Screw machine having a vacuum housing insert
A screw machine for treating at least partially powdery bulk material has a housing with at least one housing bore and a screw arranged in the housing bore. A vacuum housing portion is provided, which is formed as a vacuum housing insert, which is releasably attached in the housing, in which a metal nonwoven is exchangeably held as a gas-permeable wall portion on a base body.
1. 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.
2. A screw machine according to claim 1 , wherein the metal nonwoven ( 44 ) has a filter fineness of 1 μm to 10 μm.
3. A screw machine according to claim 1 , wherein the support body is formed as a support woven fabric ( 43 ).
4. A screw machine according to claim 3 , wherein the support woven fabric ( 43 ) has a mesh width in the range of 100 μm to 400 μm.
5. A screw machine according to claim 1 , wherein the drainage body is formed as a drainage woven fabric ( 42 ).
6. A screw machine according to claim 5 , wherein the drainage woven fabric ( 42 ) has a mesh width in the range of 500 μm to 1000 μm.
7. A screw machine according to claim 1 , wherein the holding strips ( 45 , 46 , 45 ′, 46 ′) have clamping webs ( 47 , 48 ), which hold the metal nonwoven ( 44 ) in a clamping manner against the base body ( 24 ).
8. A screw machine according to claim 1 , wherein the holding strips ( 45 , 46 , 45 ′, 46 ′) are arranged flush with the inner wall ( 30 , 31 ) of the at least one bore ( 3 , 4 ).
9. A screw machine according to claim 1 , wherein the metal nonwoven ( 44 ) is partially held in a clamping manner between the base body ( 24 ) and at least one holding strip ( 45 , 45 ′).
10. A screw machine according to claim 1 , wherein the holding strips ( 45 ′, 46 ′) are formed as a holding frame ( 52 ).
11. A screw machine according to claim 1 , wherein the metal nonwoven ( 44 ) is provided with a metal woven fabric as a reinforcement.