US3336808A

US3336808A - Liquid sampling apparatus

Info

Publication number: US3336808A
Application number: US442105A
Authority: US
Inventors: Carroll J Ryskamp
Original assignee: Marathon Oil Co
Current assignee: Marathon Oil Co
Priority date: 1965-03-23
Filing date: 1965-03-23
Publication date: 1967-08-22
Anticipated expiration: 1984-08-22

Description

Aug- 22, 1957 c. .1* RYSKAMP 3,336,808

I LIQUID SAMPLING APPARATUS Filed March 25, 1965 2 Sheets-Sheet l k\\\\\\\\\\\\\\ l mmm Xl: lli l Ill4 llt |lllll lllh Ilrlll llll lllll l Magnum! llll l'lh l-lll lllll Illu www! 8\ y 4 (4"schedme 4o) l2" 6 (4" X 2" Reducer) INVENTOR CARROLL J. RYSKAMP Aug' 22 1967 c. J. RYSKAMP 3,336,808

' LIQUID SAMPLING APPARATUS Filed March 25, 1965 f 4 22 Sheets-Sheet. 2

Air From Condenser *oi 24" Header .e 2, o

FLOW E Vdpor Nop'rho E Wafer IN VEN TOR CARROLL J. RYSKAMP United States Patent O 3,336,808 LIQUID SAMPLING APPARATUS Carroll J. Ryskamp, Allen Park, Mich., assigner to Marathon Oil Company, Findlay, Ohio, a corporation of Ohi Filed Mar. 23, 1965, Ser. No. 442,105 6 Claims. (Cl. 73-422) ABSTRACT OF THE DISCLOSURE A device is disclosed for sampling naphtha from a fluid strea-m in a conduit containing non-condensable gasses, naphtha and water. A Weir directs the immiscible liquids from the conduit into a chamber where an especially positioned baffle directs the water away from the naphtha sampling conduit. The naphtha sample is further freed of water by chilling and cyclonic separation before it is analyzed.

This invention relates to new methods and apparatus for the separation of substantially immiscible liquids from mixed fluid streams and particularly to the separation of such liquids for rapid analysis and automatic control of processes.

In the automatic control of refinery processes, it is common to sample liquids to be analyzed at points just as for example, in the automatic control of a fractionation process based on boiling point determinations on one or more components of the product coming from the f-ractionating tower, such hold-up delays make the system sluggish and slow to respond and cause wide uctuations in the quality of the product produced.

The present invention can sample the product stream immediately after it is produced without waiting for mixing to occur. Also, being gravity operated, the devices of the present invention do not require that the stream being sampled -be under any substantial pressure. Throughput through the devices is very rapid in order to reduce holdup times to a minimum. Thus, the present invention permits the sampling of process streams virtually immediately after they are produced and rapidly separates out a component for analysis, permitting rapid response of automatic control systems to variations in product quality.

FIGURE 1 is an illustration of a preferred device exemplary of the present invention.

FIGURE 2 is a schematic diagram showing the device installed in a system for sampling the eiiiuent from an air cooled condenser.

In FIGURE l a circular Weir 1 in inserted into the bottom of the exit header of an air condenser 2. 3 is a flanged gate valve. This valve is mounted with its flow pass substantially vertical and permits removal of the lower portions of the sampling apparatus without interruption of liquid flow through the header 1. An elongated cham-ber 4 having relatively low internal volume is mounted vertically below the valve 3. The elongated chamber has a sampling outlet sidearm 5 located relatively near the top of the chamber and a constricted drainV outlet 6 located at the bot-tom of the chamber so as to drain t-he chamber completely. The sampling outlet sidearm is protected from direct exposure to the liquid stream ICC which flows from the weir 1 -by a deflection plate 7 mounted at a 45 angle. A vent space 8 is provided between the upper edge of the deliector and the side wall of the elongated chamber 4 in order to prevent vapors or non-condensable gases from becoming trapped under the deflector plate.

