Having Air Inlet Separate From Access Opening Patents (Class 454/57)
  • Patent number: 6089970
    Abstract: The present invention provides a low energy consumption fume hood that provides an adequate level of safety while reducing the amount of air exhausted from the hood. A low-flow fume hood in accordance with the present invention works on the principal of providing an air supply, preferably with low turbulence intensity, in the face of the hood. The air flow supplied displaces the volume currently present in the hood's face without significant mixing between the two volumes and with minimum injection of air from either side of the flow. This air flow provides a protective layer of clean air between the contaminated low-flow fume hood work chamber and the laboratory room. Because this protective layer of air will be free of contaminants, even temporary mixing between the air in the face of the fume hood and room air, which may result from short term pressure fluctuations or turbulence in the laboratory, will keep contaminants contained within the hood.
    Type: Grant
    Filed: April 7, 1998
    Date of Patent: July 18, 2000
    Assignee: The Regents of the University of California
    Inventor: Helmut E. Feustel
  • Patent number: 6036737
    Abstract: A safety cabinet having a work area defined by an enclosure and including an air circulation and cleaning system. The air circulation and cleaning system includes a plurality of air plenums and passageways through which air is circulated by a blower assembly. A portion of the air exiting the blower is directed through a transition boot and exhaust plenum and a remaining portion of the air exiting the blower assembly is directed into the work area through a perforated divider plate and a supply plenum. The transition boot between the exhaust and supply plenums include resealable fasteners disposed along a seam between first and second ends thereof and around a first end thereof which is attached to the exhaust plenum.
    Type: Grant
    Filed: June 25, 1998
    Date of Patent: March 14, 2000
    Assignee: Forma Scientific, Inc.
    Inventors: Dennis H. Smith, Matt Brooker, Raquel Wager
  • Patent number: 6010400
    Abstract: An isolation work station comprising an enclosure, and an air circulation system and high efficiency air filter for generating a downwardly directed laminar air flow through the enclosure. Periodic sterilization of the enclosure may be accomplished by adding a sterilant, such as vaporized hydrogen peroxide, to the airstream, and the filter is impregnated with a catalyst for degrading the vaporized hydrogen peroxide during the purge cycle and wherein the airstream is circulated at a relatively low speed so as to increase the residence time in the filter.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: January 4, 2000
    Assignee: Flanders Filters, Inc.
    Inventors: Russell Edward Krainiak, Mark Anthony Huza
  • Patent number: 5997397
    Abstract: A laboratory workbench includes a housing bounding a working space. The working space communicates with the exterior through a window bordering the working space on one of its sides thereof. A fan produces a flow of air in the working space and out the window. A protective screen is arranged on the housing in such a way that it can be moved. Specifically, the protective screen is mounted on the housing in the top area of the working space window in such a way that the protective screen can be moved between a hanging position at least partially covering the window, and a folded-up position. In the folded-up position, the protective screen projects into the housing in a substantially horizontal position plane. In one embodiment, an expansion screen is movable attached to the protective screen and has reach through openings formed therethrough.
    Type: Grant
    Filed: June 5, 1998
    Date of Patent: December 7, 1999
    Assignee: Kendro Laboratory Products GmbH
    Inventors: Edmund Frickel, Walter Gluck
  • Patent number: 5997399
    Abstract: An apparatus for providing a clean working environment includes an isolation booth, a worker booth, and an access device arranged to enable a worker in the worker booth to handle material in an isolation chamber formed in the isolation booth. A pressure generator is positioned to communicate with the isolation chamber to generate an air pressure therein that is less than the air pressure of an air curtain passing through the worker booth so that air is drawn from the air curtain in the worker booth into the isolation chamber through any air leak opening that develops in and around the access device so as to block outflow of air in the isolation chamber to the worker booth through the air leak opening.
    Type: Grant
    Filed: May 8, 1998
    Date of Patent: December 7, 1999
    Assignee: la Calhene, Inc.
