Air intake system with membrane unit for siloxane removal

Patent metadata

Field	Value
Publication number	US-10208718-B2
Application number	US-201615391397-A
Country	US
Kind code	B2
Filing date	Dec 27, 2016
Priority date	Dec 27, 2016
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

An air intake system for directing intake air to an internal combustion engine of a machine is disclosed. The air intake system may comprise an air compressor configured to increase a pressure of the intake air, and a membrane unit downstream of the air compressor and having a membrane with selectivity for siloxanes. The membrane may have a first side and a second side, and the first side may be exposed to a higher pressure than the second side when the air compressor is operating. The membrane may be configured to separate the intake air into a permeate that traverses the membrane from the first side to the second side, and a retenate that remains on the first side. The permeate may have a higher siloxane content than the retenate. The retenate may be directed to the internal combustion engine for combustion.

First claim

What is claimed is:

1. An air intake system for directing intake air to an internal combustion engine of a machine, comprising:
an air compressor configured to increase a pressure of the intake air; and
a membrane unit downstream of the air compressor and having a membrane with a selectivity for siloxanes, the membrane having a first side and a second side, the first side being exposed to a higher pressure than the second side when the air compressor is operating, the membrane being configured to separate the intake air into a permeate that traverses the membrane from the first side to the second side, and a retenate that remains on the first side, the permeate having a higher siloxane content than the retentate, the retenate being directed to the internal combustion engine for combustion; and
at least one permeate conduit configured to direct the permeate released from the membrane unit upstream of the air compressor in the air intake system.

2. The air intake system of claim 1 , wherein the first side of the membrane is exposed to pressurized intake air from the air compressor when the air compressor is operating.

3. The air intake system of claim 2 , wherein the membrane unit further includes an air sweep configured to flow ambient air across the second side of the membrane.

4. The air intake system of claim 2 , wherein the membrane unit further comprises a compressed air sweep configured to flow compressed air from the air compressor across the second side of the membrane.

5. The air intake system of claim 2 , wherein the membrane unit includes at least one inlet for the intake air from the air compressor, at least one permeate outlet for release of the permeate, and at least one retenate outlet for release of the retenate, the retenate outlet being in fluid communication with a retenate conduit configured to direct the retenate to the internal combustion engine.

6. The air intake system of claim 5 , wherein the air intake system further comprises an air filter upstream of the air compressor, and an air-to-air aftercooler downstream of the air compressor.

7. The air intake system of claim 5 , wherein the membrane unit is upstream of the air-to-air aftercooler.

8. The air intake system of claim 5 , wherein the membrane unit is downstream of the air-to-air aftercooler.

9. The air intake system of claim 5 , further comprising:
at least one intake conduit configured to direct the intake air to the air filter; and
at least one filter conduit configured to direct the intake air from the air filter to the air compressor, the intake conduit and the filter conduit being at sub-ambient pressures when the air compressor is operating.

10. The air intake system of claim 9 , wherein the at least one permeate conduit is in fluid communication with the permeate outlet and is configured to direct the permeate released from the permeate outlet to the intake conduit, the permeate conduit placing the second side of the membrane in fluid communication with the intake conduit so that the second side of the membrane is at sub-ambient pressures when the air compressor is operating.

11. The air intake system of claim 9 , wherein the at least one permeate conduit is in fluid communication with the permeate outlet and is configured to direct the permeate released from the permeate outlet to the filter conduit, the permeate conduit placing the second side of the membrane in fluid communication with the filter conduit so that the second side of the membrane is at sub-ambient pressures when the air compressor is operating.

12. The air intake system of claim 10 , wherein the permeate conduit includes at least one removal device configured to at least partially remove the siloxanes from the permeate.

13. A waste-handling machine, comprising:
an internal combustion engine;
an air intake system configured to direct intake air to the internal combustion engine, the air intake system including an air compressor configured to increase a pressure of the intake air;
a membrane unit downstream of the air compressor in the air intake system, the membrane unit having a membrane selective for siloxanes, the membrane having a pressure differential thereacross with a first side of the membrane that is exposed to the intake air being at a higher pressure than a second side of the membrane when the air compressor is operating, the membrane being configured to separate the intake air into a permeate and a retenate, the permeate traversing the membrane to the second side and the retenate remaining on the first side, the permeate having a higher siloxane content than the retenate;
a retenate conduit configured to direct the retenate to the internal combustion engine; and
a permeate conduit configured to direct the permeate to a removal device, the removal device being configured to at least partially remove the siloxanes from the permeate, the permeate conduit being further configured to direct a treated permeate after treatment at the removal device to a position upstream of the air compressor in the air intake system.

14. The waste-handling machine of claim 13 , wherein the removal device is a condenser configured to condense the siloxanes to a liquid state.

15. The waste-handling machine of claim 13 , wherein the removal device is a burner configured to oxidize the siloxanes to solid silicon dioxide (SiO 2 ).

16. The waste-handling machine of claim 13 , wherein, when the air compressor is operating, the first side of the membrane is exposed to the pressurized intake air from the air compressor and the second side of the membrane is exposed to sub-ambient pressures.

17. The waste-handling machine of claim 16 , wherein the membrane unit further comprises an air sweep configured to sweep ambient air across the second side of the membrane.

18. A method for at least partially removing siloxanes from intake air flowing through an air intake system of an engine, the air intake system including an air compressor and a membrane having a selectivity for the siloxanes, the membrane being downstream of the air compressor, the method comprising:
applying a pressure differential across the membrane so that a first side of the membrane exposed to the intake air is at a higher pressure than a second side of the membrane;
separating the intake air into a permeate and a retenate with the membrane, the permeate traversing the membrane from the first side to the second side and having a higher siloxane content than the retenate, the retenate remaining on the first side;
directing the retenate to the engine for combustion;
directing the permeate to a removal device configured to at least partially remove the siloxanes from the permeate; and
directing a treated permeate after treatment at the removal device to a position upstream of the air compressor in the air intake system.

19. The method of claim 18 , wherein applying the pressure differential across the membrane comprises using the air compressor to pressurize the intake air so that the first side of the membrane is at a higher pressure than the second side of the membrane.

Assignees

• Caterpillar Inc

Inventors

• Clayton Robert D

Classifications

• B01D69/08

  Hollow fibre membranes (manufacture of hollow fibres D01D5/24, D01F1/08) · CPC title

• B01D2311/06

  Specific process operations in the permeate stream · CPC title

• F02M35/02475 Primary

  characterised by the shape of the filter element · CPC title

• F02B29/0456

  Air cooled heat exchangers · CPC title

• F02M35/042

  combined with other devices, e.g. heaters (F02M35/021, F02M35/06, F02M35/14 take precedence); for use other than engine air intake cleaning, e.g. air intake filters arranged in the fuel vapour recovery system · CPC title