US1780255A - Liquid and gas contact apparatus - Google Patents

Description

LIQUID AND GAS CONTACT vAPPARATUS Filed March 8, 1928 ZL @l 3 ,2B Q 27 8 ,20 l 23 22+ 25 7 ,9 imi'- 25 l? l y l 57 i. /8

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F.4 H. WAGNER 1,780,255

Patented Nov. 4, V19150 UNITED STATES lPATENT, y OFFICE FREDERICK H. WAGNER, OF BALTIMORE, MARYLAND, ASSIGNOR"TO THE BARTLETT HAYWARD COMPANY, 0F BALTIMORE, MARYLAND, A CORPORATION BOF, MARYLAND LIQUID AND GAS CONTACT APPARATUS Application led March 8,

rI his invention pertains to an improved liquid and gas contact apparatus and more particularly to that type designed for scrubbing gas for the removal of entrained or suspended solids.

With the use of the structure as hereinafter set forth in detail highly effective re moval of solids'has been produced, in fact, the removal of solids carried by flue gas has been so effectively carried out as to render thel outgoing gas substantially free of all entrained or suspended solid matter.

Several embodiments of the invention are disclosed in the annexed drawings wherein:

Figure 1 is a vertical sectional View, with parts in elevation, of the apparatus, hereinafter termed a scrubber,

Figure 2 a similar View of a portion of a scrubber illustrating a modified arrangement, and

Figure 3 a like view showing a `modiiica- ,tion or variation of the means employed to stream or wire draw the up-going gas.

Similar parts are denoted in all the views by like numerals to avoid unnecessary description.

Referring first to the construction shown in Figure 1, 1 denotes the shell or casing preferably cylindrical in cross section and provided at its lower end with a gas inlet 2 and at the upperend with a gas outlet 3. rIhe casing in practice will preferably be produced from a series of superimposed sections secured together in a gas tight manner; the size and number of said sections being dependent upon the capacity for which the scrubberis designed. In this connection Vit may be statedthat the drawings, insofar as structural details are concerned, are to be considered more or less diagrammatic.

Secured to the inner wall of the casing and extending transversely thereof is a series of A diaphragms or elements, each of said elements having a centrally disposed opening 4, a section 5 having a series of smaller openings or perforations 6 formed therein, and an annular gutter or collecting trough 7 Each gutter will preferably be provided with a valved drain pipe 8. These gutters each create a quiescent zone for the off-flowing 1928. Serial No. 260,038.

liquid so that it enters the overflow pipe 8 without any turbulence, which of course is a matter of importance.

A vertical centrally disposed shaft 9 eX- tends through the various openings 4, the shaft being supported in a step bearing 10 at its lower end and a bearing 11 at its.

upper end where it is provided with a driving pulley 12 or other means for imparting rapid rotation thereto.

Secured to the shaft atv each of the openings 4 is a disk-shaped element 13, said disk or spreader being of such diameter as to substantially fill the opening and so positioned as to lie substantially in the plane of the perforate diaphragm.

Above the rotary Amember 13 and spaced at its lower end vslightly above the same is a y riphery of the disk-like member'l 13. The

arms 18, as will be seen, overlie the perforate diaphragm in spaced relation thereto and. as above noted, in spacedrelation to the upper series of arms 17 which are carried around when the shaft 9 is rotated.

Surrounding the shaft above each of the funnel-shaped elements 14 is an inverted cupshaped member 19, the shaft9 passing freely therethrough. This arrangement is the same throughout the structure with the exception of the upper section or that immediately above the uppermost perforate diaphragm.

In this instance the water or other liquidwhich is introduced into the scrubber through a pipe 2O passes into a cup 21, the lower portion 22 whereof is slightly enlarged in diameter so as to be comparable in size with the lower end of the funnel-shaped members employed throughout the remainder of the apparatus.

It is designed that the liquid which' collects in the uppermost glitter 7 and above the perforate diaphragm shall be held at a given depth upon the diaphragm and any excess,`

or that which is fiowing in after the apparatus is once started up and charged, shall pass from one chamber to another or from the uppermost chamber to the next one below and so on throughout the series. To this end the casing is provided with a series of pockets 23 opening into the various chambers adjacent theY plane of the perforate diaphragm which may be. said to form the bottom of each chamber as well as the top of the next chamber therebelow, which pockets receive such outiiowing water or liquid.