    Inventor: Michael A. Szatmary
  • Patent number: 5944602
    Abstract: A portable cleanroom cabinet (20) having a portable cabinet device (22), configured for mobile transport, which provides a cavity (23) formed for receipt of at least one electronic component (21) therein. The cabinet device (22) defines at least one air flow passage (32) having a first opening (33) in flow communication with an upstream end (29) of the cavity (23), and a second opening (35) in flow communication with an opposite downstream end (36) of the cavity (23). Collectively, these passages and cavities define a recirculating airflow pathway such that substantially all the air flowing through the cavity (23) from the upstream end (29) to the downstream end (36) thereof recirculates back through the air flow passage (32) to the upstream end (29).
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: August 31, 1999
    Assignee: TUMI Manufacturing, Inc.
    Inventor: David A. Grundy
  • Patent number: 5924921
    Abstract: A ventilated cabinet apparatus for the storing of volatile chemicals. This apparatus is a ventilated cabinet for the storing of volatile or poisonous chemicals utilizes a vacuum pump drawing air out of the back of the cabinet to disperse the volatile gases or poisonous gases. In addition, the ventilated cabinet has holes running from front to back within the walls of the cabinet to allow fresh outside air to flow through the cabinet. Thus, any volatile gas buildup from the chemicals in the apparatus will be dissipated.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: July 20, 1999
    Assignee: Vanguard International Semiconductor Corporation
    Inventor: Vince W. H. Yang
  • Patent number: 5912184
    Abstract: An enclosure provided with an air supply system, an exhaust system, and controls for manipulating the flow, temperature, dewpoint and relative humidity of the air within the enclosure are disclosed. The present invention aims to achieve with these components a system for containing chemical contaminants created during processing of silicon wafers during the chemical/mechanical, polishing/planarization processes involved in creating those wafers. The system prevents drying of the slurry used to process wafers by controlling the relative humidity within the enclosure via a humidifier, sensors and a controller that dynamically reacts to changes within the enclosure atmosphere. Preventing slurry drying is critical to maintaining high wafer throughput by reducing gouging and scraping of wafers and also by reducing equipment down time needed to clean dried slurry.
    Type: Grant
    Filed: June 28, 1997
    Date of Patent: June 15, 1999
    Assignee: Intelligent Enclosures Corporation
    Inventor: Christopher O'Sullivan Young
  • Patent number: 5861305
    Abstract: The invention provides an exemplary anaerobic cabinet system which comprises as least one anaerobic cabinet which defines an enclosure interior of which is visible from outside of the cabinet. The cabinet includes a mechanism for inducing and maintaining a prescribe low oxygen internal atmosphere within the enclosure. The cabinet further includes at least one hand/arm access port, a controlled lock-type access mechanism for manually introducing and removing items through the port, and a hand/arm access port provision which is operably coupled to the lock-type access mechanism for manipulating items within the cabinet. The lock-type access mechanism comprises a door provision which in combination with the port provision define an import chamber for loading and/or unloading items to and from the enclosure through the port.
    Type: Grant
    Filed: July 1, 1997
    Date of Patent: January 19, 1999
    Assignee: Don Whitley Scientific Limited
    Inventors: Peter Silley, Donald Charles Whitley, Evan Jonathan Kitsell
  • Patent number: 5851143
    Abstract: A disk drive test chamber creates an environment for disk drives to be tested with an air circulation system that provides an even flow of air over each drive for equivalence in testing conditions. One method of providing equivalent air circulation is to have turning vanes inside air ducts to divert equal amounts of air over each shelf holding disk drives through identically sized apertures. The second method is to have apertures of varying sizes of 40, 50 and 70 percent opening per square inch in the air ducts to divert equal amounts of air. The temperature is maintained within 1/4.degree. C. of the set point by a controller through a system of heaters, air pumps, air ducts, insulation, vents, a motorized damper and an exhaust fan. The heater generates heat to simulate the actual heat of running conditions of disk drives. The pumps send air up the side air ducts and down the center air duct. The chamber has two safety features to prevent damage to the disk drives from over temperature.
