US2682277A

US2682277A - Apparatus for obtaining fluid samples and quenching same

Info

Publication number: US2682277A
Application number: US90154A
Authority: US
Inventors: Benjamin T Marshall; Mason L Downing; Paul J Harrington
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1949-04-28
Filing date: 1949-04-28
Publication date: 1954-06-29
Anticipated expiration: 1971-06-29

Description

June 29, 1954 B. T. MARASHALL ETAL APPARATUS FOR OBTAINING FLUID SAMPLES AND QUENCHING SAME Filed April 28, 1949 2 Sheets-Sheet 1 June 29, 1954 B. T. MARSHALL ETAL 2,682,277

APPARATUS FOR OBTAINING FLUID SAMPLES AND QUENCHING SAME 2 Sheets-Sheet 2 Filed April 28, 1949 BENJAMIN T. MARSHALL Ill WM!!! 1 111 I 1: 55 111.

' INVENTORS ATTORNEY 6 Wm W W 0W DR R M mufl Y Patented June 29, 1954 APPARATUS FOR OBTAINING FLUID SAMPLES AND QUENCHING SAME Benjamin T. Marshall and Mason L. Downing,

Westfield, and Paul J. Harrington, Mountainside, N. J., assignors toStandard Oil Development Company, a corporation of Delaware Application April 28, 1949, Serial No. 90,154

4 Claims.

The present invention relates to an apparatus for withdrawing fiuid samples from a process vessel. More particularly, the invention relates to a means for withdrawing samples of vaporous materials from a reaction vessel, at elevated temperatures and pressures, by which the reaction process of such materials is substantially quenched at the point of removal of the sample from a reaction vessel. The invention is also concerned with preventing the deposition of reaction or decomposition products in the sampling system. More particularly, the invention relates to an apparatus for sampling hydrocarbon vapors drawn from a cracking furnace where they may be held at temperature in the vicinity of 900 to 1100 F. or even higher, and under pressures substantially in excess of atmospheric pressure.

It is an object of the invention to provide a sampling valve structure in which flow of the sample withdrawn from a reaction zone may be positively controlled at the source. It is also an object of the invention to provide the means whereby a sample may be quenched as withdrawn so as to reduce its temperature, substantially at the source of the sample, to a degree below that at which reaction of the material may continue, and to thereby prevent the formation of reaction and decomposition products during passage through the sampling system.

In processes involving the high temperature treatment of fluid materials, such a the cracking of hydrocarbons by passing hydrocarbon materials through a cracking coil furnace, it is frequently desirable to ascertain at various points during its passage through the reaction system, the progress of the reaction taking place in the material. The information thus obtained may be utilized for the purpose of adjusting the flow rate of the materials through the heated zone in which the reaction takes place, or for the purpose of regulating and controlling heat input to such zone. Conventional apparatus for this purpose has been found to be generally unsatisfactory for the reason that the samples withdrawn do not truly represent thecondition of the material being treated, at the point of withdrawal. The difference in the characteristics of the sample, and the material from which separated, appears primarily to be due to continued reaction in the sample after withdrawal. The material of the sample, retaining a substantial portion of the reaction temperature, continues to react at such temperature during passage through the sampling apparatus, thus produc- 2 ing a change in its characteristics as compared with that of the material at the point of withdrawal. In the apparatus, according to the present invention, this deficiency of the conventional sampling apparatus is substantially overcome.

The invention and its objects may be more fully understood from the following specification when read in conjunction with the accompanying drawings, in which Figure l is a vertical section through a sampling device for connection in or to a reaction vessel;

Figure 2 is a similar view through a modified form of such sampling device; and

Figure 3 is an enlarged vertical section through the valve and seat portion of a modified form of the device a shown in Figure 2.

A sampling valve, according to the present invention, is particularly illustrated by Figure 1. In this figure, the numeral 3| designates a nipple provided for threaded connection in a passageway 5?) through a boss 5a on a tube return bend member 5 of a cracking coil. The passage 51) has a slight inward taper from the interior of the return bend 5 toward the threaded portion of the passage, and the threaded portion of the passage is provided with a slight outward taper. The nipple 31 is provided with a flanged portion 3 in adapted for engagement by a wrench in order to seat the nipple firmly and in fluidtight connection in the passageway 5b. The outer end of the nipple 3| at the flange portion 3 la is joined as by welding to a valve casing member 32 which extends outwardly from the nipple through the header box 2 and a suitable closure 2w therefor. The outer end of casing 32 is joined, as by welding, toa bonnet assembly including stuifing box member 33 having a central passageway 33a provided with an enlarged shouldered portion 331) at one end to receive the outer end of the casing member 32, and enlarged shouldered portion 330 at the other end to receive a packing material 33d. That portion of the passageway 33a intermediate the enlarged shouldered portions is threaded to engage a similarly threaded portion 34a on a hollow valve stem 34 extended through the stuifing box and the hollow casing 32. The valve stem 34 is extended outwardly beyond the stuffing box member 33 and is provided with a valve wheel 342) at its outer end. The hollow valve stem 36 is provided at its inner end with a plug valve member 35 for'disposition beyond the inner end of the nipple 3|, and adapted to engage a seat 3113 provided therefor at the inner end of the nipple.

