Abstract: Sieve screen level sensing in a filtering apparatus (10) for filtering fine powder material (M) which includes a sieve (12) having a material inlet (24) and a material outlet (26), and a sieve screen (14) is disposed within the sieve (12) between the material inlet (24) and outlet (26) such that the material (M) must pass through the sieve screen (14) to enter the material outlet (26) and thereby exit the sieve (12). An input valve (22) controls the flow of material (M) into the sieve (12) through the material inlet (24). A sieve screen level sensor assembly (20) senses a level of material (M) accumulated upon the sieve screen (14), and issues a level sense signal (66) indicative of that level. A programmable logic controller (60) receives the level sense signal (66) and controls the inlet valve (22) dependent at least in part thereon to thereby control the flow of material (M) into the material inlet (24).

Abstract: An apparatus (10) for handling bulk particulate material (M) includes a reservoir hopper (16) having a gas-permeable liner (42) and a gas inlet (44) connecting the reservoir hopper (16) to a pressurized flow of gas sufficient to fluidize the material (M). A transition and pipe assembly (18) receives a flow of material (M) from the reservoir hopper (16). The transition and pipe assembly (18) has an outer conduit (54), an inner conduit (52), and at least one gas inlet (64). The outer conduit (54) is substantially impervious to gas whereas the inner conduit (52) is permeable to gas. The inner conduit (52) is disposed within and surrounded by the outer conduit (54). The gas inlet (64) connects the outer conduit (54) to a pressurized flow of gas to fluidize the material (M) within the inner conduit (52). A variable orifice non-contact valve (24) controls the flow of material (M) from the transition and pipe assembly (18).

Abstract: An apparatus (10) for handling bulk particulate material (M) includes a reservoir hopper (16) having a gas-permeable liner (42) and a gas inlet (44) connecting the reservoir hopper (16) to a pressurized flow of gas sufficient to fluidize the material (M). A transition and pipe assembly (18) receives a flow of material (M) from the reservoir hopper (16). The transition and pipe assembly (18) has an outer conduit (54), an inner conduit (52), and at least one gas inlet (64). The outer conduit (54) is substantially impervious to gas whereas the inner conduit (52) is permeable to gas. The inner conduit (52) is disposed within and surrounded by the outer conduit (54). The gas inlet (64) connects the outer conduit (54) to a pressurized flow of gas to fluidize the material (M) within the inner conduit (52). A variable orifice non-contact valve (24) controls the flow of material (M) from the transition and pipe assembly (18).

Abstract: Sieve screen level sensing in a filtering apparatus (10) for filtering fine powder material (M) which includes a sieve (12) having a material inlet (24) and a material outlet (26), and a sieve screen (14) is disposed within the sieve (12) between the material inlet (24) and outlet (26) such that the material (M) must pass through the sieve screen (14) to enter the material outlet (26) and thereby exit the sieve (12). An input valve (22) controls the flow of material (M) into the sieve (12) through the material inlet (24). A sieve screen level sensor assembly (20) senses a level of material (M) accumulated upon the sieve screen (14), and issues a level sense signal (66) indicative of that level. A programmable logic controller (60) receives the level sense signal (66) and controls the inlet valve (22) dependent at least in part thereon to thereby control the flow of material (M) into the material inlet (24).