    Type: Grant
    Filed: May 10, 1996
    Date of Patent: December 22, 1998
    Assignee: Thermal Industries
    Inventor: Lotfizadeh S. Hamid
  • Patent number: 5711705
    Abstract: An isolation work station comprising an enclosure, and an air circulation system and high efficiency air filter for generating a downwardly directed laminar air flow through the enclosure. Periodic sterilization of the enclosure may be accomplished by adding a sterilant, such as vaporized hydrogen peroxide, to the airstream, and the filter is impregnated with a catalyst for degrading the vaporized hydrogen peroxide during the purge cycle and wherein the airstream is circulated at a relatively low speed so as to increase the residence time in the filter.
    Type: Grant
    Filed: May 25, 1995
    Date of Patent: January 27, 1998
    Assignee: Flanders Filters, Inc.
    Inventors: Russell Edward Krainiak, Mark Anthony Huza
  • Patent number: 5704833
    Abstract: The present invention concerns a clean room featuring a closed enclosure having at least two opposite walls, a first of said walls being provided with blower means adapted to blow into said room a gaseous fluid, in particular air, having a specified controlled particle concentration, and a second wall being provided with evacuation means adapted to evacuate the gaseous fluid blown into said room. In accordance with the invention, said first wall is divided into at least two blower sectors, the blower means of each of said blower sectors blowing a gaseous fluid that has a uniform particle concentration different from the particle concentration of the other blower sector.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: January 6, 1998
    Assignee: Aerospatiale Societe Nationale Industrielle
    Inventors: Jean-Michel Reix, Georges Cina, Jean-Pierre Philipoussi
  • Patent number: 5700190
    Abstract: A flowhood work station has an inspection chamber having a perforated inspection surface. An air filtration housing is in fluid communication with the perforated inspection surface. A blower is capable of directing air downwardly through the perforated inspection surface. A return air plenum is in fluid communication with the perforated inspection surface and with the air filtration housing. The return air plenum captures a substantial portion of the air passing through the perforated inspection surface and directs the air to the air filtration housing.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: December 23, 1997
    Assignee: SEH America, Inc.
    Inventors: Roy P. Johnson, Donald L. Wilkinson
  • Patent number: 5662521
    Abstract: A safety work bench with a work opening, whose lower boundary is formed by a boundary plate in which ventilation openings are arranged for the generation of a vertical air current, has at least one arm rest installed in the lower area of the work opening. In order to create a safety work bench in which the arm rests are easy to decontaminate, and in order not to significantly diminish the effective cross section of the ventilation openings, the arm rests are constructed as a separate structural member and are detachably mounted on the boundary plate at a distance from it.
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: September 2, 1997
    Assignee: Heraeus Instruments GmbH
    Inventors: Christopher Latz, Walter Gluck
  • Patent number: 5658373
    Abstract: An air cleaning system for treating contaminated air from a mechanical industrial process containing a heterogenous multi-component mixed density fluid (e.g., mist, vapor and/or smoke) that addresses the cloud-like behavior of this contaminated air. The air cleaning system continuously captures a contaminated air volume emitted during operation of the mechanical industrial process and mixes that contaminated air volume with an ambient air volume in order to produce a mixed air volume having certain characteristic temperatures and air velocities. The characteristics of the mixed air volume are controlled such that the mixed air volume does not exhibit cloud-like behavior when transferred via a conduit structure to an air cleaning apparatus or the like.
    Type: Grant
    Filed: December 6, 1995
    Date of Patent: August 19, 1997
    Assignee: Helical Dynamics, Inc.
    Inventor: Wolodymyr Diachuk
  • Patent number: 5549512
    Abstract: A method and apparatus for providing a clean working area within an enclosure while simultaneously permitting open access to the working area from outside and also preventing any toxic substances from escaping the enclosure to contaminate a worker area. A higher pressure region within the enclosure near the aperture of the enclosure prevents dirt from entering and toxic materials from escaping.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: August 27, 1996
    Assignee: Lucent Technologies Inc.
