US2084726A

US2084726A - Bubble cap

Info

Publication number: US2084726A
Application number: US70268A
Authority: US
Inventors: Duey Harold Stewart
Original assignee: Standard Oil Company of California
Current assignee: Standard Oil Company of California
Priority date: 1936-03-23
Filing date: 1936-03-23
Publication date: 1937-06-22
Anticipated expiration: 1954-06-22

Description

H. 'S. DU EY BUBBLE CAP June 22, 1937.

Filed March 23, 1936 I Patented June 22, 1937 UNITED STATES PATENT OFFICE amaze BUBBLE car Application March 23, 1936, Serial No. 70,268

11 Claim.

be positioned to vary the spacing between the lower effective edge of the cap and the plate or deck to which it is fastened, and thereby permit individual adjustment of the cap submergence.

I Inthe art to which this invention pertains, it is often necessary to arrange a great number of individual bubble caps on a single plate of large diameter, and, to obtain a low pressure drop of the gas passing through the caps and the liquid 5 on the plate, the submergence, or distance to which the lower effective edge of the plate dips into the liquid, is made very small. It is well known that the uniform flow of liquid across a plate of this nature requires a difference in hydraulic head, and the magnitude of that difference may be such that the caps on one side of theplate, where the liquid is admitted to the plate, may be submerged too deeply, while those caps on the discharge side may be entirely out of theliquid, thereby by-passing the gas or vapor without adequate contact by bubbling through the liquid.

Various plans have been proposed to prevent this action, such as the use of multiple liquid downspouts, liquid pools at various levels, weirs, baflles and the like, but all of these are expensive, bulky and not adapted to free fluid and gas flow.

The expense of making and adjusting caps with risers or supports of different fixed heights is so great that such an alternative is not practicable.

This invention, however, comprehends a combination of a bubble cap with a riser of a construction that will permit of easy and accurate individual'submergence adjustment within wide 6 limits and without removing the assembly from the bubble plate or its enclosure.

Another object is to provide a cap, riser and strongback combination that will give a minimum of pressure drop due to gas or vapor flow.

Another object is to provide a bubble cap and riser assembly in which the mutually contacting surfaces of said cap and riser are formed with a plurality of spaced seating surfaces, inclined planes, or steps so that the spacing between said cap and said riser may be varied by a partial rotation of said cap with regard to said riser.

Another object is to provide a cap, riser and strongbackcombination that may be fabricated by a simple casting operation, and that will require no machine operations other than the usual simple cleaning up.

These and other objects and advantages will be more fully apparent from the following description and from the attached drawing, which forms a part of this specification, and illustrates a preferred embodiment of this invention.

The drawing is a vertical sectional view through a bubble plate and a bubble cap, vapor riser and strongback holding said cap in place in an opening in said plate.-

In the drawing, reference numeral I0 designates a bubble plate, as for example in a fractionating column. The function of this plate is to support a liquid on its upper surface through which a gas or vapor is bubbled or otherwise contacted, the vapor rising through a plurality of openings spaced at the desired intervals about the plate l0, one of which openings is indicated at H. 4

A generally cylindrical riser I2 is provided with a circumferential shoulder l3 at its lower edge, which seats on a gasket I4 surrounding opening I I in plate l0, and thus makes a fluid tight joint at that point. The body of riser I2 is preferably of a reduced diameter or modified venturi shape indicated at l5, thus taking advantage of the normal vena contracta path of gas flow through such an opening in a plate, and thereby reducing the pressure drop therethrough. The upper end of riser I2 is preferably formed in a circumferential series of spaced inclined planes or steps It, usually three in number, on which the main cap I1 is adjustably supported, as will be described below. I 35 The cap or bell I1 is adapted to fit over the top of riser l2 and to be centered thereon by a plurality of inwardly directed webs l8, which may be stepped as at [9 to seat upon the top of inclined planes It. In their preferred form, steps I9 and planes it are relatively smooth in configuration, but if it is desired to secure them against the possibility of accidental dislodgment, small steps, serrations, or interlocking teeth could readily be provided on either or both, without departing from the invention.

