Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3776121 A
Publication typeGrant
Publication dateDec 4, 1973
Filing dateJun 23, 1972
Priority dateJun 23, 1972
Publication numberUS 3776121 A, US 3776121A, US-A-3776121, US3776121 A, US3776121A
InventorsA Truhan
Original AssigneeA Truhan
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Controlled environmental apparatus for industry
US 3776121 A
Abstract
Apparatus is provided for controlling the environment in localized areas or zones of manufacturing and/or assembly plants and the like. A gas or air treating apparatus is connected to an outlet plenum positioned above the space or zone to be controlled. The plenum is provided with a plurality of controlled outlets for directing the treated air, generally downward at a rate progressively increasing in volume from the center of the controlled zone outwardly. The system also includes a plurality of inlet plenums spaced at floor level or slightly thereabove at controlled points adjacent but outside of the area or zone to have the controlled environmental conditions.
Images(4)
Previous page
Next page
Description  (OCR text may contain errors)

United States Patent mi Truhan [111 3,776,121 Dec. 4, 1973 CONTROLLED ENVIRONMENTAL APPARATUS FOR INDUSTRY [76] Inventor: Andrew Truhan, R.D. No. 3, Box

392T, Somerset, NJ. 08873 [22] Filed: June 23, 1972 [21] Appl. No.: 265,728

[52] US. Cl. 98/33 R, 98/36, 98/40 D, 55/DIG. 29 [51] Int. Cl F241 13/06, F24f 9/00 [58] Field of Search 98/33 R; 40 D, 36, -98/1 15 LH; 55/DIG. 29

[56] References Cited UNITED STATES PATENTS 3,505,989 4/1970 Truhan 98/36 X 3,625,133 12/1971 Hayashi 98/36 3,426,512 2/ 1969 Nesher 98/40 D 3,602,212 8/1971 Howorth... 98/40 D 3,511,162 5/1970 Truhan 98/36 RESTRICTED AIR FLOW ZONE , zoo

- I woRK TABLE 3,303,771 2/1967 Nesher et al 98/40 D Primary ExaminerWilliam E. Wayner Attorneyl-1arold L. Stowell et a].

[57] ABSTRACT Apparatus is provided for controlling the environment in localized areas or zones of manufacturing and/or assembly plants and the like. A gas or air treating apparatus is connected to an outlet plenum positioned above the space or zone to be controlled. The plenum is provided with a plurality of controlled outlets for directing the treated air, generally downward at a rate progressively increasing in volume from the center of the controlled zone outwardly. The system also includes a plurality of inlet'plenums spaced at floor level or slightly thereabove at controlled points adjacent but outside of the area or zone to have the controlled environmental conditions. I 1

5 Claims, 7 Drawing Figures CONTROLLED ENVIRONMENTAL APPARATUS FOR INDUSTRY BACKGROUND OF THE INVENTION ditions to insure the proper functioningof the apparatus or components being assembled.

The invention has further utility as means for-providing a sterile and clean area in the manufacture of candies, foods, and the like during which manufacture contamination may not only produce a non-saleable product but may also create a health hazard to the purchas ing public.

While difficulty is experienced in providing for clean room conditions in relatively isolated rooms of hospitals, the problems are even more complex in zones or areas in manufacturing facilities which must provide means for receiving components and subcomponents and for removal of the finished products.

Attempts to solve these problems have generally con sisted of providing glass or plastic enclosures which are maintained at positive pressure conditions relative to the ambient atmosphere. However, it has been found that conventional air outlets in such enclosures create air movements which stir up dust and other particulate materials thereby preventing the maintenance of proper atmospheric conditions within the enclosures. Further, it has been found that even when operators are robed, gloved, and masked body convection currents, exhaled breath, and the like provide a major source of gaseous and particulate contaminants which often re sult in early failure of intricate electrical and optical components and food contamination.

THE INVENTION It is a primary objective. of the present invention to provide controlled environmental zones within manufacturing and assembly plants which reduce to a minimum the ingress of gaseous and particulate contaminates from uncontrolled zones and the controlled removal of body-produced gaseous and solid particles from the controlled zone.