Extending into each pocket is a trapped pipe 24 provided at its upper end withinthe pocket with an adjustable overflow or Weir element- 25, the pipe at the lower portion above the trap extending inwardly through the casing and terminating in the inverted cup-shaped member 19.

At the lower portion or base of the structure a trafoed overflow pipe 26 is present, said pipe extending into the loutiiow pipe 24 which extends into the lowermost pocket 23.

Above the uppermost diaphragm and standing in spaced relation thereto, so as to form in eEect an upper chamber with said diaphragm, is a cone-shaped element or bafie 27, the edge whereof is spaced from the inner Wall of the casing and held in position vby suitable brackets 28.

It will be understood that liquid inlets other than 20 may be employed and for the purpose of illustration a second inlet is shown at 20a.

From the foregoing, and assuming that the valved pipes 8 are all closed and water or other liquid is introduced into the pipe 2O and that rotary motion is being imparted to the shaft 9, action of the apparatus is as follows:

Gas entering the opening 2 under pressure and beneath the lowermost perforate diaphragm must of necessity pass through the perforations in said diaphragm. The water or liquid Which is fed centrally to the apparatus fiows down upon each of the disks or spreaders and is thrown or sprayed outwardly through centrifugal action by said disks orspreaders. A

The gas which carries the entrained or vsuspended solid matter is forced upwardly through the openings in the diaphragm and comes into Contact with the liquid which is thrown transversely .with reference to the openings 6 in the diaphragm and thereby intimate contact is had between the liquid and the gas. What is more, the gas may be said to be wire drawn as it passes through the openings and hence as it leaves the openings and comes into Contact with the liquid it tends to expand. Stated in another way the gas is subjected to compression followed by expansion within a body of liquid which latter may be said to act as a filtering medium. This recurrent compression and expansion of 'the gas is caused by the expansion of the gas in each chamber. Since, however, the perforations in the diaphragm have a total net area so much less than the area of the chamber the gas is necessarily compressed in order to pass it through these perforations, this being due to the initial pressure behind the gas when it enters the apparatus, the pressure of the gas of course 'dropping from the intake to the outlet of the apparatus. In other words in the showing iu Figure l the pressure is highest in the lowermost chamber and gradually decreases vtoward the upper end of the apparatus.

The gas pressure holds the liquid ou and above the diaphragm. seemingly the particles of solid material are surrounded h v a gas film which is protective to such small particles suspended in the gas and to secure removal of such particles the film must he ruptured in order that the particles may be wetted.

Vhen the reaches the perforate plate its velocity will increase by reason of passing through or being wire drawn through theI small orifices and hence, as above not ed. will be compressed. In this mannerthe protect ive lilm is seemingly broken by the friction and expansion. Further, the process is accelerated by violent agitation to which the gas is subjected in forcing its passage-through the overlying body of .liquid which may he looked upon as a filtering agent or medium. This4 agitation is definitely shown by the amount otl froth built up above the liquid level which is maintained above the perforate diaphragm. It is to be understood, of course, that the same action takes place or inheres as the gas passes through each of the perforated ('liaphragms. In other words, the scrubber may be said to be divided into a series of chambers with means located at the bottom of each for dividing the gas into streams and compressing the same, the gas thereafter expanding witliin the chamber above said means. Stated in another way the structure may be said to include means for dividing the gas into streams at different stages in its passage through the scrubber and by the act of subdivision compressing the gas present in said streams, the gas thereafter being allowed to expand prior to its next subdivision and compression.

It is manifest that when a suspended solid is lighter than a liquid it can be collected at the top of the liquid and floated. In the case in hand efiicient separation of the fine particles is assisted by what might be termed the bombarding effect of the fine gas bubbles which ascend from the bottom of the layer of liquid. The fine particles are thus propelled upward encased in gas bubbles, hence when the bubbles burst the liquid accompanying the gas wetsthe solid particles and they coalesce with the mass at the top.

