US2528062A - Liquid-permeable tank bottom for beds of granular material - Google Patents

Description

Oct. 31, 1950 E. LANCES LIQUID-PERMEABLE TANK BOTTOM FOR BEDS 0F GRANULAR MATERIAL Filed Feb. 12, 1948 4 Sheets-Sheet 1 FIG. I.

FIG.2.

E c m m Y T m m E R v o m N E T A 3 w I Y Mm B a W Rim a a mm 3 mu. 2 7 u /0 v. 2

a fi mmw w A 5 w L. E. LANCES 2,528,062 LIQUIDPERMEABLE TANK BOTTOM FOR BEDS 0F GRANULAR MATERIAL Oct. 31, 1950 4 Sheets-Sheet 2 Filed Feb. 12, 1948 g Q 8 gig 5O INVENTOR:

LEO E. LANGES, BY 3 i r I ATTORNEY Rm 6 F 0a. 31, 1950 E. LANCES LIQUID-PERMEABLE TANK BOTTOM FOR mans OF GRANULAR MATERIAL 4 Sheets-Sheet 3 Filed; Feb. 12, 1948 INVENTORZ LEO E; LANCES,

Oct. 31, 195B 1.. E. LANCES LIQUID-PERMEABLE TANK BOTTOM FOR BEDS 0F GRANULAR MATERIAL FIG. l2.

FIGE.

mm w W/// W/ M nu INVENTORZ LEO E. L ANCES,

ATToRE Patented Oct. 31, 1950 LIQUID-PERMEABLE TANK Bo'r'roM FOR BEDS or GRANULAR MATERIAL- r Leo E. Lances, New York, N. Y., assignorgto The Dorr Company, Stamford, Conn., a corporation I of Delaware Application February 12, 1948, Serial N0.:'7,958

This invention relates to apparatus for treating liquids, in which the liquid percolates through va bed of granular material contained in a tank.

More specifically it relates to improvements in .the structure for supporting the bed of material sectional area of the bed. Yet it is desirable that the bed-supporting structure be compact in the sense that it should occupy only a minimum. of vertical tank space in order to detract a minimum from the operative height of the tank as well as to minimize the volume of liquid which might. be detained within or by the passages of the supporting structure itself. The importance of some of the more specific problems just mentioned will appear more clearly in the course of the subsequent description. While the improvements in the bed-supporting and liquid-distributing structure of this invention may apply to plain filter operations with beds of granular filter material that is inert with respect to the liquid being filtered therethrough, the improved structure appears to be of special significance when applied to the operation of beds of granular contact material, thatis material reacting chemically with the liquid or solution percolating through the bed.

An important; application of the improved structure lies in its use for the operationof beds of granular ion exchange material,=such materials being for example in the nature of organic: or synthetic resinous materials variously also know as exchange resins or as organolites. By way of example, the bed-supporting structure of this invention may be embodied in' an apparatus adapted to gserve-for the purification On the other hand the liquid 7 Claims. (Cl. 210148) treatment liquids through-ion exchange whereby dissolved inorganic salts if ionized may-be re.- rnoved from asolution containing 13116111. Ini'this way, for example, sugar-bearing solutions or sugar juices may be freed of non-sugars or impurities represented by salts in solution, such as naturally derived sugar juices.

Taking the case of purifying and de-ionizin'g beet sugar juice as an example, the sugar solution containing the dissolved and ionizedsalts or impurities is passed sequentially through abed 1 exchange material.

