US3863506A

US3863506A - Liquid sampling

Info

Publication number: US3863506A
Application number: US369722A
Authority: US
Inventors: Charles Laird Mcclure
Original assignee: Pro-Tech Inc
Current assignee: Pro-Tech Inc
Priority date: 1973-06-13
Filing date: 1973-06-13
Publication date: 1975-02-04
Anticipated expiration: 1992-02-04

Abstract

Electrically actuated apparatus for sampling liquid from the body thereof provides visible countdown of the time interval between successive samplings and also provides visible countdown of the duration of the time in which individual samples are being taken. The samples are propelled by fluid from an external or internal source of pressure, whichever is greater, interconnected for each sample duration period to a sample intake chamber in the body of liquid being sampled.

Description

United States Patent 11 1 1111 3,863,506 McClure 1 1 Feb. 4, 1975 LIQUID SAMPLING 3,719,081 3/1973 Lynn et al. 73/421 B [75] Inventor: Charles Laird McClure, Malvern, FOREIGN PATENTS OR APPLICATIONS 649,081 8/1928 France 417/145 [73] Assignee: Pro-Tech 1nc., Malvern, Pa.

Primary Examiner-S. Clement Swisher [22] Flled' June 1973 Attorney, Agent, or Firm-Charles A. McClure [21] Appl. No.: 369,722

[57] ABSTRACT [52] U.S. Cl. 73/421 B Electrical, actuated apparatus for Sampling liquid [51] Int. Cl. C(lln l/l4 from h body themof provides visible Countdown of [58] F'eld of Search" 73/421 R1421 EJ221423 A; the time interval between successive samplings and 307/141, 141.8; 417/145, 146, 147; 137/113 also provides visible countdown of the duration of the time in which individual samples are being taken. The References C'ted samples are propelled by fluid from an external or in- UNITED STATES PATENTS ternal source of pressure, whichever is greater, inter- 2,408,799 10/1946 Melchar 137/113 connected for each Sample duration period to 3 2,885,001 5/1959 ple intake chamber in the body of liquid being sam- 3,l2(),l28 2/1964 pled. 3,335,298 8/1967 Craig 307/141 3,604,269 9/1971 Smith et al 73/423 A 12 ClalmS, 5 Drawing Figures PATEHTED 3,863,506

SHEET F 2 TIME- DURATION SAMPL'NG INTERVAL PULSER \H "HMER vENT v 7 fm SOLENOID PRETO ALIZED P LSER T p QEE L COMPRESSOR I J COUNTER 1 39\ T SAMPLE SOLENOID DIGITALIZED SAMPLE PULSER DURATION \L IS TIMER 29 51 VENT F, 2 vALvE A INTERNAL PRESSURE 59 SOURcE SHUTTLE w T V VALVE AN vENT' 45 67 49 EXTERNAL SAMPLE SAMPLE V REGULATING PRESSURE INTAKE SOURCE VALVES CHAMBER CONTAINER LIQUID To BE SAMPLED LIQUID SAMPLING This invention relates to sampling of a liquid medium. as for determination of the composition thereof or of contaminants therein, and concerns especially electrically actuated apparatus for doing so by utilizing a pressurized fluid to propel the liquid samples.

As automatic sampling means and methods for sampling liquid have developed, a division into two main classes has occurred: pressure-actuated and electrically actuated. The functions performed by the selected power source, Whether fluid pressure or electricity, include timing the interval between successive samples. timing the duration of individual samples, and valve switching between a condition of interconnection to the liquid medium to propel a sample therefrom and an alternative condition of disconnection from the liquid medium until it is time to take the next sample. Each has its disadvantages, as well as its advantages, of

course.

A primary object of the present invention is electrical timing and valve switching but fluid propulsion of liquid samples.

Another object is instantaneous change-over between internal and external sources ofpressurized propellant fluid.

A further object is interchangeability between use of automatic operation at the instance of electrical timing signals generated internally and, alternatively, external electrical signals, which may be proportional to 'flow of the liquid being sampled.

Yet another objective is visible countdown of both sampling interval (i.e., the time period between successive samples) and sample duration (i.e., the time period during which propellant fluid is being piped to the sampling locus inthe liquid being sampled).

Other objects of this invention, together with means and methods for attaining the various objects. will be apparent from the following description and the accompanying diagrams ofa preferred apparatus embodiment, which is presented by way ofexam ple rather than limitation.