It is thought that the friction which inheres between the gas andthe walls of the perforations or openings i-n the diaphragms tends to rous sulphate, aluminum oxide sulphate, or a combination of either of these with calcium carbonate or sodium carbonate. l/Vhen these agents or their equivalent are added to the water they thicken up the latter and cause increased friction between the gas carrying the solids and the liquid filter medium.

The presence of the beater'arms 17 and 18 tends also to mechanically disrupt any bub` bles and cause such an intimate contact be-I tween the liquid and solids as will cause the 'solids to be wetted and thus held against 'being carried forwardly and upwardly by the gas. The removed solids, or those which are'wetted and carried down by the liquid, will collect in the trough 7 from which they may be withdrawn from time to time through the valved pipes 8. Furthermore, the liquid which is thrown from the disks across the diaphragm or screen tends to kep such elements clear' and to carry the solids into the trough 7.

In Figure 2 the same'construction vas is set forth in connection with Figure l is employed, the only difference being that the disk-like member 13 is lowered with reference to the perforate diaphragm. As will be seen upon reference to said figure it lies in a plane below that of the under face of the perforate diaphragm and the water or liquid which is deposited thereon is thrown outwardly heneath the diaphragm and is carried upwardly along with the up-flowing gas through the perforations in the diaphragm.

In Figure 3 a further modificatlon 1s shown 'wherein a wlre screen of fine mesh 1s placed above the perforate diaphragm. lSaid screen is denoted by 29 and is held in position and in spaced relation above the perforate diaphragm by spacing elements 30 and rivets or bolts 31.

. It has been found that this dual arrangement just set forth is very effective andl in;

fact is more effective than the single diaphragm. It seemingly Atends to break up anew any reformed gas bubbles carrying en` trained solids.

The pressure of the gas must of course in every instance be such as to hold the water from reflow downwardly through the openings 5 in the diaphragm. The depth of the water layer which is maintained above each of the diaphragms may be readily reg.- ulated by adjustment of the weir member 25, by the amount of water which is introduced into the apparatus, and the gas pressure employed to force the gas upwardly from the opening 2 to the outlet 3.

It is to be understood that the apparatus may be employed for various purposes. While it has been described more particularly applicable to gas washing or scrubbing it will also be found efficient in connection with absorbent processes and others where an intimate and effective liquid and gas contact is desired.

What is claimed is:

1'. In a liquid and gas contact apparatus the combinationl of a casing having a gas inlet and a gas outlet, a diaphragm extendingr transversely thereof-from wall to wall, said diaphragm being perforate'; a member A located adjacent an opening formed in the diaphragm; means for feeding liquid onto said member; and means for imparting motion to said member.l

2. In a liquid and gas contact apparatus the combination of a casing having a gas inlet adjacent its lower end and a gas outlet at its upper end; at least one diaphragm extending transversely of the casing and dividing the casing into separate chambers, said diaphragm having aseries of openings therein, and a relative larger opening formed centrally thereof; a disk-like member mount'- ed for rotation in line with said larger opening; and means for feeding liquid onto said member.

'3. In a liquid vand gas contact apparatus of the scrubber type the combination of a' casing; a plurality of foraminous plates standing in spaced relation and dividing the space within the casing into a series of chambers; means for forcing they gas to be treated through the plates; and means associated with the plates for projecting liquid Y into the subdivided gas stream immediately after it passes through said plates.A

4. In a liquid and gas contact apparatus of the scrubberl type the combination of a casing having a gas inlet and a gas outlet; at least one diaphragm extending across the casing and dividing the interior thereof into a series of chambers, said diaphragm having a series of openings therein; a wire screen element overlying said diaphragm and standing in spaced relation thereto; and means associated with the diaphragm for projecting liquid transversely of the diaphragm.

5. In a liquid and gas contact apparatus of the scrubber type the combination of a casing having a gas inlet and a gas outlet;

at least one diaphragm extending across the same. and dividing the saine into a series of chambers, said diaphragm having a series of openings extending therethrough, and a relatively larger central opening; a disk-like member associated with the arger open- `ing; means for supplying liquid to said member; and a wire screen element overlying` the diaphragm in spaced relation thereto and above the series of openings.

