GB1586148A - Creación de Inventos y Patentes con Inteligencia Artificial

GB1586148A – Filters for fan ducts
– Google Patents

GB1586148A – Filters for fan ducts
– Google Patents
Filters for fan ducts

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Publication number
GB1586148A

GB1586148A
GB15961/78A
GB1596178A
GB1586148A
GB 1586148 A
GB1586148 A
GB 1586148A
GB 15961/78 A
GB15961/78 A
GB 15961/78A
GB 1596178 A
GB1596178 A
GB 1596178A
GB 1586148 A
GB1586148 A
GB 1586148A
Authority
GB
United Kingdom
Prior art keywords
layer
polypropylene
face
pad
glass wool
Prior art date
1978-02-22
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.)

Expired

Application number
GB15961/78A
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.)

PIFAN PLASTIC IND FANS Ltd

Original Assignee
PIFAN PLASTIC IND FANS 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.)
1978-02-22
Filing date
1978-02-22
Publication date
1981-03-18

1978-02-22
Application filed by PIFAN PLASTIC IND FANS Ltd
filed
Critical
PIFAN PLASTIC IND FANS Ltd

1978-02-22
Priority to GB15961/78A
priority
Critical
patent/GB1586148A/en

1981-03-03
Priority to AU68003/81A
priority
patent/AU6800381A/en

1981-03-18
Publication of GB1586148A
publication
Critical
patent/GB1586148A/en

Status
Expired
legal-status
Critical
Current

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Classifications

B—PERFORMING OPERATIONS; TRANSPORTING

B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL

B01D—SEPARATION

B01D39/00—Filtering material for liquid or gaseous fluids

B01D39/08—Filter cloth, i.e. woven, knitted or interlaced material

B01D39/083—Filter cloth, i.e. woven, knitted or interlaced material of organic material

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts

B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed

B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer

B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary

B—PERFORMING OPERATIONS; TRANSPORTING

B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL

B01D—SEPARATION

B01D39/00—Filtering material for liquid or gaseous fluids

B01D39/14—Other self-supporting filtering material ; Other filtering material

B01D39/20—Other self-supporting filtering material ; Other filtering material of inorganic material, e.g. asbestos paper, metallic filtering material of non-woven wires

B01D39/2003—Glass or glassy material

B01D39/2017—Glass or glassy material the material being filamentary or fibrous

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

B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer

B32B5/026—Knitted fabric

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B5/028—Net structure, e.g. spaced apart filaments bonded at the crossing points

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B5/08—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer the fibres or filaments of a layer being of different substances, e.g. conjugate fibres, mixture of different fibres

B—PERFORMING OPERATIONS; TRANSPORTING

B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL

B01D—SEPARATION

B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids

B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material

B01D2239/065—More than one layer present in the filtering material

B—PERFORMING OPERATIONS; TRANSPORTING

B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL

B01D—SEPARATION

B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids

B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material

B01D2239/065—More than one layer present in the filtering material

B01D2239/0654—Support layers

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives

B32B2262/02—Synthetic macromolecular fibres

B32B2262/0253—Polyolefin fibres

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B2305/00—Condition, form or state of the layers or laminate

B32B2305/38—Meshes, lattices or nets

B—PERFORMING OPERATIONS; TRANSPORTING

B32—LAYERED PRODUCTS

B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

B32B2307/00—Properties of the layers or laminate

B32B2307/40—Properties of the layers or laminate having particular optical properties

