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WO1997034680A1 - Filtre pour air comprime - Google Patents

Filtre pour air comprime Download PDF

Info

Publication number
WO1997034680A1
WO1997034680A1 PCT/AU1997/000171 AU9700171W WO9734680A1 WO 1997034680 A1 WO1997034680 A1 WO 1997034680A1 AU 9700171 W AU9700171 W AU 9700171W WO 9734680 A1 WO9734680 A1 WO 9734680A1
Authority
WO
WIPO (PCT)
Prior art keywords
filter
compressed air
air
microfilter
oil
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/AU1997/000171
Other languages
English (en)
Inventor
Mario Ragusa
Joseph Borg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Pneumatics Pty Ltd
Original Assignee
General Pneumatics Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Pneumatics Pty Ltd filed Critical General Pneumatics Pty Ltd
Priority to AU20177/97A priority Critical patent/AU2017797A/en
Publication of WO1997034680A1 publication Critical patent/WO1997034680A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/54—Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms
    • B01D46/546—Particle separators, e.g. dust precipitators, using ultra-fine filter sheets or diaphragms using nano- or microfibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/0027—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions
    • B01D46/003—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions including coalescing means for the separation of liquid
    • B01D46/0031—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with additional separating or treating functions including coalescing means for the separation of liquid with collecting, draining means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
    • B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/56—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with multiple filtering elements, characterised by their mutual disposition
    • B01D46/62—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours with multiple filtering elements, characterised by their mutual disposition connected in series
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D50/00—Combinations of methods or devices for separating particles from gases or vapours
    • B01D50/20—Combinations of devices covered by groups B01D45/00 and B01D46/00
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2267/00—Multiple filter elements specially adapted for separating dispersed particles from gases or vapours
    • B01D2267/40—Different types of filters