    Inventors: James D. Sinclair, Constance A. Jankoski
  • Patent number: 5522767
    Abstract: The apparatus for treating small items is provided with a workbench surface which is supplied with air from above from a flow space and which is sealingly surrounded by a double-wall housing. The housing forms continuously extending flow cross-sections at edges of the surface. Disposed in front of the housing wall is a partition which defines therewith the flow cross-sections and forms in the interior of the housing a deflection edge at a spacing from the workbench surface.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: June 4, 1996
    Assignee: Metall + Plastic GmbH
    Inventors: Thomas Rertsche, Christoph von Stenglin, Ewald Springmeier
  • Patent number: 5513792
    Abstract: An outer-lead bonding apparatus according to the present invention comprises:(1) a punching die to stamp out chips from a film carrier tape,(2) a mounter to mount TAB chips on a substrate,(3) a first cover to enclose the mounter,(4) a second cover to enclose the punching die,(5) a pressure regulator to supply higher air pressure than outer air into inside space of the first cover, and(6) a exhaust to exhaust air from inside space of the second covering means. The outer-lead bonding apparatus of this invention keeps the environment around the mounter clean with air supplied from a pressure regulator and also by exhausting the air polluted by the punching operation through the exhaust. Neither products nor outer environment is thus contaminated.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: May 7, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Yasuto Onitsuka
  • Patent number: 5441708
    Abstract: A coved corner facility for providing a sealed work area to handle, manipulate and formulate materials which includes a walled enclosure having a plurality of mutually adjoining generally planar walls which define a work area. The planar portions of at least a plurality of mutually adjoining pairs of the walls intersect at angles of less than about 135.degree.. Each of the plurality of adjoining pairs of the walls are connected by preformed generally arcuate transition areas extending continuously between the planar portions of the adjoining pairs of walls. An inlet port in the walled enclosure is provided for allowing air to flow into the work area. An outlet port is provided in the walled enclosure for allowing air to flow out of the work area. An air flow control device causes air to flow through the inlet port into the work area and out of the enclosure work area through the outlet port.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: August 15, 1995
    Inventors: Anthony M. Diccianni, Eric A. Diccianni
  • Patent number: 5421320
    Abstract: A hood is assembled of modules including a central make-up air plenum module directly over the heating stations of a conveyorized double-deck oven, an exhaust plenum module atop the makeup air plenum and downwardly-opening end modules overhang the conveyor end portions extending outside the sides of the oven heating chambers. The end modules have make-up air directors aiming make-up air upward along the undersides of removable panels having slots therein to accelerate exhaust flow into a chamber below filters to effectively remove fumes from the areas above the conveyor ends. The overhanging end modules also have partitions therein cooperating with the walls of the overhang portions to provide ducts at the front of the overhang portions to capture fumes from the area above the front of the conveyor ends. Air flow guides around the extending portions of the conveyors assist.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: June 6, 1995
    Assignee: LDI Mfg. Co., Inc.
    Inventor: C. Scott Brown
  • Patent number: 5413527
    Abstract: A substrate holder containing semiconductor substrates is held in an air-tight container for conveyance which is placed over the entrance of a chamber. The gas drawn by a first fan for circulating gas through the bottom wall of the chamber flows through a first duct for circulating gas so as to be cleaned by a first high-efficiency filter and to be supplied into the chamber again in a horizontal laminar flow. The clean gas is supplied into the chamber in a vertical laminar flow from a second duct for circulating gas which has a second fan for circulating gas and a second high-efficiency filter.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: May 9, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshitaka Dansui, Hiroko Sakai
  • Patent number: 5401212
    Abstract: An environmental control systems including a modular isolation chamber is disclosed. Together with associated atmospheric regulatory equipment, the connectable modular chambers provide a smaller, cost-effective alternative to the traditional clean rooms utilized for fabricating or processing semiconductors and other products. Because the work pieces and processing or other machinery are isolated from the remainder of the rooms in which they are located, decontamination of much of each room is not required. Use of the portable, modular chambers of the present invention also permits increased control over particulate contaminates smaller than heretofore satisfactorily regulated and individualized regulation of differing processing environments within a single room.
