Frictional charging device

• US 6,271,492 B1
• Filed: 07/27/2000
• Issued: 08/07/2001
• Est. Priority Date: 11/05/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi Zosen Corporation
• Original Assignee: Hitachi Zosen Corporation
• Inventors: Inoue, Tetsuya, Tsukahara, Masanori, Maehata, Hidehiko, Tamakoshi, Daisuke
• Primary Examiner(s): Walsh, Donald P.
• Assistant Examiner(s): Jones, David A.
• Application Number:
  US09/582,514
• Time in Patent Office: 376 Days
• Field of Search: 209/127.1, 209/128, 209/129, 209/130, 209/127.3, 209/127.4
• US Class Current: 209/127.1
• CPC Class Codes: B03C 7/006 Charging without electricity supply, e.g. by tribo-electricity, pyroelectricity
• CPC Class Codes: B03C 7/06 with cylindrical material carriers
• CPC Class Codes: B29B 17/02 Separating plastics from other materials
• CPC Class Codes: B29B 2017/0203 Separating plastics from plastics
• CPC Class Codes: B29B 2017/0265 Electrostatic separation
• CPC Class Codes: B29K 2023/06 PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/00 Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2027/06 PVC, i.e. polyvinylchloride
• CPC Class Codes: Y02W 30/52 Mechanical processing of waste for the recovery of materials, e.g. crushing, shredding, separation or disassembly
• CPC Class Codes: Y02W 30/62 Plastics recycling; Rubber recycling

Abstract

A frictional charging device (30) for charging crushed chips (1) of a plurality of kinds of plastics by stirring them. A stirring vessel (31) has a friction assisting material (52) put therein, the particles of the friction assisting material (52) being so formed that they are larger than the plastic chips (1). A delivery port (34) formed in one end of the stirring vessel (31) is provided with a plurality of delivery area wires (47) arranged at predetermined intervals and parallel to each other. The spacing between adjacent delivery area wires (47) is set larger than the plastic chips (1) and smaller than the particles of the friction assisting material (52).

Claims

1. A frictional charging device that charges crushed chips of a plurality of kinds of plastics by stirring them and feeds them to an electrostatic separator used for sorting, said frictional charging device being characterized in that

said device is provided with a stirring vessel rotatable around its axis, and a rotary driving device for rotating said stirring vessel,

said stirring vessel having a loading port formed at one end thereof for loading plastic chips,

said stirring vessel having a delivery port formed at the other end thereof for delivering charged plastic chips,

said delivery port being provided with a plurality of delivery area wires arranged along the cross-section of the stirring vessel, at predetermined intervals and parallel to each other,

wherein in order that chips of a particular kind of plastic to be sorted out and plastic chips having a positive or negative polarity reverse to that of said chips of said particular kind of plastic, in the electrification rank for said kinds of plastics forming the chips, may be equal in proportion to each other, particles of either of said plastics are put as a friction assisting material in the stirring vessel,

the particles of said friction assisting material being so formed that they are larger than the plastic chips,

the spacing between said delivery area wires being set larger than the plastic chips and smaller than the particles of the friction assisting material.

2. A frictional charging device as set forth in claim 1, characterized in that

disposed intermediate between the loading port and the delivery port are a plurality of intermediate wires arranged along the cross-section of the stirring vessel, at predetermined intervals and parallel to each other,

the spacing between said intermediate wires being set larger than the plastic chips and smaller than the particles of the friction assisting material,

the delivery area wires and the intermediate wires differing from each other in direction peripherally of the stirring vessel.

3. A frictional charging device as set forth in claim 1, characterized in that the stirring vessel is inclined such that the delivery port side is positioned below the level of the loading port side.

4. A frictional charging device as set forth in claim 1, characterized by including a delivery area adjuster for adjusting the area of the opening in the delivery port.

5. A frictional charging device as set forth in claim 1, characterized by including a stirring member disposed in the stirring vessel for stirring the plastic chips.

6. A frictional charging device that charges crushed chips of a plurality of kinds of plastics by stirring them and feeds them to an electrostatic separator used for sorting, said frictional charging device being characterized in that

an inner sleeve having a number of openings extending therethrough is rotatably installed inside an outer sleeve,

said outer sleeve being provided with a loading port for loading plastic chips into the outer sleeve, and a delivery port for delivering the plastic chips, delivered from the inside of the inner sleeve, to the outside of the outer sleeve,

wherein in order that chips of a particular kind of plastic to be sorted out and plastic chips having a positive or negative polarity reverse to that of said chips of said particular kind of plastic, in the electrification rank for a plurality of kinds of plastics forming the chips, may be equal in proportion to each other, particles of either of said plastics are put as a friction assisting material in the inner sleeve,

the particles of said friction assisting material being so formed that they are larger than the plastic chips,

the openings in said inner sleeve being formed to be larger than the plastic chips and smaller than the particles of the friction assisting material.

7. A frictional charging device as set forth in claim 6, characterized in that

the inner sleeve is rotatable around a horizontal axis,

the loading portion is formed in the upper region of the outer sleeve, while the delivery portion is formed in the lower region of the outer sleeve, and

said inner sleeve is located at a vertical position between the loading portion and the delivery portion.

8. A frictional charging device as set forth in claim 6, characterized in that

the inner sleeve is composed of an inner sleeve main body shaped like a sleeve, and end members for closing opposite ends of said inner sleeve main body, and

said inner sleeve main body and said end members are respectively formed with a number of openings.