Definitions

  • COMPRESSED AIR FILTER This invention relates to a compressed air filter. It relates particularly to an air filter for removing particulate matter, water and oil, whether in the form of vapour or droplets, from compressed air systems such as air braking systems. Hot compressed air has a greater propensity for carrying water and oil vapour, suspended water and oil droplets and other particles than has non- compressed room temperature air. Contaminants such as exhaust fumes, oil, dirt and water can be drawn into a compressed air system at the compressor intake. Other contaminants such as metal, carbon and plastic particles can be introduced into the compressed air stream from the system itself.
  • Contaminants in a compressed air system can cause significant damage, depending upon the uses to which the compressed air is put. Contaminants typically block up small orifices, rendering pneumatic machinery and equipment ineffective. Where the air is to be breathed by a person, significant harm can be caused by contaminants. In air braking systems, contaminants may prevent brakes from closing properly. Contaminants, and in particular water, can cause corrosion and rust. It is therefore important for filtering apparatus to be provided for removing contaminants from compressed air systems.
  • filters there are numerous different types of filters available for compressed air systems.
  • One common type is a filter which includes a porous filter medium which traps particles and droplets which are larger than the mesh size of the filter medium.
  • Another type is an air cooler, which encourages precipitation of water and oil vapours.
  • Another type is a desiccant dryer, which passes the air stream through a chamber filled with desiccant material. Water vapour is adsorbed by the desiccant.
  • a further type is a coalescing filter for removing oil. It is common to place several filters of different types in series in an air stream. However, it is often inconvenient and expensive to use several filters in this manner, and each filter has an air pressure drop associated with it, and the amount of work required to be done by the air compressor increases as the total pressure drop brought about by filters increases.
  • Some filter units are available which incorporate more than one type of filter within a single unit.
  • An example is provided in United Kingdom Patent Specification 1 ,236,396 in the name of CA. Norgren Limited.
  • the filter comprises a hollow cylindrical coarse pre filter located within a larger diameter hollow cylindrical fine filter.
  • the compressed air stream passes into the centre of the pre filter, out through the pre filter, and then out through the fine filter.
  • the pre filter traps larger particles and oil and water drops, while the finer filter traps finer particles and droplets.
  • the filter unit is highly effective in removing water, oil and other contaminants from a compressed air stream, but for some applications such as applications in which the air is to be breathed by a person, or when instrument quality air is required, a greater degree of contaminant removal is required. It is an object of the present invention to provide an air filter which overcomes some of the disadvantages described above. According to the present invention there ts provided a compressed air filter including.
  • an inlet for compressed air a pre filter; an expansion chamber; a micro filter; and an air outlet; wherein compressed air enters the inlet, passes through the pre filter, expands in the expansion chamber, passes through the micro filter and leaves through the air outlet; wherein further the micro filter includes oil escape means allowing droplets of oil trapped by the micro filter to fall off the surface of the micro filter
  • the air filter may include impaction means located between the pre filter and the micro filter, whereby air is directed at high speed against a surface, encouraging precipitation of water and oil.
  • impaction means may be provided by a baffle plate of the type illustrated in International Publication WO93/04761 , in combination with Venturis.
  • impaction means may include means for directing the air stream to rotate at a rapid rate so that water and oil entrained in the air stream is directed by centrifugal force against the walls of the air filter or expansion chamber or some other surface or surfaces provided for the purpose.
  • the micro filter is substantially in the form of a hollow cylinder whose walls are made of a micro-porous material arranged such that air passes from the centre to the outside of the cylinder, and the oil escape means includes an open bottom to the hollow cylinder, permitting droplets of oil trapped on the internal surfaces of the cylinder to fall off those surfaces
  • further oil escape means may be provided at the bottom of the external surfaces of the cylinder
  • the further oil escape means may comprise one-way valves which may be opened when there is a pressure drop within the air filter for a short time while a dram valve is activated to discharge accumulated contaminants from the filter; the rest of the time, the one-way valves are kept closed.
  • the contaminants trapped by the expansion chamber, by the oil escape means, and by the further oil escape means all accumulate in a single pool at the bottom of the air filter, and are all discharged through a single drain valve.
  • a compressed air filter including: an inlet for compressed air; a pre filter; an expansion chamber; means for directing the air in a circular path so that a centrifugal force is applied to particles and droplets entrained within the air; a micro filter in the form of an open bottomed substantially hollow cylinder whose walls are made from a micro porous material; and an air outlet; wherein compressed air enters the inlet, and passes sequentially through the pre filter, expansion chamber, and means for directing air in a circular path, before passing upwards through the open bottom of the centre of the hollow cylindrical micro filter, through the micro filter walls, and out through the air outlet.
  • the invention may optionally further include a desiccant chamber incorporating a desiccant material, through which air passes after passing through the micro filter, before proceeding to the outlet.
  • the invention may optionally further provide one or more meshes, baffle plates, or other devices for trapping entrained droplets or encouraging precipitation, located in the expansion chamber.
  • the invention may optionally further include an air flow separator such as a sieve, located towards the bottom of the filter, allowing oil, water and other contaminants to pass through and accumulate below the air flow separator, but preventing or reducing the likelihood of contaminants accumulated at the bottom of the filter becoming re-entrained in the air flow.
  • Figure 1 is a schematic cross-sectional view of one embodiment of the present invention.
  • Figure 2 is a detailed view of an altemative arrangement for a one-way valve.
  • the compressed air filter includes inlet 1 for compressed air, pre filter 2, expansion chamber 3, micro filter 4 and air outlet 5.