Ports 36 are provided in the wall of the hollow valve stem opening therethrough into the annular space between the valve stem and the easing 32. Preferably, these ports are disposed substantially at a 45 angle, with reference to the center line of the valve stem and open rearwardly into the annular space around the stem. At the other end of the valve stem intermediate the valve wheel 34b and the stuifing box member 33, port 31 open outwardly from the interior of the valve stem, through the wall thereof, into the hollow interior of a header member 38.

The header member 38, as shown, is formed by means of annular, disc-shaped top and

bottom elements

39 and 40 respectively, separated and joined by means of a cylindrical wall element 4|, the valve stem 34 extending through the central opening in each of the top and

bottom elements

39 and 40. The center opening in the top element 39 is provided with an enlarged portion, lying substantially within an exterior boss 39a, in which is disposed a packing material 39b, compressed and held in fluid-tight engagement with the valve stem by means of a flanged gland member 390. The gland member 390 is made to compress the packing material 3% by means of nuts 39d acting on the threaded outer ends of stud bolts 39c. The bottom element 40 is provided with an annular boss 40a concentric with the central opening through such element, which boss serves as a gland member to compress and hold the packing material 33d in fluid-tight relation to the valve stem, pressure being applied for this purpose by means of stud bolts 4% threaded into the bottom element 40 and extending outwardly through bolt holes in a flanged portion on the element 33 for engagement by nuts 40c.

Provision is made for the supply of a quenching fluid to be introduced into the hollow header member 38 by means such as the coupling element 41a secured as by welding in a suitable passageway through the wall of the element 4|, the coupling lla being interiorly threaded to receive a supply conduit such as conduit 1. An alternate location for the conduit 7 may be provided as by means of coupling element 41b, and a plug member 4lc provided to close either one of the coupling elements Me or 4lb, whichever is not connected in the supply system. Means for a supplementary supply of quenching fluid is provided by

coupling elements

42 and 43 joined to the casing 32 in fluid-tight relation as by welding.

Ports

32c and 32b in the wall of the casing 32 providing an inlet and an outlet, interchangeably, from the interior of the casing through the coupling elements and lines 9 and I respectively. Quenching liquid from the interior of the casing, and the sample material introduced through the nipple 3| may be discharged, with quenching liquid introduced through line 9, by way of line 10.

In the operation of the valve as shown, a quenching fluid is introduced normally through a line i into the header 38 and thence through the ports 3] into the interior of the valve stem. Simultaneously, a supplementary supply of quenching fluid may be introduced through the line 9, if desired. The valve is then opened by threading the valve stem into the casing and passageway 33a by means of the handle 34b, the plug 35 thus being moved inwardly away from the seat 3lb admitting a stream of material from the return bend through the passage 5?) in boss 5a, and the nipple 3|. The sample thus admitted passes through the annular passage in the casing 32 surrounding the valve stem 34 and is quenched by means of quenching fluid issuing from the ports 36 at the inner end of the stem adjacent the plug 35. The sampled material along with the quenching fluid flows through the annular passageway in the casing 32 and is discharged through the port 32b and the conduit In, As indicated, if desired, additional quenching fluid may be passed through the casing at this point by means of the conduit 9, or, if desired, the coupling 42 may be provided with a suitable closure plug. It is also contemplated that, if found necessary, the connection of the line 9 and line ID to the casing 32 may be made through an eductor mechanism for the purpose of producing a slightly negative pressure in the annular passage through the casing 32, thereby tending to accelerate removal of the quenching fluid and the sample passed therethrough. When it is desired, the valve may be flushed with a cleaning liquid, or a fluid such as steam, by introducing such fluid through lines '5 and 9. If suflicient pressure is applied to the cleaning fluid, it may be discharged into the return bend 5, otherwise it may be exhausted through line [0.

In the apparatus, as illustrated by Figure 2, the numeral 5| designates a nipple provided to be threaded into a passageway 5b through the boss 5a and having an end portion 51a provided with an annular valve seat member 5H) and an inwardly faced valve seat 5lc. In this modification, a two part casing element 52 is provided, the parts 52a and 521) being joined by a 4-way coupling member 53. The inner portion 52a of the casing element is joined at its inner end, as by welding, to the nipple member 5| and at the outer end is provided for threaded engagement with the coupling 53. The outer portion 52b of the casing 52 is provided for threaded engagement at its inner end with the coupling 53 in opposed relation to the outer end of the portion 52a. The outer end of the portion 52b is provided to serve as a stuifing box, and is adapted to receive a packing gland member 54, packing 55, and a stop member 56, which may be an annular shoulder portion in the casing or a separate member rigidly secured therein. This member 56 and a comparable member 51 at the inner end of the casing also serve as bearings for a valve stem 58 extending concentrically through the casing 52. The packing 55 may be compressed between the element 56 and the gland 54 to bear against the valve stem 58 and provide a fluid-tight seal therewith, by means of bolt and nut members 59 passed through co-incidental bolt holes in opposed flange portions on casing portion 52b and gland 54.

