Controlled atmosphere enclosure
First Claim
1. A controlled atmosphere enclosure comprising:
- a housing defining a controlled gas atmosphere chamber having an outlet and an inlet;
a gas recirculation path exterior to the chamber extending from the chamber outlet to the chamber inlet;
a filter in the gas recirculation path;
means for recirculating gas from the chamber outlet through the filter to the chamber inlet;
means for determining downstream from the filter, the concentration of a constituent gas of the recirculating gas;
means for adding the constituent gas to the recirculating gas in response to a control signal; and
control means, coupled to the means for determining the concentration of the constituent gas, for coupling a control signal to the constituent gas adding means to maintain a selected concentration of the constituent gas in the controlled gas atmosphere chamber,each of said means for gas recirculation, determination and addition located totally outside of said chamber, said filter for eliminating contamination of said gas determination means and the interior of said chamber upon recirculation of said constituent gas.
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0 Petitions
Accused Products
Abstract
An incubator for laboratory use which includes a housing defining a thermally insulated inner chamber having a controlled gas atmosphere. Devices for sensing characteristics of the incubator chamber atmosphere, and for conditioning the atmosphere, are positioned in a gas recirculation path outside the incubator chamber. The gas atmosphere of the incubator chamber circulates from a chamber outlet in an upper portion of the chamber, through the recirculation path, returning to the incubator chamber through a chamber inlet in a lower portion of the chamber. Included in the recirculation path are a blower for recirculating the chamber atmosphere, a filter, a CO2 sensor, and a humidifier. A microprocessor-based controller is responsive to the output of the CO2 sensor to effect the addition of CO2 to the recirculating gas to maintain a selected CO2 level in the chamber atmosphere. Upper and lower diffuser plates in the incubator chamber define upper and lower plenums, respectively. The upper plenum communicates with the chamber outlet, and the lower plenum communicates with the chamber inlet, to produce an upward vertical laminar flow of the gas atmosphere through the chamber. The incubator chamber walls are spaced inwardly from insulated outer walls to provide an enclosed air space about the outside of the chamber wall. Heaters inside the air space, spaced apart from the inner wall, are sized to produce substantially even heating of the chamber through convection in the air space.
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Citations
28 Claims
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1. A controlled atmosphere enclosure comprising:
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a housing defining a controlled gas atmosphere chamber having an outlet and an inlet; a gas recirculation path exterior to the chamber extending from the chamber outlet to the chamber inlet; a filter in the gas recirculation path; means for recirculating gas from the chamber outlet through the filter to the chamber inlet; means for determining downstream from the filter, the concentration of a constituent gas of the recirculating gas; means for adding the constituent gas to the recirculating gas in response to a control signal; and control means, coupled to the means for determining the concentration of the constituent gas, for coupling a control signal to the constituent gas adding means to maintain a selected concentration of the constituent gas in the controlled gas atmosphere chamber, each of said means for gas recirculation, determination and addition located totally outside of said chamber, said filter for eliminating contamination of said gas determination means and the interior of said chamber upon recirculation of said constituent gas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A controlled atmosphere incubator comprising:
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a housing defining a thermally insulated controlled gas atmosphere chamber having an outlet and an inlet; a heater in the housing for heating the chamber; a gas recirculation path exterior to the chamber extending from the chamber outlet to the chamber inlet; a filter in the recirculation path; means for recirculating gas from the chamber outlet through the filter to the chamber inlet; means, downstream from the filter, for determining the concentration of a constituent gas of the recirculating gas; means for adding the constituent gas to the recirculating gas in response to a control signal; means for sensing the temperature of the recirculating gas; and control means, coupled to the means for determining the concentration of the constituent gas and to the means for sensing the temperature of the recirculating gas, for supplying a control signal to the constituent gas adding means, to maintain a selected concentration of the constituent gas in the chamber, and for controlling the heater, to maintain a selected gas temperature in the chamber, each of said means for gas recirculation, determination and addition located totally outside of said chamber, said filter for eliminating contamination of said gas determination means and the interior of said chamber upon recirculation of said constituent gas. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A controlled atmosphere enclosure comprising:
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a housing defining a controlled atmosphere chamber having an outlet and an inlet; a gas recirculating path exterior to the chamber extending from the chamber outlet to the chamber inlet; a filter in the recirculation path; means for recirculating gas from the chamber outlet through the filter to the chamber inlet; means for determining, downstream from the filter, the concentration of a constituent gas of the recirculating gas; means for adding the constituent gas to the recirculating gas in response to a control signal; means, in the recirculation path downstream from the gas recirculating means and the filter, for adding moisture to the recirculating gas; and control means, coupled to the means for determining the concentration of the constituent gas, for coupling a control signal to the constituent gas adding means, to maintain a selected concentration of the constituent gas in the controlled gas atmosphere chamber, each of said means for gas recirculation, determination and addition located totally outside of said chamber, said filter for eliminating contamination of said gas determination means and the interior of said chamber upon recirculation of said constituent gas. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification