US3121618A - Hood and air scrubber - Google Patents

Description

Feb. 18, 1964 F. L. YERZLEY HOOD AND AIR SCRUBBER Original Filed March 22, 1956 4 Sheets-Sheet 1 INVENTOR. Fe/A L yerz/ey A TTOR/VEY Feb. 18,1964 F. YERZLEY noon AND AIR SCRUBBER 4 Sheets-Sheet 2 INV EN TOR.

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HOOD AND AIR SCRUBBER Original Filed March 22, 1956 4 Sheets-Sheet 3 IN VEN TOR;

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Feb. 18, 1964 F. 1.. YERZLEY HOOD AND AIR SCRUBBER Original Filed March 22, 1956 4 Sheets-Sheet 4 ZOEbam OF INVENTOR. WW

6 d H W. N /W L a W .x A 4 F United States Patent 3,121,618 HOOD AND AIR SCRUBBER Felix L. Yerzley, 66 Harrison St., Verona, NJ.

Application Oct. 24, 1960, Ser. No. 64,553, now Patent No. 3,005,679, dated Oct. 24, 1961, which is a continuation of application Ser. No. 573,166, Mar. 22, 1956.

Divided and this appiication June 14, 1961, S91. No.

4 Claims. (Cl. 23-292) This invention relates to a gas-liquid contact method and apparatus, shown as a chemical hood or the like, i.e., apparatus which provides a work space for operations which may result in dust or dangerous fumes and which provides for disposal of such by-products.

Among the objects of the present invention are to provide a self-contained, unitary hood unit which purges the air from the hood of fumes and dust before exhausting the air; to provide a hood unit which may be used with no exhaust from the room other than the regular air-conditioning exhaust from the room; to provide a unitary hood unit which may be prebuilt in complete form and which requires only electrical, water supply and drain connections thereto upon being installed; to provide a hood unit which is portable in the sense that it can be readily moved into the work-room and put into use and then be readily transferred from location to location as occasion may require; to provide a small, compact hood unit having the foregoing features and advantages; and generally to improve the effectiveness, efficiency and simplicity of chemical-hood units.

Further objects, and objects relating to details and economies of construction, operation and use, will more definitely appear from the detailed description to follow.

My invention is clearly defined in the claims. In the claims, as well as in the description, parts of the construction and parts of the operating system may at times be identified by specific names for clarity and convenience, but such nomenclature is to be understood as having the broadest meaning consistent with the context and with the concept of my invention as distinguished from the pertinent prior art. A form in which I have contemplated applying my invention is illustrated in the accompanying drawings forming part of this specification, in which:

FIG. 1 is a somewhat diagrammatic exploded view of a chemical-hood unit embodying the invention, the view being simplified and certain parts being omitted.

FIG. 2 is a partly diagrammatic front elevation of the chemical-hood unit.

FiG. 3 is a transverse, vertical section of the chemicalhood unit taken on the line 3-3 of FIG. 2.

FIG. 4 is a longitudinal, vertical sectional view illustrating the scrubbing unit shown in FIGS. 1, 2 and 3, the plane of the section being generally on the line '44 of FIG. 3.

Referring to FIG. 1, the complete chemical-hood unit includes three subunits, viz., a base unit 10, a scrubbing unit 11 and an enclosure unit 12. When assembled as shown in FIGS. 2 and 3, the scrubbing unit 11 nests within a sink in the base unit 1t and the enclosure unit overlies the two.

The construction of the base unit 161 will be understood from FIGS. 1, 2 and 3. This unit comprises a horizontal, rectangular frame preferably made of rectangular, seamless tubing, the frame having front and back portions 14 and 15 and side portions 16 and 17. This frame is supported by four legs 19. Attached to and supported by the horizontal frame is a sink unit comprising a Work surface or drainboar-d 20 which slopes ice toward and merges with a sink proper 21. The horizontal frame, the supporting legs, the work surface and the sink may be of welded-steel construction. Supported .from the rear legs 19, is a motor and blower unit designated as a whole by 22 (FIGS. 2 and 3) which will be referred to later. Resting upon the horizontal frame composed of portions 1*4, 15, .16 and 17 is a member 24 made of rectangular, seamless tubing and which is U- shaped in a horizontal plane so that it registers with frame members 15, 16 and 17. The member 24 is also of welded-steel construction.