. 2 of cation exchange material and a bed of anion The treatment unit containing-theqcati'on exchange material is herein alsocalled a, cation exchange cell or station, while the unit containing the anion exchange material is also termed ananion exhange cell or station. The principle of the chemical mechanism per se of such a, de-ionizing or purification operation through ion exchange .is well known. Briefly the cation exchange material having been loaded with exchangeable H-ions by regeneration or treatmentwith a strong mineral acid such as H2804 of a suitable concentration upon contact with the sugar juice takes up the cations of the ionized salt while releasing the molar equivalent of; H-ions into the solution or juice and to that extent acidifying that solution. The thus acidified sugar juice then passes through the anion exchange material which has previously been regenerated, by contact with an alkali such as NazCOs of a suitable strength. The thus conditioned anion exchange material upon contact with the acidified 'sugar juice adsorbs the acid previously induced in the juice and thus there passes from the bed a juice that is purified, that is, freed of salts as well as substantially neutralized. ,The'anion exchange ,material therefore is also termed an acid-adsorbing exchange material. Another interpretation is that the anion exchange material by regeneration becomes loaded with exchangeable OH-ions which are subsequently contained in sugar juices tend to be changed to invert sugars in an acid medium whereby they 'lose the ability to crystallize. Where the objective is to obtain crystallized sugar as the end product following ionic purification of the sugar juice,

"it is desirable to minimize the time of detention ofthe juice; in the acid-phasethat is temporarily inducedin -the juice due to the exchange of cations against-H-ions, in order that inversion .might bediscouraged; The compactness of the bed-supportingstructure according to this in'-- vention; is a contributing that detention. H

In the case of ionic sugarjuicepurification it is 'impor'tant fo'r several reasons that the flow of liquid be uniformly distributed throughout the cross-sectional area of the bed. One reason is that the bed should be progressively and uniformly exhausted in the direction of the flow of the juice through the bed. Another reason is that when displacing residual sugar juice or regenerant solution from the bed with water .there should be as nearly as possible a volumetric displacementof the residual volume from the bed,

factor in minimizing that is the displacement should take place with a minimum of intermixing between the displacing volume of water and the respective volume of liquid that is being displaced by it. This illustrates the specific importance of the improvements in the bed-supporting and liquid-distributing structure according to thisinvention.

In view of the foregoing objects, this invention or cormnunicating openings between the channel system and the bed of granular material resting upon the cover plate. Each of the openings in turn is provided upwardly with a multiple passage distributing head or distributing cap.

According to one feature a member or gasket of liquid permeable or porous or finely reticulated material is interposed between the distributing cap and the cover plate.

According to another feature the distributing cap is in the form of a flange member held to the cover plate by anchoring bolts. Other features lie in the specific construction of the distributing heads and in the manner of their attachment to the cover plate. Still other features lie in more specific arrangements of multiple passages or liquid-distributing slots in the distributing heads.

In one embodiment strip-like sections longitudinally coextensive with the secondary channels take the place of the cover plate. More specifically, each distributing head is held by bolts or studs extending'through the cover plate sections or strips although anchored in or screwed into the bottom plate.

The invention possesses other objects and features of advantage, some of which with the foregoing will be set forth in the following description. In the following description and in the claims, parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit; In the accompanying drawings there has been illustrated the best embodiment of the invention known to me, but such embodiment is to be regarded as typical only of many possible embodiments, and the invention is not to b limited thereto.

The novel features considered characteristic of my invention are set forth with particularly in the appended claims. The invention itself, however, both as to its organization and its method of operation together with additional objects and advantages thereof, will best be under stood from the following description of 'a s-peciiic embodiment when read in connection with the accompanying drawings in which Fig. 1 is a diagrammatic sectional viewof a tank embodying the flow-distributing system taken longitudinally of the primary channel 'Fig. 2 is a diagrammatic sectional view taken at right angles to the section of Fig. 1, that is, transversely of the primary channel and thus longitudinally of the transverse secondary channels;

Fig. 3 is a plan view of the distributing system with strip-lik cover-plate sections broken'away to show the arrangement of the channel system,

flow-distributing and bed-supporting 4 and distributing units mounted on the coverplate sections;

Fig. 4 is a greatly enlarged partly broken away plan detail view of a distributing unit of Fig. 3 and structure directly adjoining it;

Fig. 5 is a partial vertical section taken on line 5-5 in Fig. 4.;

Fig. 6 is a perspective view of a portion of the distributing system or tank bottom of Figs. 3 to 5 with parts broken away to show the primary channel with secondary channels branching therefrom;

