US1794764A - Fumeproof spray cabinet - Google Patents

Description

March 3, 1931.

A. C. GOETHEL FUMEPROOF SPRAY CABINET Filed June 28, 1926 2 Sheets-Sheet l w a ZN VEN TOR.

ATTORNEYS March 3, 1931.

A. C. GOETHEL FUMEPROOF SPRAY CABINET 1926 2 Sheets-Sheet. 2 7

Filed June 28 INVENTOR. WC. eilvb h w+ &

ATTORNEY.

Patented Mar. 3, 1931 rman eon r inr or MILWAUKEE, W sconsin EUMELERQQE sPnaY CABINET I Application filed June '28,

This invention relates; to improvements infume proof 'spraycabinets. 1

Such cabinets are usually providedwlth powerful airdraftSWhich not only interfere saidslotted tubes, showing a portion of the 55 with the application of the spray the operator, but also-subjec th per tor to considerableinconvenience, annoyance, and, attimes, to danger from chilling drafts. It has also been foundthat, the use of-powerful W aircurrents carry away large quantities of the material during painting,- varnishing, or

other-spraying operations, and arefrequently ineffective to fully accomplish the object of protecting the workmen from. the fumes and rebounding atoms of poisonous ordeleterious substances. 7 I, i I f a k The object of this invention isto provide a cabinet having an open side 1 protected by an effective air curtain between the 'position'occupied by the operator and theobject to be sprayed. Y V

A further object is to provide means, wherebysuch an air curtain can be produced by air currents having minimum volume and pressure or velocity, whereby materials, heavier than the air may be permitted to pass by gravity to thebottomof'thecabinet, and whereby"workmen' may be protected with minimum inconvenience andmaximum secu- -rity.v I V A further object of the invention to provide means; whereby air under '--press'ure slightly greaterthan that in the atmosphere, may be delivered in ithe formof converging sheets "across ac'abinet opening and withdrawn by suction induced by an ejector" air current in an exhaust passage, therebyi-avoid- 1 ing the use ofsucti on fans for exhaustingair "from the cabinet and avoiding theuse of any "other movable. parts in" the exhaust passage which might become c' logged by= materials condensed or precipitated from the'ioutgoing air. t l V "In the drawings i "sage.

views.

r-sn ze a cras seem; V ew 'e s'io 192 s r lito, 119,041.

the slotted tubes employed for producing the air curtaimthe section being taken on line 2-2 of Figurel," p ,I

F'gure 3 's a fragmentary view; ofone of provedcabinet. 1

i ures is a sectional view. of- ,portions of the baffle curtains,'drawn on linef5 -{i fof 9.

Figure 4;; t

Like parts are identified by the same ref- 7 eren'ce characters throughoutv the several The improved cabinet has" a as wall 10 which is provided with apertures near the front corners throughwhich air supply pipes 11; extend, these, pipes being elbowed above the top wall and connected with an air supply main 12 leading from any suitable source, such as a fanvor pump. Thefronto fthe cabinet is open exceptalong'the margins and side walls, which are preferablyprovided withinturned flanges .13,i-which may compriseportions of corner pieces, or angle pieces, secured to the margins of these walls. Ineachfront corner of'the-s'pace enclosed vby the walls of the cabinet, a substantially yertiQaIly dispQsed, slotted'tube 15 iscon-i ,n e'teagtaone or the pipes'll andhas' avclosed 2 lcw erclld which is preferably tapered as .in-

iafi a 1 Swed n a Q p-s p do'r Liter -re e m 7. s c dt h be Wall'lS or beam19; of the cabinet. Each tube 15 is not only provided with a. longitudinal 8 slot 20, but the sidemargins of this" slot are fla ked by s li wa d y. P ojec i fl ges 21 whi h orm hat may b te m d-a .n z e slot through; which a sheet of airmay flow, the I dimensions of which from top to bottom are substantially equal to the vertical ,di-

Zmension' of the opening at the front of the V Y'cabinetL- The' slotted tube 15 has its upper 1 v 1 t g endrotata'blyseated over the loweren'd of the; v {Figurel is av'ertica-l"sectional view of the" improved cabinet, drawn'to'a central Plane, ichn lude fli esi le the a stre supplypipe or duct ll'so that'by' rotating the mb rs; the air may be directed .throughfthe slet: atflthe 'desiredlpitch or: angle of diverf Igencefrom'the planejof the opening i'n the 7 front of'theeab'inetf i I"- pipe 27 leading from the main '12 downward-* ly through an aperture in said top wall, with another elbow 28 within the cabinet, as clear ly'shown in Figure l.

At the rear, the cabinet is provided with rearwardly converging back walls'30 leading to an outlet aperture 31 with which a stack. or outlet flue 32 is connected.v An induced.

draft is preferably promoted in this outlet flue by means of a pipe 33 leading from the main 12 into the flue "andprovided with an upturned elbowed portion 34:. The lower.

portion of the flue is large enough to allow for the space occupied by the ejector pipe 33 sothat thispipeoffers no material obstruction to the flow of air outwardly through the flue. Battle curtains are preferably suspended in the rear portion of the cabinet to prevent particles of the sprayed material from being carried'by the air into'the outlet flue to any great extent. These baffles are preferably formed of thin sheet metal chan- 'nel bars 35, those in the rear curtain being staggered with referenceto those in the front curtain, whereby the air strikes the baflles and is deflected in order to pass between those of the front curtain and those of the rear curtain, as indicated by the arrows in Figure '5.

