HIGH PRESSURE COMPRESSOR AND STEAM EXPLOSION PULPING METHOD

• US 20080277082A1
• Filed: 03/28/2008
• Published: 11/13/2008
• Est. Priority Date: 05/07/2007
• Status: Abandoned Application

• Current Assignee: Andritz Incorporated
• Original Assignee: Andritz Incorporated
• Inventors: Pschorn, Thomas, Mraz, Peter, Sabourin, Marc
• Application Number:
  US12/057,409
• Publication Number:
  US 20080277082A1
• Time in Patent Office: Days
• US Class Current: 162/23
• CPC Class Codes: D21B 1/12 by wet methods, by the use of steam beaters D21D1/00
• CPC Class Codes: D21C 1/02 with water or steam
• CPC Class Codes: D21C 5/00 Other processes for obtaining cellulose, e.g. cooking cotton linters obtaining fibres for spinning D01C; Processes characterised by the choice of cellulose-containing starting materials

Abstract

A steam explosion pulping method including: impregnating a cellulosic biomass feed material in a pressurized reactor vessel; discharging the impregnated feed material from the vessel to a high pressure compressor; elevating a pressure of the feed material in the compressor; discharging the pressurized feed material from the compressor to a conduit coupled to a blow valve; rapidly reducing pressure of the pressurized feed material as the feed material passes through the blow valve, and pulping the feed material by expansion of fluid in the feed material during the rapid pressure reduction.

Claims

1. A steam explosion pulping method comprising:

impregnating a cellulosic biomass feed material in a pressurized reactor vessel;

discharging the impregnated feed material from the vessel to a high pressure compressor;

elevating a pressure of the feed material in the compressor;

discharging the pressurized feed material from the compressor to a conduit coupled to a blow valve;

rapidly reducing pressure of the pressurized feed material as the feed material passes through the blow valve, and

pulping the feed material by expansion of fluid in the feed material during the rapid pressure reduction.

2. A steam explosion pulping method as in claim 1 wherein the high pressure compressor includes a rotating disc and the elevation of pressure of the feed material includes applying centrifugal forces from the disc to the feed material.

3. A steam explosion pulping method as in claim 2 wherein the rotating disc is an impeller.

4. A steam explosion pulping method as in claim 2 wherein the rotating disc includes vanes directing the feed material radially outward.

5. A steam explosion pulping method as in claim 1 wherein the pressure of the feed material to a pressure at least 10 bars.

6. A steam explosion pulping method as in claim 1 further comprising a high pressure liquid stream added to the pulped feed material downstream of the blow valve.

7. A steam explosion pulping method as in claim 1 wherein the feed material is discharged at a pressure of at least 15 bar.

8. A steam explosion pulping method as in claim 7 wherein the pressure of the feed material passing through the blow vale is reduced to less than 2 bar.

9. A high pressure compressor comprising:

a centrifugal impeller assembly including a disc and at least one removable vane plate attached to the disc, and

a high pressure casing for the impeller assembly.

10. A high pressure compressor as in claim 9 further comprising an inlet device including a feed screw.

11. A high pressure compressor as in claim 9 wherein the feed screw is at least one of a ribbon feeder and a full flight screw.

12. A high pressure compressor as in claim 10 wherein the at least one removable vane plate comprises an annular array of removable vane plate segments.

13. A high pressure compressor as in claim 12 wherein each vane plate segment includes radial vanes extending radially to a periphery of the segment.

14. A high pressure compressor as in claim 10 wherein the high pressure compressor is a modified mechanical disc refiner.

15. A high pressure compressor as in claim 10 further comprising a high pressure discharge coupling to a conduit including a blow valve.

16. A high pressure compressor as in claim 10 further comprising a stator disc opposite to the centrifugal impeller assembly.

17. A method to convert a mechanical refiner to a high pressure compressor having an impeller, comprising:

replacing a refining plate with a vane plate on a rotor disc, and

converting a stator disc to a stator housing for the vane plate and rotor disc.

18. A method as in claim 17 wherein the modification to the stator disc is adding a flat faced stator plate to the stator disc.

19. A method as in claim 17 wherein a shaft for the rotor disc is axially adjusted to form a narrow a gap between the stator disc and rotor disc.

20. A method as in claim 17 wherein a diffuser housing is modified to include a high pressure discharge outlet.