Waste fluid treatment apparatus and processing water regeneration system

Patent metadata

Field	Value
Publication number	US-11618698-B2
Application number	US-202017116352-A
Country	US
Kind code	B2
Filing date	Dec 9, 2020
Priority date	Dec 19, 2019
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A waste fluid treatment apparatus includes a sedimentation tank that stores the processing waste fluid with the processing debris contained therein, an inflow port provided on the sedimentation tank for introduction of the processing waste fluid into the sedimentation tank, an acidification unit configured to acidify the processing waste fluid to be introduced from the inflow port into the sedimentation tank, whereby the processing debris is allowed to settle at a higher rate compared with a rate at which the processing debris would settle if the processing waste water is neutral, and an outflow port provided on the sedimentation tank for discharge of acidic supernatant that is obtained by allowing the processing debris in the processing waste fluid to settle in the sedimentation tank from the sedimentation tank.

First claim

What is claimed is:

1. A waste fluid treatment apparatus for receiving processing waste fluid discharged from a processing machine that processes a workpiece with processing water supplied thereto, the processing waste fluid containing processing debris, and for allowing the processing debris to settle for removal of the processing debris from the processing waste fluid, comprising:
a sedimentation tank that stores the processing waste fluid with the processing debris contained therein;
an inflow port provided on the sedimentation tank for introduction of the processing waste fluid into the sedimentation tank;
an acidification unit configured to acidify the processing waste fluid to be introduced from the inflow port into the sedimentation tank;
an outflow port provided on the sedimentation tank for discharge of acidic supernatant obtained when the processing debris in the processing waste fluid settles in the sedimentation tank;
a plurality of baffles provided within the sedimentation tank, wherein the plurality of baffles each extend in the upright direction and are spaced from each other with respect to a direction that extends between the inflow port and the outflow port, and further wherein the baffles sequentially increase in height when considered in the direction that extends between the inflow port and the outflow port;
a control unit configured to control the waste fluid treatment apparatus;
a pH measuring instrument that measures a pH value of the processing waste fluid;
a material setting section incorporated in the control unit and configured to receive an input to set a material of the processing debris; and
a correspondence table that is incorporated in the control unit and that presents pH values at which zeta potential is 0 V for a plurality of materials respectively including the material of the processing debris,
wherein the control unit is further configured to control the acidification unit so that the pH value measured by the pH measuring instrument becomes equal to the pH value at which the zeta potential is 0 V for the material of the processing debris from the correspondence table that corresponds to the material input into the material setting section.

2. The waste fluid treatment apparatus according to claim 1 , wherein the acidification unit includes a carbon dioxide supply unit configured to supply carbon dioxide gas to the processing waste fluid.

3. The waste fluid treatment apparatus according to claim 1 , wherein the plurality of materials in the correspondence table includes polystyrene latex, silicon carbide, and silicon dioxide.

4. The waste fluid treatment apparatus according to claim 1 , wherein the plurality of materials in the correspondence table includes polystyrene latex.

5. The waste fluid treatment apparatus according to claim 1 , wherein the plurality of materials in the correspondence table includes silicon carbide.

6. The waste fluid treatment apparatus according to claim 1 , wherein the plurality of materials in the correspondence table includes silicon dioxide.

7. A processing water regeneration system comprising:
a waste fluid treatment apparatus for receiving processing waste fluid discharged from a processing machine that processes a workpiece with processing water supplied thereto, the processing waste fluid containing processing debris, and for allowing the processing debris to settle for removal of the processing debris from the processing waste fluid, the waste fluid treatment apparatus including:
a sedimentation tank that stores the processing waste fluid with the processing debris contained therein,
an inflow port provided on the sedimentation tank for introduction of the processing waste fluid into the sedimentation tank,
an acidification unit configured to acidify the processing waste fluid to be introduced from the inflow port into the sedimentation tank,
an outflow port provided on the sedimentation tank for discharge of acidic supernatant obtained when the processing debris in the processing waste fluid settles in the sedimentation tank,
a plurality of baffles provided within the sedimentation tank, wherein the plurality of baffles each extend in the upright direction and are spaced from each other with respect to a direction that extends between the inflow port and the outflow port, and further wherein the baffles sequentially increase in height when considered in the direction that extends between the inflow port and the outflow port,
a control unit configured to control the waste fluid treatment apparatus,
a pH measuring instrument that measures a pH value of the processing waste fluid,
a material setting section incorporated in the control unit and configured to receive an input to set a material of the processing debris,
a correspondence table that is incorporated in the control unit and that presents pH values at which zeta potential is 0 V for a plurality of materials respectively including the material of the processing debris,
wherein the control unit is further configured to control the acidification unit so that the pH value measured by the pH measuring instrument becomes equal to the pH value at which the zeta potential is 0 V for the material of the processing debris from the correspondence table that corresponds to the material input into the material setting section,
a processing water regeneration apparatus for regenerating processing water by removing organic materials and inorganic materials from acidic supernatant discharged from the waste fluid treatment apparatus and removed of the processing debris, the processing water regeneration apparatus including:
an ultraviolet ray irradiation unit that radiates an ultraviolet ray to the acidic supernatant to decompose the organic materials and the inorganic materials into organic material ions and inorganic material ions, and
an ion exchange resin that removes the organic material ions and the inorganic materials ions contained in the acidic supernatant, and
wherein the acidic supernatant delivered from the ultraviolet ray irradiation unit and that contains the organic material ions and the inorganic material ions flows through the ion exchange resin of the processing water regeneration apparatus to neutralize the acidic supernatant, so that the processing water is regenerated.

8. The processing water regeneration system according to claim 7 , wherein the acidification unit of the waste fluid treatment apparatus includes a carbon dioxide supply unit configured to supply carbon dioxide gas to the processing waste fluid.

9. The processing water regeneration system according to claim 7 , wherein the plurality of materials in the correspondence table includes polystyrene latex, silicon carbide, and silicon dioxide.

10. The processing water regeneration system according to claim 7 , wherein the plurality of materials in the correspondence table includes polystyrene latex.

11. The processing water regeneration system according to claim 7 , wherein the plurality of materials in the correspondence table includes silicon carbide.

12. The processing water regeneration system according to claim 7 , wherein the plurality of materials in the correspondence table includes silicon dioxide.

Assignees

• Disco Corp

Inventors

• Takenouchi Kenji
• Kashiwagi Hiroyuki
• Suwano Jun

Classifications

• C02F2103/346

  from semiconductor processing, e.g. waste water from polishing of wafers · CPC title

• C02F2209/03

  Pressure · CPC title

• C02F1/32

  with ultraviolet light · CPC title

• C02F1/008

  Control or steering systems not provided for elsewhere in subclass C02F · CPC title

• C02F1/52 Primary

  by flocculation or precipitation of suspended impurities {(C02F1/463 takes precedence)} · CPC title