METHOD AND APPARATUS FOR REMOVING WATER FROM COMPRESSED AIR

• US 20150336047A1
• Filed: 12/23/2013
• Published: 11/26/2015
• Est. Priority Date: 01/02/2013
• Status: Active Grant

• Current Assignee: Norgren Ltd. (New Zealand) (IMI PLC)
• Original Assignee: nano-porous solutions limited (Atlas Copco AB)
• Inventors: Billiet, Colin
• Granted Patent: US 9,782,716 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2253/202 Polymeric adsorbents
• CPC Class Codes: B01D 2253/34 Specific shapes
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 2259/40003 Methods relating to valve switching
• CPC Class Codes: B01D 2259/40009 using sensors or gas analysers
• CPC Class Codes: B01D 2259/40052 Recycled product or process gas
• CPC Class Codes: B01D 2259/40081 Counter-current
• CPC Class Codes: B01D 2259/401 using a single bed
• CPC Class Codes: B01D 2259/4525 for storage and dispensing systems
• CPC Class Codes: B01D 2259/4533 for medical purposes
• CPC Class Codes: B01D 2259/4566 for use in transportation means
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/0407 Constructional details of adsorbing systems
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: B01D 53/053 with storage or buffer vessel
• CPC Class Codes: B01D 53/261 by adsorption
• CPC Class Codes: B01D 53/28 Selection of materials for use as drying agents
• CPC Class Codes: B01J 20/18 Synthetic zeolitic molecular sieves
• CPC Class Codes: B01J 20/262 obtained otherwise than by reactions only involving carbon to carbon unsaturated bonds, e.g. obtained by polycondensation macromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds per se C08G
• CPC Class Codes: B01J 20/2803 : Sorbents comprising a binder, e.g. for forming aggregated, agglomerated or granulated products
• CPC Class Codes: B01J 20/3007 : Moulding, shaping or extruding
• CPC Class Codes: B01J 20/3491 : by pressure treatment
• CPC Class Codes: B01J 2220/56 : Use in the form of a bed

Abstract

A method and apparatus for removing water from compressed air is disclosed. The method includes the steps of passing a stream of compressed air through a pressure swing adsorption (PSA) dryer. The dryer includes at least one vessel containing a desiccant material bound into pieces, for example tubes, using a polymer binder. The PSA dryer also has a control system for controlling the flow of the compressed air and switching between drying and purging modes. In particular the vessel and desiccant material contained therein are sized to produce a dew point suppression of less than 50° C.

Claims

1. A method of removing water from compressed air comprising, passing a stream of compressed air through a pressure swing adsorption dryer, the dryer including:

at least one vessel containing at least one desiccant material formed into desiccant members using a polymer binder; and

at least one control system for controlling the flow of said compressed air and switching the flow of said compressed air between a drying mode and a purging mode,

wherein said vessel and said desiccant material contained therein are sized to produce a dew point suppression of less than 50°

C.

2. A method according to claim 1, wherein said vessel receives compressed air with a dew point of up to 50°

C.

3. A method according to claim 1, wherein said desiccant material produces compressed air with dew points of greater than −

10°

C.

4. A method according to claim 1, wherein said desiccant members comprise a plurality of tubes extending along said vessel.

5. A method according to claim 1, wherein said dryer is not provided with means for heating the desiccant material during the purging mode.

6. An apparatus for removing water from compressed air comprising, a pressure swing adsorption dryer for passing a stream of compressed air therethrough, the dryer including:

at least one vessel containing at least one desiccant material formed into desiccant members using a polymer binder; and

at least one control system for controlling the flow of said compressed air and switching the flow of said compressed air between a drying mode and a purging mode,

wherein said vessel and said desiccant material contained therein are sized to produce a dew point suppression of less than 50°

C.

7. An apparatus according to claim 6, wherein said desiccant members comprise a plurality of tubes extending along said vessel.

8. An apparatus according to claim 6, wherein said vessel is not provided with means for heating the desiccant material during the purging mode.

9. An apparatus for removing water from compressed air and for location between a compressor and a compressed air storage tank, the apparatus comprising:

at least one vessel defining a volume and containing at least one desiccant material formed into desiccant members using a polymer binder;

at least one inlet for allowing a stream of compressed air to enter said vessel, said inlet having an inlet valve for controlling the flow of air through said inlet;

at least one first outlet for allowing said stream of compressed air to exit said vessel after passing at least partially through said volume, said first outlet having a first outlet valve for controlling the flow of air through said first outlet; and

at least one second outlet, located adjacent said inlet, for allowing the exhaust of purging gases passing back through said vessel from the storage tank, said second outlet having a second outlet valve for controlling the flow of air through said second outlet, wherein said second outlet valve comprises a solenoid valve adapted to open in response to the compressor turning off and close after a predetermined period of time.

10. An apparatus according to claim 9, wherein said desiccant members comprise a plurality of tubes extending along said vessel.

11. An apparatus according to claim 9, wherein said second outlet valve opens in response to a signal from a pressure switch on the compressor.

12. An apparatus according to claims 9, wherein said second outlet valve is provided with a variable timer controlling the period of time the valve remains open.

13. An apparatus for removing water from compressed air and for location between a compressor and a compressed air storage tank, the apparatus comprising:

at least one vessel defining a volume and containing at least one desiccant material formed into desiccant members using a polymer binder;

at least one inlet for allowing a stream of compressed air to enter said vessel, said inlet having an inlet valve for controlling the flow of air through said inlet;

at least one first outlet for allowing said stream of compressed air to exit said vessel after passing at least partially through said volume, said first outlet having a first outlet valve for controlling the flow of air through said first outlet; and

at least one second outlet, located adjacent said inlet, for allowing the exhaust of purging gases passing back through said vessel from the storage tank, said second outlet having a second outlet valve for controlling the flow of air through said second outlet, wherein said second outlet valve is provided with a variable timer controlling the period of time the valve remains open thereby allowing variable dew point suppression to be achieved.

14. An apparatus according to claim 13, wherein said desiccant members comprise a plurality of tubes extending along said vessel.

15. An apparatus according to claim 13, wherein said second outlet valve opens in response to a signal from a pressure switch on the compressor.

16. An apparatus according to claims 13, wherein said second outlet valve comprises a solenoid valve adapted to open in response to the compressor turning off and close after a predetermined period of time.

17-18. -18. (canceled)