B32B2307/42—Polarizing, birefringent, filtering

Description

(54) FILTERS FOR FAN DUCTS
(71) We, PIFAN PLASTIC INDUSTRIAL FANS LIMITED, a British Company of Silvene
House, 1 Chilworth Mews, London W.2,
England, formerly of 8f, Hyde Park Mansions, Cabbell Street, London N.W.1.,
England, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a mist eliminator filter, for example to be used in a fan duct and constituting a pack which can be either fitted into a mist eliminator box or mounted elsewhere in a fan duct.
Hitherto there have been various types of mist eliminators available but these have been limited as to the degree of mist elimination. The elimination of mist is important with regard to avoiding environmental pollution, for example in the field of electro-plating where fumes of chromic acid are present in the air above the plating tank and these fumes should be eliminated before that air is discharged to ambient atmosphere.
In accordance with the present invention we provide a filter pack comprising a first layer formed of glass wool textile web material, and at least a second layer formed as a knitted mesh structure of polypropylene fibres placed in face-to-face contact with a respective face of the said first layer.
We have surprisingly found that we can obtain an improved degree of mist elimination using a combination of different layers of which at least one is formed of polypropylene mesh and at least one other is of glass wool.
It is particularly convenient for the elimination to be achieved by passing the contaminated air through a three layer sandwiched filter pad consisting of a first layer formed of glass wool textile web material having on its respective faces second and third layers formed of knitted polypropylene mesh. In such an arrangement, particularly advantageous results have been obtained using a substantially 1″ thick inner layer built up of the glass wool textile web material, and a thickness of substantially 2Q» for the two outer layers of knitted polypropylene mesh. Such a pad is capable of stopping particles as small as 2 microns without any long term clogging of the pack, and when dealing with chromic acid fumes, the degree of extraction has been found to be capable of reducing the residual chromic acid content to as little as 0.005 mg/M3.
In order that the present invention may more readily be understood the following description is given merely by way of example, reference being made to the accompanying drawings in which the sole Figure is a cross-section through the mist-eliminating pad in accordance with the present invention.
The mist eliminator pack 20 shown in the drawing includes a first inner filter medium in the form of a layer 21 which is built up to be 1″ thick and formed of textile material of glass wool strands. Used alone, this glass wool filter layer is capable of stopping particles of no smaller than 2 microns but would tend to become soaked with larger-sized droplets of liquid which would then pass through to the clean, upper, surface of the layer 21.
A second upper layer 22 and a third lower layer 23 of the mist eliminator are both formed of a mesh of knitted polypropylene fibres capable alone of eliminating particles of no smaller than 5 microns.
Whereas these pads alone could give a contamination reading of only 0.06 mg/M3, they have the surprising advantage, when combined with the glass wool layer, of allowing a residual contamination level of as low as 0.005 mg/M3 to be attained. This was the result when using the pack illustrated in the Figure and with the 22″ thick mesh layer of knitted polypropylene fibres surrounding a glass wool layer of merely 1″ thickness.
The pack is enclosed within a lateral wall 24 of polypropylene sheet having a thicknessness of 1/4″, and the top and bottom walls 25 and 26, respectively, were formed of the same 1/4″ thick polypropylene sheet but perforated so as to be permeable to gas to be treated.
The above-mentioned residual contamination value of 0.005 – mg/M3 was attained using a gas velocity through the pad which was at minimum 250 feet per minute, and at maximum 400 feet per minute to give both the advantageous residual contamination result, even with chromic acid mist from an electro-plating plant, and also an acceptable working life for the pad between cleaning operations.
The particularly advantageous results due to combining the layers in a polypropyleneglasswool-polypropylene sandwich as illustrated in the Figure are thought to reside in the fact that large droplets of liquid entering the pack through the lower wall 26 will be stopped by the polypropylene mesh 26 before arriving at the glass wool pad.
Thus only particles having a diameter of smaller than 5 microns will impinge on the glass wool pad, and the glass wool pad has the effect of coalescing these finer particles to a larger size which the upper polypropylene pad 22 effectively handles.
For the avoidance of environmental hazards in the atmosphere, it has been particularly advantageous to provide fan ducting incorporating at its downstream end a cowl which may be of sound attenuating construction, and upstream of the cowl, either before or after the fan in the direction of air flow through the fan and ducting, the mist eliminator pack 20 illustrated in the drawing. Thus the air issuing from the cowl does so with a very low noise level and a tolerable residual contamination level, even with such undesirable substances as chromic acid present in the feed stream to the mist eliminator pack.
In the above description, preferred forms of materials for the glass wool and polypropylene mesh are those obtained under the
Trade Mark «KNITMESH.»
WHAT WE CLAIM IS:
1. A filter pack comprising a first layer formed of glass wool textile web material, and at least a second layer formed as a knitted mesh structure of polypropylene fibres placed in face-to-face contact with a respective face of the said first layer.
2. A filter pack according to claim 1, and further including a third layer formed as a knitted mesh structure of polypropylene fibres, placed in face-to-face contact with the face of said first layer opposite the face with which said second layer is in contact.
3. A filter pack according to claim 1 or 2, wherein said first layer has an overall thickness of substantially one inch and the or each layer of polypropylene mesh has an overall thickness of substantially 2 1/2 inches.
4. A filter pack according to any one of claims 1 to 3, wherein said first layer has a sieve size to block particles no smaller than 2 microns and the or each other layer has a sieve size to eliminate particles no smaller than 5 microns.
6. A filter pack according to any one of the preceding claims and including an envelope of polypropylene sheet bounding side edges of the various layers.
7. A filter pack according to claim 6, and further including a perforated polypropylene sheet forming a support extending across the two exposed faces of the multi-layer asembly of filter medium layers.
8. A filter pack substantially as hereinbefore described with reference to and as illustrated in, the accompanying drawings.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. of the same 1/4″ thick polypropylene sheet but perforated so as to be permeable to gas to be treated. The above-mentioned residual contamination value of 0.005 – mg/M3 was attained using a gas velocity through the pad which was at minimum 250 feet per minute, and at maximum 400 feet per minute to give both the advantageous residual contamination result, even with chromic acid mist from an electro-plating plant, and also an acceptable working life for the pad between cleaning operations. The particularly advantageous results due to combining the layers in a polypropyleneglasswool-polypropylene sandwich as illustrated in the Figure are thought to reside in the fact that large droplets of liquid entering the pack through the lower wall 26 will be stopped by the polypropylene mesh 26 before arriving at the glass wool pad. Thus only particles having a diameter of smaller than 5 microns will impinge on the glass wool pad, and the glass wool pad has the effect of coalescing these finer particles to a larger size which the upper polypropylene pad 22 effectively handles. For the avoidance of environmental hazards in the atmosphere, it has been particularly advantageous to provide fan ducting incorporating at its downstream end a cowl which may be of sound attenuating construction, and upstream of the cowl, either before or after the fan in the direction of air flow through the fan and ducting, the mist eliminator pack 20 illustrated in the drawing. Thus the air issuing from the cowl does so with a very low noise level and a tolerable residual contamination level, even with such undesirable substances as chromic acid present in the feed stream to the mist eliminator pack. In the above description, preferred forms of materials for the glass wool and polypropylene mesh are those obtained under the Trade Mark «KNITMESH.» WHAT WE CLAIM IS:

