US2232561A - Paint spray booth - Google Patents

Description

Feb. 18, 1941. R. M. RICHARDS PAINT SPRAY BOOTH Filed April 25, 1939 2 Sheets-Sheet 1 INVENTOR. FLEEPT Mf CW5 ATTORNEYS.

Feb. 18, 1941. R. M. RICHARDS PAINT SPRAY Boom Filed April 25 1959 2 Sheets-Sheet 2 v AINVENTOR. EUEEFT Emma .75

BY Zulu/r 3W ATTORNEYS.

Patented Feb 18, 1941 UNITED STATES PATEN F Y i 22.23am 1 V rsm'r Bran Boom Application April 25, 1939, Serial No. 289,967

a Claims. (01,9140) This invention relates to improvements in wet booth structures such as are exemplified in] spraybooths wherein articles or structures are paint sprayed. I

An object is to provide an improved booth structure of the character described wherein the air stream that is withdrawn therethroughis filtered and cleaned of foreign material picked up by thestream by the improved structure here disclosed. Specifically the improvement relates to the provision of means in the form of 2. ourtain or the like, which curtain is advanced across the path of the air stream flowing through the booth to intercept the movement of the foreign material particles carried by the air stream removing such particles therefrom, and depositing the same. The reclaimable portion of such'ioreign particles such as thepaint particles-may be salvaged and the undesired forei a. material par ticles may be Wasted. Means is provided to continuously clean the curtain during its advance of any foreign particles collected on the curtain.

The improved curtain is so cotructed that the air stream can pass readily therethrouch but foreign material particles oi a liquid or solid state carried by the air cannot pass directly therethrough but are intercepted by the curtain and either knocked. do by it into a collector hasin.

or receptacle or picked up by the curtain and washed therefrom by the washings means which is provided for this ose.

An important characteristic is that the curtain presents a multiplicity of porous thiclmesses to the passage of the air stream thercthrouuh and that the curtain in revolvahle contihucuisluacrom such air stream. At its lower end the during the revolution of the curtain. the cur tain is advanced across the air sire these ne rous overlapping strips are held contactinu overlapping relationship by will which is provided for the purpose. As the curtain moves through the vat of cleaning fluid the striiws'are preferably allowed to swing pd separate from each other to facilitate the cleaning of the i strips. Preferably also. separate fluid cleaning means is associated with the curtain and may be arranged at one end between the front and rear curtain wall sections. a

Other objects, advantages'and meritorious features of this invention will more iully appear-from the following description, appended claims, and accompanying drawings, wherein:

Figure l is an end elevation partly broken away and taken on, the line of l l of Fig. 2,

Fig. 2 is a rear elevation taken at'right angles to the view in Fig. l and being also partly in sec- 'tion and broken away to show the construction,

Fig. 3 is a horizontal sectional view taken on 15 line H of Fig. 2, i Fig. 4 is a verticahsectional view through a fragment of the curtain structure, and

Fig. 5 is an elevation oi a fragment of the cur tain structure to show the pivotal support the overlapping scree section.

This invention is shown as embodied in a paint spray booth which is Widely used in the manufactoring industry for thepainting of both large and small articles and wherein paint is sprayed by an operator upon the articles as they are hung within the booth or advanced therethrough. It is of the type commonly known as a wet-heath.

Thisinvention relates to the cleaning of the air stream'as it is exhausted from the booth and '30 to the removal of foreign material particles iro such air stream to prevent them nassinu out with the exhausted air and also to reclaim such particlcs as arecapable of salvage for re-use such usnthepaint particles. Such hooth comprises an 35 enclosure within which the articles can be sprayed or hung and through which the air stream is withdrawn and an exhaust air duct adapted to draw a stre or current of air through the booth and means for removing the solid or liquid particles carried by the air from the air stream and mocking them down into a receptacle from which they may later he moved. m the drawings herewith the enclosure is indicatcd generally as id'and comprises side walls, a bottom and top wall and-is open at the front. At the rear the enclosure is provided with an enlargement which is also a walled in extension of the enclosure and indicated as ii in Fig. 1. This enlargement is continuous and open at the bottom into a liquid carryinn vat indicated senorally as it in Fig, 1. This vat has a lid or cover It through which its contents may be removed and inspected. The rear wall of the rear enlarged portionoi the enclosure is cut'throueh with an air exhaust duct l8 through which a stream of air is drawn so as to maintain a current of air flowing actively through the enclosure at all times. This carries away the paint fumes and vapor particles in the air and provides clean fresh air always flowing through the enclosure. This assemblage of elements is conventional in paint spray booths of the present time;

I provide a revolvably supported foraminous 10 curtain indicated generally as 20 in Fig. 1 which is adapted to be advanced across the air stream travelling through the booth for discharge through the exhaust duct III. This curtain may be supported at opposite ends for advancement upon upper and lower shafts 22 and 24, respectively. These shafts are here shown as provided with gear elements 26 and 28 respectively. The shafts may be driven in any suitable manner. An electric motor 30 is here shown which drives through a chain drive and gear mechanism indicated generally as 32. The upper shaft 22 drives the curtain 20 through sprocket gears 26.