A further objective is to provide such a system or apparatus that may be installed, with a minimum of ex FIG. 1 is a transverse partial sectional view through v a factory, having installed therein three controlled environmental zones constructed in accordance with the teachings of the present invention;

FIG. 2 is a fragmentary, partially diagrammatic view taken at right angles to the illustration of FIG. 1;

FIG. 3 is a top plan view of the outlet face of one of the outlet plenums shown in FIGS. 1 and 2;

FIG. 4 is an enlarged partial sectional view of another form of the present invention;

FIG. 5 is a section, substantially on-line 55 of FIG.

FIG. 6 is a plan view of the outlet surface of a modified form of outlet plenum; and

FIG. 7 is a vertical sectional view of gas treating apparatus for use with the environmental control system of the invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS Referring to the drawings, and in particular FIGS. 1, 2, 3 and 7, 10 generally designates a factory having a floor 12 and a ceiling 14. Within the factory 10 are positioned a plurality of elongated assembly tables, generally designated 16, supported above the floor 12. Associated with each of the assembly tables 16 is a controlled environmental zone, generally designated 18, extending from just below the exposed surface of the ceiling 10 to just above the exposed surface of the floor 12 and extending laterally in the plane of the top surface of the tables 16, a width and length slightly greater than the width and length of the tables.

In order to provide and maintain the controlled zones 18, the factory 10 is equipped with a plurality of outlet plenum chambers, generally designated 20, 22 and 24,

positioned immediately adjacent to the ceiling l0 and having length and width dimensions generally coextensive with the plane area of the zone to be controlled. The lower surface 26 of each plenum chamber 20, 22 and 24, as more clearly shownin FIG. 2, is provided with a pluralityof perforations varying in area with the smallest 28a appearing in the center portion of the zone to be controlled, and the largest 282 appearing adjacent to the peripheral margins of the plate 26 with openings intermediate in area 28b, c, d, e, etc. being provided therebetween.

In FIG. 3 certain of the openings 28a, b and c are illustrated as being circular in plan, whereas openings 28d, e and z appear as quadrangular slots. It will be apparent to those skilled 'in'the art that the specific configuration of the openings is not critical; however, the area of the openings is critical as the size of these openings determines for a given pressure the volume of the gases which will issue therefrom as to be more fully described hereinafter.

The system also includes a plurality of return or inlet plenums, generally designated 30a, 30b, 30c and 30d. The inlet plenums 30a through 30d are positioned at -floor level or slightly thereabove and just outwardly of the peripheral extent of the controlled environmental zone. I v l I The outlet plenum 20, 22 and 24, etc. are connected to apparatus generally designated 32 for providing a source of properly conditioned air or gas. The apparatus 32 comprises an enclosure having top 34, bottom 36, and'side walls 38. A refrigeration unit, generally designated 40, is mounted separate from the main housing 32 in order to permit its location externally of the building or factory containing the zones, the environment of which is to be controlled. Such units are well known in the art and may comprise conventional freon-type refrigeration units or one wherein the primary refrigerant liquid is in heat exchange relationship to a relatively inert fluid such as brine whereby the cooling medium brine may be safely transmitted into the control cabinet 32 without danger of contamination of the air to be cleaned in the case of rupture of one of the refrigerant lines.

In FIG. 7 a freon/brine system is illustrated with heat exchange between the brine and the freon taking place in heat exchanger 42 and the chilled brine being circulated to a cooling bath, tank or pond 44, maintained in a lower portion of the chamber 32.

A vertical interior wall 44 and a perforate horizontal wall 46 are arranged within the enclosure defined by the aforedescribed walls and panels to form therein a gas purifying chamber 48. A horizontal wall 50 is disposed surjacent the perforate wall 46 and in spaced relation thereto to define therewith a pre-treatment plenum chanber 52. The chamber 52 has disposed therein a heating coil 54 connected, through a a control 56, to a suitable source of electric power (not shown). A temperature sensing device 58, located in the chamber 48, is also connected to the control 56.

