US3162699A

US3162699A - Vapor liquid contacting apparatus

Info

Publication number: US3162699A
Authority: US
Inventors: Robert B Sivyer
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-02-13
Filing date: 1961-02-13
Publication date: 1964-12-22
Anticipated expiration: 1981-12-22

Description

Dec. 22, 1964 R. B. SIVYER VAPOR LIQUID CONTACTING APPARATUS 2 Sheets-Sheet 1 Filed Feb. 15, 1961 IIZIIAlI/ILLIZ IIMQINQI' I Robe/f 5. J/ Myer INVENTOR.

Dec. 22, 1964 VAPOR Filed Feb. 15, 1961 2 Sheets-Shee 2 O R. O

00 0c 5 o o oo oo o@ o oo 00 0c 0 oo 00 0e 0 N O0 000 0 06 0 OtflU/p u o oo oo ocF fioer/ 5. J/ vye/ INVENTOR.

ATTORNEY United States Patent Ofilice 3,162,699 Patented Dec. 22, 1964 3 162 699 VAPOR LIQUEED CdNTACTING APPARATUS Robert B. Sivyer, 1314 Bentei Drive, Houston, Tex. Filed Feb. 13, 1961, Ser. No. 89,062 7 (Claims. (Cl. 261-114) This application is a continuation-in-part of my copending application Serial No. 20,475, filed April 6, 1960, for Vapor Liquid Contacting Apparatus, now aban doned.

This invention relates to vapor liquid contacting apparatus and, more particularly, to a tray assembly for vapor liquid contacting apparatus to promote intimate contact between a vapor and a liquid.

In general, a vapor liquid contacting apparatus is one in which a liquid, for example, a reflux fluid is continuously passed over a series of horizontal trays spaced vertically with respect to one another while a vapor is passed upwardly through the trays. Various devices heretofore employed to pass the vapor through the trays include many types of so-called bubble caps. In a typical bubble cap construction, there is provided a chimney which extends upwardly from a tray above the liquid level and a slotted cap over the chimney which extends downwardly into the liquid thereby channeling vapor entering the chimney through two 180 turns and thus through the liquid. Another device is theso-called sieve tray containing numerous holes where the vapor velocity is sufficient to prevent the fluid from leaking through the holes. These devices are generally designed for given operating conditions so that variations in the operating conditions very greatly affect the efliciency of the operation. Moreover, sudden variations in the vapor velocity or loading will widely aifect the operation of the apparatus.

Accordingly, it is an object of the present invention to provide new and improved trays for vapor liquid contacting apparatus which are operable in an efiicient manner over a wide range of vapor loading conditions.

Another object of the present invention is to provide new and improved trays for vapor liquid contact apparatus which are relatively economical in construction and maintenance.

Apparatus in accordance with the present invention includes a tray assembly for vapor liquid contacting apparatus wherein a fluid is to be passed over the tray assembly. The tray assembly is comprised of a lower, rigid, base plate member and a plurality of juxtaposed, upper valve plate members which are independently movable in a vertical direction with respect to the base plate member. The base member has a set of flow openings, the flow openings being spaced laterally from one another. Each of the valve plate members superimposed over the base plate are similarly provided with a set of flow openings spaced laterally from one another, the set of openings in a valve plate member-being ofiset relative to the set of openings in the base plate member in such a way that openings in either plate do not overlap. Thus, if the plates are forced in contact with one another, a liquid level or seal is maintained by the tray assembly. According to the degree of vapor loading, the valve plates are forced up vertically to pass vapor through the liquid between the two plate members and through the liquid above the valve plate members.

' The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. l is a view in section through the column shell of a conventional column showing view of a tray embodying the present invention;

FIG. 2 is a plan view of the present invention taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged view of the tray of FIG. 1 in one operating position;

FIG. 4 is an enlarged view of the tray of FIG. 1 in another operating position;

FIG. 5 is a plan view of a portion of a tray assembly of another embodiment of the present invention;

FIG. 6 is an enlarged plan view illustrating a single top valve plate segment of a tray disclosed in the embodiment of FIG. 5;

FIG. 7 is a side view of one operating relationship of the tray embodiment of FIG. 5; and

FIG. 8 is a side view of another operating relationship of the tray embodiment of FIG. 5.

