US2899183A - Gas washing apparatus - Google Patents

Description

Aug l1, 1959 E UMBRxcHT ETAL 2,899,183

GAS WASHING APPARATUS 2 Sheets-Sheet l Filed March 6, 1956 E MWC ,o N u TCA S mmL ,b w.. VBVI WN NMR. R IUG .MO S .l U oT LN A IA .m MR 1 EF .m W m Ali@ 11. 1959 E. UMBRlcHT Erm. v'2,899,183

Y GAS WASHING APPARATUS l Filed "March 6, 1956 2 Sheets-Sheet 2 INVENToRs EMIL UMBRICHT ,2/ By FRANCIS GRYLANCE 2 -I y .mmn'm Q 50.\\on.

ATTORNEYS Eivonia, Mich;v

Application Maren' 6', '1956, se'rliarNd. 5658891" relaas.: (almere-221)."

invention relates to gas-washing apparatus is illustratively described as embodied in air-washing apparatus of the type fused for removing particles such as dustV or paint spray `from the" air.r Such air-washing apparatus is particularly well adapted for use` inconnection with industriall spray painting,` polishing and sanding; operationsl and prevents the overspray material or dust-from th'ese processes from contaminating the surrounding-air and collecting upon nearby machinery. This apparatus greatly improves the extremely dicultl` working conditions which formely used to` accompany these processes. The present invention isrinlthefnature of' a further improvement of gas-washing l apparatus now o n lein U.S. applications Serial Nos; 515,997 and 458,336.

Among themany advantages ofthe airv'vashing apparatus described hereinas embodying this inventionI are those resulting from the fact-that-the apparatus a high efficiency and air-cleaning capacity. A relatively small installation handles a large; quantity of contaminated air, thoroughly: washing the airyrernovingsubstantially all foreign particles therefrom, and 4returning the air to the `atmosphere in clean, relatively dry'condition.` It has become possible by the use of this invention kmarkedly to reduce the1 size of air-washing apparatus and yet to assure the user of-ecientandthorough treatment of a large quantity of contaminated air. Another advantage is the suitabilityof this apparatus for` continuous operation in connection with massproduction industries. It requiresasubstantiallyy no'- maintenance or attention evenA d uringoperation over long periods of time. Moreover, the compactness ofthe airwashing devicegdescribed herein, enables a manufacturer readily toflocate the apparatus at an'y desired-point along an assemblyline Because of the large size of previous air-washingap paratus, certain manufacturing operations heretofore have required theuse of separate vrooms oi`th e employment of an--isolated corner of the factory to which the manufactured articles Were carried; In many cases this caused awkward arrangementsj'of the assembly. lines. -Now these operations can be carried out 'smooth1y" inthe assembly lner- This invention notjonlyreduces the oor areabutflowers ftheminimum height- Yfrom that required by other devices of similar capacity. A5 higher efficiency of manufacture results from yusing this device andl many heretofore unusable spaces of a factory can now be utilzedto increase=the plant capacity.

In -our co-pendingA applications `we have described a gas-washing apparatus having a single serpentine passage through which" the contaminated gases pass and throughwhich, at a predetermined'rate, a washing liquid is directed against thepassage oftlie gas.` Theuhdla tions of the serpentine passage desirably`-`create-a turbulence atfcertain points in thepath of the gases whichh mixesfthe` Washing liquid' with the gas. Foreign particle's ventrained by `the1gas-are picked up and conveniently carried oif by the Vwashing liquid.

States Patent 2,899,183 Patented Aug. 11, 1959 Inf the illustrativel embodiment of this invention We" use a :plurality of relatively small, pa rallel serpentine' passages arranged to deecti andsvvirl the air from'fside to side as; it passes through. These passages are Sider by side, the air in passing through the apparatus'issub divided uniformly into separate streams flowing upwardly through these passages. Thus,- each passage contributes? ecpuallygtol the airwashingjoperation: K

In the accompanying drawings;` weA have; shownfapreferred embodiment of ourinvention' and have -described the same inthe specification; it is"` to `be under-l stood that this description is not'intended to be exhaustive, but'on the contrary, is chosen forthe purpose o f -illu, s= trating. theinvention in order that others-skilled in- 'thel art mayfully understandthe invention,its'principles and, the application thereof and that Athey may; embody and; adapt it in various forms; each` as may be best suited to the requirements of its particular use, withoutvdepartingfrom the scope `of the claim.