In a liquid and gas contact apparatus of the scrubber type the combination of a casing; means located therein for wire drawing the gas passing therethrough; means for projecting liquid into the gas while in its Wire drawn condition and means for mechanically agitating the admixed gas and liquid.

7. In a liquid and gas contact apparatus of the scrubber type ,the combination of a casing having a gas inlet at its lower end and a gas outlet at its upper end; a series of diapbragms extending transversely thereof in spaced relation to each other, each of said diaphragms having a centrally disposed opening` a plurality of perforations formed in said diaphragm beyond said opening, and a gutter at the outer edge thereof; a. shaf-t extending through the scrubber and through the central openings inthe diaphragms; a disk or spreader secured to the shaft adjacent each of said central openings; means for rotating the shaft; means for introducing liquid onto the upper disk. or spreader at least; and means for maintaining the liquid at a given level on sa'iddiaphragms as the gas passes upwardly therethrough and to feed the excess water flowing from a diaphragm Kto that next below.

8. In a liquid and gas contact apparatus of the scrubber type the combination of a casing having a gas inlet at its lower portion and a gas outlet at its upper portion; a series of diaphragms extending transversely of the casing in spaced relation to each other, each diaphragm having a centrally disposed opening and laterally thereof a series of smaller openings, the outer edge of the. diaphragm being depressed to form a gutter; a shaft extending through the openings; means for rotating said shaft; a disk mounted upon the shaft adjacent each of the centrally disposed openings in the diaphragm; means for introducing a liquid onto the uppermost disk at least; and means for conveying the liquid when it reaches a predetermined level from a point that next below and the same throughout the series.

9. In a liquid gas and Contact apparatus of the scrubber type the combination of a easing having a gas inlet at its lower end and a `gas outlet at its upper end; a series of diaphragms extending transversely of the Casing in spaced relation to each other, each of above the uppermost diaphragm to.

said diaphragms having a centrally disposed opening and outwardly thereof a series of smaller openings, the outer edge of each of said diaphragms being depressed to form a gutter; a shaft extending through the centrally disposed openings in the diaphragms; a spreader secured to the shaft adjacent each of the centrally disposed openings in the di-v aphragms; means for introducing a liquid onto the uppern'lost diaphragm at least: a box-like element opening into the casing in line with each of the diaphragnis and at a level substantially coincident with the upper portion of the gutter; and a trapped conduit extending from said box to the spr xader next below said box for delivering liquid to said spreader.

10. In a liquid gas and contact. apparatus of the scrubber type the combination of a casing having a. gas inlet at its lower end and a gas outlet at its upper end; a series of diaphragms extending transversely of the casing in spaced relation to each other, each of said diaphragms having a centrally disposed opening and outwardly thereof a series of smaller openings, the outer edge of each of said diaphragms being depressed to form a gutter; a shaft extending through the centrally disposed openings in the diaphragms; a spreader secured to the shaft adjacenteach of the centrally disposed openings in the diaphragms; means for introducing a liquid onto the uppermost diaphra gm at least; a box-like element opening into the casing in line with each of the diaphragme and at a level substantially eoincident with the upper portion of the gutter; a trapped conduit extending from said box to the spreader in the series next below said box for delivering liquid to Said spreader: and means for varying the height of the ofitake end of said conduit.

l1. In a liquid gas and contact apparatus of the scrubber type the combination of a casing having a gas inlet at its lower end and a gas outlet at its upper end; at least one diaphragm extending transversely thereof. said diaphragm having a centrally disposed opening and a series of smaller openings formed therein outwardly of said central opening; a shaft extending through said central opening; a spreader secured to the shaft adjacent said central opening; means for delivering liquid to said spreader; a series of fixed arms extending inwardly from the wall of the casing and overlying the perforate diaphragm; and a second series of arms extending outwardly from the shaft and rotatable therewith.

12. In a liquid gas and contact apparatus. the combination of a casing having a gas inlet adjacent its lower end and a gas outlet at its upper end; at least one diaphragm extending transversely of the casing, said diaphragm having a series of openings therein and a. relative larger opening formed centrally thereof; a disk-like member disposed in the central opening and in substantially the same plane as the diaphragm; means for rofitting said member; and means for feeding liquid onto said member.

In testimony whereof I have signed my -name to this specication.

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