Referring now to FIGS. 1 and 2, the numeral 10 designates the shell of a conventional column which has a typical manhole opening 11 (FIG. 2) for access to the tray assembly 12. A base plate 13 extends horizontally across the column 10 and vertical inlet and

outlet weirs

14 and 15, respectively, are provided on opposite sides of the base plate 13 to generally enclose therebetween, the tray assembly 12. A reflux fluid 16 received on one side of the weir 14 is passed over the inlet weir 14, the tray assembly 12 and the outlet weir 1.5, and thereafter through downpipes 17 to the next lower tray assembly (not shown). assembly 12 (as indicated by the arrow 18 in FIG. 1) in a manner which will become more apparent from the discussion to follow.

A typical tray assembly 12 embodying the present invention includes a lower base plate section 13a defined between the inlet and

outlet weirs

14, 15 and the walls of the column 10, and a plurality of juxtaposed, upper valve plate members 20. While only six such valve plate members are shown, it will be appreciated, from the discus sion to follow, that this number may be varied as may be suitable. The width of the valve plate members is related to the size of the manhole opening 11 (FIG. 2) in the column it) to facilitate installation, maintenance and replacement of the valve plate members. Each of the upper valve plate members 20 is thin relative to the thickness of the lower base plate section.

To permit the passage of vapor through the tray assembly 12, the lower base plate section 13a is provided with a set of circular flow openings 24 spaced from one another, while the upper plate members 20 are also provided with a set of circular flow openings 25 spaced from one another.

Openings

24 and 25, for convenience of illustration, are shown in only one section in FIG. 2 although it will be appreciated that each member 20 and the corresponding portion of the base section 13a have similarly arranged flow openings.

As shown in FIG. 2, the sets of

openings

24 and 25 in the base plate section 13a and valve plate members 20 are offset from one another so that, if the valve plate members 20 are in contact with the lower base plate section, the respective sets of

openings

24, 25 are closed to prevent fluid communication therebetween (FIG. 3). More specifically, the size of the

openings

24 and 25, as well as the spacing between their centers, is such that solid portions in the plate section 13a are great enough to overlap the flow'openings 25 in the valve plate members 20 and vice versa. Thus, when the reflux fluid 16 is flowing over the tray assembly 12 and a minimum vapor loading exists, fluid will not leak through the flow opening-s24 and 25. However, when vapor is forced against the underside of the lower base plate section, theupper valve plate members 29 are displaced upwardly. Thus, the vapor flows through the flow openings 24 in the lower plate member, the space between the valve plate members i and the base plate section, and the openings 25 in'the Ascending vapor passes through the tray 3 upper plate members. The velocity of vapor passing through the tray assembly prevents the liquid from leaking through the openings in the base plate section.

To assure that liquid is present between the valve plate members and base plate section, the openings in the lower base plate section are made smaller than the openings in the valve plate members.

To limit the movement of the upper valve plate members 20, relative to the lower base plate section in both a horizontal and vertical direction, the upper valve plate members 20 are provided with guide openings 2% (FIG. 3) at spaced locations Post members 31, such as bolts threadedly secured to the lower base plate section, are loosely received by the guide openings 30. A stabilizer member 32, such as a flat spring, is secured, and has ends extending over and cont-acting the upper face of a valve plate 20. Preferably, the stabilizer provides a slight force or spring load to balance the plate members and thereby maintain them in a substantially horizontal position.

In operation of the above-described apparatus, it will be appreciated that, for a selected vapor loading condition, the vapor will urge all the valve plate members 20 to their uppermost position, where they are limited by a stabilizer bar 32. The vapor passes along a path from the flow openings 24 in the base plate section, between the valve plates and base section, and through the offset flow openings 25 in the upper valve plate members 20. Thus, eflicient intermixing of vapor and fluid is first achieved between the base plate section and the valve plate members 20 because of the relatively long path that the vapor must travel through the fluid to escape through flow openings 25 in the valve plate members 20. A secondary intermixing occurs as vapor passed through flow openings 25 to the surface of the liquid. The solid area on the valve plate members 20 between the openings 25 then affords a calming or baflling area for the foam to condense and thereby minimize foaming without sacrificing plate area that could be utilized for vapor-liquid intermixing. Preferably, at the selected vapor loading condition, the upper valve plate members 20 are within the fluid seal to insure intermixing between the base and valve plates, and also mixing above the valve plate mem bers.