Fig. 6 is a greatly enlarged perspective view of a broken-01f portion of a reticulated screening member or plate associated with a distributing head, and through which the liquid must pass;

Figs. 7 to are views of a modified multiple passage distributing-head with narrow slot openings, Fig. '7 being a part-sectional top view taken on line 1-1 of Fig. 8, Fig. 8 being a partsectional side view taken on line 8-8 in Fig. '7, Fig. 9 being a cross-sectional view taken on line 99 of Fig. '7, and Fig. 10 being a section on line I'D-H) of Fig. 8;

Figs. 11 to 14-. are views of a further modified distributing unit, Fig. 11 being a part-sectional top view, Fig. 12 being a part-sectional side view taken on line I2|2 of Fig. 11, Fig. 13 being a cross-sectional view taken on line l3l3 of Fig. 11, and Fig. 14 being a partial cross-section. on line l4.l4 of Fig. 12.

The diagrammatic sectional view in Figs. 1 and 2 shows a tank H1 comprising a cylindrical wall ll having a top flange l2 and a bottom flange 13, a top or cover M connected to the top flange l2 and a bottom member l5 connected to the bottom flange [3. The bottom member I5 is formed with a flange l6 and with a system of channel-like depressions comprising a main or primary channel H from which extend lateral tom chamber H: for a purpose hereinafter to appear.

The bottom member 5 or channel system is overlain by cover-plates or plate-like strips !9 fastend to the bottom member I5. The coverplates l9 have flow passage openings registering with the channel system and disposed in a substantially uniform pattern over the cross-sectional area of the tank for the sake of an even distribution with respect to that area. Each flow passage opening 20 is covered by a flow-distributing unit or head 21. The bottom member I5 together with the apertured cover-plates l9 and the distributing-heads. 2| are herein termed the bottom structure since'a bed 22 of granular material, in the present instance of ion exchange material, is supported by it. The primary bottom channel I I has abottom inlet or outlet in the form of pipe 23, while the tank wall has inlet or outlet connections such as indicated by pipes 24 and 25 shown to have control valves 2i and 25 respectively.

Fig. 3' may be said to be a plan view of the bottom structure of the tank of Fig. 1 and to represent an enlarged section on line 33 of Fig. 1. A number of strips or strip-like coverplates 49 corresponding to plates I 9 in Figs. 1

. and 2 are co-extensive with and overlying individual flow channels of the channel system. -In other words, there is a bottom member 50 which corresponds to the bottom chamber l5 of Fig. 1 and has a channel system similar to that .5 of Figs. 1, 2, and which comprises a diametrically disposed main or primary channel which corresponds to primary channel H in Fig. 2, and from which extend laterally in both directions secondary channels'52 which correspond to the secondary channels l8 in Fig. 1. The primary channel 5| is modified by embodying bridge portions 53 unitary with the bottom member 50 and extending from side to side across the channel 5!, this being for the purpose of sealing corresponding gaps 54 between the strips 49.

The cover strips or plates 49 are provided with flow passage openings 55 registering with respective flow channels. A flow-dividing or'distributing head 56 similar to the ones indicated at 2! in Figs. 1 and 2, is associated with each flow passage opening 55 in such a manner that the flow through the opening is subdivided by a plurality of small flow passages through which subdivisions of the flow pass close to the bottom or associated cover plate 49.

A distributing head 56 as shown more clearly in the greatly enlarged detail view of Figs. 4 and 5, as Well as in the large partial Fig. 6 perspective view of the bottom structure, comprises an elongated flange member 51 of a material that is acidas well as alkali-resistant, such as for example a plastic composition. The flange member 51 is formed with a conical recess 58 at the bottom and about centrally of the flange member, from which recess radiate horizontal inverted or bottom channels 59. Whereas four such horizontal bottom channels are shown, any suitable number of such channels may be provided. There is also provided a narrow vertical bore 6!! representing a fifth flow channel rising from the highest point of the conical recess 58.