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: March 28, 1995
    Assignee: Intelligent Enclosures Corporation
    Inventors: Greg A. Marvell, Robert M. Genco, Gregory K. Mundt, Michael B. Tanaka
  • Patent number: 5380244
    Abstract: A safety cabinet having a work area enclosed by a hood structure and including an air circulation and cleaning system. The air circulation and cleaning system includes a plurality of air ducts and passageways through which air is circulated by a blower within the cabinet. A portion of the air exiting the blower is directed through an exhaust after passing through a first filter and the remaining portion of the air exiting the blower is directed through the work area after passing through a second filter. A pressure gauge is connected between the first and second filters for measuring the pressure differential between the two filters to give an indication of the loading and efficiency of the filters. A third filter is disposed upstream of the pressure gauge to remove airborne contaminants in the air flowing to the gauge to prevent such contaminants from leaking from the gauge.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: January 10, 1995
    Assignee: Forma Scientific, Inc.
    Inventor: Russell C. Tipton
  • Patent number: 5295902
    Abstract: A biological safety cabinet comprising an enclosure having two side walls, a rear wall, a bottom wall defining a work surface, a top wall and a front window, below which access can be had to the work surface, the enclosure defining a work area. A plenum surrounds the enclosure and communicates with the work area. A blower induces a negative pressure within the plenum to circulate contaminated air through a filter within the enclosure, which creates a downwardly directed air curtain of work area air below the window. A vertically oriented outwardly facing channel section is secured to each side wall adjacent the window. Each channel section has a downwardly and forwardly sloping upper end, a rear edge of which extends above a lower edge of the window and a front edge of which extends below the lower edge of the window. The plenum communicates with each channel.
    Type: Grant
    Filed: May 7, 1992
    Date of Patent: March 22, 1994
    Assignee: Forma Scientific, Inc.
    Inventor: Kuah T. Hock
  • Patent number: 5267895
    Abstract: An apparatus for use with a multi-station workspace including a predetermined number of core walls which define an enclosed core. The core walls include an inlet at or below a predetermined height. The apparatus includes a platform positioned in the core at a location above the predetermined height substantially separating the core into a lower air intake chamber and an upper air discharge chamber. The platform further includes a filter in the lower chamber and a blowers drawing air from the intake chamber through the filter to the upper chamber. Finally, a core lid is positioned at the top of the core and includes air discharge vents. The discharge vents are side vents proximate each of the core walls for discharging air in a substantially horizontal direction out from each of the core walls to form an envelope of clean, filtered air for the workspace.
    Type: Grant
    Filed: July 27, 1992
    Date of Patent: December 7, 1993
    Assignee: CenterCore, Inc.