In a situation of high vapor load and extremely low fluid level, eflicient vapor-fluid intermixing is achieved because valve plate members 20 can be set below the level of the liquid. Thus, vapor passes horizontally through liquid and is somewhat baffled by the valve plate members until the vapor escapes through valve plate openings 25. It will therefore be appreciated that a range of vapor and fluid loadings may be employed in the column with little fluid leakage from a tray assembly and, at the same time, provide an excellent intermixing of the vapor with the fluid.

It will also be appreciated that, while circular flow openings are disclosed, the shape and size of the openings may be varied in either plate to improve the efficiency of the operation.

Referring now to FIGS. 5-8, another tray embodiment of the present invention is illustrated. As shown in FIG. 5, the tray assembly 34 includes a plurality of valve plate members 35 which are disposed over a lower base plate section. The Valve plate members 35 are generally rectangular in shape with their lengthwise or longitudinal axes disposed transverse to the direction of fluid'flow. Each plate member 35 is provided with a set of circular openings 36 and the base plate section subjacent to the respective valve plate members has openings 37. The

openings

36, 37, as described heretofore, are offset relative to one another thereby permitting. the valve plate members 35 to effect an intermixing of the liquid between the valve plate members and base plate section with the vapor as well as intermixing of the fluid above the plate members with the vapor. I

As shown in FIG. 6, openings 36 in plate members 35 may be equidistantly spaced from one another on axes 38 which extend lengthwise or longitudinally of a plate member and may also be uniformly arranged with equ1= distant spacings on axes 39 disposed perpendicular to the lengthwise axes 38. Openings 37 in the base plate section can be arranged on axes in a manner similar to the arrangement of openings 36. The number of openings 37 in the base plate section is dependent upon the area and number of valve plate members 35. In each valve plate member 35, a line or row of openings 36 which would normally be disposed along w axis 38 adjacent to a longitudinal edge 40a is omitted. The omission of a line of openings 36 adjacent to edge 40a presents a relatively wide, unperforated section 40. The u-nperforated section 49 extends inwardly from the one longitudinal edge 40a towards the central section of a plate member and has, for example, a width roughly equal to twice the spacing between adajcent longitudinal axes 38. The unique effect of this unperforated section 4%) relative to the action of the valve plate member 35 will be hereinafter more fully explained.

A hold down mechanism 41 for the valve plate members 35 may include bolts 42 extending loosely through access openings 43 in the plate members 35 and attached to the base plate section. A disc member 43 with a larger diameter than access opening 43 may be fixed relative to the head of the bolt to limit upward movement of a plate member. A hold down mechanism 41 is provided for each longitudinal edge of a plate member. Hence, the valve plate members may assume inclined positions as well as parallel positions relative to the base plate section but are retained within a generally fixed horizontal location by the hold down mechanism 41.

The operation and a further description of the tray assembly may best be understood by a reference to FIGS. 7 and 8. As shown in FIG. 7, the unperforated sections 40 of the valve plate members are disposed transverse to the direction of fluid flow across the tray and to the leeward direction of fluid flow across the tray. For example, if the fluid flow is from left to right in FIG. 7, then the unperforated section 40 is the trailing edge. As before, the valve plate members are contained by the hold down mechanism 41 to a point below the surface of the fluid flow.

By making the openings of the base plate section slight- 1y smaller in diameter than the openings in the valve plate members, the base plate section has a greater pressure drop than the valve plate members to assure the presence of liquid between the valve plate members and base plate section.

The function of the unperforated sections 40 is to control the vapor release to the fluid by maintaining a fairly uniform pressure under the entire base plate section. Uniform mixing occurs because the uniform pressure tends to bring all of the valve plate members into action. At low or designed vapor velocity conditions, the unperforated sections 40 of the plate members 35 provide a resistance or deflection surface to the vapor thereby to raise first by tilting or pivoting the plate members. The plate members which are tilted are thus inclined into the direction of fluid flow. The vapor is passed mainly through openings 36 and the liquid between the plate members and base plate member and out around edge 40a. The unperforated section 40 thus provides a trailing edge section with sutficient resistance surface area to tilt the plate valve members into the fluid flow under given vapor loading conditions. As the vapor velocity increases, intermixing of the vapor and liquid increases and of course at high vapor velocities, the plate members are completely separated from the base plate section (FIG. 8).

