Method for determining the absolute humidity and apparatus for carrying out the method
AssigneeATEX Explosionsschutz GmbH
InventorFranz Alfert
Life of this patent
Estimating the term…
Abstract
A method and a device for determining the absolute humidity of a gas sample of a process gas are disclosed. The process gas is filtered for purification, before the gas sample obtained in this way is directed via a chilled mirror hygrometer. The process gas is withdrawn via an inner tube, which is located in a filter cartridge. The filter cartridge projects into a gas flow of the process gas. The inner tube has openings via which a gas sample that is representative over the length of the filter cartridge can be obtained and which allows for an even backwashing of the filter cartridge.
Claims10
A method, comprising:
- conducting a process gas through a filter cartridge having a filter jacket which surrounds the filter cartridge, with the filter jacket functioning as a depth filter for purification of the process gas passing through the filter jacket to obtain a purified gas sample;
- withdrawing the process gas via an inner tube located in the filter cartridge, with the filter cartridge projecting into a gas flow of the process gas;
- conducting the purified gas sample via a gas sample line from the inner tube to a chilled mirror hygrometer, external from the filter cartridge, for determining an absolute humidity of the gas sample of the process gas;
- connecting a backwash device to the inner tube;
- introducing a purge gas into the inner tube for backwashing in order to remove particle deposits from an outer side of the filter cartridge;
- and
- conducting the purge gas via a plurality of openings, arranged on a circumference of the inner tube, into an annular gap between an outer side of the inner tube and an inner side of the filter cartridge, with the openings being arranged at an opening spacing from an adjacent opening in a longitudinal direction, wherein the opening spacing is smaller at a first end of the inner tube than at a second end of the inner tube, so that more purge gas is conducted out of the inner tube in a region of the first end than in a region of the second end of the inner tube, with the first end projecting deeper into the gas flow of the process gas than the second end.
Apparatus for determining absolute humidity, the apparatus comprising:
- a filter cartridge having a filter jacket which surrounds the filter cartridge, with the filter jacket functioning as a depth filter to filter a process gas passing through the filter jacket to obtain a gas sample;
- an inner tube located in the filter cartridge and designed to receive the gas sample via an annular gap between the filter jacket of the filter cartridge and the inner tube, said inner tube including a plurality of openings distributed over a length of the inner tube for introducing the gas sample into a longitudinal channel of the inner tube, wherein the openings are each arranged at an opening spacing from an adjacent one of the openings in a longitudinal direction of the inner tube, with the opening spacing at a first end of the inner tube being smaller than at a second end of the inner tube;
- a chilled mirror hygrometer, external from the filter cartridge, for determining the absolute humidity of the gas sample;
- and
- and a gas sample line conducting the gas sample from the inner tube to the chilled mirror hygrometer.
Dependencies are inferred from the claim text.