The interior of the sink proper 21, the work surface 20, the top and front of frame member 14 and the inwardly-facing portions of frame members 14, 15, 16 and 17 which lie above the sink unit are covered with a -inch thick sheet of acid-resisting plastic, with sealed joints. This may be the polyvinyl chloride sold by B. F. Godrich under the name of Korosea A fragment of this covering is shown at 25 in FIG. 1. This covering is continued upwardly over the tops of the three branches of member 24-, and, when the enclosure member 12 is put in place, acts as a gasket between the member 24 and the enclosure unit 12. Once the three subunits 10, 11 and 12 of the hood unit have been placed in assemled relation, this relationship may be retained in any suitable manner, as by suitably located bolts or clamps (not shown).

The scrubbing unit 11 which, as shown in FIG. 1, is generally boxlike as regards its exterior shape, rests in the sink 21 and is supported from the bottom of the sink by blocks or other suitable means which are spaced from one another, and may be perforated in addition, to permit liquid to flow freely in all directions beneath the scrubbing unit. These blocks are shown in dotted lines at 26 in FIGS. 3 and 4. The interior construction of the scrubbing unit will be described later.

The enclosure unit 1 2 has top 27, sides 29, 29, back 30 and a transparent front panel 31. The front edges of sides 29, 29 may be provided with trim pieces 28, 28 which extend toward each other and overlie the free ends of U-shaped member 24. Access to the work space 20 is obtained through the rectangular space at 32 which extends across the front of the enclosure unit 12 and upwardly from the top of frame member 14 to the bottom edge of transparent panel 34 which lies in an inclined position and has its upper edge hinged to panel 31. A greater degree of access to the work space 20, and to the interior of the enclosure unit 12, may be obtained by swinging upwardly the hinged panel 34. Fixed panel 31 and hinged panel 34 may each be made of thick, rigid sheets of suitable transparent plastic.

Reference will now be had to the showing in FIG. 4 of the scrubbing unit 11 located in the sink 21. As will presently appear, the air and fumes within the enclosure unit 12 laden with fumes or dust generated in the vicinity of the work surface 20, are drawn downwardly around the outside of the scrubbing unit 11, in at the bottom of the scrubbing unit, and upwardly through the scrubbing unit to remove the fumes and dust, after which the cleansed air is drawn downwardly through a conduit and returned to the room at a point below the level of the sink.

There is provided a water-discharge pipe 35 which leads through a trap 23 to a drain. The top or inlet of discharge pipe 35 may be positioned above the bottom of the sink, as shown. Thus, when the apparatus is in operation a depth of water will be maintained in the sink equal to the height of discharge pipe 35 above the bottom of the sink. This water level is indicated at 21a. The gas enters the scrubbing unit at or slightly below this water level.

'locity, thereby throwing out droplets of The scrubbing unit 11 is supported in the sink in the position shown in FIG. 4, resting on spaced blocks such as block 26 in FIG. 3 as previously referred to. The casing of the scrubbing unit 11 includes a front wall 36, a back wall 37, a left-end wall 39, a right-end wall 40, a top 41 and a bottom 42. The bottom '42 projects horizontally a short distance beyond the vertical walls 36, 37, 39 and 40 and is provided, as shown in FIG. 4, with a short, upwardly extending lip 44 which extends entirely around the perimeter of the bottom. Above discharge pipe 35 the bottom 42 is provided with a domelike member 45 which overlies the discharge pipe 35 and provides a vent in conjunction with space for water to flow from the sink into the top of pipe 35.