FIG. 1 is a block diagram of electrical apparatus according to the present invention;

FIG. 2 is a block diagram of pneumatic and hydraulic apparatus according to the invention;

FIG. 3 is a schematic circuitdiagram of the apparatus of FIG. 2;

FIG. 4 is a schematic circuit diagram for the electrical apparatus of FIG. 1; and

FIG. 5 is a schematic diagram of alternative circuitry for part of FIGS. 1 and 4.

In general, the objects of the present invention are accomplished, in apparatus for sampling liquid from a body thereofat predetermined intervals of time and for predetermined periods of time at each sampling, by electrical means for determining the sampling interval, electrical means for determining the duration of sampling, conduit means to and from the body ofliquid and adapted to receive gaseous fluid at superatmospheric pressure to propel samples of liquid from the body thereof to a collection location during sampling periods.

FIG. 1 shows in block form Switching Relay interposed between Sampling lnterval Timer 21 and Sample Duration Timer 29, with oppositely directed pairs of arrows linking the relay with each of the timers. Interconnected in parallel to the relay, as indicated by arrows leading therefrom, are Vent Solenoid 31, Compressor 35, and Sample Solenoid 39. lnterconnectable to the sampling interval timer. as indicated by broken lines with arrow leading thereto, is Time-Duration Pulser 11. Similarly connectable to the sample duration timer through the switching relay are Pretotalized Pulser l3 and (alternatively) Counter 17 fed by Digitalized Pulser 15. Further details appear in a subsequent schematic circuit diagram.

FIG. 2 shows in block form Shuttle Valve 55 interposed between lnternal Pressure Source 41 and External Pressure Source 45, as indicated by arrows leading from each of the latter two components to the former. Vent Valve 51 parallels the shuttle valve downstream from the internal source, while the line from the external source contains regulating valves 49. lnterposed in series downstream of the shuttle valve are Sample Valve and Vent 59, Sample lntalce Chamber 65. and Sample Container 67. Upstream of the chamber are Liquid to be Sampled 61 and intervening Check Valve 63. Further details appear in the next view.

FIG. 3 shows fluid circuitry of this invention corresponding to the block diagram in the last view. Vent Valve 51 is normally in the venting position. Shuttle Valve 55 is in whichever position corresponds to connection of the higher pressure source (internal 41 or external through valve V and regulator R (collectively identified as 49) to sample valve (and vent) 59, which normally is in the position of venting sample chamber 65 and thus does not pass pressurized propellant to the chamber until switched. In the normally venting position of the sample valve, liquid from body 61 thereof can enter the sample chamber through check valve 63 (shown in broken lines). In the switched position of the sample valve, the check valve seals under the pressure of incoming propellant from whichever source, whereupon the liquid contents areforced out dip tube 66 (also shown in broken lines) through the interconnecting tubing to sample container 67, which is vented to the atmosphere.

FIG. 4 shows schematically electrical circuitry corresponding to the block diagram of FIG. 1. Respective sampling interval and

sample duration timers

21 and,29 are outlined in broken lines at the right and left. Each timer comprises a motor, a clutch, a countdown indicator, and a switch interconnected mechanically, as indicated by broken lines, such that activation of the motor moves the countdown indicator continuously toward its zero position and eventually moves the switch arm from the normal position (shown in solid) to the alternative position (shown in broken-lines). The timer construction is such that upon inactivation of the motor (and concurrent declutching) the switch arm is springbiased back to its original position, together with the countdown indicator. Switching relay 25 is outlined in broken lines and comprises actuating coil L and triplepole double-throw switch K shown normally posi tioned to the left and with an alternative actuated position to the right.

Outlined in broken lines at the upper left in FIG. 4 is flow-proportional (FP) adapting component, which corresponds generally to the left bank of blocks in FIG. I. Flowmeter F with its switch shown interconnected thereto by broken lines, corresponds to time-duration pulser ll. Flowmeter F with its similar switch is adapted to function through its upper switch arm as pretotalized pulser l3, and through its lower switch arm as digitalized pulser by reason of counter 17 having its input terminals connected in series therewith. Quadruple-pole triple-throw FP mode switch K, is interposed between the flowmeter switches and the counter. on the one hand, and quadruple-pole doublethrow AUTOMATIC-FLOW PROPORTIONAL (AUTO-FP) switch K, on the other hand, all within FP adapter component 5.