It will be appreciated that the tray assembly provides two zones of intermixing, a zone between the valve plate members and base plate section and a zone above the valve plate members. The'impact of vapor with the liquid between the valve plate members and base plates section causes a violent intermixing under the valve plate members due to their bafliing effect. The vapor, however, escapes through the openings 36 and is again intermixed with the fluid above the valve plate members. It should further be noted that less entrainment is expected With this tray assembly because of the baffling ellect of the valve plate members. Facility of design is also readily apparent since pressure drop can easily be changed by plate sections with difierent diameter openings.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects. For example, the frequency, size, shape and location of the openings in the plate members may be varied to regulate capacity and efficiency of the apparatus. Also, many other types of securing means to prevent dislocation of the relative positions between the upper and lower plate members will be readily apparent to one skilled in the art. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A tray assembly for vapor-liquid contacting apparatus, for use in a fractionating column or the like wherein a fluid passes over the tray assembly while a vapor is to be passed through a section of the tray assembly to intermix With the fluid comprising: a lower, rigid base plate 1 arranged to be horizontally disposed in a tubular column and a plurality of juxtaposed, upper valve plates superimposed on said base plate, said base plate having a first plurality of cylindrical flow openings respectively spaced laterally from one another thereby forming lower open and solid areas, said valve plates each having a second plurality of cylindrical flow openings respectively spaced laterally from one another thereby forming upper open and solid areas, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed over lower open areas so that the first flow openings do not overlap the second flow openings thereby preventing fluid leaking with minimum vapor loading and providing solid areas sized for bathing vapor passing through said base plate, means for permitting independent vertical movement of said valve plates between a contact position with the base plate and a position below the expected fluid level.

2. A tray assembly for vapor-liquid contacting apparatus comprising: a lower, rigid base plate and a plurality of juxtaposed, upper valve plates superimposed on said base plate, means mounting said upper valve plates on said base plate section for vertical movement, said base plate having a first plurality of lower flow ports respectively spaced laterally from one another thereby forming lower open and solid areas, each of said valve plates having a second plurality of upper flow ports respectively spaced laterally from one another thereby forming upper open and solid areas, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed above lower open areas so that the upper flow ports in the valve plates donot overlap the lower flow ports in the base plate and said solid areas of said valve plates are sized to provide substantial baflling areas.

3. A tray assembly for vapor-liquid contacting apparatus comprising: a lower, rigid base plate and a plurality of juxtaposed, upper valve plates superimposed on said base plate, means mounting said upper valve plates on said base plate section for vertical movement and for limiting vertical movement of said valve plates relative to said base plate, said base plate having a first plurality of lower flow ports respectively spaced laterially from one another thereby forming lower open and solid areas, each of said valve plates having a second plurality of upper flow ports respectively spaced laterally from one another thereby forming upper open and solid areas, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed above lower open areas so that the upper flow ports in the valve plates do not overlap the lower flow ports in the base plate and said solid areas of said valve plates are sized to provide substantial baffling areas, said upper flow ports being larger than said lower flow ports.

4. A tray assembly for vapor-liquid contacting apparatus for use in a fractionating column or the like comprising: a lower, rigid base plate arranged to be horizontally disposed in a tubular column and a plurality of juxtaposed, upper valve plates superimposed on said base plate, means for securing said upper valve plates in their juxtaposed position yet permitting each valve plate to move independently in a vertical direction relative to said base plate, said base plate having a first plurality of lower flow ports respectively spaced laterally from one another thereby forming lower open and solid areas, said valve plates each having a second plurality of upper flow ports respectively spaced laterally from one another thereby forming upper open and solid areas, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed above lower open areas so that the upper flow ports in the valve plates do not overlap the lower flow ports in the base plate and said solid areas of said valve plates are sized to provide substantial baifling areas.

5. A tray assembly for vapor-liquid contacting apparatus wherein a liquid is to flow generally in a horizontal direction across the tray assembly and a vapor is to flow generally in a vertical direction through the tray assembly and liquid, such apparatus comprising: a lower, rigid base plate and a plurality of juxtaposed, upper valve plates superimposed on said base plate, means for vertically biasing said upper valve plates toward said base plate, said base plate having a first plurality of lower flow ports respectively spaced laterally from one another thereby forming lower open and solid areas, said valve plates each having a second plurality of upper flow ports respectively spaced laterally from one another thereby forming upper open and solid areas, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed above lower open areas so that the upper flow ports in the valve plates do not overlap the lower flow ports in the base plate and said solid areas of said valve plates are sized to provide substantial baflling areas.