Referring to FIGS. =1 and 3, it will be seen that the bottom edge of front wall 36 is recessed upwardly for a considerable-portion of its length, providing an elongated slitlike port 36a. A similar elongated slitlike port 37a is provided at the bottom of back wall 37 as shown in FIG. 4. Air and fumes are drawn from the interior of enclosure unit 12 through these two ports to the interior of the scrubbing unit 11. After entering the scrubbing unit 11, the air passes upwardly through a horizontal wire screen 46, a layer of aggregate 47, another horizontal wire screen 49, the space between screen '49 and a third horizontal screen 50, through a layer of aggregate 51 and thence through a fourth horizontal wire screen 52. The layers of aggregate 47 and 51 are kept substantially flooded with water issuing in finely divided form through a number of spray nozzles at 53 fed by pipes 54 and 55 (see also FIG. 3). Screen 46 supports the aggregate 47, screen 49 serving to retain the aggregate in fixed or unyielding position. Likewise screen 50 serves to support the aggregate layer 51,

screen 52 overlying the aggregate layer to assure that the aggregate remains in a fixed position.

During its passage upwardly through the scrubbing chamber, the air is scrubbed and the dust and fumes removed therefrom. Upon reaching the space above screen 52, the air is drawn over the top of vertical partition 56, beneath the bottom of bafile 57 and into downwardly extending exhaust conduit 59, in the path indicated by the serpentine arrow 60. This serpentine path involves abrupt changes in direction at high vewater that may beentrained, and with the result that the cleansed air is relatively free of entrained water when it enters the air-discharge conduit 59 that is under suction.

The aggregate in layers 47 and 51 is composed of relatively small particles, that are packed or shaken together sufliciently to prevent the individual particles from shifting under the action of air currents as the air is drawn upwardly through the layers of aggregate. Thus, the air being scrubbed cannot channel its way through the aggregate, but instead is forced to widely'disperse and, in finely divided form, come into contact with a very large area of water that is on the surface of the pieces of the aggregate. and which also substantially fills the space between the pieces of the aggregate since the supply of water is sufiicient to maintain the beds of aggregate at 47 and 51 in substantially flooded condition.

For the absorption of acid fumes, of nitric, hydrofluoric, hydrochloric and others, I have employed an aggregate composed of marble (calcium carbonate) very successfully. In particular I have used the commercial product Carrara Italian marble, No. 2 chips. The smaller No. l chips and the larger No. 3 chips are also useful under some conditions. I have used a scrubbingchamber area in'horizontal cross section of from one to four square feet per 100 cubic feet of air per minute with depths of the aggregate (in both beds taken together) up to eight inches, and with water fed by the sprays of from one-half to two gallons per minute.

After descending through the beds of aggregate 51 and 47, the water passes through an outlet opening 61 in the bottom 42 of the scrubbing unit. As shown in FIG. 4, this opening is remote from the water-discharge pipe 35 and hence the water must make its way quite a distance before entering the discharge pipe. The space in the sink beneath the bottom 42 of the scrubbing unit may be filled with marble chips as shown at 63 so that the Water has to work its way slowly through the interstices between the chips before it reaches the discharge pipe 35. These chips may be the same as in beds 47 and 51. By the time the water reaches the discharge pipe 35, it has been largely neutralized by the action of the marble chips at 63.

Due to the negative pressure in exhaust conduit 59, Water will rise from the sink into the vertical chamber between partition 56 and end wall 40 to the level indicated at 21c since this chamber or conduit communicates with the space above aggregate bed 51 and conduit 59. Horizontal bafiles 65, 66 and 67 separate the water in this chamber into more or less stratified layers.