For ready reference the four leads from the FP component are identified by reference to K, switch ar'm contact or pivot points, from left to right, as a, b, c, d. The lead from contact a connects to the normally closed contact of sample duration timer switch K and to the middle of switch K and switching relay 25. The lead from contact b interconnects to the normally open contact of the same arm of switch K, and to the normally open contact of sampling interval timer switch K,. The lead from contact c connects to one side of main power switch K1, through which it is connectable to high side H of the supply power line. The neutral or N side of the power line is connectable through the other side of that switch to the switch arm of sampling interval timer switch K,, as well as to one side of motor M, and clutch C, thereof and of motor M and clutch C of the sample duration timer, also vent solenoid S, and sample solenoid S The H power lead reaches the opposite side of the solenoids and of clutch C, and motor M also one side of compressor K via the normally open contact of the right arm of the switching relay, whose coil is connected between that lead and the normally open contact if switch K,. The other side of the compressor is connectable to the N power lead via one side of switch K,,. Pilot lamps L7 and L, across respective power switches K and K indicate their ON position.

Operation of the apparatus of this invention, which is readily understood by reference to the foregoing description and the diagrams, will be described first by reference to the action with switch K, in its right or AUTOMATIC (AUTO) position, which excludes any further consideration of the FP adapter component.

Sampling interval timer motor M, is supplied with power through the N lead from one side of switch K (which is closed to apply main power) and through the H lead from the other side of that switch, through the jumper across the two rightmost normally closed contacts of AUTO-FP switch K through the normally closed leftmost contact of switching relay switch K After a time interval determined by internal setting of conventional gear reductions (not shown) to a predetermined time-equivalent value, M, closes its normally open switch K, through normally connected clutch C,, whereupon electric power is supplied across coil L of switching relay 25 and the three arms of switch K are thrown from their normal left positions to their actuated right positions. Throwing of the left arm removes the power from motor M,, which stops; throwing of the middle arm applies power to the FP adapter component (which will be discussed separately); and throwing of the right arm of switch K removes power from sample duration timer clutch C which was being held declutched thereby, and applies it to motor M, of that timer (which begins to run) and to sampling duration timer clutch C,, which is declutched therebypermitting switch K, to be released to its normally open position. Nothwithstanding the opening of switch K,, the switching relay is retained in its actuated position by alternative N lead path closed thereby through the middle arm of relay switch K and the normally closed arm of sample duration timer switch K Application of power to solenoid S, when switching relay 25 is actuated closes .normally open vent valve 5] (FIG. 3), as well as actuating compressor K of internal pressure source 41 (if switch K is thrown) to supply air under superatmospheric pressure to shuttle valve 55. Simultaneous actuation of solenoid S closes sample valve vent and interconnects whichever pressure source has the higher pressure, from the shuttle valve. to the interior of sample chamber 65, thereby closing intake check valve 63 and forcing the liquid contents of the chamber through dip tube 66 and the interconnecting tubing into sample container 67, any excess air or externally supplied propellant being vented therefrom.

When sample duration timer motor M has run for the desired period (predetermined similarly to that for M,) it opens switch K thereby interrupting power to the switching relay, which returns to its original position, removing power from motor M and from compressor K and solenoids S, and S, but applying power (through the right arm of switch K,,) to clutch C deswitching it and permitting the arm of switch K, to return to its normally closed position. Sampling interval timer 21 is reactivated by the release of the switching relay, and the timer recycles. Thus in the AUTO mode, the respective timers (21 and 29) operate alternately so long as the apparatus has power applied thereto, whether the power switch for compressor K is thrown or not, as is optional when an external pressure source is being used.

Operation FP adapter component 5 is readily understood as a variant of the operation just described. With switch K thrown to the left of FF position, flowmeters F, and F are interconnectable to the body ofthe apparatus through setting of PP MODE switch K,. The mode switch is shown in the rightmost or TIME DURA- TlON (TD) position, in which the switch of flowmeter F is connected in circuit between power lead H from main power switch K1 through the AUTO-FP switch to sampling interval timer motor M, through normally closed leftmost contact of switch K Accordingly, closing of the F, switch actuates motor M,, which runs so long as the switch is closed, thereby totalizing successive closure periods of that flowmeter switch up until an entire sampling interval is completed, whereupon the switching relay is actuated as before to effect sample recovery.