In place of a bonnet for the valve, a yoke member 60 is provided which is secured to the valve casing as at 60a and extends outwardly beyond the end of the gland 54. The outer end of the yoke 60 is provided with threaded passageway to receive the end of the valve stem, also threaded. By this means, the valve stem is engaged in the passageway for reciprocal movement of the stem when rotated by means of the valve wheel 6 l. The inner end of the stem is provided with a conical valve portion 62 adapted to be seated against the inwardly faced seat 5 la in the annular member 51b. In the form of the valve, as illustrated, quenching liquid is supplied through the coupling 53 by way of the line 3 and is discharged therefrom by way of the line [0. Preferably, this connection is made through a conventional form of eductor mechanism for the purpose or" creating a negative pres-sure in the casing portion 52a and the nipple -51, whereby the material entering the nipple through the member 5!?) is quickly withdrawn and quenched. Operation of the valve described, and illustrated by Figure 2, is otherwise comparable to that set forth with reference to Figure 1. The line 9 is connected to a source of quenching fluid, while the line 10 is connected to suitable means for recovering the sample.

In the modification illustrated by Figure 3, the hollow valve stem 34 is provided at its inner end With a plug valve member 6|, comparable to the member 35 of Figure 1, but hollow, and opening into communication with the hollow valve stem. The stem 34 in this form opens into the valve 6|, ports 62 in the valve member Bl being substituted for the stem ports 36 shown in Figure 1. The ports 62 are disposed so as to remain open at all times, being located beyond the seating face 61a of the valve member, and the valve seat 3llb. By this means a continuous stream of quenching fluid may be discharged through the passageway 52) when the valve is closed tending to prevent deposition of reaction products between the valve member and the walls thereof, and preventing seizure of the valve member in the passage.

When the valve is opened, the ports Gla tend to direct the flow of quenching fluid toward the entrance to the nipple 3I and the fluid and sample may be discharged into the casing under ressure from the coil. Also by introducing the quenching fluid beyond the valve seat 3 lb, small particles of foreign matter may be more readily prevented from depositing on the seat.

What is claimed is:

1. A valve structure, comprising a hollow casing, having an inner end and an outer end, a valve inlet port in the inner end of said casing, a valve seat in said port facing outwardly therefrom, a hollow header member carried on the outer end of said casing in fixed relation thereto, a hollow valve stem longitudinally of said casing extending outwardly therefrom through said header member and disposed in annularly spaced relation to said casing, a valve member on said stem disposed exteriorly of the casing and engageable with said valve seat by reciprocal movement of the stem, a fluid-tight seal for said stem at the outer end of said casing, said seal also separating the interior of said casing from that of said header, inlet ports in said stem communicating between the interior of said header member and the interior of said stem, discharge ports in said stem adjacent said valve inlet port communicating with the interior of said stem and opening angularly outward therefrom substantially in the direction of flow through said port into the casing, an outlet from said casing intermediate the ends thereof, and means for reciprocally moving said stem longitudinally of said casing.

2. A valve structure according to claim 1, in which the discharge ports communicating with the interior of said stem open therefrom into the interior of the casing inwardly of the valve port.

3. A valve structure according to claim 1, in which the discharge ports communicating with the interior of said stem open therefrom through said valve member beyond the surface of said valve seat when the valve member is in engagement therewith.

4. A valve structure, comprising a hollow casing element, having an inner inlet end and an outer end, a valve inlet port at the inner end of said casing and a valve seat in said port facing outwardly therefrom, a combination header and packing gland member in rigid, fluid-tight engagement with the other end of said casing, a hollow valve stem extended through said headergland member and casing, in threaded, fluid-tight relation to said header-gland member and reciprocally moveable therethrough, a valve member on said stein disposed exteriorly of the casing for engagement with said seat by reciprocal movement of the stem, inlet ports in said stem communicating between the header and interior of the stem at one end and discharge ports communicating with the interior of the stem at the other end to open angularly outward therefrom substantially in the direction of flow through said inlet port into the casing, conduit means for supplying a fluid material through the header and stem, conduit means, intermediate the ends of said casing, opening from the casing to discharge fluids therefrom, an operating element for said valve stem, and supplementary conduit means, intermediate the ends of said casing, for introducing a fluid material into said casing exteriorly of said hollow valve stem and intermediate the inlet and discharge ports therein.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,834,305 Goodwin Dec. 1, 1931 2,084,397 Hildebrandt June 27, 1937 2,209,296 Jewell et al July 23, 1940 2,376,542 Kimmell May 22, 1945 2,380,977 Lewis Aug. 7, 1945 2,410,960 Bunn Nov. 12, 1946 2,520,692 Powell Aug. 29, 1950