GB2475737A

GB2475737A - Filtration device

Info

Publication number: GB2475737A
Application number: GB0920902A
Authority: GB
Inventors: John Andrew Timmins
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-30
Filing date: 2009-11-30
Publication date: 2011-06-01
Also published as: GB0920902D0

Abstract

A filtering machine 10 for filtering a condensate with entrained oily contaminant; the machine 10 including a filter 14 through which the condensate passes, the filter 14 including an exterior housing 15 through which the condensate, in use, passes into a filter interior, and through which filtered liquid, in use, passes from the filter interior, and the filter interior including a mass of filter material which includes oleophillic fibres 29. Preferably the fibres are silica based glass wool or polypropylene and may support an anti-packing material such as particles of an activated oleophillic adsorbent for example activated carbon or clay. Preferably the filtering machine includes an ante-chamber 9 for collecting incoming condensate, a weir outlet 7, a filter inlet 17 and filter outlet 24, a secondary filter chamber 20 housing a carbon filter 21 and a machine discharge outlet 22. Advantageously the filtering machine is used when filtering condensate from air compressors.

Description

Title: Filtering Machine

Description of Invention

This invention relates to a filtering machine and more particularly but not exclusively to a filtering machine for filtering condensate from air compressors.

Such condensate typically is predominantly water, with some entrained impurities1 specifically oil.

it is known to remove the oil from the condensate using filter material, typically by filtering the condensate though activated Carbon material. This is very efficient at removing the oil, but is expensive, and this can quickly become contaminated where the condensate contains larger amounts of oil.

Where at least some of the oil in the condensate separates from the water arid floats on the water, it has been proposed to pre-filter the condensate before final filtering through activated Carbon -for example using the proposal of EP-A-I 185347 in which a filter including ribbons of oleophillic material is used.

According to a first aspect of the invention I provide a filtering machine for filtering condensate with entrained oily contaminant, the machine including a filter through which the condensate passes, the filter including an exterior housing through which the condensate., in use, passes into a filter interior, and through which filtered liquid, in use, passes from the filter interior, and the filter interior including a mass of filter material which includes oleophillic fibres.

It has been found that using a mass of oleophillic fibres, and more particularly short fibres, by which we mean that predominantly the fibres are less than 20 mm in length, more efficient filtering of the condensate can be achieved than using a fitter material such as oleophillic strands. Preferably the fibres have a diameter in the range 5.0 pm to 5.5 pm.

Although any fibres which exhibit an affinity for oil i.e. are oleophillic, may be used, it has been found that silica based fibres, such as glass woo! made to the parameters indicated above, provides a particularly effective solution, and economically. However polypropylene fibres are one example of an alternative fibre kind.

Because the condensate tends not to be produced in large quantities, even from large scale.air compressors, the flow rate of the condensate to the filtering machine tends not to be large, and the flow rate may in any event be controlled, e.g. through the use of a weir, to a low flow rate. In such an environment, the flow of condensate to the filter does not tend to compact the fibres to an extent that liquid flow through the filter is obstructed. However, some beneficial compaction of the fibres may occur in use.

If desired, the fibres may support within their mass, an anti-packing material, such as for example only, particles of e.g. perlite or a similar material.

Whereas such anti-packing material may take nO active part in filtering the condensate, *such material may assist in preventing the fibres in the filter packing such as to obstruct the flow of liquid through the filter, by mechanically separating the fibres and maintaining this separation in use.

Preferably, the fibres support an activated oleophillic adsorbent which may be in particulate form. Such activated oleophillic adsorbent may function as an anti-packing material, but preferably will also improve the filtering efficiency of the filter.

The particulate material may be entangled In the fibres e.g. prior to Inserting the fibres Into the exterior housing, and/or the fibres of the filter material may be arranged In layers with particulate material interposed between the layers.

The fibres of the filter may be packed In the exterior housing to a density of between 80 grams per lItre and 200 grams per litres preferably In the order of 123-130 grams per litre.

The particles of the particulate material may all be able to pass through a sieve of mesh size 4 I.e. may have a maximum dimension In the order of 4.76mm.

The activated oleophillic adsorbent may In one example include clay, such as Bentonite clay. In one specific example, the particulate material may Include Organoclay. In another example the particulate material may include activated Carbon.

The exterior housing of the filter may be provided at least in part, by a flexible material e.g. a woven or non-woven material, and/or at least In part in a more rigid material such as a rigid or semi-rigid material.

