Drainage medium for gas filter

Patent metadata

Field	Value
Publication number	US-11298644-B2
Application number	US-201816620558-A
Country	US
Kind code	B2
Filing date	Jun 12, 2018
Priority date	Jun 12, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

A coalescence filter including an inlet for supplying the gas to a filter element present in the coalescing filter, which filter element includes a coalescence medium for coalescing at least one disperse liquid phase during a displacement of a gas through the coalescence medium in a flow direction. The filter element downstream of the coalescence medium includes a drainage medium for draining the at least one coalesced disperse phase leaving the coalescence medium. The filter element contains a barrier layer positioned downstream of the coalescence medium, where the coalescence medium and the barrier layer are held at a distance from each other by one or more spacers to provide a drainage zone in the drainage layer of a drainage medium between a surface of the coalescence medium facing the barrier layer and the barrier layer for draining the coalesced disperse phase in a drainage direction.

First claim

The invention claimed is:

1. A gas filter for coalescing at least one dispersed liquid phase present in a gas, the gas filter comprising:
an inlet for supplying the gas to a filter element present in the gas filter, which filter element comprises a coalescence medium for coalescing the at least one dispersed phase during a displacement of the gas through the coalescence medium in a flow direction,
wherein the filter element downstream of the coalescence medium comprises a drainage medium for draining the at least one coalesced dispersed phase leaving the coalescence medium in a drainage direction which is transverse to the flow direction,
wherein the filter element is composed of a single package of the coalescence medium, the drainage medium and a barrier layer,
wherein the barrier layer is located downstream of the coalescence medium,
wherein the coalescence medium and the barrier layer are held at a distance from each other by one or more spacers extending in the flow direction to provide a drainage layer in the drainage medium between the barrier layer and a surface of the coalescence medium facing the barrier layer, the coalescence medium, the drainage medium and the barrier layer being layer-like materials positioned adjacent to each other,
wherein pores in the drainage medium have an average pore diameter greater than an average pore diameter of pores of the barrier layer and greater than an average pore diameter of pores of the coalescence medium,
wherein the drainage medium has a thickness greater than a thickness of the coalescence medium and a thickness of the barrier layer,
wherein the drainage medium contains the drainage layer with a drainage surface for receiving and draining the at least one coalesced dispersed phase, the drainage surface facing the coalescence medium, wherein the drainage medium contains an anisotropic porous material having a higher air permeability than the barrier layer, and
wherein the barrier layer is positioned downstream of the drainage medium, the drainage medium having a permeability for the at least one coalesced dispersed phase in the drainage direction which is higher than a permeability in the flow direction of the fluid.

2. The gas filter according to claim 1 , wherein the drainage medium further comprises a capturing layer for capturing the coalesced dispersed phase from the coalescence medium and guiding the coalesced dispersed phase to the drainage layer, wherein the capturing layer contacts a surface of the coalescence medium which faces the drainage layer.

3. The gas filter according to claim 2 , wherein the capturing layer contains a material selected from a knitted fabric, a crocheted material, a tufted material, a woven fabric or a combination of two or more of the aforementioned materials.

4. The gas filter according to claim 1 , wherein the pores in the drainage layer have an average pore diameter which is greater in the drainage direction than in the flow direction.

5. The gas filter according to claim 1 , wherein a maximum of 10% of the pores of the drainage medium have a diameter which is smaller than 5 μm, and at least 50% of the pores of the drainage medium have an average diameter which is greater than 500 μm.

6. The gas filter according to claim 1 , wherein the pores in the drainage medium have a diameter which ranges between 5.0 and 20000.0 μm.

7. The gas filter according to claim 1 , wherein the drainage layer is configured to have an average pore diameter of the pores in the drainage direction greater than an average droplet size of the at least one coalesced dispersed phase.

8. The gas filter according to claim 1 , wherein the drainage medium has a thickness between 0.5 and 20.0 mm.

9. The gas filter according to claim 2 , wherein the barrier layer has a lower permeability in flow direction for the coalesced dispersed phase than the drainage medium and the capturing layer.

10. The gas filter according to claim 1 , wherein the barrier layer comprises a material with pores whose diameter is situated between 5.0 and 1000.0 μm.

11. The gas filter according to claim 1 , wherein the barrier layer has a thickness between 0.01 and 20.0 mm.

12. The gas filter according to claim 2 , wherein the pores of the capturing layer have a diameter in the range of 5.0 to 20000.0 μm.

13. The gas filter according to claim 2 , wherein the capturing layer has a thickness between 0.1 and 20.0 mm.

14. The gas filter according to claim 1 , wherein the drainage medium comprises a material selected from a knitted fabric, a crocheted material, a tufted material, a fabric, a polymeric foam, or a combination of two or more of the aforementioned materials, wherein at least a portion of the surface is facing and preferably in contact with the surface of the coalescence medium facing the drainage medium.

15. The gas filter according to claim 1 , wherein the drainage medium comprises a material selected from the group consisting of a spacer textile, a spacer fabric, a spacer knitting, a polymer foam, or a combination of two or more of the aforementioned materials.

16. The gas filter according to claim 2 , wherein the capturing layer comprises a material selected from a knitted fabric, a crocheted material, a tufted material, a woven fabric, a polymeric foam, or a combination of two or more of the aforementioned materials.

17. The gas filter according to claim 16 , wherein the capturing layer comprises a plurality of protrusions which extend towards the coalescence medium.

18. The gas filter according to claim 16 , wherein at least a part of fibers forming the capturing layer extend in the drainage direction.

19. The gas filter according to claim 2 , wherein the drainage medium comprises a polymer foam, in particular a polyurethane foam, with a first foam layer for providing the drainage layer, the drainage layer containing pores which are open in the drainage direction, wherein on a downstream side of the drainage medium a second layer of a polymeric foam is provided for providing the barrier layer containing pores which are closed in the flow direction of the gas.

20. A method for separating a dispersed phase present in a fluid from a carrier using the gas filter according to claim 1 , said method comprising the steps:
supplying the fluid to the gas filter with the coalescence medium for coalescing the at least one dispersed phase,
contacting the at least one coalesced dispersed phase when leaving the coalescence medium through a downstream exit surf ace of the coalescence medium, with the drainage medium contained in the gas filter,
draining the coalesced dispersed phase along the drainage surface or through the drainage medium, and
collecting the carrier present in the fluid downstream of the drainage medium.

Assignees

• Atlas Copco Airpower Nv

Inventors

• Goris Ken
• Wouters Jo
• Bultinck Evi Marcel J
• De Wolf Isabelle Denise M

Classifications

• B01D46/0031 Primary

  with collecting, draining means · CPC title

• B01D2258/06

  Polluted air · CPC title

• B01D17/045 Primary

  with coalescers · CPC title

• B01D2239/1258

  Permeability · CPC title

• B01D46/42

  Auxiliary equipment or operation thereof · CPC title