Claims
- 1. A method of minimizing the release of malodorous TRS-containing gases from a comminuted cellulosic fibrous material feed system, said method comprising:
(a) providing comminuted cellulosic fibrous material at a first pressure in the feed system and ultimately discharging the comminuted cellulosic material from the feed system; (b) discharging malodorous gases from the feed system at a gas discharge point, substantially independently of the discharge of comminuted cellulosic fibrous material therefrom; (c) pressurizing at least some of the malodorous gas discharged in (b) to increase the pressure thereof; and (d) re-introducing the pressurized gas from (c) into the flow of comminuted cellulosic material downstream of the gas discharge point.
- 2. A method as recited in claim 1 further comprising a treatment vessel downstream of the feed system; and wherein (d) is practiced by re-introducing the malodorous gases into the treatment vessel.
- 3. A method as recited in claim 1 wherein (c) is practiced using a thermocompressor, and introducing low pressure steam into the thermocompressor.
- 4. A method as recited in claim 1 wherein (d) is practiced to reintroduce pressurized gas into the feed system, and (c) is practiced to increase the pressure by at least 2 psig.
- 5. A method as recited in claim 1 wherein (d) is practiced by discharging the material into a horizontal steaming vessel in the feed system.
- 6. A method as recited in claim 5 further comprising (e) steaming the material in the horizontal steaming vessel, and discharging steamed material from the horizontal steaming vessel from a bottom portion thereof; remote from the pressure isolation device; and (f) discharging malodorous gases from a top portion of the horizontal steaming vessel adjacent the bottom portion thereof from which the material is discharged; and (g) treating or disposing of the gases from (f) in an NCG system.
- 7. A method as recited in claim 1 further comprising a treatment vessel downstream of the feed system; and wherein (c) is practiced to increase the pressure of the gases to between about 11-31 psig, and at least one psig higher than the pressure in the treatment vessel.
- 8. A method as recited in claim 2 wherein (c) is practiced to increase the pressure of the gases to between about 11-31 psig, and at least one psig higher than the pressure in the treatment vessel.
- 9. A method as recited in claim 3 further comprising a treatment vessel downstream of the feed system; and wherein (c) is practiced to increase the pressure of the gases to between about 11-31 psig, and at least one psig higher than the pressure in the treatment vessel.
- 10. A method of minimizing the release of malodorous TRS-containing gases from a comminuted cellulosic fibrous material feed system having a pressure isolation device with an inlet and outlet, and a treatment vessel connected to the outlet, said method comprising:
(a) introducing comminuted cellulosic fibrous material at a first pressure to the inlet of the pressure isolation device; (b) transferring the material to the outlet of the pressure isolation device at a second pressure, higher than the first pressure; (c) discharging the material from the pressure isolation device to the treatment vessel; (d) discharging malodorous gases from the pressure isolation device substantially independently of the discharge of comminuted cellulosic fibrous material therethrough; (e) pressurizing at least some of the malodorous gases discharged in (d) to increase the pressure thereof; and (f) re-introducing the pressurized malodorous gases into the flow of comminuted cellulosic material downstream of the pressure isolation device.
- 11. A method as recited in claim 10 wherein (f) is practiced by re-introducing the malodorous gases into the treatment vessel connected to the outlet of the pressure isolation device.
- 12. A method as recited in claim 10 wherein (e) is practiced using a thermocompressor or an eductor, and introducing steam into the thermocompressor or eductor.
- 13. A method as recited in claim 12 wherein (c) is practiced by discharging the material into a horizontal steaming vessel and wherein (f) is practiced by re-introducing the malodorous gases into the horizontal steaming vessel.
- 14. A method as recited in claim 13 further comprising (g) steaming the material in the horizontal steaming vessel, and discharging steamed material from the horizontal steaming vessel from a bottom portion thereof remote from the pressure isolation device; (h) discharging malodorous gases from a top portion of the horizontal steaming vessel adjacent the bottom portion thereof from which the material is discharged; and (i) treating or disposing of the gases from (l) in an NCG system.
- 15. A method as recited in claim 10 further comprising screening the gases passing out of the pressure isolation device during (d) to substantially prevent the passage of chips, pins, or fines out of the pressure isolation device with the malodorous gases.
- 16. A feed system for a digester in a pulp mill, comprising:
a pressure isolation device having an inlet into which comminuted cellulosic fibrous material is fed at a first pressure, and an outlet from which the material is discharged at a second pressure, greater than the first pressure; a superatmospheric pressure treatment vessel having a material inlet connected to said outlet of said pressure isolation device, and a material outlet; a gas discharge outlet from said pressure isolation device separate and distinct from said material discharge outlet; a pressurized fluid introduction port in said pressure isolation device, said port remote from said gas discharge outlet and closer to said material discharge outlet of said pressure isolation device than is said gas discharge outlet; a conduit connected to said gas discharge outlet; and a pressurizing device, which pressurizes gases, connected to said conduit.
- 17. A feed system as recited in claim 16 further comprising a screen at said gas discharge outlet for screening chips, pins and fines out of gas being discharged through the outlet.
- 18. A feed system as recited in claim 16 wherein said pressurizing device comprises a thermocompressor or an eductor, connected to a source of steam providing a source of pressurizing fluid therefor.
- 19. A feed system as recited in claim 18 wherein a discharge of steam and pressurized gases from said thermocompressor or eductor is fed to a treatment vessel at a point downstream of said pressure isolation device.
- 20. A feed system as recited in claim 19 wherein said treatment vessel is said superatmospheric pressure treatment vessel.
- 21. A feed system as recited in claim 20 wherein said superatmospheric pressure treatment vessel comprises a horizontal steaming vessel; and further comprising a gas outlet from said horizontal steaming vessel operatively connected to an NCG system, said gas outlet downstream of said point at which said discharge of steam and pressurized gases is connected to said horizontal steaming vessel.
- 22. A feed system as recited in claim 16 further comprising a plurality of conduits connected to said discharge outlet, and a manual or automatic controller for controlling valves in each of said conduits, one of said conduits connected to a chip bin which in turn is connected to said inlet to said pressure isolation device, another of said conduits connected to the atmosphere through a standpipe, and the third of said conduits connected to a pressurizing device which pressurizes gases.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of provisional application serial no. 60/118,697 filed Feb. 4, 1999.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60118697 |
Feb 1999 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09483021 |
Jan 2000 |
US |
Child |
09726393 |
Dec 2000 |
US |