  • compressed air enters inlet 1 it passes through pre filter 2, expands in expansion chamber 3, passes through micro filter 4 and leaves through air outlet 5.
  • Micro filter 4 includes oil escape means 6, which allows droplets of oil trapped by micro filter 4 to fall off the surface of the micro filter.
  • the air filter as shown includes impaction means located between pre filter 2 and micro filter 4, for directing air at high speed against a surface, encouraging precipitation of water and oil.
  • the embodiment illustrated includes two different types of impaction means. Impaction means 7 directs the air stream to rotate at a rapid rate so that water and oil entrained in the air stream are directed by centrifugal force against walls 9 of expansion chamber 3.
  • the embodiment illustrated also includes a baffle plate 8 onto which air from pre filter 2 is directed at high speed, either through Venturis 11 of the type described in International Patent Publication WO93/04761 or standard openings 12.
  • pre filter 2 is made from any suitable material or materials.
  • An especially preferred type of material is sintered bronze.
  • pre filter 2 is in a frusto-conical shape.
  • Pre filter 2 is protected by pre filter guard 13.
  • Pre filter guard 13 traps large objects caught up in the compressed air stream, preventing them from blocking the surface of pre filter 2, and reducing the amount of wear caused on the surface of the pre filter.
  • pre filter 2 is housed within pre filter chamber 14. Air which has passed through pre filter 2 leaves pre filter chamber 14 either through Venturis 11 or openings 12. Although both Venturis and openings are shown in figure 1 , actual embodiments will normally include one or the other type of opening, not both.
  • baffle plate 8 The air strikes baffle plate 8 at a rapid rate, and must pass around the outside of baffle plate 8 to move further into expansion chamber 3. Water and oil droplets in the air stream strike against baffle plate 8 and the walls 9 of expansion chamber 3, with the result that droplets of oil and water fall down the sides of expansion chamber 3, accumulating in pool 15 at the bottom of the filter housing.
  • meshes 16 may include gauzes, baffles or other devices for trapping entrained droplets or encouraging precipitation.
  • the air stream After passing through meshes 16, the air stream encounters means for directing the air stream to rotate at a rapid rate. This may include a spiral coil, turbine or cyclonic arrangement, imparting centrifugal force to oil and water droplets and encouraging coalescence on expansion chamber walls 9 and the walls of bowl 17.
  • Circulating air in the lower region of expansion chamber 3 creates turbulence in lower region 18 of the filter.
  • Water, oil and other contaminants also accumulate at the bottom of the filter, in pool 15, and such contaminants can be re-entrained in the air flow by turbulent air.
  • an optional separator 19 may be installed above pool 15 to protect pool 15 from the turbulence of air in lower area 18.
  • Separator 19 should of course allow free passage of water, oil and other contaminants down into pool 15.
  • Separator 19 may be a sieve-type device.
  • the air stream then passes up into the inside of micro filter 4.
  • Micro filter 4 may be made from many suitable materials. Suitable materials include glass fibre and borosilicate fibre. In conventional micro filters, the air stream enters the micro filter from the top and passes out through the side walls.
  • the bottom must be closed to ensure that air does not escape without passing through the filter.
  • the largest quantities of oil are trapped at or near the inside surfaces of the micro filter, and in conventional arrangements, because the bottom of the filter is closed, the trapped oil builds up from the bottom of the filter (wet-zone), and air is no longer able to pass through those parts of the filter which are clogged up with oil. After a relatively short time, the filter must be replaced.
  • the top of the filter is closed to ensure that all air must pass through the filter walls.
  • Oil which is trapped at or near the inside surfaces of the filter can trickle down those inside surfaces (i.e. no blocked wet zone) and fall down towards pool 15 at the bottom of the filter.
  • Oil which is trapped at or near the outside surfaces of micro filter 4 can trickle down the outside surfaces of the micro filter to the bottom of those surfaces, where it accumulates until one-way valves 10 are opened, allowing trapped oil to escape and fall towards pool 15.
  • Pool 15 may periodically be discharged through a drain valve (not shown) located at the bottom of the filter.
  • a drain valve (not shown) located at the bottom of the filter.
  • the drain valve When the drain valve is opened, the pressure inside the filter is reduced, and this reduction in pressure is sufficient to activate the opening of one-way valves 10.
  • the drain valve When the drain valve is reclosed, pressure builds up again and one-ways valve 10 are reclosed.
  • Figure 2 shows an alternative arrangement for one-way valves 10.
  • a resilient flange is provided around the bottom of micro filter 4, pressing firmly against the internal walls of bowl 17. Oil trapped near the external surface of micro filter 4 trickles down the external surface and accumulates on the resilient flange.
  • the drain valve When the drain valve is opened, the decrease in pressure is sufficient to allow the flange to fall downwards, permitting accumulated oil to fall down the gap created between the flange and the internal walls of bowl 17.
  • the drain valve is reclosed, the flange is restored to its position pressing firmly against internal walls of bowl 17. After air has passed through micro filter 4, it passes towards outlet 5.
  • an optional additional desiccant chamber is provided.
  • Air which has passed through micro filter 4 passes upwards through air passages 18,19 to filtered air desiccant inlet chamber 20. From desiccant inlet chamber 20, air passes through perforated tubular cartridge cavity 21 , then through desiccant material in which water is adsorbed by the desiccant, and then through external desiccant cartridge wall 22, and then onto air outlet 5 via purified dry air path 23.
  • the additional desiccant chamber is provided by means of a cartridge 24 which can be replaced at regular intervals as the desiccant material becomes saturated.
  • the main body of the filter may be engineered in any suitable manner.
  • the major pieces are: cap piece 25, which incorporates air inlet 1 , air outlet 5 and pre filtration chamber 14; insert piece 26, which is attached to cap piece 25, and to which are attached expansion chamber body 9, baffle plate 8, pre filter 2, pre filter guard 13 and micro filter 4; and bowl 17, which is attached to cap piece 25 and together with cap piece 25 defines the external housing of the filter.
  • the filter may optionally further include a means for air regulation.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Separating Particles In Gases By Inertia (AREA)
  • Filtering Of Dispersed Particles In Gases (AREA)

