Rotary feeder for dosing bulk material

• US 6,129,246 A
• Filed: 08/24/1998
• Issued: 10/10/2000
• Est. Priority Date: 09/01/1997
• Status: Expired due to Fees

• Current Assignee: Waeschle GmbH
• Original Assignee: Waeschle GmbH
• Inventors: Metzler, Eugen
• Primary Examiner(s): Recla, Henry J.
• Assistant Examiner(s): Prunner, Kathleen J.
• Application Number:
  US09/138,432
• Time in Patent Office: 778 Days
• Field of Search: 222/368, 222/189.11, 414/219, 277/348, 277/350, 277/408, 277/431, 277/432
• US Class Current: 222/368
• CPC Class Codes: B65G 53/4633 the element having pockets, rotated from charging position to discharging position, i.e. discrete flow

Abstract

A rotary feeder for dosing bulk material, includes a casing having an inner chamber and formed with a top inlet, a bottom outlet and spaced-apart bearing covers flanking the inlet and the outlet. A rotor is accommodated in the chamber and is mounted on a shaft for rotation about a pivot axis. The shaft supports a plurality of vanes extending radially outward from the shaft between lateral end disks, with the shaft being supported on opposite sides of the rotor by bearings. In order to minimize the length of the shaft and a flexure of the shaft when encountering a substantial pressure differential between the inlet and the outlet, the chamber of the housing is sealed from the ambient environment by at least one shaft seal situated axially outwardly from the one bearing of the first and second bearings which is located on a same side of the rotor as the shaft seal.

Claims

1. A rotary feeder for dosing bulk material, comprising:

a housing having a top inlet, a bottom outlet, a chamber between the inlet and the outlet, and spaced-apart bearing covers flanking the inlet and the outlet;

a rotor accommodated in the chamber and mounted on a shaft for rotation about a pivot axis, said shaft supporting a plurality of vanes extending radially outwards from the shaft between lateral end disks;

bearing means for supporting the shaft on opposite sides of the rotor, said bearing means including a first bearing for supporting the shaft on one side of the rotor and a second bearing for supporting the shaft on the other side of the rotor; and

a sealing arrangement for sealing the chamber of the housing from the ambient environment, said sealing arrangement including at least one shaft seal situated axially outwardly from the one bearing of the first and second bearings which is located on a same side of the rotor as the shaft seal; and

a first fitting for admitting a barrier fluid into an area of the one bearing, a second fitting for admitting a barrier gas into a space between one of the lateral disks and a corresponding one of the side covers which is located on a same side of the rotor as the one end disk, and a filter, said first fitting being fluidly connected to the second fitting via the filter.

2. The rotary feeder of claim 1 wherein the sealing arrangement includes at least one further shaft seal positioned between one of the lateral disks and a corresponding one of the first and second bearings which is located on a same side of the rotor as the one end disk.

3. The rotary feeder of claim 1 wherein the shaft seal is a mechanical seal, and further comprising a fitting for admitting barrier fluid into the mechanical seal.

4. The rotary feeder of claim 1 wherein the seal arrangement includes two shaft seals situated axially outwardly from the one bearing of the first and second bearings, and further comprising a fitting for admitting a barrier gas into the space between the two shaft seals.

5. The rotary feeder of claim 1 wherein the housing has an inner wall surface and each of the end disks is defined by a peripheral surface which is spaced from the inner wall surface of the housing for defining an annular gap, and further comprising a second annular seal arrangement received in the annular gap between the peripheral surface of the lateral disks and the inner wall surface of the housing.

6. A rotary feeder for dosing bulk material, comprising:

a housing having a top inlet, a bottom outlet, a chamber between the inlet and the outlet, and spaced-apart bearing covers flanking the inlet and the outlet;

a rotor accommodated in the chamber and mounted on a shaft for rotation about a pivot axis, said shaft supporting a plurality of vanes extending radially outwards from the shaft between lateral end disks;

bearing means for supporting the shaft on opposite sides of the rotor, said bearing means including a first bearing for supporting the shaft on one side of the rotor and a second bearing for supporting the shaft on the other side of the rotor;

a sealing arrangement for sealing the chamber of the housing from the ambient environment, said sealing arrangement including at least one shaft seal situated axially outwardly from the one bearing of the first and second bearings which is located on a same side of the rotor as the shaft seal; and

a first fitting for admitting a barrier fluid into an area of the one bearing, a second fitting for admitting a barrier gas into a space between one of the lateral disks and a corresponding one of the side covers which is located on a same side of the rotor as the one end disk, and a pressure equalizing device, said first and second fittings being connected to separate sources and linked to one another via the pressure equalizing device.

7. The rotary feeder of claim 6 wherein the pressure equalizing device is formed by a cylinder and a piston slideably guided in the cylinder.

8. The rotary feeder of claim 6 wherein the pressure equalizing device is formed by a surge tank and an elastic membrane situated in and subdividing the surge tank.

9. The rotary feeder of claim 6 wherein the pressure equalizing device is formed by a surge tank and a flexible bubble situated in and subdividing the surge tank.

10. The rotary feeder of claim 6 wherein the shaft seal is a mechanical seal, and further comprising a fitting for admitting barrier fluid into the mechanical seal.

11. The rotary feeder of claim 6 wherein the seal arrangement includes two shaft seals situated axially outwardly from the one bearing of the first and second bearings, and further comprising a fitting for admitting a barrier gas into the space between the two shaft seals.

12. The rotary feeder of claim 6 wherein the housing has an inner wall surface and each of the end disks is defined by a peripheral surface which is spaced from the inner wall surface of the housing for defining an annular gap, and further comprising a second annular seal arrangement received in the annular gap between the peripheral surface of the lateral disks and the inner wall surface of the housing.