    Inventors: George E. Mitchell, Michael H. Pelosi, III
  • Patent number: 5259812
    Abstract: The clean room, which exceeds the Class 100 standards, constructed out of structural materials that are free of metal, in particular aluminum. The room is sterile and allows for a variety of manipulations to be performed including sensitive analysis steps. Intrinsic aluminum and most metal contamination is eliminated by constructing the clean room with aluminum free structural materials. Extrinsic contamination is prevented by following standard clean room procedures in a two-door positive pressure entry system under a single self-motorized ULPA filtered air flow. Analysis of samples is conducted under a vertical laminar ULPA filtered air flow at at least a Class 10 limit particle concentration standard. In addition, a clean room containment center wherein samples are prepared and processed inside a modular containment center that is under a negative pressure allowing a horizontal laminar ULPA filtered air flow that provides a Class 1 limit particle concentration rating.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: November 9, 1993
    Inventor: Don A. Kleinsek
  • Patent number: 5257957
    Abstract: A facility for providing a sealed work area to handle, manipulate and formulate materials which includes a walled enclosure having an interior periphery defining a work area. The enclosure includes an inlet port for allowing air to flow into the enclosure work area and an outlet port for allowing air to flow out of the enclosure work area. A replaceable liner is positioned within the enclosure work area in facing relationship with the interior periphery to further define the enclosure work area. The liner includes an inlet aperture in complementary sealed engagement with the inlet port and an outlet aperture in complementary sealed engagement with the outlet port. The liner is readily removable from the work area to be replaced with a second liner to facilitate decontamination of the work area. A blower causes air to flow through the inlet port into the enclosure work area and out of the enclosure work area through the outlet port.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: November 2, 1993
    Inventors: Anthony M. Diccianni, Eric A. Diccianni
  • Patent number: 5213059
    Abstract: An air conditioning unit comprises a housing (1) which consists of a bottom (2), a roof (3), two side walls (4, 4'), a rear wall (5), and a front wall (6) having an opening (8) which is closeable by means of at least one door (7, 7') and which permits access to the interior of the housing; means for introducing supply air into the housing; and means for evacuating exhaust air therefrom. Two vertical air ducts (13, 13') provided adjacent to the front wall (6) have a large number of small holes (14) through which supply air can be introduced into the housing in the form of partial currents which are directed away from the front wall (6) towards the rear wall (5), both when the door (7, 7') is closed and when it is open.
    Type: Grant
    Filed: March 22, 1990
    Date of Patent: May 25, 1993
    Assignee: Airchitecht I Soderhamn AB
    Inventor: Anders Krantz
  • Patent number: 5209273
    Abstract: The cabin is integral with a shield which separates it from the working environment and which can replace a perimetral part of the wall or the like which separates said environment from the outside. In correspondence with said shield the cabin comprises a sealed (by suitable seal gaskets), flameproof and explosion-proof door providing access from said environment and comprising an armoured viewing window. On the side opposite that comprising the door the cabin has a movable wall which is hinged and ejectable. In the walls perpendicular to the preceding there are apertures or passageways for the entry and exit of the can conveyor. Analogous apertures or passageways are provided in the shield, these being at least partly closable by guillotine plates when required. In the region in which the conveyor extends in the open between the shield and cabin, means are provided to direct air streams onto the cans.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: May 11, 1993
    Assignee: Coster Tecnologie Speciali S.p.A.
    Inventors: Giancarlo Giuffredi, Domenico Crespiatico, Carmelo Rigano
  • Patent number: 5195922
    Abstract: An environmental control system including a modular isolation chamber wherein the work pieces and processing or other machinery are isolated from the remainder of the rooms in which they are located. Use of the portable, modular chambers also permits control over particulate contaminates and individualized regulation of differing processing environments within a single room.
    Type: Grant
    Filed: April 19, 1991
    Date of Patent: March 23, 1993
    Assignee: Intelligent Enclosures Corporation
    Inventor: Robert M. Genco
  • Patent number: 5188136
    Abstract: A cleaning device in the present invention comprises cleaning chambers each for cleaning subjects to be cleaned, transport units for transporting the subjects, transport chambers each having one of the transport units, first decompression means for decompressing each of the transport chambers to keep its internal atmospheric pressure lower than the external atmospheric pressure of the cleaning device by 0 through 0.02 mmH.sub.2 O, and second decompression means for decompressing each of the cleaning chambers to keep its internal atmospheric pressure lower than the internal atmospheric pressure of each of the transport chambers by 0 through 0.02 mmH.sub.2 O.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: February 23, 1993
    Assignee: Tokyo Electron Limited
    Inventor: Yoshio Kumagai
  • Patent number: 5181883
    Abstract: A smoker's booth for isolating, containing, venting, and filtering tobacco smoke. The booth has a walled enclosure with a smoker's access aperture. The presence of a smoker is detected, thereby activating the venting, filtering, and lighting mechanisms. The booth can be wall mounted or freestanding.
