Abstract The device concerns the circulation of cabin air through canisters which absorb and adsorb carbon dioxide, together with excess moisture, and return the scrubbed air to the cabin for recirculation. A coating on an inert substrate in granular form absorbs and adsorbs the impurities at standard temperatures and pressures, but desorbs such impurities at low pressures (vacuum) and standard temperatures. This fact is exploited by making the device in a stack of cells consisting of layers or cells which are isolated from one another flow-wise and are connected to separate manifolds and valving systems into two separate subsets. A first subset may be connected for the flow of breathable air therethrough until the polyethyleneimine of its cells is saturated with CO 2 and H 2 O. During the same period the second subset of cells is manifolded to a vacuum source. After the first period the first subset is re-valved to connect it to the vacuum system to draw off the collected impurities, while the newly purified subset B is connected to the breathable air of the cabin. These phases or half cycles are repeated, making it unnecessary to collect and discard any used-up materials. The cells of the device are separated from one another by sheets of a lightweight but impervious metal which is both physically strong and a good conductor of heat. To assist in the heat transfer process, a high conductivity foamed metal is disposed throughout the polyethyleneimine bed of each stratum, such foamed metal being formed into blocks which preferably touch both the upper and lower parting sheets defining the cell, to transfer heat to both the superior cell and the inferior cell so that the stack of cells operates essentially isothermally.
Inventors
👤 with respect to an invention of Fletcher James C. Administrator of the National Aeronautics and Space Administration
In a breathable air circulation system a module for the control and purification of air, said module comprising an array of cells in which every other cell is connected in common to a first pair of opposed manifolds in said circulation system while the intermediate cells are connected to a second pair of manifolds in said circulation system, said cells in the array being separated from their neighbors only by an airsealing parting sheet of high thermal conductivity, each said cell being filled with a foamed metal comprising a continuous phase of metal wire of high heat conductivity defining a mass of sub-cells or small spaces forming a second continuous phase, a filling of granular material in at least the major portion of said foamed metal, such that the air flowing through said cell must flow through said granular material within the foamed metal, said granular material being sorbent to carbon dioxide at standard temperature and pressure but not to other gases in the air other than water vapor and also being desorbent to carbon dioxide and moisture at standard temperatures and vacuum pressures, and means in each cell between the connections of each cell to said manifolds to present the untoward leakage of said granules into said manifolds, said foamed metal in each cell contacting said parting sheets for the passage of heat therethrough and providing the principal structural strength for the cell.
Claim 2
Dependent Claim
234 words
In a breathable air circulation system a module for the control and purification of air, said module comprising an array of cells in which every other cell is connected in common to a first pair of opposed manifolds in said circulation system while the intermediate cells are connected to a second pair of manifolds in said circulation system, said cells in the array being separated from their neighbors only by an airsealing parting sheet of high thermal conductivity, each said cell being filled with a foamed metal comprising a continuous phase of metal wire of high heat conductivity defining a mass of sub-cells or small spaces forming a second continuous phase, a filling of granular material in at least the major portion of said foamed metal, such that the air flowing through said cell must flow through said granular material within the foamed metal, said granular material being sorbent to carbon dioxide at standard temperature and pressure but not to other gases in the air other than water vapor and also being desorbent to carbon dioxide and moisture at standard temperatures and vacuum pressures, and means in each cell between the connections of each cell to said manifolds to present the untoward leakage of said granules into said manifolds, said foamed metal in each cell contacting said parting sheets for the passage of heat therethrough and providing the principal structural strength for the cell.
Claim 3
Dependent Claim
180 words
The module of claim 1 in which said foamed metal in each cell is divided into a large center section and a pair of long outer sections disposed lengthwise one on either side of said center section, each said outer section having a narrow end and a broad end and diverging substantially uniformly from said narrow end to said broad end and forming with said center section a generally parallelepiped configuration with the broad end of one outer section being connected to one of said manifolds of a pair of manifolds while the broad end of the other outer section is connected to the diagonally opposed manifold, and said means to prevent untoward leakage of the granules comprises a pair of fine mesh metal screens characterized by openings of a size less than the size of said granules but just sufficient to prevent the passage of said granules therethrough, one of said screens being disposed between said center section and one of said outer sections and the other screen being disposed between said center section and the other outer section.
Claim 4
Dependent Claim
34 words
The module of claim 2 in which the metal portion of said foamed metal material occupies only about 4% of the available volume, the balance being space occupied by said granules of sorbent material.
Claim 5
Dependent Claim
21 words
The module of claim 1 wherein said granular material is granules of a polyethyleneimine coated on a substrate of polymerized divinylbenzene.