device is to place the empty sample bottle in place in frame i l], take several turns of cord about pulley 45 or 46, the latter alternative depending on the tank depth, and, with one side of the cord held securely, pay out the other side, allowing the device to move downwardly into the liquid to be sampled. The relative motion of the outgoing side of cord 4'! rotates the pulley around which bottom of the tank is reached, or the desired distance is traversed, if more than one stage is to be taken, the device is pulled up, using both sides of cord 41, so that no further rotation of the pulley and actuation of the pump will result. This procedure obviously may be modified as desired, the only requirement being that the pump mechanism be actuated continuously during the traverse of the desired vertical distance in which the average sample is to be obtained.

In the alternative embodiment of this invention shown in Figure 3, where the sample is to be taken by displacing water or a similar heavier immiscible liquid from bottle H, the arrangement of the pumpdischarge and bottle vent tubes are modified. In this case, the sample is usually lighter than the liquid to be displaced, so that the pump discharge tube 21 is relatively short and. only extends a short distance into bottle H, where it terminates in ball check valve 28'. Vent tube 32' is long and extends substantially to the bottom of the bottle H, to permit all of the displaced liquid to escape therefrom beneath the liquid being sampled.

Although :a specific construction embodying this invention has been described andillustrated, it is to be understood that the invention is not limited to that particular device, and all such modifications and changes as come within the scope of the appended claims are embraced thereby.

We claim:

1. A sampler for liquids in tanks, comprising a frame, a receptacle, means for securing said receptacle in said frame, a pump on said frame adapted to discharge liquid into said receptacle, and flexible suspension means controlled from the top of said tank for actuating said pump.

2. .-A sampler for liquids in tanks, according to claim 1, in which said pump actuating :means includes a pulley, and flexible suspension means adapted to surround said pulley to actuate the 'same as the sampler is moved through the liquid in a tank, whereby a true average sample of said liquid is secured.

3. A sampler for liquids in tanks, according to claim 1, with the addition of means in said frame to permit outflow of fluid from said receptacle into said tank as liquid is pumped into said receptacle.

4. A .sampler for liquids in tanks comprising a frame, a receptacle, means for detachably securing and sealing said receptacle in said frame, a pump on said frame, flexible suspension means controlled from the top of said tank for actuating said pump, an inlet tube for said pump, a discharge tube from said pump leading into said receptacle, and an outlet in said frame to permit displacement of fluid from said receptacle as it is filled with liquid.

5. A sampler for liquids in tanks, according to. claim 4 in which said pump discharge tube terminates in the upper portion of said receptacle and said fluid outlet from said receptacle communicates with the lower portion thereof, whereby a heavy liquid such as water may be displaced from said receptacle as a sample is pumped therein. W

6. A sampler for liquids in tanks, according to claim 4, in which said pump discharge tube terminates in the lower portion of said receptacle and said fluid outlet communicates with the upper portion thereof, whereby a gas such as air may be displaced from said receptacle as a sample is pumped therein.

7. A sampler for liquids in tanks, according to claim 4, in which said pump inlet tube terminates adjacent the bottom of said frame, whereby a sample may be withdrawn from the lowest accessible point in a tank.

8 A sampler for placing in a receptacle an average sample of liquid from a tank, comprising a pump having a discharge outlet, means for connecting said receptacle to said pump outlet, a pulley on said pump, and a flexible suspension means adapted to surround said pulley to actuate said pump when said sampler is moved vertically.

9. A sampler for liquids comprising a frame, a sample bottle, means for detachably securing said bottle in said frame, sealing means for said bottle,

a pulley driven pump on said frame, an inlet for said pump, a discharge tube from said pump leading into said bottle, a vent for said bottle, and a flexible suspension means adapted to surround said pulley to actuate said pump when said sampler is moved vertically.

10. Apparatus for placing in a receptacle a sample of liquid from a tank, comprising a pump, means for detachably securing a receptacle to said pump, and extensible means for adjustably positioning said pump in said tank and actuating said pump to fill said receptacle.

AUGUSTUS W. GLEASON. ERNEST L. MOYER.

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