Referring to FIGS. 2 and 3, the air-exhaust conduit 59 extends downwardly at 59a to a point a little above the floor level, thence upwardly at 5% to a point a little below the level of the frame member 15 and thence downwardly at 59c and into the inlet of blower 68 which is driven through any suitable mechanical connection as by means of an electric motor 70, as shown. After passing through the blower, the cleansed air is returned to the room through blower outlet 69 on which may be fastened a muslin bag 72. The purpose of the muslin bag is to help ditfuse the air, prevent drafts, and minimize blasts when the blower is started. The lower curved bend between conduit sections 59a and 59b is sufliciently below the upper recurved bend between conduit sections 5% and 590 to prevent water from accidentally entering the blower. Ordinarily there will be no water in this air conduit, but should water be drawn over into it for any reason the head of water between the two recurved bends in the conduit is sufiicient, be cause of the limited suction of the blower, to'prevent water from being drawn into the blower. Any water accidentally collecting in the duct 59 can be removed through the drain plug 5 8, as shown.

The chemical-hood unit is provided with an electrical system, a water system and a drain connection which, upon installation of the unit, are simply connected to points in the supply and drainage systems of the building. Trap 23 (FIGS. 2 and 4) is shown as connected to the building drain.

This application is a division of my prior application, Serial No. 64,553, filed October 24, 1960, now'U.S. Patent No. 3,005,679, issued October 24, 196 1, which in turn is a continuation of my prior application Serial No. 573,166, filed March 22, 1956, now abandoned.

' I claim:

1. A self contained, unitary hood, comprising a work station, a liquid receiving sink beneath said work station, a scrubbing chamber positioned in said sink, enclosed at its upper portion and opening into said sink adjacent the lower portion thereof, an enclosure above and around said work station, sink and scrubbing chamber, said enclosure provided with an opening adjacent said work station for admitting outside air into said enclosure, said scrubbing chamber including a fixed horizontal bed of packing material and a packing supporting screen extending transversely across said chamber, means for introducing .acki-nc material, with.

the down-fiowin g liquid flooding said bed, the upward flow of air opposing downward liquid flow through said bed and providing intimate contact between said air and flooding liquid for scrubbing said air, and means for discharging liquid from said sink.

2. A unitary hood unit comprising a casing formed with a lower sink portion and a scrubbing chamber mounted in said sink, said chamber having side walls and top and bottom enclosures, a horizontal bed of aggregate particles of predetermined vertical thickness mounted at an intermediate point therein and provided with open upper and lower surfaces, open to permit fluids to pass into and from the passages in said bed provided by said aggregate particles, said bed being positioned to intersect said chamber between the upper and lower portions thereof to prevent the passage of liquid or gas between the upper and lower portions of said chamber except on passage through said bed, a liquid retaining sump constituting the lower portion of said sink, positioned to receive liquid passing through and from said bed and means to retain liquid in said sump at a predetermined liquid level, a vertical channel extending from a point beneath the liquid level in said sump to a point in said chamber above said bed of aggregate, providing an open conduit between said points, the vertical height of said channel being greater than the thickness of said aggregate bed, means for supplying liquid to the upper portion of said chamber above and onto said bed for flooding said aggregate bed, means for introducing gas into said casing for conduction into the lower portion of said chamber, beneath said bed, and means for creating a reduction of hydrostatic pressure in the upper portion of said chamber for creating an upward passage of gas through said bed against the down-flow of liquid therein and for drawing liquid upwardly in said channel to a height corresponding to the difference in pressure in said chamber above and below said aggregate bed.

3. A unitary hood unit comprising a casing formed with a lower sink portion and a scrubbing chamber mounted in said sink, said chamber having side walls and top and bottom enclosures, a horizontal bed of aggregate particles mounted in said chamber and provided with fixed, open, upper and lower surfaces, open to permit fluids to pass into and from the passages in said bed provided by said particles, and positioned to intersect said chamber between the upper and lower portions thereof to prevent the passage of liquid or gas between the upper and lower portions of said chamber except on passage through said bed, a liquid retaining sump constituting the lower portion of said sink, means for conducting liquid from the lower portion of said chamber into said sump at one horizontal position therein, means for discharging liquid from said sump at a difierent horizontal position therein and at a level to maintain a body of flowing liquid in said sump, and particles of aggregate positioned in said sump between said two positions therein, means for supplying liquid to the upper portion of said chamber above said aggregate bed, means for introducing gas into the lower portion of said chamber beneath said bed and means for creating a reduction of hydrostatic pressure in the upper portion of said chamber for drawing gas from said introducing means upwardly through said bed in contact with the particles and with the down-flowing liquid therein and means for discharging said gases so drawn through said bed outwardly from said chamber and hood.

