US2836978A

US2836978A - Automatic liquid sample dispenser

Info

Publication number: US2836978A
Application number: US543521A
Authority: US
Inventors: Fred H Warren
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-10-28
Filing date: 1955-10-28
Publication date: 1958-06-03
Anticipated expiration: 1975-06-03

Description

June 3, 1958 F. H. WARREN AUTOMATIC LIQUID SAMPLE DISPENSER Filed Oct. 28, 1955 Isl /9 22 INVENTOR.

Fred H; Warren B a I ATTOF? NE75 United tates atent 2,836,973 Patented June 3, 1958 Flee AUTOMATIC mourn SAMPLE DISPENSER Fred H. Warren, Findlay, Ohio Application October 28, 1955, Serial No. 543,521

3 Claims. c1. 73-422 This invention relates to means for collecting and dispensing measured quantities of liquids from a flow line, and particularlyto improvements on the sampling means described and claimed in my Patent No. 2,692,502, of October 26, 1954.

In the use of said patented sampler, it is found that in the handling of some heavy oils and also in cold temperatures the flow of the oil is so sluggish that the discharge passage from the admission valve sometimes becomes clogged or the measured slug may not be entirely freed therefrom and delivered to the sample container. In the handling of certain light volatile oils, said patented sampler, which stores the sample under atmospheric pressure, permits more evaporation than can be tolerated.

The object of the present invention is the provision of means operable during the sample discharging action to augment the gravity flow of the liquid by induced pressure in the flow line whereby a full sample in each operation is obtained and its complete discharge into the receiving container insured.

Another object of the invention is the provision of means in association with the liquid sample receiver for preventing or materially reducing the customary evaporation loss in the collected samples.

Further objects and advantages of the invention will be apparent from the following detailed description, and from the accompanying drawings illustrating one embodiment thereof, and in which Fig. 1 is an elevation of a sampler embodying the invention, with parts in section and with the moving parts in position for cleaning the sampling line after a previous sample taking operation, and

Fig. 2 is a sectional view of the valve parts with the admission valve closed and with the discharge of liquid from the sampler taking place.

The illustrated embodiment of the invention includes an admission valve and an ejector pump unit A, a distributor valve unit B, a sample taking space C between the units A and B, a sample container D which receives samples from the distributor valve B, and the operating and control means E for the valve and pump unit.

The unit A comprises a preferably cylindrical stationary body or casing 1 having one end, its top in the present instance, open and its opposite end provided with a restricted outlet passage 2. The flow or supply line for the sampler is designated 3 and this communicates with the interior of the casing 1 through a side thereof and adjacent to the outlet passage 2. The lower end of the casing 1 immediately above the outlet 2 is provided with a space 4 into the top of which the flow line 3 opens and which has its side wall provided near its top but below said flow line with an annular valve seat 5.

A valve 6 of cylindrical form is reciprocally mounted in a restricted portion of the casing 1 above the space 4 and when lowered seats on the valve seat 5 to close the communication between the supply line 3 and space 4. The upper end of the valve 6 enters an enlarged portion of the casing bore which forms the open upper end of the casing and is received within the lower end of a. gasket sleeve 7 that is threaded or otherwise adjustably secured in said upper end bore. A coiled expansion spring 10 is mounted in the sleeve 7 between the upper or outer end of the valve 6 and an internal flange at the upper end of the sleeve, thus tending to normally force the valve to the seat 5 and close the communication between the space 4 and supply line 3.

A pump plunger 12, the purpose and manner of operation of which will hereinafter be described, is mounted for coaxial reciprocation in the valve 6 and has its outer or upper end projected without the casing 1 through the sleeve 7 and spring 10, and has its inner or opposite end projected into the space 4 below the valve and provided with a flange 13 for stop coaction with the valve to cause a lifting of the valve with the plunger during a portion of the latters movement. When the valve 6 is seated and the lower plunger end is forced downward into the space 4 it acts to force liquid from such space and through the discharge outlet passage 2, as hereinafter described.

The distributor valve unit B is located below the unit A and comprises spaced upper and lower

stationary parts

18 and 19, respectively, between which a slide valve 20 operates. The part 18 has a port 21 in communication with the lower end of the outlet passage 2 through the sample taking space C, while the part 19 has a port 22 in connection with the sample receptacle D through a discharge tube 23. The slide valve 20 has a passaga 24 therethrough which, when the valve is in one position of its movement, registers with and opens communication between the two ports 21 and 22, as in Fig. 2. The valve 20 also has an angled passageway 25 therein which, when the valve is in another position of its movement, opens communication between the port 21 and a drainage pipe 26 leading to any suitable point of disposal of drainage from the sampling system, as set forth in said prior patent. The volume of liquid collected for each sampling operation is determined by the diameter and length of stroke of plunger 12 in the admission valve unit. The volume of the sample slug delivered to sample receptacle D is determined by the diameter and length of stroke of plunger 12.