At the top of the elongated flange member 51 at each end thereof there is provided a cylindrical depression or recess 58 in the flange member, the bottom face of which recess forms a shoulder 59 against which is tightened a nut (ill having a washer 6|. This nut is tightened upon astud 62 extending through holes 63 and 64 provided in the flange member 51 and in the plate 49 respectively, the lower or foot end of the stud 62 being fixed in the bottom member 50, for example by welding as indicated at .65. A threaded closure cap 66 also consisting of acid-resisting or plastic material is screwed tightly upon the exposed threaded top end portion 61 of stud 62, and through a washer 68 of suitable material closes the recess 58 thereby encasing the top end portion 6! of the stud as well as nut 60 against contact with surrounding liquid. In this way a pair of studs 62 hold a flange member 51 tightly to the top face of the cover-plate 49 and over a flow passage opening 55 in the cover plate. A plate of finely reticulated or screening material 69 is interposed and confined between the flange member 5'! and its associated cover-plate 49. A coating of acid and alkali resistant material such as rubber may be provided upon the cover-plates 49 as well as upon the bottom member 50 such coatings being indicated at Ill and at H respectively.

Figs. 7 to represent another embodiment of the distributing head 56 shown in Figs. 1, 2, 3, 4, 5, and 6, this embodiment residing mainly in a difference in the arrangement of the subdivisional flow passages, the concept being to provide narrow vertical slot outlet openings instead of those having round or half-round crosssection, such as shown in the flange member 51. Inview of the narrowness of the vertical slots, this embodiment dispenses with the additional screening plate or member such as shown at 69 i Figs. 5 and 6 aswell as inftheidetatil Hence, the Figs. '7 to 10 embodiment comprises an elongatedflange member .12 which is 'I! and over a flow passageopening 1-8 therein is the same as previously described in connection with the flow distributing head of Figs. 4 and 5.

The embodiment of the distributing-head in Figs. ll'to 14 as represented by a flange member 19 is similar in principle to that of Figs. 7 to 10 with respect to flow distribution by way of narrow vertical slot-like; openings, although this embodiment lacks the central block-like extension of the Figs. 7 to 10 embodiment. That is to say, there are provided narrow vertical slot-like outlet openings in the sides of the flange member 19 which correspond to, Vertical bores or distributing channels or passages 8i supplied from a chamber or recess 82 provided in the bottom of the flange member 19. By comparison with the Figs. 7 to 10 embodiment the vertical slot-like openings 86 areof considerably lesser height although greater in-number. and are sup,- plied from the bottom. "chamber"8 2 that is larger than the corresponding bottom chamber .in the Figs. 7 to 10 embodiment. At, 83 are in.- dicated depressions for the nuts of anchoring studs (not shown), while a portion of the associated cover-plate is shown at84.

Operation For the purpose of describing the operation, it will now be assumed that there is an'upflow of liquid through the bottom structure of'the tank into and through the bed of granular material upon it. This operation will 'be' described in view of the embodiment of Figs. 1, 2, 3, 4, 5, 6, and 6. The main flow of the liquid beingsupplied to the bottom flows upwardly through the vertical inlet connection or pipe 23 into the main or primary channel [1. Upon entering into channel I1 the flow splits in opposite horizontal directions with one-half of it flowing towards one end of the channel, that is in the direction of arrow 84*, while the other half fiowstowards the other end of the channel, that is in the direction of arrow 85 (see Fig. 6). Each half portion of the main flow in turn splits into subdivisional streams passing into the secondary channels l8, branching ofi at right angles to the main channel I1 in both lateral directions. T

For the understanding of the further operation it will suflice to follow the flow of the subdivisional stream of liquid through one of the secondary channels I8 .120 and through an opension or recess 58 of flange member 51, whence the liquid issues in final subdivisional streams through the radial channels 59 andthrough the vertical bore 60 as indicated by arrows 86 and 87 respectively in Fig. 6.

While the final or liquid-issuing channels or bores 59 and 60 may be so dimensioned and disposed as to discourage the passage therethrough of granules of the material of the bed above, should undersized grains nevertheless pass through these final channels and into the chamber 58, they are then retained or arrested by the screening member 69 which prevents them from reaching the underlying distributing channel system of the bottom member or to reach the main supply or discharge connections 23 through which such grains might get lost.