4. A self contained unitary hood, comprising a casing formed with a lower sink portion and a scrubbing chamber mounted in said sink, said scrubbing chamber including a transversely extending bed of aggregate particles, means of communication between the interior of said casing and the space surrounding the same and between the interior of said casing and the interior of said scrubbing chamber beneath said aggregate bed, means for supplying liquid to the upper portion of said bed of aggregate particles for down-flow by gravity therethrough, means for producing a flow of gas into said casing and into said chamber and upwardly through said aggregate bed and outwardly from said chamber, liquid discharge means extending into said sink at a position above the bottom thereof to provide a liquid level between the bottom of said sink and said aggregate bed and means of communication between the space within said chamber above said aggregate bed and a position within said sink beneath the liquid level thereof into which said liquid rises dependent upon the difference of pressure within said chamber above and below said bed of aggregate.

References Cited in the file of this patent UNITED STATES PATENTS 1,046,915 Wedge ec. 10, 1912 2,043,109 McKee et a1 June 2, 1936 2,337,983 Fischer Dec. 28, 1943 2,431,455 Blanding Nov. 25, 1947 2,544,769 Sperry et a1 Mar. 13, 1951 2,602,417 Medcalf July 8, 1952 2,715,359 Mackintosh et al Aug. 16, 1955 2,856,259 Bollinger Oct. 14, 1958 3,005,679 Yerzley Oct. 24, 196 1 FOREIGN PATENTS 206,258 Switzerland Oct. 16, 1939

Claims (1)

1. A SELF CONTAINED UNITARY HOOD, COMPRISING A WORK STATION, A LIQUID RECEIVING SINK BENEATH SAID WORK STATION, A SCRUBBING CHAMBER POSITIONED IN SAID SINK, ENCLOSED AT ITS UPPER PORTION AND OPENING INTO SAID SINK ADJACENT THE LOWER PORTION THEREOF, AN ENCLOSURE ABOVE AND AROUND SAID WORK STATION, SINK AND SCRUBBING CHAMBER, SAID ENCLOSURE PROVIDED WITH AN OPENING ADJACENT SAID WORK STATION FOR ADMITTING OUTSIDE AIR INTO SAID ENCLOSURE, SAID SCRUBBING CHAMBER INCLUDING A FIXED HORIZONTAL BED OF PACKING MATERIAL AND A PACKING SUPPORTING SCREEN EXTENDING TRANSVERSELY ACROSS SAID CHAMBER, MEANS FOR INTRODUCING LIQUID INTO SAID CHAMBER ABOVE SAID BED OF PACKING MATERIAL FOR FLOODING SAID BED AND FOR DOWN-FLOW BY GRAVITY BOILING IMPURITIES FROM A CRUDE FEED GAS HAVING A MAIN CONSTITUENT BOILING BELOW ABOUT -- 245*C. INCLUDING THE STEPS OF PROVIDING A FEED STREAM INCLUDING SAID MAIN CONSTITUENT AND CONTAINING MINOR AMOUNTS OF SAID LOW BOILING IMPURITIES AT A SUBSTANTIAL WORKING PRESSURE AND A LOW TEMPERATURE BELOW ABOUT -- 150*C.; PROVIDING A WASH LIQUID AT ABOUT SAID LOW TEMPERATURE AND SAID WORKING THE DOWN-FLOWING LIQUID FLOODING SAID BED, THE UPWARD FLOW OF AIR OPPOSING DOWNWARD LIQUID FLOW THROUGH SAID BED AND PROVIDING INTIMATE CONTACAT BETWEEN SAID AIR AND FLOODING LIQUID FOR SCRUBBING SAID AIR, AND MEANS FOR DISCHARGING LIQUID FROM SAID SINK.

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