Stratified bulk material filter

Claim 1

In a crude gas filter having layers of granulated bulk material, the filter comprising a housing provided with a crude gas inlet and a purified gas outlet, and being subdivided by a partition into a crude gas spaced and a purified gas space, a plurality of vertical bulk material layers disposed in said crude gas space, said layers feedable from the top of said crude gas space and closed off and the bottom thereof, gas permeable members defining the bulk material layers on opposite sides thereof so as to form a crude gas flow arrival space on one side of the bulk material layers and a purified gas flow departure space on the opposite side thereof, loose bulk material of the layers being formed in slopes at the gas permeable members, means for supplying or replenishing bulk material to the bulk material layers and means for extraction of bulk material from the bulk material layers, which means communicate with the bottom of the bulk material layers, the improvement which comprises said gas permeable members forming the crude gas flow arrival sides of the bulk material layers are provided with perforations having a diameter larger than the diameter of the bulk material grains and the bulk material slopes are formed from within the perforations, and said gas permeable members forming the purified gas flow departure sides are so formed that no bulk material passes therethrough into the purified gas flow departure space, means for providing a cyclic flushing compressed gas counterflow for flushing and cleansing the bulk mterial layers in a flow direction contrary to that of the crude gas, said flushing gas counterflow providing means comprising a source of compressed gas, a distributor pipe for compressed gas connected to the compressed gas source and projecting into the purified gas space, at least one nozzle communicating with said distributor pipe and spaces so as to facilitate a brief cyclic counterflow flushing and cleansing of the bulk material layers at the crude gas flow arrival sides and a simultaneous lateral removal or sideways extraction of charged or exhausted bulk material of the bulk material slopes at the crude gas flow arrival sides, and said bulk material extraction means comprising a bottom extraction grid acting briefly and simultaneously with said flushing gas counterflow providing means for bottom removal of the bulk material, so that, as bulk material is removed at the bottom, the bulk material layers are thereby placed in motion from the top towards the bottom.