Patent ID: 8360627

Claim:
A screw machine for treating at least partially powdery bulk material, with a housing ( 2 ; 70 ), which has at least one housing bore ( 3 , 4 ; 71 ) with an inner wall ( 42 , 43 ), with a feed opening ( 9 ; 74 ) for the bulk material arranged at one end of the housing ( 2 ; 70 ), with a respective screw ( 7 , 8 ; 73 ) arranged in the at least one housing bore ( 3 , 4 ; 71 ), with a metering device ( 22 ) arranged upstream of the feed opening ( 9 ; 74 ) for feeding the bulk material with a vacuum housing portion in the intake zone ( 14 ), which has a gas-permeable wall portion ( 24 ) delimiting the at least one housing bore ( 3 , 4 ; 71 ), and with a drive ( 19 ; 77 ) for the at least one screw ( 7 , 8 ; 74 ), wherein the vacuum housing portion is formed as a vacuum housing insert ( 23 ) releasably attached in the housing ( 2 ; 70 ), in which a metal nonwoven ( 44 ) is exchangeably held as a gas-permeable wall portion on a base body ( 24 ) and the metal nonwoven ( 44 ) is supported by means of a gas-permeable support body with respect to the base body ( 24 ), wherein a gas-permeable drainage body is arranged between the support body and the base body ( 24 ) and, wherein the base body ( 24 ) has at least one partially cylindrical support face ( 28 , 29 ) adapted to the inner wall ( 30 , 31 ) of the at least one bore ( 3 , 4 ), against which support face the metal nonwoven ( 44 ) is supported and in that holding strips ( 45 , 46 , 45 ′, 46 ′) are releasably attached to the base body ( 24 ) and hold the metal nonwoven ( 44 ) in a clamping manner on the base body ( 24 ) and the base body ( 24 ) is provided with edge webs ( 40 , 41 ) surrounding the at least one support face ( 28 , 29 ), between which edge webs at least one of the support body and the drainage body are arranged.