In one embodiment the machIne Includes a main filter chamber b which the filter Is located, there being an Inlet to the chamber for condensate, and an outlet from the chamber hr filtered lIquId, the condensate passing3 In use, through the exterior housing wall Into the interior of the filter, and filtered liquid passes back through the exterior housing wall to the main filter chamber outlet In this case, openings which permit condensate/filtered liquid flow to and from the Interior of the filter may be provided by the construction of the housing material, e.g. between weaves, and/or by perforating the material. Where the housing material Is In the nature of a cloth, the openings may be provided by needle punching.

in each case though preferably the openings which permit condensate/filtered liquid flow are smaller or at least not substantially larger than the particles of the particulate material. However the particulate material will primarily be retaIned by being embedded In the mass of fibret The exterior housing of the filter may include over at least a part of its extent, multiple layers, e.g. an outer housing layer with openIngs, and an inner, lining, layer e.g. of a felt-like material, with passages smaller than the openings In the outer housing layer.

The filter may Include an external seal whIch seals with the interior wail of the maIn filter chamber, so that condensate which passes Into the main filter chamber through the inlet Is constrained to pass Into the fitter Interior before b&ngabletopasstothemahifilterthamberoutlet The main filter chamber may include at or towards an upper end thereof, a removable lid, which when closed with the remaInder of the chamber3 seals or substantially seals the main filter chamber, and when opened permits removal and replacement of the filter from the maIn filter chamber.

The filter machine may Include a secondary filter chamber which receives filtered lIquid from the main filter chamber, the secondary filter chamber IncludIng a further filter such as a Carbon filter.

Where the exterior housIng Is provided by a rigid or Semi-rigid material without openings, the machines need not have a filter chamber for the filter. The filter may Include at or towards one end, an Inlet icr condensate, and at or towards an opposite end, an outlet for filtered lIquid.

S

According to a second aspect of the invention, we provide a fitter for a filtering machine of the first aspect of the invention.

According to a third aspect of the invention we provide a method of filtering using a filtering machine of the first aspect of the invention, the method including passing condensate into the filter interior, and contacting the condensate with the mess of filter material in the interior of the filter, passing the filtered liquid back out of the filter.

According to a fourth aspect of the invention we provide a method of making a filter for filtering a condensate with entrained oily contaminant, the fitter including an exterior housing through which the condensate, in use, passes to contact filter material within the interior of the filter housing, and through which filtered liquid passes out of the filter, and the filter further including in the interior, a mass of filter material, the method including providing the mass of filter material by taking oleophillic fibres and embedding in the fibres, particulate material and placing in the filter interior, the mass of filter material.

The particulate material may include an activated oleophillic adsorbent.

Embodiments of the invention will now be described with reference to the accompanying drawings in which:-FIGURE 1 is an Illustrative view of a filtering machine in accordance with the invention; FIGURE 2 is a perspective illustrative view of the filter of the machine of figure 1; FIGURE 3 is an illustrative sectional side view of the filter of figure 2; and FIGURE 4 is a view similar to that of figure 3 but of an alternative embodiment.

FIGURE 5 is an illustrative view of a filter of another embodiment.

Referring to figures 1 to 3 of the drawings, a filtering machine 10 has a main filter chamber 12 in which a filter 14 is provided. In the example the main filter chamber 12 is substantially cylindrical, and the filter 14 is of a corresponding configuration but the filter chamber 12 and/or the filter 14 could be of another configuration as required. The filter 14 includes an external housing 15, and at one axial end, i.e. the upper end of the filter 14, the filter 14 includes an external seal 19 which when the filter 14 is received in the chamber 12, provides a seal with an internal walt 16 of the main filter chamber 12.

The filtering machine 10 further includes an inlet 17 to the main filter chamber 12 through which condensate to be filtered enters the chamber 12 at a position located above the filter 14 in this example.

The inlet 17 in this example receives condensate from beneath a weir device 18. *Condensate from one or more air compressors, cooling plants etc. with entrained oily contaminant is collected in an ante-chamber 9 of the weir device 18 to which it flows though a machine inlet 14. As the liquid collects in the ante-chamber 9, there will be some separation between the water component of the condensate and the oily contaminant, although some water will remain emulsified with the oily contaminant, When the liquid level in the ante-chamber 9 rises to that of an outlet weir 7, lighter floating oily contaminant (and such contaminant emulsified with water) will pass over the weir 7 and pass to a collector (not shown) for disposal.

Condensate which does not pass from the weir device 18 over the weir 7, i.e. which is the predominantly water faction! passes from a lower region of the ante-chamber 9 to the inlet 17 to the main filter chamber 12, which is at the same height as the weir 7.