Abstract

Ce filtre pour air comprimé comprend une entrée (1) pour l'air comprimé, un élément de préfiltrage (2), une chambre de détente (3), un microfiltre (4) et une sortie d'air (5). Lorsque l'air comprimé entre par l'entrée (1), il passe à travers l'élément de préfiltrage (2), se dilate dans la chambre de détente (3), passe à travers le microfiltre (4) et sort par la sortie (5). Un ou plusieurs chemins (6, 10) sont prévus pour permettre à l'huile piégée dans le microfiltre (4) de s'échapper, afin d'éviter l'engorgement de ce dernier.
PCT/AU1997/000171 1996-03-19 1997-03-18 Filtre pour air comprime Ceased WO1997034680A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU20177/97A AU2017797A (en) 1996-03-19 1997-03-18 Compressed air filter

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AUPN8772 1996-03-19
AUPN8772A AUPN877296A0 (en) 1996-03-19 1996-03-19 Compressed air filter

Publications (1)

Publication Number Publication Date
WO1997034680A1 true WO1997034680A1 (fr) 1997-09-25

Family

ID=3793085

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU1997/000171 Ceased WO1997034680A1 (fr) 1996-03-19 1997-03-18 Filtre pour air comprime

Country Status (2)

Country Link
AU (1) AUPN877296A0 (fr)
WO (1) WO1997034680A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1718392A4 (fr) * 2004-02-27 2009-08-19 Skf Usa Inc Sechoir a air a double cartouche presentant un separateur d'huile et des vannes facilement remplacables
CN105935532A (zh) * 2016-06-02 2016-09-14 珠海市思卡净化技术有限公司 一种多功能压缩空气过滤器
EP3202482A1 (fr) * 2016-02-02 2017-08-09 General Electric Technology GmbH Séchoir à gaz pour une machine électrique
EP3650107A1 (fr) * 2018-11-08 2020-05-13 KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH Système d'élimination de polluants de gaz de purge pour véhicule
EP3650106A1 (fr) * 2018-11-08 2020-05-13 KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH Dispositif d'élimination de polluants de gaz de purge et système pour véhicule

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1236396A (en) * 1967-08-17 1971-06-23 Norgren Ltd C A Apparatus for the filtration of air or other gaseous media
GB1479753A (en) * 1974-06-20 1977-07-13 Norgren Ltd C Apparatus for the filtration of air of other gaseous medi
WO1987004945A1 (fr) * 1986-02-24 1987-08-27 Donaldson Company, Inc. Installation de filtrage d'air
EP0337248A1 (fr) * 1988-04-05 1989-10-18 Maeda Shell Service Co., Ltd. Assemblage en ligne de filtration pour l'air comprimé
WO1993004761A1 (fr) * 1991-09-03 1993-03-18 Guiseppe Ragusa Filtre a air

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1236396A (en) * 1967-08-17 1971-06-23 Norgren Ltd C A Apparatus for the filtration of air or other gaseous media
GB1479753A (en) * 1974-06-20 1977-07-13 Norgren Ltd C Apparatus for the filtration of air of other gaseous medi
WO1987004945A1 (fr) * 1986-02-24 1987-08-27 Donaldson Company, Inc. Installation de filtrage d'air
EP0337248A1 (fr) * 1988-04-05 1989-10-18 Maeda Shell Service Co., Ltd. Assemblage en ligne de filtration pour l'air comprimé
WO1993004761A1 (fr) * 1991-09-03 1993-03-18 Guiseppe Ragusa Filtre a air

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1718392A4 (fr) * 2004-02-27 2009-08-19 Skf Usa Inc Sechoir a air a double cartouche presentant un separateur d'huile et des vannes facilement remplacables
EP3202482A1 (fr) * 2016-02-02 2017-08-09 General Electric Technology GmbH Séchoir à gaz pour une machine électrique
CN105935532A (zh) * 2016-06-02 2016-09-14 珠海市思卡净化技术有限公司 一种多功能压缩空气过滤器
EP3650107A1 (fr) * 2018-11-08 2020-05-13 KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH Système d'élimination de polluants de gaz de purge pour véhicule
EP3650106A1 (fr) * 2018-11-08 2020-05-13 KNORR-BREMSE Systeme für Nutzfahrzeuge GmbH Dispositif d'élimination de polluants de gaz de purge et système pour véhicule
WO2020094377A1 (fr) * 2018-11-08 2020-05-14 Knorr-Bremse Systeme für Nutzfahrzeuge GmbH Système d'élimination de contaminant de gaz de purge pour un véhicule
WO2020094372A1 (fr) * 2018-11-08 2020-05-14 Knorr-Bremse Systeme für Nutzfahrzeuge GmbH Dispositif et système d'élimination de contaminants de gaz de purge pour un véhicule
CN113301983A (zh) * 2018-11-08 2021-08-24 克诺尔商用车制动系统有限公司 用于车辆的吹扫气体污染消除装置和系统
CN113382799A (zh) * 2018-11-08 2021-09-10 克诺尔商用车制动系统有限公司 用于车辆的吹扫气体污染消除系统
CN113301983B (zh) * 2018-11-08 2024-06-11 克诺尔商用车制动系统有限公司 用于车辆的吹扫气体污染消除装置和系统

Also Published As

Publication number Publication date
AUPN877296A0 (en) 1996-04-18

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