A transverse channel 60, formed in conjunction with the horizontal wall 44, interconnects the plenum chamber 62 with the return conduit 64. A fan or blower 66 is disposed between the channel 60 and the return conduit 64 to circulate the gas as is shown by the arrows in the figure.

The fluid holding tank 44, located subjacent the channel 60, is in communication therewith through openings 68 and 70. A valve means, illustrated as a movable flapper valve 72, is disposed in the channel 60 between the opening 68 and the opening 70 whereby a portion of gas stream passing along the channel 60 may be bypassed from the gas treating zone 62 in the tank 44 and recirculated directly to the plenum 48. This valve means provides additional control for the controlled environment device as will be described hereinafter.

Arranged in the tank 44 is a heater coil 72 connected to a suitable source of electric power (not shown) through a control device 74. A sensing element, which may comprise a thermister 76, is disposed in the tank 44 and is connected to the control 74. The coil 72 and sensing element 76 are submerged in the liquid sump formed in the tank 44.

Above the perforated air diffusing plate 46 in chamber 48 are one or more filters 80 which remove particles from the gas stream not removed by the spray device 82, connected via pump 84 to the cooling liquid in the tank 44. Further, where the air is to be sterile, the

upper portion of the chamber 48 may be fitted with a plurality of banks of ultra-violet ray tubes, generally designated 86.

In operation of the apparatus 32, air from the plurality of inlets 30a, b, c and d is drawn via conduit 88 by fan 66 forced through the cooling chamber 62, the reheating chamber between transverse plate and perforated plate 46, thence through the filter and, where desired, about the ultra-violet lights 86 to exit from the chanber 32 via outlet conduit 90 and into one or more of the outlet plenum chambers 20, 22 and 24. It will be appreciated that each of the outlet plenum chambers 20, 22 and 24 may be provided with its own air conditioning and purifying means 32, or one such unit may serve a plurality of outlet plenum chambers, depending upon the size or capacity of the conditioning unit and the area served by the outlet plenum chambers.

Referring to FIGS. 5 and 6, the outlet plenum chamber, generally designated 100, is circular in cross sec- 'tion and serves agenerally cylindrical zone 102 extending from the floor 104 upwardly to the outer surface of the perforated wall 106 of the plenum chamber 100. In FIG. 5, the cylindrical zone encompasses a circular work table, generally designated 108.

Referring particularly to FIG. 6, it will be seen that the wall 106 of the plenum chamber is provided with a plurality of concentric ring-type outlets 108a, b, c, d, e, and f which, like those illustrated in FIG. 3, increase in area from the center outwardly. Referring again to FIG. 5, the flow arrows 110 diagrammatically illustrate that the flow volume increases from the center of the controlled zone, indicated by broken line 112, outwardly and forms a downwardly moving blanket of air. The blanket of air has a greater velocity head at the periphery than at the center and the arrows in FIGS. 1, 2, 4 and 5 have lengths which generally and diagrammatically represent typical velocity heads at the stated points. Preferably, the air issuing from the outlet plenums is such that the entire air within the controlled zone is replaced on the order of 100 to 400 plus changes per hour. While the air enters the controlled zone at a rate of, for example, 50 to 100 linear feet per minute, air movement immediately adjacent to the surface of the work table 108 is practically undetectable by operators stationed about the table. Notwithstanding, the almost undetectable nature of the air movement, exhaled breath, and particles from the body of the operator are moved downwardly and outwardly to exhausts through outlet chambers 114 and 116, again positioned at or slightly above the level of the floor 104.

Referring to FIG. 4 of the drawing, the air flow pattern for the controlled zone 200 is illustrated by flow arrows 202 which again illustrate that the volume of air passing through the plural outlets 204 of the upper plenum chamber 206 is less in the center of the zone and increases near the peripheral margins thereof. While the air flow is greatest adjacent to the periphery of the controlled zone, the rate of flow is not such as to create what is conventionally known as an air curtain. Air curtains operate at a very high velocity and are unsuited for maintaining a controlled environmental space as the turbulance created by the high velocity air has been found to re-suspend particulate materials and prevent outward movement of those initially in the zone to be controlled or brought into the zone by operators and the like.