Condensate which entem the main filter chamber 12 vIa the Inlet 17 Is constrained to pass through the filter 14 where It Is filtered, and then to a main filter chamber outlet 24 below the filter 14 In this example. The filtered liquid then passes Into the secondary filter chamber 20, flows through a Carbon filter 21, and from the Carbon filter 21 to a machine discharge outlet 22 whIch Is at the same level as the welr 7.

Byflhlerlngthe condensate In bothofthe malnfliterchamber 12 and the secondary filter chamber 20, the liquid which is dlschatged at 22 Is substantially cleansed of oily contamlnant and the object Is for It to be sufficiently clean that the filtered liquId can be discharged safely to the environment.

The exterior housIng 15 of the filter 14 In the main filter chamber 12 defines Internally, a filter Interior. The housIng 15 In this example has either a cloth, ven, non-woven or the like generally flexible c1lndi1cal side wall 25, and substantially rigid upper and low end waDs 27,28 respectively. The upper and lower end walls 27, 28 have openings provIded by perforations (or the openings may be Integrally formed with the upper and/or lower end walls 27, 28 material), and the flexible side waD 25 Is provided with openings by perforating by needle punching. In another example an alternative part/the entire exterior housIng 15 may be rigid, semi-rigid or flexible, or the side wall 25mayberlgidandoneorbothoftheendwalls2l,28fiexlble.lneachCase the openings In the exterior housing 15 In at least the upper end wall 27, provide passages through which condensate may pass Into the filter Interior, and the openings In the side wall 25 and the lower end wall 28 provide passages through which filtered liquid can pass back out of the filter Interior.

Of course, depending on where and how the seal 19 Is provided, If at all, the condensate entering the main filter chamber l2is separated from the filtered

S

liquid, and so different openings to those identified may allow for the passage of condensate/filtered fluid in to and back out of the filter interior. For example, if the seal 19 was provided axially part-way along the side wall, 25, the openings in the side wall 25 above the seal would allow condensate to pass into the filter interior, and openings in the side wall 25 below the seal would permit the filtered liquid to pass back out of the filter interior.

Within the filter interior there is provided filter material, which according to the invention includes a mass of oleophillic fibres 29.

In the examples shown in the drawings, although any fibres which exhibit an affinity for oil may be used, the fibres 29 are short glass fibres, by which we mean that predominantly the fibres are less than 20 mm in length. The fibres 29 have a diameter in the range 5.0 pm to 5.5 pm. Such fibres when massed, provide a glass wool.

The fibres of the glass wool mass 29 exhibit a particular affinity for oil, and thus as the condensate contacts, e.g. passes though the filter material, predominantly the oily contaminant is adsorbed by the fibres 29, and the water component is allowed to pass.

Using such short fibres of this diameter, particularly efficient filtering of the condensate can be achieved as the fibres 29 collectively present a large surface area to the condensate. However, instead of glass wool, any other fibres which exhibit oleophillic properties may be massed, and particularly but not exclusively silica based fibres provided as a wool provides a particularly effective solution, and economically. However polypropylene fibres are one example of an alternative fibre kind.

Because the condensate which flows into the main filter chamber 12 tends not * to be provide a constant and sustained fluid flow, even from large scale air compressor(s), i.e. the flow rate of the condensate to the filtering machine 10 tends not to be large, the condensate flowing through the filter 14 does not * 5 tend in use, to compact the fibres at least to an extent that liquid flow through the filter is obstructed.

Within the interior of the filter 14, the glass wool or other fibre filter material 29 may be packed in the exterior housing 15 to a density of between 80 grams per litre and 200 grams per litre and preferably in the order of 120-130 grams per litre. Thus the mass of filter material provides a substantial flow volume made up of the interstitial spaces between the fibres 29 so as not substantially to obstruct the flow of fluid through the filter material, at least prior to adsorption of a significant quantity of the oily contaminant.

In the example of figures 1 to 3, embedded in the glass wool filter material 29, are particles 30 of a particulate material. Thus the fibres 29 support within their mass, the particulate material 30, such as for example only, particles of e.g, perlite or a similar material, such particles 30 providing an antipacking function.

Whereas such anti-packing material may take no active part in filtering the condensate, such material will assist in preventing the fibres in the filter packing such as to obstruct the flow of liquid through the filter 14, by separating the fibres 29 and maintaining this separation in use.