The curtain comprises longitudinal side chains 34 made up of suitably connected links which 25 mesh with the upper sprocket gears 26 and the lower sprocket gears 28 so that the curtain is driven upon rotation of the shaft 22 as described. These links are fitted with supporting means here shown as lugs 36 which carry tubular ele- 30 ments 38 into which are fitted the cylindrical ends of bars 40. Fig. 4 is through an intermediate section of the bars at which point they are shown as square. Obviously they might be of any desired shape. The cylindrical ends are fitted within the elements 38 so that the bars and the screen mesh strips carried thereby have a permitted swinging movement as hereinafter described.

The curtain is made up of a succession of 40 foraminated curtain elements here shown as screen mesh strips. A strip of screen 42 issecured to each curtain element and extends down overlapping screen mesh strips therebelow. The overlapping element may be as desired, but as 45 here shown some four overlapping thicknesses are illustrated. The lower edge of each screen strip may be provided with an edge binding 44 which serves to hold thescreen mesh in alignment and cause it to hang fiat. It will be seen that guide rails indicated as 46 are illustrated in Fig. 1 and that the guiderails are so disposed with respect to the extent of the front and rear elevations of the curtain as to hold the overlapping screen strips in contacting overlapping relationship as they are advanced across the air stream. The guide rails terminate at about the upper level of the vat or tank "so that as the strips enter the tank they are permitted to fall apart so that when they are passed through the cleaning liquid they will be more effectively cleaned. The tank contains any suitable type of cleaning liquid, carbon tetrachloride, or any other suitable paint dissolving or removing solvent and the level might 55 be as indicated in the view of Fig. 1.

This cleaning fluid is preferably recirculated and a conventional recirculating pump 50 driven by a motor 52 (Figs. 2 and 3) may be employed. The communication pipe 54 from the pump leads to a spray pipe or tube 56 within the vat which is provided with discharge nozzles to spray cleaning liquid'toward both the front and rear surfaces of the curtain and a separate spray tube 58 may be led off to spray liquid against the opposite surfaces of the screen strips. This pump communicates with the vat so that a continuous circulation is maintained.

It will be seen that in the operation of the,

structure the articles to be sprayed which are positioned within the enclosure in are sprayed with paint which will strike against the curtain as it is advanced across the rear of the enclosure and any solid or liquid particles of the paint spray fluid or other foreign matter which is picked up by the air stream being drawn through 10 the enclosure will be intercepted by the revolving curtain which is preferably continuously being advanced and will be either knocked down into the vat M or picked up by the curtain and carried along thereby upon the screen mesh strips 15 to be washed from such strips as they move through the vat.

The overlapping of the plurality of thicknesses of screen mesh will provide air passageways through the curtain for the passage of air stream 20 but these passageways due to the overlapping arrangement of the successive strips of mesh will be of such a tortuous character that there will not be any direct passageway for solid or liquid particles of material to'pass with the air stream 25 therethrough. Due to the fact that the air stream is continuously wet by the cleaning fluid it will have an even greater tendency to pick up any particles that are not knocked down by it into the vat and these will be washed therefrom 30 as the successive strips swing through the cleaning fluid of the vat and are exposed to the liquid vat streams discharged from the spray pipes 56 and 58 so that the surface'of the curtain that is presented to the paint spray in the enclosure 5 will be kept clean and the strips will not become fouled with material so as to require constant cleaning but will remain relatively free of foul material.

What I claim is: 40

1. A wet booth of the character described having side walls forming an enclosure, an air exhaust duct communicating with the interior of the booth to withdraw an air stream therefrom, an endless belt air filter curtain supported for 45 advancement across the air stream passing through the booth into the air duct, said curtain comprising a succession of screen mesh strips arranged in shingled overlapping relationship presenting at all points of the curtain advancing 50 across the air stream a plurality of overlapped screen strips, said strips being individually pivotally supported for permitted swingable move- .ment and through which the air stream must pass for exhaust from the booth, and a source of liquid supply adapted to wet said screen strips during their advance.

2. A wet booth of the character described havmg side walls forming an enclosure, an air exhaust duct communicating with the interior of 60 the booth to withdraw an air stream therefrom, an endless belt air filter curtain supported for advancement across the air stream passing through the booth into the air duct, said curtain being formed of a succession of screen mesh 65 strips supported for endless belt advancement and arranged in shingled overlapping relationship presenting at all points in the, rise of the curtain a plurality of screen mesh thicknesses and through which the air stream must pass for exhaust from the booth, said strips being individually pivotally supported for swingable movement during the advance of the curtain, means holding said strips in contacting overlapping relationship throughout the length of rise and fall of the curtain across the air stream, and a liquid vat through which thelower end of the curtain travels.

3. A wet booth of the character described having side walls forming an enclosure, an air ex 7 haust duct communicating through one or said nesses and supported to be advanced across the path of the air stream passing from the booth into said duct; said screen strips being individually pivotally supported for swingabie movement, means holding said strips in contacting overlapping relationship during the advance of the curtain across said air stream, and a liquid containing vat through which the bottom of the curtain is advanced, spray means disposed within the endless belt curtain to spray liquid cleaner 10 upon the inner surface of the curtain.

RUBERT M. RICHARDS.

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