    Type: Grant
    Filed: November 8, 1991
    Date of Patent: January 26, 1993
    Assignee: Quality Air Systems, Inc.
    Inventors: Joseph S. Hofstra, Ronald J. Karaskiewicz, Mark R. Fischer
  • Patent number: 5167572
    Abstract: An air curtain fume cabinet, in which an air curtain jet is directed across the face opening to an exhaust duct. Sufficient flow is exhausted at the exhaust duct to swallow (i) the entire air curtain jet, plus (ii) all of the air which the jet entrains from outside the face opening, plus (iii) a substantial additional amount of air. This greatly increases the velocity of air moving into the curtain at its top, beyond the normal entrainment velocity, and prevents spill-back of jet air to the outside even with substantial crosswinds. Preferably the ratio of exhaust flow to jet flow is between 2 and 3 for a jet height to jet thickness ratio of up to about 15. Preferably auxiliary air is supplied to the working space interior to replace air entrained into the jet from inside the working space.
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: December 1, 1992
    Assignee: Aerospace Engineering and Research Consultants Limited
    Inventor: Bernard Etkin
  • Patent number: 5145459
    Abstract: In order to ensure a bidirectional dynamic separtion between two zones (10,12), between said zones is formed a gas curtain constituted by three juxtaposed gas streams or jets (28,30,32). The central stream or jet is relatively fast and serves to stabilize the two relatively slow lateral streams or jets (30,32). The latter ensure the relative confinement of the two zones by means of their tongues (30a,32a) and their flow rate is determined in such a way as to supply the relatively fast stream with the gas necessary for its full development. In the case where one (10) of the zones has a reduced volume, a low flow rate, additional gas flow can be injected into the said zone.
    Type: Grant
    Filed: March 12, 1991
    Date of Patent: September 8, 1992
    Assignee: SGN-Societe General Pour les Techniques Nouvelles
    Inventors: Francois Meline, Robert Guetron
  • Patent number: 5113749
    Abstract: An apparatus for producing an air curtain comprising a central opening bounded by a frame on the top, bottom, and sides which defines internal channels which fluidly communicate with one another. The bottom and sides of the frame define apertures of varying diameter proximate to the lower portion of the central opening. The apertures are arranged in an array whereby rows of apertures more closely proximate to the front edge of the central opening have diameters greater than the diameters of the apertures in rows more closely proximate to the rear edge of the central opening. Air is drawn into the channels through the apertures, and the array of apertures produces a forwardly biased pressure gradient, the result of which is to cause a stream of air being expelled downwardly from the top of the central opening to ramp or curl forwardly toward the front edge of the central opening as that stream of air traverses the central opening.
    Type: Grant
    Filed: August 3, 1990
    Date of Patent: May 19, 1992
    Inventor: Kenneth E. Perbix
  • Patent number: 5083558
    Abstract: Surgical procedures are conducted in a protected environment wherein a laminar flow of micro filtered air is passed from a top to a bottom of an enclosure with transparent panels defining a space for manual access of the surgeon's hands and arms. Air circulation is forced through a high performance HEPA filter between an inlet including the bottom of the enclosure and an outlet at the top, both including panels with an array of apertures for establishing substantially laminar flow. A duct along an endwall of the enclosure carries filtered air to the top. A positive pressure differential is maintained between the inside of the surgical compartment and the outside, to protect the patient operative site from contamination by airborne particles. The enclosure rests on top of a mobile cabinet and has access ports for connection lines and also for bringing the surgical subject into the enclosure. For experimental animals, an access port for cage boxes can be provided.
    Type: Grant
    Filed: November 6, 1990
    Date of Patent: January 28, 1992
    Inventors: William R. Thomas, Robert F. Hoyt, Jr.