For an area having transverse cross dimensions of, for example, 10 feet by 10 feet total air movement in the order of from about five to ten thousand cubic feet per minute has been found to be about optimum. Thus, an area eight feet by eight feet can be efi'ectively controlled by a flow rate of from about 4,000 to 8,000 cubic feet per minute.

I claim:

1. A system for controlling the environment in a zone such that the gas flow in the zone moves generally downwardly at a rate progressively increasing in vol ume from the center of the zone outwardly comprising an enclosure having top, bottom and side walls, at least one outlet plenum chamber associated with the top wall, the outlet plenum chamber having a planar bot tom panel, means defining a plurality of gas outlet openings in the bottom panel, said openings varying in area with the smallest in the center and progressively increasing in area toward the peripheral margins of the controlled zone to thereby provide gas flow within the controlled zone having a progressively increasing velocity head from the center outwardly and substantially coextensively with the cross dimensions of the controlled zone, a plurality of gas inlet plenums positioned surjacent the bottom wall of the enclosure and about the outer periphery of the controlled zone, a gas treating means having a gas inlet and a gas outlet, first conduit means connecting the gas inlet of the gas treating means and the gas inlet plenums, second conduit means connecting the outlet plenum chamber and the outlet from the gas treating means, said gas treating means containing in serial arrangement between the gas inlet and the gas outlet gas moving, heating, cooling, humidifying, dehumidifying and filtering means.

2. The system for controlling the environment in a zone as defined in claim 1 wherein the volume of air issuing from the openings in the bottom panel of the outlet plenum chamber is such as to replace the air in the control zone from about to about 400 plus changes per hour.

3. A system for controlling the environment in a zone as defined in claim 1 wherein the air issuing from the openings in the bottom panel of the outlet plenum chamber is in the order of from about 5,000 to about 10,000 cubic feet per minute perlOO sq. ft. of area.

4. A system for controlling the environment in a zone as defined in claim 1 wherein the planar bottom panel of the outlet plenum chamber is rectangular.