1. A filter pack comprising a first layer formed of glass wool textile web material, and at least a second layer formed as a knitted mesh structure of polypropylene fibres placed in face-to-face contact with a respective face of the said first layer.

2. A filter pack according to claim 1, and further including a third layer formed as a knitted mesh structure of polypropylene fibres, placed in face-to-face contact with the face of said first layer opposite the face with which said second layer is in contact.

3. A filter pack according to claim 1 or 2, wherein said first layer has an overall thickness of substantially one inch and the or each layer of polypropylene mesh has an overall thickness of substantially 2 1/2 inches.

4. A filter pack according to any one of claims 1 to 3, wherein said first layer has a sieve size to block particles no smaller than 2 microns and the or each other layer has a sieve size to eliminate particles no smaller than

5 microns.

6. A filter pack according to any one of the preceding claims and including an envelope of polypropylene sheet bounding side edges of the various layers.

7. A filter pack according to claim 6, and further including a perforated polypropylene sheet forming a support extending across the two exposed faces of the multi-layer asembly of filter medium layers.

8. A filter pack substantially as hereinbefore described with reference to and as illustrated in, the accompanying drawings.

GB15961/78A
1978-02-22
1978-02-22
Filters for fan ducts

Expired

GB1586148A
(en)

Priority Applications (2)

Application Number
Priority Date
Filing Date
Title

GB15961/78A

GB1586148A
(en)

1978-02-22
1978-02-22
Filters for fan ducts

AU68003/81A

AU6800381A
(en)

1978-02-22
1981-03-03
Mist eliminator pack

Applications Claiming Priority (2)

Application Number
Priority Date
Filing Date
Title

GB15961/78A

GB1586148A
(en)

1978-02-22
1978-02-22
Filters for fan ducts

AU68003/81A

AU6800381A
(en)

1978-02-22
1981-03-03
Mist eliminator pack

Publications (1)

Publication Number
Publication Date

GB1586148A
true

GB1586148A
(en)

1981-03-18

Family
ID=25635542
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB15961/78A
Expired

GB1586148A
(en)

1978-02-22
1978-02-22
Filters for fan ducts

Country Status (2)

Country
Link

AU
(1)

AU6800381A
(en)

GB
(1)

GB1586148A
(en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

WO1988010146A1
(en)

1987-06-25
1988-12-29
Scientific Glass Engineering Pty. Ltd.
Filter element for liquid chromatography

AU631024B2
(en)

1989-12-04
1992-11-12
Mark Snyders
Improvements to microfilters for infant incubators

1978

1978-02-22
GB
GB15961/78A
patent/GB1586148A/en
not_active
Expired

1981

1981-03-03
AU
AU68003/81A
patent/AU6800381A/en
not_active
Abandoned

Also Published As

Publication number
Publication date

AU6800381A
(en)

1982-09-09

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