The deiiector plate may, of course, lbe curved as well as at and a vent 8 may be made more elaborate with a tube extending upward from the vent to a point near the top of the conduit 2. In the embodiment shown, most ow occurs at the upstream edge of the weir and, therefore, liquid ilow does not occur downward through the vent 8. Under other circumstances it may .be preferable to form a V notched Weir or, as a weir, employ a hole drilled in a pipe extending upward through the header 2. Alternatively, a cap plate may be iitted over the top of some portion of the circular weir shown in FIGURE 1 in order to minimize tlow of liquid downward through the vent 8, and permit easiest escape of vapor upward through the vent.

FIGURE 2 shows the device of FIGURE l in operation mounted in the header which collects the effluent from a series of air condensers arranged in parallel. A mixed stream of non-condensable gases `and vapors and a partially mixed liquid phase consisting of naphtha and water flows along the header 2 and a portion of the latter naphtha phase together with some water flows over the weir 1 downward into the elongated vertical chamber 4. A constriction at t-he drain outlet 6 together with adjustable drain valve 11 causes the liquid to accumulate in elongated cha-mber 4 and maintains the liquid lever above the top of the sample outlet sidearm 5. The lighter naphtha rapidly forms a virtually pure naphtha phase at the top of the liquid in the elongated chamber 4 and this phase is tapped by the sidearm 5. This substantially pure naphtha sample may be conducted directly to an analyzer, or, as shown in FIGURE 2, may be cooled in a water cooled or other chiller and any water released by cooling separated in a cyclone separator. In the present embodiment, a water cooled chiller operating at about 50 to 80 F. serves the dual purpose of cooling the sample and also of preventing freezing of the sample in the tubing during cold weather.

Flow from the drain outlet 6 of the elongated chamber may be conducted back to the header 2 or to another point in the system or may be run to a drain. The effluent from the cyclone separator may also be either returned to the system or run to a drain.

A cyclone separator found useful with the above-described naphtha water system is the model manufactured by Borg-Warner Mechanical Seals, a division of Borg- Warner Corporation, P.O. Box 2017, Terminal Annex, Los Angeles 54, Calif., and described in their brochure, Special Issue No. A, dated Nov. 20, 1961.

FIGURE 1 gives the dimensions of a sampling device being successfully used -to sample a mixed stream from an .air condenser header which contains a stream consisting of about 93.7% by volume non-condensables and vapors, 0.8% lby volume water and, partially mixed with the water, 5.5% by volume naphtha. In operation, the sampling device discharges from its sampling sidearm a stream consisting of 99.5% --by volume of naphtha together with about 0.5% by volume of water. Water content is reduced to below 0.1% by cooling and subsequent treatment in the cyclone. Efliuent from the cyclone is fed to an end point analyzer which emits a signal proportional to the end point of the naphtha. This signal, operating through a controller, modulates a pneumatic valve controlling the flow of reflux from the overhead receiver back to the fractionating column which feeds the air condenser from which the sample was taken. Thus, the

end -point of the product flowing from the air condenser to the overhead receiver is controlled by the sampling device-end point analyzer-control system.

While the above preferred embodiment of the invention utilizes an end point analyzer, it will be obvious that a chrom-atograph, X-ray -defraction spectometer, photometer, or other analytical instrument either continuous or periodic in its operation, may be used to analyze the sample stream owing from the sidearm of the sarnpling device of t-he present invention.

Also, it will be understood that although the dimensions of the devices of the present invention are not narrowly critical, it will be highly desirable to maintain all the volumes at a minimum in order to decrease hold-up time and permit maximum speed of response to changes in product quality.

It will be yapparent that by reversing the positions of the drain and sample outlets, it will be possible to elect separations in which it is desirable to sample a heavier lrather than a lighter component. By locating the sample outlet at a mid-point of the elongated chamber, it will be possible to sample liquids intermediate in density between other components of the stream to be sampled.