6. A tray assembly for use with a vapor-liquid contacting apparatus wherein a liquid is to flow generally in a horizontal direction across the tray assembly and a vapor is to flow generally in a vertical direction through the tray assembly and liquid, said assembly comprising: a lower, rigid base plate and a plurality of juxtaposed, upper valve plates superimposed on said base plate, means for attaching said upper valve plates relative to said base plate to permit limited vertical movement'within given horizontal confines, said base plate having a first plurality of lower flow ports respectively spaced laterally from one another thereby forming lower open and solid areas, each of said valve plates having a second plurality of upper flow ports respectively spaced laterally from one another thereby forming upper open and solid areas, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed above lower open areas so that the upper flow ports in the valve plates do not overlap the lower flow ports in the base plate and said solid areas of said valve plates are sized to provide substantial baflling areas, said valve plates respectively having trailing edge sections of solid areas transverse to the direction of fluid flow dimensioned to provide sufficient resistance surface area where, under given vapor loading conditions, the upper surface of a valve plate will be inclined into the fluid flow.

7. A tray assembly for use with a vapor-liquid contacting apparatus wherein, a liquid is to flow generally in a horizontal direction across the tray assembly and a vapor G is to flow generally in a vertical direction through the tray assembly and liquid, said assembly comprising: a lower, rigid base plate and a plurality of juxtaposed, upper valve plates superimposed on said base plate, means for attaching said upper valve plates relative to said base plate to permit limited vertical movement within given horizontal confines, said base plate having a first plurality of lower flow ports respectively spaced laterally from one another thereby forming lower open and solid areas, each of said valve plates having a second plurality of upper flow ports respectively spaced laterally from one another thereby forming upper open and solid areas, said upper flow ports being larger than said lower flow ports, said upper open areas being disposed above lower solid areas and said upper solid areas being disposed above lower open areas so that the upper flow ports in the valve plates do not overlap the lower ilow ports in the base plate and said solid areas of said valve plates are sized to provide substantial baffling areas, said valve plates respectively having trailing edge sections of solid area transverse to the direction of fluid flow dimensioned to provide sufficient resistance surface area whereby, under given vapor loading conditions, the upper surface of a valve plate will be inclined into the fluid flow.

References Cited by the Examiner UNITED STATES PATENTS 502,750 8/93 ONeil 1375l6.l1 1,768,843 7/30 Holdsworth 137516.1l 2,415,048 1/47 Sharp 26 ll24 2,627,397 2/53 Hendrix.

2,658,737 11/53 Nutter. 2,690,763 10/54 Seligrnan 137-516.ll 2,718,900 9/55 Nutter. 2,836,406 5/58 Nutter.

GEORGE D. MITCHELL, Primary Examiner.

HERBERT L. MARTIN, Examiner.

Claims

2. A TRAY ASSEMBLY FOR VAPOR-LIQUID CONTACTING APPARATUS COMPRISING: A LOWER, RIGID BASE PLANT AND A PLURALITY OF JUXTAPOSED, UPPER VALVE PLATES SUPERIMPOSED ON SAID BASE PLATE, MEANS MOUNTING SAID UPPER VALVE PLATES ON SAID BASE PLATE SECTION FOR VERTICAL MOVEMENT, SAID BASE PLATE HAVING A FIRST PLURALITY OF LOWER FLOW PORTS RESPECTIVELY SPACED LATERALLY FROM ONE ANOTHER THEREBY FORMING LOWER OPEN AND SOLID AREAS, EACH OF SAID VALVE PLATES HAVING A SECOND PLURALITY OF UPPER FLOW PORTS RESPECTIVELY SPACED LATERALLY FROM ONE ANOTHER THEREBY FORMING UPPER OPEN AND SOLID AREAS, SAID UPPER OPEN AREAS BEING DISPOSED ABOVE LOWER SOLID AREAS AND SAID UPPER SOLID AREAS BEING DISPOSED ABOVE-LOWER OPEN AREAS SO THAT THE UPPER FLOW PORTS IN THE VALVE PLATES DO NOT OVERLAP THE LOWER FLOW PORTS IN THE BASE PLATE AND SAID SOLID AREAS OF SAID VALVE PLATES ARE SIZED TO PROVIDE SUBSTANTIAL BAFFLING AREAS.