Preferably, though the particulate material 30 supported by the fibre mass 2 is an activated oleophillic adsorbent, Such activated oleophillic adsorbent not only will have a fibre anti-packing function, but improves the filtering efficiency of the filter 14.

The activated oleophllllc adsorbent may In one example Include clay particles, such as Bentonite clay particles, in the example shown In the drawhgs, the partIculate materIal Includes Organoclay. In another example the particulate materiel may Include Carbon. The activated oleophlHlc adsorbent may be a mixture of any of these, or any other suitable, preferably particulate, oleophiillc material.

if desired the particulate material 30 may be a mixture of an activated oleophllllc adsorbent and a filler particulate material such as perlite. Other material may be hicluded which serves to separate the fibres 29, such as for examples, needle felt pieces, woven or non-woven material.

In each case, desIrably the particulate material will all pass though a mesh of sleveslze4.

In the example of figures 1 to 3 the particulate materIal 30 Is entangled in the fibres2goftheflltermaterlalbybelngntedlnwlththeflbres29beforethe filter material Is packed Into the exterior housIng 15.

In figure 4 a modification is Illustrated hi whIch the glass wool or other fibre material 29 of the filter material, Is arranged in discreet layers 29a, 29b, 29c, 29d In the exterior housIng 15, I.e. In four layers indicated In the example, and between the layers 29a-29d Is pmidded the particulate material 30, whIch thus Is Interposed between the layers 29a-29d.

Thus the particulate material may be embedded In the fibrous mass 29 as the filter 14 Is made.

However, if desired, the particles of the particulate material may both be entangled in the fibres and interposed between layers of fibres.

At least in the embodiment illustrated in figures 1 to 3, the openings in the side wall 15 and the upper and lower end walls 27, 28 of the exterior housing which permit condensate/filtered liquid flow are all smaller or at least not substantially larger than the particles of the particulate material, e.g. the openings may be smaller than 10mm. This is to deter the migration of the particulate material 30 from the filter 14 though the openings. However the particulate material 30 will primarily be retained by being embedded in the fibres 29.

In the figure 4 embodiment, it can be seen that at least the lower end housing wall 28 is lined with an inner lining 35 which covers the openings in the lower end wall 28. In the example the lining 35 is of a felt-like material, and so fluid flow passages in the felt material 28 will be very small at least smaller than the openings in the lower end wall 28. This lining 35 will provide a further guard to deter the particulate material 30 being washed from the filter 14 through the openings in the lower end wall 28.

fri the generality, the exterior housing 15 of the filter 14, or any part of it, may include over at least a part of its extent, multiple layers, including an outer housing layer 15 with openings, and an inner or outer lining layer such as the felt-like material layer 35, with passages smaller than the openings in the outer housing layer 15.

In the figure 5 embodiment, the filter 14 has an exterior housing 15 of rigid or semi-rigid material which is liquid-tight. The filter 14 though has an inlet at one end, indicated at 14a for receiving condensate, and an outlet 14b at an opposite end for filtered liquid. The filter 14 does not need to be accommodated in a filter chamber as with the previous embodiments. The filter 14 does not require a seal 19.

Various further modifications may be made without departing from the scope of the invention.

Another filtering machine in accordance with the invention need not have a weir device 18 to collect condensate, but condensate may directly enter the main fitter chamber 12 via an inlet 17 where a chamber 12 is provided, or directly into the filter via the inlet I 4a as in the figure 5 embodiment.

In the example of the figures 1 to 4 embodiments, the main fitter chamber 12 includes at an upper end thereof a lid 38 which when closed as shown, seals the main filter chamber 12. When the lid 38 is removed or otherwise opened, access can be gained to the interior of the main filter chamber 12 to permit of removal and replacement of the filter 14 through the upper end of the main filter chamber 12, when the filter 14 is clogged and/or saturated with oily contaminant. To facilitate this operation, the filter 14 is provided in the example, at the upper end thereof, with a handle 13. In another example the filter 14 could be a floating filter which descends as more and more oily contaminant is adsorbed.

In another example of the figures 1 to 4 embodiments, a secondary filter chamber 20 may not be provided, or at least such a secondary filter chamber with a Carbon filter 21 need not be provided, but some other means of further filtered liquid treatment may be provided for, within or externally of the filtering machine 10, to enable the filtered liquid to be cleansed to such an extent that it may be released to the environment.