The lower and outer edge of cap I! may be serrated or notched as at 20 or may have any of the customary types of perforations, slots or similar shapes to insure fine division of the gas issuing from beneath the edge into the liquid on the plate Ill.

In order to retain riser l2 and cap ll in place in opening H, a strongback 2| preferably is provided, adapted to engage the lower face of plate l0 asby arms 22, which extend outwardly and terminate in shoulders 23 seating in opening H and being guided by slots 24 in the lower edge of riser l2. Strongback 2| is preferably made oi? skeleton form, with arms 22, in this case three in number, radiating outwardly and upwardly from a central boss 25, and of such configuration and projected area as to offer little resistance to vapor flow. Boss 25 may be centrally bored out Or cored as at 26 to receive a through bolt 21,- the head 28 of the bolt being retained in a squared recess 29 to prevent its turning relative to the' strongback 2|.

Cap I1 is also provided with a central hole 30 through which the upper end of bolt 21 passes and to which the cap is secured as by washer 3| and threaded nut 32. The inside of cap 30 may be shaped into a boss as shown at 33, to form a passage of substantially uniform area for the vapor or gas passing up through riser I12 and thence downwardly under the edge of the cap 11 into the liquid.

The operation and advantages of the assembly, to obtain the desired vertical spacing of the top of serrations 20 from plate II] are quite obvious from the drawing. Loosening nut 32 on bolt 2'! permits cap I! to be turned relative to the riser l2, and steps l9 are adjusted on inclined planes 46, to give the desired spacing between the edge of the cap and the top of plate III, which also is a function of the height of cap I! above riser l2.

Although a specific construction of a bubble cap assembly is described and illustrated, it will be understood that many variations may be made from the example shown, and all such modifications as come within the scope of the appended claims are embraced thereby.

I claim:

1. A bubble cap assembly comprising a. riser, a cap for said riser, and mutually contacting means on said riser and said cap provided with circumferentially spaced seating surfaces of such a character that the spacing between said riser and said cap may be varied by a partial rotation of said cap with regard to said riser.

2. A bubble cap assembly according to claim 1 with the addition of means for seating said riser over a hole in a plate and means engaging said plate for holding said cap and said riser in place thereon.

3. A bubble cap assembly according to claim 1 with the addition of means 'for seating said riser over a hole in a plate and means engaging said plate and said riser for holding said cap in place on said riser.

4. A bubble cap assembly adapted to cover an opening in a plate, comprising a generally cylindrical riser adapted to be seated over said opening, said riser being provided with a plurality of spaced inclined planes, a cap for said riser, and. means on said cap adapted to be selectively seated .on said planes to vary the spacing between said cap and said plate.

5. A bubble cap assembly according to claim 4 with the addition of means engageable with said plate to hold said cap and said riser in position thereon.

6. A bubble cap assembly according to claim 4 with the addition of a member adapted to straddle said opening beneath said riser and means passing through said member and said cap for clamping said cap and said riser to said plate.

7. A bubble cap assembly adapted to cover an opening in a plate, comprising a generally cylindrical riser with a base adapted 'to be seated over said opening, the upper end of said riser being provided with seating surfaces at varying distances from said base, a cap for said riser, and means on said cap adapted to be selectively seated on said surfaces of said riser to determine the spacing between said cap and the base of said riser.

8. A bubble cap assembly according to claim 7 with the addition of means engaging the plate on the opposite side from said riser, said last named means provided with means adapted to clamp said cap and said riser in the desired position.

9. A bubble cap assembly according to claim '7 in which theseating surfaces on said riser are symmetrically and circumferentially spaced therearound so that the spacing between said cap .and the base may be varied by a partial rotation of said cap with regard to said riser.

10. A bubble cap assembly adapted to 'cover an opening in a plate, comprising a generally cylindrical riser seated in said opening, a plurality of inclined planes at the top of said riser, a cap for said riser,'webs in said cap adapted to center it over said riser, and to seat on said inclined planes, a strongback for said opening below said plate, and a bolt passing through said strongback :and said cap to clamp said assembly together and to said plate.

11. A bubble cap assembly according to claim 10 in which said riser tapers inwardly toward its