The sample receptacle D, in the present instance, is illustrated as comprising a cylindrical liquid container closed at its top by a tightly fitting cover 28 centrally through which the tube 23 projects preferably to near the bottom of the container. The tube has an airtight fit in the cover. The cover is removably held to the container by a fastening means 29 and carries an adjustable automatic pressure relief valve conventionally shown at 36 and a hand control relief valve 31. A float piston 32 is preferably mounted in the container and has a central opening through which the tube 23 projects in a manner to permit the float to raise under pressure ofliquid in the lower portion of the container. The engagement of the float piston with the container wall and with the tube is sealed against fluid leakage by suitable gaskets. To empty the container the cover 28 is removed with the tube 23-, the float piston is withdrawn and the contents of the container poured out. The primary purpose of the piston will be hereinafter explained. It is preferable to provide the tube 23 with a check valve 33 and a hand control valve 34.

The control means E for the slide valve 29 comprises, in the present instance, a fluid pressure operated motor 35 having a piston rod 36 attached to the outer end of said valve and carrying within the motor casing a piston 37 successively driven in opposite directions by fluid pressure alternately admitted to the opposite ends of the casing and exhausted therefrom through

tubes

38 and 39. Two three-way solenoid valves, conventionally shown at 40 and 41, are connected to the a respective tubes 38. and 39 3 i and each valve operates to connect its tube either 'to a pressure supply line 42 or a pressure exhaust line 43, depending on theposition of the valve plug in its'casing; For instance, a simultaneous energizingof' the solenoids inthe two valves 40 i A sequence timerifi'isconnected.withelectric current supply. Wires F Sl. and. 52. and automaticallycontrols the supply :of current to the. two-solenoid valves through leads 53-:a'nd their branches as shown. "For. safety purposes a :limitswitch, conventionally shown at55, is preferably. interposed in the leads 51 and 52 in advance of the sequence timer '50 with the switch. located on the cover of the sample container in position to be opened by the float piston when raised a predetermined extent in the container by the sample liquid discharged therein. For this purpose the movable member of the switch has a part 56 projecting down into the containerto be contacted and raised by the piston 32 ata certain point inits upward movement on'the container whereby to open the switch and stop further sample producing operations until the container has been emptied and the cover again placed in position thereover. The principal novelty in the present case resides in the provision of the. plunger 12 and the control means therefor, whereby at each downstroke thereof a sample slug of. uniform volume is ejected from thesample taking portion of the discharge passage and subsequently into the sample container irrespective of any ordinary sluggish flow condition of the liquid and frequency of taking samples.

This control means is shown, in the present instance, as comprising an L-arm fiiiwiill its short arm fixedly attached to the outer end of the slide valve to move therewith and its long arm extending forward across the casing for the slide, parallel to the latter and guided by fitting into a slideway or recess 61 in the casing top. The forward end of said long arm has a longitudinally extending slot 62 therein in which a pin 63 at one end of a bell-crank lever 64 has free movement lengthwise of the arm. 'This lever is fulcrumed at its elbow to a frame part 65 and its upper arm extends forward therefrom and has suitable pin and slot connection with the upper end of the pump plunger lZ Whereby a rocking of the-lever imparts predetermined reciprocatory movements to the plunger. The extent of free or lost-motion movement of the slide arm 60 relative to the lever pin 63 is determined by the. position of adjustment of a stop-block 66. in the lever slot 62. This block is clamped to the arm 6% by bolt and washer means, indicated at 67, and has limited adjustment in a widened rear end portion of the slot.

When the slide valve 24 is at the inner or right end of its stroke, as shown in Fig. l, the drainage port 25 is in register with the port 21 and the pump plunger 12 is raised, lifting the admission valve 6 from its seat 5, thus admitting liquid to the space 4 and passage 2. Upon the forward stroke of the slide valve 20 the valve passage 24- is moved into register with the ports 21 and'22 to permit discharge of the sample slug from the metering connection C tothe receptable D. During the last portion of this forward movement the lever 64 is rocked in crosswise direction to lower the plunger 12 and permit seating of the admission valve 6, under action of the spring 10, and then to continue downward a distance into the space 4- to displace liquid therein and thus discharge a'sample slug from the connection C into the container D, The down stroke of the pump plunger i2. relative to the valve 6 .is determined by the position of the stop plug 66 in the slot 62 and the assesses 4 consequent length of the lost-motion portion ofthe slot 62 in which the lever pin 63 works.

It will be understood from the foregoingthat in the operation of the sampler the ports thereof are in the position indicated in Fig. 2 during rest periods or intervals between cycles, and also that the taking of a sample occurs during each inward and outward stroke of the motor piston 37.

.At the start of .a cycle the sequence timer 50 *closes the electric circuit to both

solenoid valves

40, 41, admitting pressure to the left or slide valve side of the piston 37 and placing the valves 28 and 6 inthe positions indicated in Fig. l. The solenoid valve circuit is maintained a suflicient period for all the liquid remaining in the sam- 1 pling line from a previous sample to'be displaced With.