What is claimed is:

1. A continuous, short-time-leg system for sampling a liquid from a mixture of substantially immiscible iluids llowing through a conduit, comprising in substantially adjacent 'relationship a weir located within said conduit at a point below the surface of the liquid and .above the bottom of the conduit, said weir being located at an elevation to permit its withdrawal of a stream containing substantial amounts of the liquid to be sampled, said stream flowing by gravity downward from the weir; a substantially vertical low-volume conduit located below said weir to `receive the stream from the weir, said low-volume conduit having a sample outlet and a constricted drain outletl located a substantial vertical distance from said sample outlet, said drain outlet being suiciently constricted to cause said liquid stream from said weir to accumulate in said low-volume conduit to a depth sufcient to maintain said sample outlet below the surface of the liquid in said low-volume conduit; a dellector located within said low-volume conduit dellecting said stream from said weir away from said sample outlet; vent means for preventing fluids lighter than lthe liquid to be sampled from accumulating under said deflector', and llow adjustment means for regulating the rate of flow through said low-volume conduit so that said sample outlet discharges a substantially pure ow of the liquid to be sample.

2. The device of claim 1 wherein the sample outlet is located above the drain outlet and the drain outlet is located substantially at the bottom of said elongated lowvolume chamber.

3. The device of claim 1 wherein the weir is located at an elevation sucient to cause it to withdraw its stream from the least dense of the liquid `phases of the mixed fluids and wherein the weir is located at a point where the mixed fluids are llowing in a substantially horizontal plane.

4. The device of claim 2 wherein the drain outlet is fitted with a variable orice valve and is connected by a conduit to a point on the conduit carrying the mixed fluids which is downstream from the weir.

5. The device of claim 1 wherein the sample outlet is connected to an analyzing instrument which measures at least one physical property of the sample stream and automatically makes corresponding adjustments in apparatus from which said mixed lluid stream llows toward said weir.

6. The apparatus of claim 4 wherein the mixed fluids comprise naphtha, water, and non-condensable gases, the stream llowing from the sample outlet is substantially pure naphtha, and analyzer measures the end point of the naphtha stream flowing from the sample outlet.

References Cited UNITED STATES PATENTS 1,649,241 1l/1927 Lewis 73-422 2,917,926 12/1959 Jaquith 73-422 LOUIS R. PRINCE, Primary Examiner.

S. C. SWISHER, Assistant Examiner.

UNITED STATES PATENT oEFICE CERTIFICATE OF CORRECTION Patent No 3 ,336 ,808 August Z2 1967 Carrol J.Ryskamp It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 25, for "short-time-leg" read short-tme-lag Signed and Sealed this 13th day of August 1968.

(SEAL) Attest:

EDWARD I. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

Claims

1. A CONTINUOUS, SHORT-TIME-LEG SYSTEM FOR SAMPLING A LIQUID FROM A MIXTURE OF SUBSTANTIALLY IMMISCIBLE FLUIDS FLOWING THROUGH A CONDUIT, COMPRISING IN SUBSTANTIALLY ADJACENT RELATIONSHIP A WEIR LOCATED WITHIN SAID CONDUIT AT A POINT BELOW THE SURFACE OF THE LIQUID AND ABOVE THE BOTTOM OF THE CONDUIT, SAID WEIR BEING LOCATED AT AN ELEVATION TO PERMIT ITS WITHDRAWAL OF A STREAM CONTAINING SUBSTANTIAL AMOUNTS OF THE LIQUID TO BE SAMPLED, SAID STREAM FLOWING BY GRAVITY DOWNWARD FROM THE WEIR; A SUBSTANTIALLY VERTICAL LOW-VOLUME CONDUIT LOCATED BELOW SAID WEIR TO RECEIVE THE STREAM FROM THE WEIR, SAID LOW-VOLUME CONDUIT HAVING A SAMPLE OUTLET AND A CONSTRICTED DRAIN OUTLET LOCATED A SUBSTANTIAL VERTICAL DISTANCE FROM SAID SAMPLE OUTLET, SAID DRAIN OUTLET BEING SUFFICIENTLY CONSTRICTED TO CAUSE SAID LIQUID STREAM FROM SAID WEIR TO