In another example, the main filter chamber 1.2 need not be cylindrical but may be of another configuration. In this case the filter 14 may need to be correspondingly configured.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing. the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMSI. A filtering machine for filtering condensate with entrained oily contaminant, the machine including a filter through which the condensate passes, the filter including an exterior housing through which the condensate, in use,passes into a filter interior, and through which filtered liquid, in use, passes from the filter interior, and the filter interior including a mass of filter material which includes oleophillic fibres.
2. A machine according to any one of the preceding claims wherein predominantly the fibres are less than 20 mm in length.
3. A machine.according to claim 1 or claim 2 wherein the fibres have a diameter in the range 5.0 pm to 5.5 pm.
4. A machine according to any one of the preceding claims wherein the fibres are silica based.
5. A machine according to claim 4 wherein the fibres are glass wool.
6. A machine according to claim 4 wherein the fibres are polypropylene.
7. A machine according to any one of the preceding claims wherein the fibres support within their mass, an anli-packing material.
8. A machine according to claim 7 wherein the anti-packing material includes particles.
9. A machine according to claim 8 wherein the particulate material supported by the fibres includes particles of an activated oleophillic adsorbent.
10. A machine according to claim 8 or dalm 9 wherein the particulate material is entangled in the fibres.
11. Amachineaccordingtoclalmaorclalm9orclalm lowherelnthefibres of the filter material are arranged In layers wIth particulate material interposed between the layers.
12. A machine according to any one of the preceding claims wherein the fibre filter material is packed In the exterior housing to a density of between 80 grams per litre and 200 grams per litre.
13. A machine according to any one of claims 7 to 12 whereIn the particles of the particulate material are all able to pass through a sieve of mesh ske 4.
14. A machine according to any one of claims 9 to 13 where dependent upon claim 9 whereIn the activated oleophiilic adsorbent includes at least one of clay, Bentonite clay, Organoclay, and activated Carbon.
15. A machine according to any one of the preceding claims wherein the exterior housing of the filter is provided at least in part by a flexible material.
16. A machine according to claIm 15 whereIn the machine includes a main filter chamber In which the filter Is located, there being an Inlet to the chamber for condensate, and an outlet from the chamber for filtered liquid, the condensate passing, in use, through the exterior housing wall into the Interior of the filter, and filtered liquid passes back through the exterior housing wall to the main filter chamber outlet
17. A machine according to cLaim 16 wherein the exterior housing has openings which permit condensate/filtered liquid flow to and from the interior of the filter which are provided by the construction of the housing material and/or by perforating the material.15, A machine according to claim 17 where dependent upon claim 7 wherein the openings which permit condensate/filtered liquid flow are smaller or at least not substantially larger than the particles of the particulate material.19. A machine according to any one of claims 15 to 18 wherein the exterior housing of the filter includes over at least a part of its extent, multiple layers.20. A machine according to any one of claims 16 to ig wherein the filter includes an external seal which seals with the interior wall of the main chamber, so that condensate which passes into the main filter chamber through the inlet is constrained to pass into the filter interior before being able to pass to the main filter chamber outlet.21. A machine according to any one of claims 16 to 20 wherein the main filter chamber include at or towards an upper end thereof, a removable lid! which when closed with the remainder of the chamber, seals or substantially seals the main filter chamber! and when opened permits removal and replacement of the filter from the main filter chamber.22. A machine according to any one of claims 16 to 21 wherein the filter machine includes a secondary filter chamber which receives filtered liquid from the main filter chamber, the secondary filter chamber including a further filter.23. A machine according to any one of the preceding claims wherein the exterior housing of the filter is provided at least in part by a rigid or semi-rigid material.24. A machine according to claim 23 wherein the filter includes at or towards one end, an inlet for condensate, and at or towards an opposite end, an outlet for filtered liquid.25. A filtering machine substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.26. A filter for a filtering machine of any one of the preceding claims.27. A filter for a filtering machine substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.28. A method of filtering using a filtering machine of any one of claims I to 25, the method including passing condensate into the filter interior, and contacting the condensate with the mass of filter material in the interior of the filter, passing the filtered liquid out of the filter.29. A method of filtering substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.30. A method of making a filter for filtering a condensate with entrained oily contaminant, the filter including an exterior housing through which the condensate, in use, passes to contact filter material within the interior of the filter housing, and through which filtered liquid passes out of the filter, and the filter further including in the interior, a mass of filter material, the method including providing the mass of filter material by taking oleophillic fibres and embedding in the fibres, particulate material, and placing In the filter Interior, the mass of filter material.31. A method accordIng to claim 30 whereIn the particulate material Includes an activated oleophllllc adsorbent.32. Any novel feature or novel combination of Matures described herein andlor as shown In the accompanying drawings.