5. A system for controlling the environment in a zone as defined in claim 1 wherein the planar bottom panel of the outlet plenum chamber is circular.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3303771 *Feb 11, 1965Feb 14, 1967Robert J Sigel IncVentilated ceiling construction
US3426512 *Jun 28, 1967Feb 11, 1969Nesher Alexander GVentilation device for producing laminar flow
US3505989 *May 29, 1967Apr 14, 1970Johnson & JohnsonControlled environmental apparatus
US3511162 *Feb 20, 1969May 12, 1970Johnson & JohnsonApparatus and method for isolating a patient zone
US3602212 *Apr 28, 1969Aug 31, 1971Howorth & Co Ltd JamesSurgical operating theatre with sterile air admitting means
US3625133 *Aug 22, 1969Dec 7, 1971Sanko Air PlantAir-curtaining apparatus for forming an internal-isolated zone
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4009647 *Apr 16, 1975Mar 1, 1977Howorth Air Engineering LimitedClean air zone for surgical purposes
US4094232 *Jan 13, 1977Jun 13, 1978Howorth Air Engineering LimitedClean air zone
US4133255 *Mar 21, 1977Jan 9, 1979Guice John JPaint spray booth and method of painting an article therein
US4137831 *Apr 8, 1977Feb 6, 1979Howorth Air Engineering LimitedClean air zone
US4140105 *Jun 30, 1977Feb 20, 1979Zinon DuvlisGas curtain for shielding person on an operating table
US4237780 *Jan 30, 1979Dec 9, 1980Andrew TruhanHydrocarbon fume disposal system particularly for use in paint spray booths
US4319899 *Apr 28, 1980Mar 16, 1982Pure Air CorporationAir handling system for laminar flow clean enclosure
US4412849 *Nov 20, 1981Nov 1, 1983Klenzaids Engineers Private LimitedMethod and apparatus for control of gas-borne particulates
US4531956 *Oct 12, 1982Jul 30, 1985Howorth Air Engineering LimitedSterile air trolley
US4890544 *Dec 28, 1987Jan 2, 1990Halton OyAir distribution system
US4927438 *Dec 22, 1988May 22, 1990Varian Associates, Inc.Horizontal laminar air flow work station
US5167681 *Jun 25, 1991Dec 1, 1992Clean Rooms International, Inc.Air filtration unit
US5192348 *Aug 21, 1991Mar 9, 1993Brod & Mcclung-Pace Co.Directional air diffuser panel for clean room ventilation system
US5259812 *Sep 23, 1992Nov 9, 1993Kleinsek Don AClean room and clean room containment center
US5290331 *Nov 5, 1991Mar 1, 1994University Of BathLocalized clean air system
US5395410 *Dec 21, 1993Mar 7, 1995Jang; Sun-SingFume exhauster
US5454756 *Jan 28, 1994Oct 3, 1995Pace CompanyAir diffuser panel
US5457270 *Oct 4, 1993Oct 10, 1995Hildebrand; Philip B.Chemical control system for confining volatile liquids
US5518450 *Sep 23, 1992May 21, 1996Overseas Publishers AssociationMethod and apparatus for protecting uultraclean surfaces
US5553417 *Apr 26, 1995Sep 10, 1996Chambers; John E.Fluid distribution panel and method
US5792259 *Nov 21, 1996Aug 11, 1998Dainippon Screen Mfg. Co., Ltd.Substrate processing apparatus and air supply method in substrate processing apparatus
US5803721 *Oct 29, 1996Sep 8, 1998Enviroflex, Inc.Clean room fan unit
US6113486 *Apr 9, 1997Sep 5, 2000U.N.I.R. Ultra Propre Nutrition Industrie RechercheFabric sheath for ventilation and laminar flow hood
US6390755 *Apr 6, 2000May 21, 2002Motorola, Inc.Exhaust device for use in a clean room, cleanroom, and method
US6632260Apr 28, 2000Oct 14, 2003Stratotech CorporationAdjustable clean-air flow environment
US6811587 *Nov 18, 2002Nov 2, 2004The United States Of America As Represented By The Secretary Of The NavyBiological hazard mitigation apparatus for mail/package handling personnel safety and operating methods therefor
US6960244 *Dec 17, 2001Nov 1, 2005American Safe Air, Inc.Reducing cross-contamination caused by a letter laced with anthrax or another harmful biological substance
US7052531 *Mar 31, 2003May 30, 2006Takashi KishiokaLocal cleaning system for constructing clean shielded space with no need for dedicated partition wall, using charged air shower unit providing ion wind and local exhaust device
US7597617 *Mar 2, 2007Oct 6, 2009Andrew SolbergGas diffusion device
US20120244793 *Apr 11, 2011Sep 27, 2012Hon Hai Precision Industry Co., Ltd.Container data center
DE2615904A1 *Apr 10, 1976Oct 20, 1977Karl Weiss Giessen Fabrik ElekZuluftdecke zum klimatisieren von operationssaelen u.dgl.
DE19958659A1 *Dec 6, 1999Jun 7, 2001Duerr Systems GmbhCell for surface treating workpieces has roof wall with air outlet area whose outlet surface has partial area with local surface normal directed into interior of cell underneath remaining area of roof for better air flow and dust removal
WO1988005147A1 *Dec 28, 1987Jul 14, 1988Halton OyAir distribution system
WO1997040325A1Apr 9, 1997Oct 30, 1997Alix Guy PaulFabric sheath for ventilation and laminar flow hood
WO2011028101A1Aug 18, 2010Mar 10, 2011Qrisp B.V.Device and method for supplying a cooled airflow to at least one location for cooling
Classifications
U.S. Classification454/187, 454/296, 454/236, 454/190, 55/DIG.290
International ClassificationF24F9/00, F24F3/044, F24F13/06
Cooperative ClassificationF24F3/044, Y10S55/29, F24F9/00, F24F13/06
European ClassificationF24F13/06, F24F9/00, F24F3/044