Back to results
US 4,435,194 AGranted
Circuit for ventilating and filtering the medium contained in a confinement enclosure
AssigneeLa Calhene
InventorsClaude Picard, Bernard Saint Martin
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeLa Calhene
InventorsClaude Picard, Bernard Saint Martin
Estimating the term…
The invention relates to a circuit for ventilating and filtering the medium contained in a confinement enclosure (10) and also a method for sterilizing such an enclosure and its supply and discharge filters. An emergency or standby circuit is associated with the circuit ensuring ventilation and filtration under normal operating conditions and which comprises a supply pipe (20) and a discharge pipe (12), equipped with a suction fan (14). The said emergency circuit comprises the same pipes used in the opposite direction under the action of a suction fan (28) located in supply pipe (20), whereby said fan (28) can be automatically controlled by a pressostat (30). Sterilization is performed chemically, using a sterilizer which is connected to the supply duct between a valve and the supply filters disposed downstream of the valve. The sterilizer delivers a sterilizing agent which passes successively through the supply filters, the enclosure and the discharge filters. Once sterilization has been performed, the ventilating circuit is started up, so as to sweep away the sterilizing agent. Application to biological or nuclear experimentation enclosures.
A process for establishing and maintaining a vacuum within a ventilated and filtered air tight enclosure, said process comprising:
A circuit for ventilating and filtering the medium contained in an air tight enclosure and for establishing and maintaining a permanent vacuum within said enclosure, comprising a normal ventilating circuit, means for introducing the medium into the circuit including a supply pipe issuing into the enclosure to supply the enclosure with said medium, and a discharge pipe which discharges the medium from the enclosure in a normal flow direction, flow rate regulating means and first filtering means for said supply pipe, second filtering means and means for establishing the vacuum within the enclosure for said discharge pipe, said circuit further comprising means for maintaining the vacuum within the enclosure, said means for maintaining the vacuum including means for actuating said vacuum maintaining means upon a predetermined rise in pressure in the enclosure in case of failure in the normal ventilating circuit, said means for maintaining the vacuum being located in said supply pipe upstream of said first filtering means reversing the flow of the medium in the circuit from the normal direction of flow.
A circuit for ventilating and filtering the medium contained in an air tight enclosure and for establishing and maintaining a permanent over-pressure within said enclosure, comprising a normal ventilating circuit, means for introducing the medium into the circuit including a supply pipe issuing into the enclosure to supply the enclosure with said medium, and a discharge pipe which discharges the medium from the enclosure in a normal flow direction, flow rate regulating means and first filtering means for said discharge pipe, second filtering means and means for establishing the over-pressure within the enclosure for said supply pipe, said circuit further comprising means for maintaining the over-pressure within the enclosure, said means for maintaining the over-pressure including means for actuating said over-pressure maintaining means upon a predetermined decrease in pressure in the enclosure in case of failure in the normal ventilating circuit, said means for maintaining the over-pressure being located in said discharge pipe downstream of said first filtering means reversing the flow of the medium in the circuit from the normal direction of flow.
Dependencies are inferred from the claim text.