In the other positions of the FP MODE switch flowmeter F is interconnected either directly through the middle position thereof, or indirectly through digital pulse counter 17 in the leftmost position. In the midposition, whenever flowmeter F closes its upper switch, a so-called pre-totalized" pulse is applied through a power circuit completed to coil L of switching relay 25 through normally closed switch K, of the sample duration timer, thereby actuating therelay independently of the sampling interval timer and effecting a cycle of sample recovery. In the left position of the FP MODE switch, flowmeter F supplies a digital pulse every time its lower switch closes to connect counter 17 in a series with the power source in like manner, and when the counter has tallied a preset number of such pulses it closes the power circuit to coil L and effects sample recovery as already described. lt will be understood that the switching action of the respective flowmeters is an indication of the flow of a given volume of liquid past the sample chamber in the body to be sampled, so that sampling is proportioned to such volume, thereby rendering a composite of a succession of samples more nearly representative of the liquid that has flowed by than if sampling had proceeded automatically at regular intervals.

FIG. 5 shows a simplified alternative construction of PP adapter component, designated as 5', in which flowmeter F may deliver either pretotalized or timeduration pulses (i.e., contact closures) with the same effect as just described. A three-position switch is shown in its central or AUTOMATIC position. The four leads at the bottom of the view have contacts designated a, b, c, and d, which correspond to and can be substituted for respective contacts a, b, c, and d of component 5 in FIG. 4. Double-pole switch component K at the right, when thrown to the right, puts the apparatus in a TD FP mode of operation (as in the rightmost position of switch K, on component 5), whereas triplepole switch component K at the left, when thrown to the left, puts the apparatus in a PT FP mode (as in the midposition of switch K.,). It will be understood that movement ofrespective switch components K and K of this three-position switch do not affect one another. A prime advantage of this alternative arrangement is that only a single pair of contacts is required to accom' modate FP signals of either TD or PT type. This modification can be adapted to use with a digitalized pulse flowmeter by incorporating the counter in the flowmeter circuit.

Both sampling interval and sample duration timers are conveniently furnished'with conventional dial and moving pointer indicators (1, and I for visual-countdown of the time period remaining in the sampling in-' terval or sample duration period, as the case may be. Pilot lights (not shown) pa'rallelling the respective motors also facilitate observation of the timer actuated at any given moment. The timers, which have similar synchronous motors, may have similar or different gear reductions for the same or different timing ranges. ln normal practice, it is convenient to have a range from a minute or so to about a day or so for the sampling interval timer, depending upon desired sampling frequency; and a range from a few seconds to about a minute for the sample duration timer, depending upon sample head or lift and upon length and diameter of sample lines. Such timers are readily available commercially, as are all the other parts of the described apparatus.

This apparatus and the methods of automatic and flow-proportional sampling disclosed here represent a highly versatile and effective advance in the art of liquid sampling, whose convenience andeffectiveness will be best appreciated and understood by those undertaking to practice it. Although a principal embodiment and at least one modification have been described and illustrated, the invention is not to be deemed limited thereto. Additional modifications may be made therein, as by addition, combination, or subdivision of parts and steps, which retaining advantages and benefits of the invention, which itself is defined in the following claims.

The invention claimed is:

1. In apparatus for sampling liquid from a body thereof at predetermined intervals of time between and for predetermined periods of time at successive samatmospheric pressure to propel samples of liquid fromv the body thereof to a collecting location during the sampling periods, the improvement comprising a pair of like electrical timing means, one for determining the interval between successive samplings and one for de termining the duration of each sampling period. and including an indicator of the time remaining in any current sampling interval and the time remaining in any current sampling period; means for switching the respective timer means alternately off and on, each one being switched on when the other has counted down to zero time remaining, for an automatic mode of operation; switch means for inactivating such automatic switching and interconnecting the apparatus for operation in accordance with signals supplied from an external source, the first timing means including electrical means for totalizing time-duration signals and the second timing means including electrical means for determining the duration of sampling periods; and switch means interposed between the electrical means and the external signal source together with electrical interconnectors therebetween such that in one position of the switch means the external signal source is connected to the totalizing electrical means and in another position of the switch means the external signal source is connected to'the electrical means for determining the duration of sampling periods.

2. Liquid sampling apparatus according to claim 1, including switching valve means, actuated by the electrical means, for alternately permitting and precluding such flow of propellant.

3. Liquid sampling apparatus according to claim 1, including relay means, actuated by the electrical means, for switching the respective electrical means alternately on and off.

4. Liquid sampling apparatus according to claim 1, including an internal source of gaseous fluid at superatmospheric pressure and an inlet for gaseous fluid at superatmospheric pressure from an external source thereof, both connected to the conduit means, and shuttle valve means for interconnecting the external inlet to the conduit means when the external gaseous fluid pressure exceeds a given value and for otherwise connecting the internal pressure source to the conduit means.

5. Liquid sampling apparatus according to claim 1, wherein the electrical means for determining the sampling interval and the electrical means for determining the sample duration are identical.