These baffles are preferably suspended from Y the upper portion of the back wall by means of suitable brackets 37. Theside walls of the cabinet may be provided with openings which are normally closed by slides or doors rized as follows: The object to be painted,

In order to control the quantity of air to bedelivered to the respective slotted tubes j Q and and through the: ejector tube 33, "each of the tubes 11,27 and-33 isprovided witha gate valve 40 which may be opened or closed to a desired extent to regulate theproportionatequantityof air to be delivered through the tube. i

fume proof cabinet may be briefly summavarnished, or otherwise sprayed, 'will' be placed within the cabinet in front of the baffles 35', and the slotted'no z'z'le tubes jwill be adjusted fordelivery'of three sheets of air-across the cabinet in frontjof'the object,

two of these sheets; coming from the tubes 15 at the respective sides near the front corners and-the third sheet coming from'the top. Thetubes willpreferably be adjusted in such a manner that the sheets of air will converge toward a point lorsareain front of the object. The upper portions of theair sheets of airconverge.

currents from the tubes 15 will of course intersect portions of the sheet of air delivered from the upper tube 25, but this intersection will occur near the side walls of the cabinet and the resulting deflections will be clownwardly and toward the center, thereby increasing the thickness of the air current in frontof the'obj ect to be sprayed. Theentire body of air will of course move rearwardly along. oblique lines and will eventually pass the'object in thedi're'ction of the outlet 31, the capacity of which is such as to provide for a withdrawal of all of the air which passes through the tubes; 15 and 25, together with some additional air entering the cabinet through the open front.' I have discovered that these obliquely moving sheets of air form a curtain which effectively intercepts and deflects all rebounding particles and reversely moving fume carrying currents,

whereas air currents moving directly from frontto rear frequently develop counteractlng currentsbycontact with the rear walls andbaflies and'these tend to carry the fumes and entrained particles of poisonous material outwardly through the front of the cabinet. 1 I have also discovered thatthese low velocity oblique currents, delivered in the vform of sheets of converging air int-he direction .of an outlet through which air is being exhausted under light suction, not only deflect rebounding particles and eddies, but that they also tend to progressively neu tralize each other as to initial direction and combine to. form, a continuously; flowing steady through the exhaust, flue. 1

current of air passing outwardly lI claim 1 I 1. The combination of aspray cabinet pro vvldedywlth an opening. flanked by: slotted tubes atthe sides and top thereof, means for dellvering air underpressur'e to saidslotted tubes, means foradjusting said tubes to. direct the air through, saidslots in inwardly converging sheets, and means for withdraw-' ingairjfrom the 'side ofthe cabinet: toward which said sheets of air'fconverge.

2The combination. ofa spraycabinet pro- .vided with an openingfianked'by slotted. V tubes'atthe sides andtopthereof, means The mode, ofoperation of the improved for deliveringair under pressure to said slotted tubes, means for adjusting saidtubes tubes; and -means 1 for withdrawing air from the side of the cabinet toward which. said 3. The combination ofasprayfcabi'net provided' with-an opening; in v its front wall V flanked by axially; adjustable slotted tubes, air directing q flanges extending outwardly from said tubes along the side margins of the slotstherein, and means for supplying air under pressure to: said tubes in independently V controlled volume, each of said tubes being rotatably adjustable to regulatethe pitch of the air current delivered through its slot, I said cabinet having an outlet n he side opposite said tubes.

4. The combination of a spray cabinet pro-.

vided with amain for supplying air under pressure, of a set of branch pipes leading f from said main downwardly andthrough the Walls of the cabinet near the front upper corners thereof, vertically extending slotted 7 tubes rotatably embracing the delivery ends.

of some of said pipes, and a horizontally extending slotted tube rotatably embracing the delivery end of another of said pipes, said last mentioned pipe having a horizontally disposed extremity, said cabinet having an opening in its front Wall flanked by said tubes at the sides and top and said tubes being rotatably adjustable to directv sheets of air convergingly toward the central portion of the cabinet.

5. In a spray cabinet having an open front Y and an outlet, the combination With air delivery tubes upon opposite sides ofsaid open front adapted to deliver air across said opening, of an ejector in operative relation to said outlet, an air supply main connected With each of said tubes and With said ejector, and means for controlling the flow of air from said supply main to each of said tubes and said ejector independently to substantially balance the volume of air; discharged into and Withdrawn from the cabinet,

6. In a spray cabinet having an open front and an outlet, the combination of means for passing air through said cabinet in substantial absence of in-draft through said open front, said means comprising perforated conduit means adapted to discharge sheet-like streams of air across said open front, air supply means for said conduit means, saidair supply means having an intake remote from said open front, and means fordrawing the air through said outletat substantially the rate of discharge inthe cabinet' and discharging it at a point remote from both said intake and said open front.

ALFRED o. GOEVIIHEL.

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