Figure 1 shows a rear perspective View o f the air# washing apparatus vpartially broken away to disclose tlie multiple serpentine air passages containedjthereinf Figure 2 is a vertical sectionaliview'off the airWash ing apparatus taken generally 'alongfthe line 2*-2 of Figure l vertical-ly through the center of the apparatus showing the path the air takes upon entering and leavingAr onepf th'efseve'ral"serpentinepassages; Figure `3/ is a sectionalview on a horizontal plane taken along-the line 3"-3 of Figure 2 lookingl down and illustrating the uniform vdistribution ofthe incoming-air as it passes into the multiple serpentine` air passages.; A

Referring first to1Figures-l and 2, the Work piece, to be spray painted or sanded or otherwise processedis conveyedinto and out of a boothpclose to a front recess 2A of the air washingdevice. rIlle Work piecegis` maintained in this-position duri-ngthe spray painting or sanding operationl The overspray pr dust'fr'orrr this operation is sucked by the air into the air-washingapparams-where it is eiiiciently'trappedand removed from the air. The air= intake entrance 4 of thejgas-Washing apparatus is located at the lower end of a-flood sheetj 6 andY extends across thebottom of the air washer in the form of'a long rectangular opening. `Usually the amount ofoverspray ordust or other `foreign material resulting from the industrial operation, being-carriedcn in/the region 2 is far in" excessg of the quantity which can be suspended in the air. For this reason thefoperatdr and location of thel work piece is s o arranged-that the foreign material is directed toward the ilopd sheet 6.A Ig ca tch this foreign material and carry itdown into `a rese'rvoir tank 12 at the bottom from whieh itis conveniently remove d`,a liquidi screen `8` continually ows down over this Hoodv sheet.VVA This liquid sc reen advantageously: prevents -thefloodfsheet from becoming-coatedmwith paintand dust. Liquid ispumped into a sp-ray pipe 1Q, which'extends across the yfull width of the top' of' the rflood* sheet. Alongj the bottom lof this spray'pipe; are spaced a' number of nozzles which direct a spray of liquid downwardlyandinwardly against theiiloodjs'heet, asseen in- 'Figure' 2. When the jdescenfding liquid screen" 8 reaches the bottom edge 9; of the ood sheet `it cades, across the" air intake'forming ajliquid curtain 11' and t hen falls-into the-reservoir tank 1 2:

The` Washing liquid used is usually watercarrying in,` solution' suitable surfae-activeagents, detergents,anti

foamants', and rust-inhibitinglagents. And where paintL overspray is being-` handled, suitable paint killingA agents `are added, for eXamplef, such Vas thosehdisclo; in the co-p'ending US. applicationsof Orlan` M. varnold, senalfNa. 3'1'6,o'49 n -ledj'october' 21; 1952;- ana' ,issua as Patent No. 739;906; dated' M'fehfzv; 1956,"a 21j sria1'No-4'79go'3'2, l'd'neefbf '31,' v1954; ia'fhe names" of Arnold and Harbin. The foreign material is then removed from the liquid in the reservoir by suitable filtering and the liquid is recirculated through the apparatus. This filtering may advantageously be carried on by apparatus such as that disclosed by Emil Umbricht, Dewey Evans, and Gerrit Steenhagen in copending application Serial No. 483,026, filed January 20, 1955, now Patent No. 2,833,417, dated May 6, 1958. This recirculation is carried on bywa suitable pump (not shown) having its intake in the reservoir 12, for example, this pump may advantageously be as disclosed by Emil Umbricht in application Serial No. 357,450, filed May 26, 1953, with its discharge connected to the pipe and Yalso to a pipe 20, for reasons explained later.

The contaminated air in the front region 2 is drawn downwardV through the entrance 4 and is then sucked up into a number of serpentine passages 18 by operation of a fan 13. The air in passing through the entrance 4 is given a further cleaning by passing through the liquid curtain 11 descending from the flood sheet across the entrance 4.

Behind the entrance 4 is an intake chamber 15 defined by an upwardly curved wall 16 and including an upwardly curved baliie 14 which smooths the air iiow as it is deflected upwardly into the serpentine passages. At the sameV time as the incoming air is being deflected upwardly, it is divided by diverging baiiies 19 and 21 (please see also Figure 3). The air thus separates uniformly and passes up into the serpentine passages 18.

In Figure l, the rear of the air washing apparatus is shownvbroken away to reveal the arrangement of these multiple serpentine passages. These passages are defined by a number of box-like members 23, each having a fiat bottom panel 34. Thesepanels close over the top of the intake chamber 15 except for the rectangular openings between them, seen most clearly in Figure 3, which serve as the mouths of the serpentine passages 18. The tops of these box-like members 23 are defined by troughs 24 and downwardly sloping water sheds 26 and 28, whose purpose is explained later. Pairs of generally upright Asmoothly undulating walls 30 and 32 form the sides of the box-like members and define the surfaces of the serpentine passages. These walls 30 and 32 may be uniformly spaced apart with the convex portions of one wall directly opposite the concave portions of the adjacent wall or lthe walls may be increased in distance apart from bottom to top. Thus, the cross sectional area of the serpentine passages 18 is constant throughout, or, in certain instances where these Walls 30 and 32 diverge somewhat in an upward direction, this cross sectional area increases gradually in progressing from bottom to top of the individual passages 18.