41 will act to admit pressure from line 42 to the rightside' of power piston 37, while valve 4%) will permit exhaust of pressure from the opposite or' left side of the piston.

This will cause the piston to move to the left, first releasing pressure on lever pin 63, thus allowing admission valve 6 to seat and stop the flow of oil and trapping a measured quantity of oil in the sample taking passage comprising the space 4, passage 2 and port 21. Thenyas the movement of slide'v-alve 20 continues, its port '24'will register with the ports 21 and 22 and the stop block 66 will strike the pin 63 and move it outward or'to the. left! This drives the plunger valve downward permitting the admission valve 6'to close and projectingthe lower end'of the plunger into the space 4 to forcibly displace liquid therein. The liquid sample discharged into tube 23 opens check-valve 33 and is delivered to sample receiver D below the float-piston 32, displacing it upward. By discharging the sample through a tube entering the sample receiver at the top and extending down through a leak-proof fit in the piston, objectionable side pockets that are presentwhere liquid is introduced through the side wall of the receiver are eliminated. As the piston rises, the air pressure above increases, and this is relieved at predetermined pressure by the pressure relief valve 32 or'manually by the hand valve 39. Should the piston risesufficiently toraise the switch rod 56 thelimit switch 55 will be opened, thus stopping further sample producing operation. a

In most cases of sampling'crude oil streams, the normal buildup of internal pressure in the sample receiver will prevent loss of the sample by evaporation, with the consequent increase of specific gravity. The use of the floating piston prevents, or at least materially reduces, such evaporation loss. In sampling volatile liquids it may be necessary to build up an initial pressure in the sample receiver by introducing compressed dry air or gas above the piston prior to starting the sampling operation. In extreme cases, it may be desirable to saturate the vapor space of the sample receiver by placing a small quantity of volatile liquid of the nature being sampled in the cupped upper side of the piston.

At the end of a sampling periodythe valve 34 is closed the discharge tube 23 is separated at the coupling 70 and the sample receiver removed to a point of inspect-ion and testing the sample. In case the liquid collected is ordinary crude oil the internal pressure in the receiver is vented by opening the valve '31, the cover 28 and piston 32 are removed, the collected sample is agitated in the receiver, and a portion transferred to a test tube for analysis. In the caseof highlyvolatile liquids, and tests such as Reid vapor tests are to be made, the test bomb may be tilled directly'from the sample'receiver by connecting the coupling 7% through a suit-able .valve'and fitting.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of such modifications and changes as do not depart from the spirit of the claims.

I claim:

1. In a liquid sampler, means forming a passage from a flow line and including a sample taking space, an admission valve between said flow line and said space, a distributing valve at the outlet end of said space, a plunger projecting through said admission valve and coacting therewith to open it when the plunger is moved outward, said plunger when moved inward permitting a closing of the admission valve and projecting into said space to efiect displacement of liquid therein, means for closing the admission valve when relieved of the opening pressure of said plunger, and mechanism operable to move said plunger to open said admission valve and move said distributing valve to close said passage during one portion of a sample taking cycle and to open said distributing valve and move said plunger to permit closing of the admission valve and displacement of liquid in said space during another portion of said cycle.

2. In a liquid sampler, means forming a passage from a flow line and including a sample taking space, an admission valve between said flow line and said space, a distributing valve at the outlet end of said space and having a waste discharge position, a plunger projecting through said admission valve and coacting therewith to open it when the plunger is moved outward, said plunger when moved inward permitting a closing of the admission valve and its own projection into said space to afiect displacement of liquid therein, means for closing the admission valve when relieved of the opening pressure of said plunger, and mechanism operable to move said plunger to open said admission valve and move said distributing valve to the waste discharge position during one portion of a sample taking cycle and to open said distributing valve to the sample container and move said plunger to permit closing of the admission valve and displacement of liquid in said space during another portion of said cycle.

3. In a liquid sampler, means forming a passage from a flow line and including a sample taking space, a sleeve type admission valve between said flow line and said space and guided for reciprocatory movements by said means, a distributing valve at the outlet end of said space and having a waste discharge position, a plunger projecting through said admission valve and cooperating therewith to open it when the plunger is moved outward, said plunger when moved inward permitting a closing of the admission valve and its own projection .into said space to efiect displacement of liquid therein, means for closing the admission valve when relieved on the opening pressure of said plunger, and mechanism operable to move said plunger to open said admission valve and move said distributing valve to the waste discharge position during one portion of a sample taking cycle and to open said distributing valve to the sample container and move said plunger to permit closing of the admission valve and displacement of liquid in said space during another portion of said cycle.

References Cited in the file of this patent UNITED STATES PATENTS 394,214 Shaw Dec.l1, 1888 2,260,419 Wrightsmen Oct. 28, 1941 2,277,714 Polston Mar. 31, 1942 2,525,295 Harrington Oct. 10, 1950 2,692,502 Warren Oct. 26, 1954