In the operation the bed 22 of ion exchange material is to be kept in submergence substantiall at all times, such submergence being indicated in Figs. 1 and 2 by a tentative liquid level L shown to be substantially at or somewhat above the top of the bed 22.

While the bed-supportingand flow-distributing structure as well as its operation have been described on the assumption that there is an upfiow of liquid through the flow-distributing bottom structure into the tank, it should be understood that the direction of flow of the liquid through the tank may be reversed so as to be from the tankthrough, the bottom structure which condition could be indicated by a reversal of the flow arrows now shown. Indeed, when conducting ion exchange operations some phases of the operating cycle may require upflow, while others may require downfiow of liquid through the ion exchange bed. j

Where the'ion exchange treatment system requires passing the liquid sequentially through a cation exchange bed and an anion exchange bed,

there will be experienced an acid as well as an alkali condition of the liquids passing through the beds. Such conditions will be due to the fact that the liquid passing through the cation exchange bed becomes acidified, although it is being de-acidified when subsequently passing through the anion exchange bed. Conditions which are either strongly acid or strongly alkali are also experienced inasmuch as the cation exchange material when exhausted must be regenerated with a strong mineral acid of suitable concentration, for example H2SO4 or I-lCl, while an exhausted anion exchange bed must be regenerated with a suitable solution of astrong alkali, for example Na2CO3. It is for this reason that acidand alkaliresistant coatings have been indicated upon parts coming in contact with the liquids, or that such parts have been described as consisting of an acidor alkali-resistant material.

I claim:

l. A liquid-distributing bottom structure for a tank comprising a bottom plate provided with depressionsrepresenting a channel system comprising a primary channel and a plurality of secondary channels extending laterally from said primary channel having transverse bridge portions the top face of which is co-planar-with the top face of said bottom plate and dispose'din staggered relationship with respect to said secondary channels, strip-like plate elements longitudinally coextensive with respective secondary chann'els and having a plurality of flow passage openings spaced from one another along the length thereof, said plate. elements alternating with Ill and marginally overlying said bridge portions and having sealing contact with the top face of said bottom plate as well as with the top face of said bridge portions so that liquid through said channel system must pass through said openings, and a plurality of flow subdividing di tributing heads each associated with a respective flowpassage opening and having sealing relationship with the top face of the plate elements, and bolt connections for fastening said distributing heads andsaid plate elements to said bottom plate all in sealing relationship with one another.

2. A liquid distributing structure according to claim 1, in which said bolt connections comprise studs threaded into said bottom' plate extending as a commonfastening through said distributing heads as Well as through said plate elements. f.

3. A liquid distributing structure according to claim '1, in which at least oneof said distributing heads comprises a flange member having a plurality of subdivisional flow passages, and in which said bolt connections comprise studs threaded into said bottom plate and extending as a common fastening through said flange members as well as through said plate elements.

4. A liquid distributing structure according to claim 1, in which at least one of said distributing heads' comprises a flange member having a plurality of subdivisional flow passages, with the addition of a flat screening member interposed between said flange member and its plate element.

5. A liquid distributing structure according to claim 1, in which at least one of said distributing heads comprises a flange, member having a recess at the underside thereofto form a chamber overlying an associated flow passage opening and provided with subdivisional flow channels extending from said chamber.

6. A liquid distributing structure according to claim 1, in which at least one of said distributing heads comprises a flat screening member interposed between it and the associated plate element.

7. A liquid distributing structure according to claim 1, in which at least one of said distributing heads comprises a flange member having a plurality of subdivisional flow passages, in which said bolt connections comprise a pair of studs with nuts for said distributing head, and an internally threaded closure cap surrounding each nut and screwed upon the exposed end of the stud and tightened against the top face of the flange member for tightly encasing said nut.

VLEO E. LANCES.

REFER N ES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 2,412,032 Bill, J1. Dec. 3,

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