The multiple serpentine passages 18 formed between these box-like members are generally parallel and identical. The contaminated air is directed smoothly upward into them by the curved surfaces of the baffles 14, 19 and 21. As soon as the air has entered a passageway 18 and begins its upward ascent, it is swirled back and forth into intimate contact with further washing liquid. This liquid is carried up from the pump through a manifold pipe 20 and into individual supply pipes 22. These pipes 22 feed the liquid at a predetermined rate into each of the horizontal supply troughs 24. The liquid overflows from the trough 24 and main tains a continuously moving film of water on the inclined shed surfaces 26 and 28. From these inclined surfaces 26 and 28 the water ows down along the surfaces 30 and 32 of the serpentine passages 18. These inclined surfaces are connected to the tops of the two side walls of the adjacent serpentine passages as shown in Figure 1. Thus, with the exception of the two end troughs 35 and 36, each supply trough 24 advantageously furnishes liquid to the two serpentine passages; each trough being located midway between one passage and the next so that ow of water down both sides of each passage is assured.

This downward ow of water collects the particles of foreign matter which are thrown against the walls 36 and 32 and thus further cleans the air.

The quantity of water which ows down each of the serpentine walls 30 and 32 is slightly in excess of the water which can be retained on them by surface tension. Theefore, under each convex portion 48 of these walls some of the water falls away from the wall and drops across the air passage and strikes the opposite wall. Similar release of the water occurs underneath other convex portions of the walls 30 and 32. Thus, because of the undulations along the air passage, water droplets cascade back and forth across the air path and intimately mix with the air which is in a swirling, turbulent condition at these points due to the undulations in the passages. The contaminating matter in the air is thereby thoroughly mixed with the descending water and is carried away.

After traveling through one of the several serpentine air passages and after being cleaned by the cascading washing liquid in the respective passages the cleaned air then passes up into a plenum chamber 52. This plenum chamber is located in the gas-washing apparatus immediately above the multiple serpentine air washing passages and below a group of moisture eliminators 54. This plenum chamber is relatively large in volume in relation to the total volume of the serpentine air passages, for the box-like members 23 which form the sides of the serpentine passages occupy a large portion of the space in the lower part of the apparatus. Thus, advantageously, as the air emerges from the serpentine passages and enters the plenum chamber 52 its velocity is sharply reduced because the effective volume of the plenum chamber is much greater than the volume of the serpentine passages.

This sudden reduction in velocity drops out any remaining particles carried by the air from the serpentine passages. s These particles drop down and become trapped in the liquid films on the inclined sheds 26 and 28. Then the air is drawn upward and passes through the moisture eliminators 54, constructed of a series of bent metal strips and arranged to provide a zig-zag path for the air. As the air passes through these moisture eliminators, any few remaining water droplets are removed from the air as the droplets strike the metal strips in the eliminator. The clean air is then drawn on up and expelled to the atmosphere by the fan 13.

From the foregoing it will be understood that the embodiment of the present invention described above is well suited to provide the many advantages set forth, and since different embodiments may be made of this invention` and as the apparatus herein described may be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter 'hereinbefore set forth or shown in the accompanying drawings to be interpreted as illustrative and not in a limiting sense and that in certain instances, some of the features of the invention may be used without a corresponding use of other, features, or without departing from the scope of the invention.

We claim:

Apparatus for handling air having contaminating material entrained therein comprising a substantially vertical wall defining a flood sheet having a substantially horizontal lower limit and means defining an elongated horizontal air entrance opening beneath the lower limit of said ood sheet, first liquid supply means supplying liquid to the upper portion of said ood sheet and forming a liquid curtain owing down over said ood sheet and across said air entrance opening, a plurality of continuously smoothly curved walls arranged in spaced generally upright positionsV and extending back behind said ood sheet, said walls having vertically spaced concave and convex areas, pairs of adjacent Iwalls defining a plurality of serpentine passages passing upwardly therebetween, the lower limits of said serpentine passages beginning behind said elongated horizontal air entrance opening at spaced points therealong, said serpentine passages Ihaving progressively increasing cross sectional areas from bottom to top, second liquid supply means feeding liquid at a controlled rate to the upper portions of all of said serpentine passages, a plurality of vertically spaced horizontally extending air deectors behind said air entrance opening and curving inwardly and upwardly, the lower limits of said serpentine passages beginning above the inner upper limits of said air deectors, a plurality of horizontally spaced vertically extending air dellectors, adjacent pairs of said latter deectors converging toward the respective lower limits of said serpentine passages, and blower means forcing the contaminated air in through said vair entrance opening and upwardly through said serpentine passages.

References Cited in the file of this patent UNITED STATES PATENTS 386,735 Armstrong July 24, 1888 2,077,427 Lissman Apr. 20, 1937 y2,196,644 Rubel Apr. 9', 1940 2,198,305 Crawford Apr. 23, 1940 2,227,465 Roche et al. Jan. 7, 1941 2,231,088 Richardson Feb. 1l, 1941 FOREIGN PATENTS 4,570 Great Britain July 8, 1909

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