6. Liquid sampling apparatus according to claim 1, wherein the electrical means for determining the sampling interval and the electrical means for determining the sample duration have respective indicator means associated therewith for displaying the time thereof remaining at any given instant.

7. Liquid sampling apparatus according to claim.6, wherein the respective indicator means are identical and include respective actuation indicators.

8. ln apparatus for sampling liquid from a body thereof, in accordance with contact closure signals supplied from an external source, including means in contact with the liquid and adapted to propel a sample from the body thereof to a collection location during sampling periods and including electrical means for totalizing time-duration signals from such source and electrical means for determining the duration of such sampling periods, the improvement comprising switch means having a plurality of positions and interposed between the electrical means and the external signal source, with electrical interconnectors therebetween such that in one position of the switch means the external signal source is connected to energize the totalizing electrical means rather than the means for determining sample duration,-and in another position of the switch means, the external signal source is connected to enter gize the electrical means for determining duration of sampling periods rather than the totalizing electrical means.

9. Liquid sampling apparatus according to claim 8, wherein the sample is propelled by gaseous fluid at superatmospheric pressure, and including valve means actuated by the electrical means alternately to interconnect such fluid for sample propulsion and to disconnect such fluid during the interval between successive 8 periods of sample propulsion.

10. Liquid sampling apparatus according to claim 8, including a contact closure at the external signal source end of the electrical interconnectors.

11. Liquid sampling apparatus according to claim 8, wherein a two-wire electrical interconnection to the external signal source is adapted to accommodate both time-duration and momentary signals therefrom. the former in one position of the switch means and the latter in the other position of the switch means.

12. Liquid sampling apparatus according to claim 8. including switch means for inactivating the apparatus relative to the external source of signals and enabling it to operate automatically and including means for switching the respective electrical means alternately off and on, each being adapted to be so switched on when the other has counted down to zero time remaining.

Claims

1. In apparatus for sampling liquid from a body thereof at predetermined intervals of time between and for predetermined periods of time at successive samplings, including conduit means to and from the body of liquid and adapted to receive gaseous fluid at superatmospheric pressure to propel samples of liquid from the body thereof to a collecting location during the sampling periods, the improvement comprising a pair of like electrical timing means, one for determining the interval between successive samplings and one for determining the duration of each sampling period, and including an indicator of the time remaining in any current sampling interval and the time remaining in any current sampling period; means for switching the respective timer means alternately off and on, each one being switched on when the other has counted down to zero time remaining, for an automatic mode of operation; switch means for inactivating such automatic switching and interconnecting the apparatus for operation in accordance with signals supplied from an external source, the first timing means including electrical means for totalIzing time-duration signals and the second timing means including electrical means for determining the duration of sampling periods; and switch means interposed between the electrical means and the external signal source together with electrical interconnectors therebetween such that in one position of the switch means the external signal source is connected to the totalizing electrical means and in another position of the switch means the external signal source is connected to the electrical means for determining the duration of sampling periods.

7. Liquid sampling apparatus according to claim 6, wherein the respective indicator means are identical and include respective actuation indicators.

8. In apparatus for sampling liquid from a body thereof, in accordance with contact closure signals supplied from an external source, including means in contact with the liquid and adapted to propel a sample from the body thereof to a collection location during sampling periods and including electrical means for totalizing time-duration signals from such source and electrical means for determining the duration of such sampling periods, the improvement comprising switch means having a plurality of positions and interposed between the electrical means and the external signal source, with electrical interconnectors therebetween such that in one position of the switch means the external signal source is connected to energize the totalizing electrical means rather than the means for determining sample duration, and in another position of the switch means, the external signal source is connected to energize the electrical means for determining duration of sampling periods rather than the totalizing electrical means.

9. Liquid sampling apparatus according to claim 8, wherein the sample is propelled by gaseous fluid at superatmospheric pressure, and including valve means actuated by the electrical means alternately to interconnect such fluid for sample propulsion and to disconnect such fluid during the interval between successive periods of sample propulsion.

11. Liquid sampling apparatus according to claim 8, wherein a two-wire electrical interconnection to the external signal source is adapted to accommodate both time-duration and momentary signals therefrom, the former in one position of the switch means and the latter in the other position of the switch means.

12. Liquid sampling apparatus according to claim 8, including switch means for inactivating the apparatus relative to the externaL source of signals and enabling it to operate automatically and including means for switching the respective electrical means alternately off and on, each being adapted to be so switched on when the other has counted down to zero time remaining.