GB2045647A

GB2045647A - Ionizing devices

Info

Publication number: GB2045647A
Application number: GB7910754A
Authority: GB
Original assignee: BURGESS Manufacturing AIR CLEANERS Ltd
Current assignee: BURGESS Manufacturing AIR CLEANERS Ltd
Priority date: 1979-03-28
Filing date: 1979-03-28
Publication date: 1980-11-05

Abstract

An electrostatic air cleaner ionizing device comprising a frame (10, 12, 14, 16) across which is stretched a conductive wire (18) to form a series of parallel passes. The wire is enlarged at opposite ends and passes through openings in the sides of the frame, the wire being bent around to form a U-shape (42, 44) between adjoining openings on each side of the frame, externally thereof. Bushes (24, 26), e.g. of plastics or ceramic, which may have adjustment screws, provide anchorage points at the opposite ends of the wire. Other bushes (34, 36, 38, 40) are also threaded on the wire and constitute guides for the wire as is passes through the openings in the frame. The openings are in the form of open-ended slots into which the wire and/or bushes can be fitted. Springs (50, 52, 54, 56) are provided to tension the wire, and sleeves of electrically insulating material (46, 48) protect the external loops of wire. The sleeves (46, 48) may be of resilient material to tension the wire (18). <IMAGE>

Description

SPECIFICATION Improvements in and relating to ionizing devices Field of invention This invention concerns ionizing devices typically but not exclusively for air cleaners.

Background to invention In electrostatic air cleaners it has been proposed to incorporate an ionizing device comprising one or more lengths of wire stretched across a frame and insulated therefrom through which the air to be ionized is passed. lonisation is achieved by subjecting the stretched wire or wires to a high potential.

During routine maintenance and cleaning of electrostatic air cleaners these ionizing devices can become damaged and/or in time one or more of the stretched lengths of wire can break or sag thereby rendering the ionizing device less efficient. Where a single length of wire is used which is threaded from one side of the frame to another to break in the wire means that the whole device must be rethreaded and this can be a difficult operation when it has to be performed on location with the unit mounted perhaps high in a room.

Consequently it is one object of the present invention to provide an improved form of construction of an ionizing device in which the actual ionizing element can be readily replaced when in the field.

As a corollary it is an object of the present invention to provide an improved method of construction of an ionizing device for units such as electrostatic air cleaners which will allow the ionizing element to be set up and tensioned in a correct manner.

The invention According to the present invention an ionizing device for an electrostatic air cleaner or the like comprises an open-ended box frame two sides of which provide support for an elongate conductive ionizing wire, each of the sides having formed therein a plurality of openings through which the wire is passed, the wire extending between the two supporting sides of the frame and passing from first one side to the other and then back again and one end of the wire being anchored in one of the openings on one of the sides of the frame and the other end of the wire being anchored in another opening in the opposite side of the frame.

Preferably means is provided for tensioning the wire. This may comprise one or more tension springs or resilient sleeves may be threaded on the wire as it extends between one opening and the next externally of the box frame.

The frame is preferably formed from electrically insulating material.

In an arrangement in which the box frame is not formed from electrically insulating material, insulating bushes are conveniently threaded along the wire and anchored in the openings in the sides of the box frame so that the wire extends therethrough and the said anchoring of the wire is made by anchoring the wire to the insulating bushes at the opposite ends of the wire so that no conductive connection is made between the wire and the box frame.

The anchorage at one end of the wire may be formed by crimping the end of the wire to form an enlargement thereof. By arranging that the hole through which the wire passes is smaller than the crimped enlargement so the wire is prevented from passing through the opening in the frame or the bush. A coiled spring may be located between the crimped enlargement and the wall of the box frame or the insulating bush to tension the wire.

A similar anchorage may be provided at the opposite end of the wire.

Where the wire extends externally of the frame and forms a U-shaped curve so as to reenter the frame through an adjoining opening on the same side, a sleeve is to advantage threaded on the wire. The sleeve not only serves to protect the wire but can also be formed or fitted around a resilient member so as to further tension the wire. The resilient member may for example comprise a coiled spring, the uncompressed length of which is somewhat greater than the path length of the wire between the two adjoining openings so that the wire compresses the spring. In this way the wire is protected externally of the frame both electrically and mechanically and further tension is imparted to the stretched wire.

The initial tension can be set up the wire by crimping one end of the wire, threading thereon all the intermediate sleeve members and insulating bushes where required and then cutting the wire to a desired length and crimping an enlargement onto the cut end of the wire and thereafter inserting the wire into the openings (or inserting the bushes into the openings as the case may be) so that the wire is stretched between the opposite sides of the box frame. The tension in the wire is maintained by means of the springs which may be located as previously described at opposite ends of the wire and/or around the intermediate length of the wire extending between adjoining openings on the sides of the box frame and any slack in the wire is taken up by the compression springs.

In some applications it may be desirable to be able to adjust the tension of the wire when the unit is in situ or during the initial settingup of the device and to this end the invention also includes provision of at least one bush having an adjustable member acting on the wire so as to effectively increase the path length over which the wire is extended so as to increase the tension in the wire. Such a bush is preferably of electrically insulating material although where the frame itself is formed from electrically insulating material this is not so important. The adjustment conveniently comprises a rotatable member threadedly engaged in or on the bush whereby the bush can be moved relative to the frame so as to increase or decrease the path length of the wire.

Conveniently the bush having the adjustable member is located at one end or the other of the wire or similar adjustable bushes are provided at opposite ends of the wire and where provided intermediate bushes are not adjustable.

Preferably the wire is stainless steel or tungsten. Convenient diameter of wire is .0008" although the invention is not limited to these particular materials or these dimensions.

Where the frame is of an electrically conductive material such as metal the anchoring bushes must not only be formed from electrically insulating material but from a material which does not absorb water to any appreciable extent. Preferred materials are plastics materials or ceramic materials and preferred material is polyurethane or polytetrafluoroethylene.

An advantage of the invention is that a complete wire ionizer element can be produced with both ends having crimped enlargements and having threaded thereon all the requisite insulating bushes and mounting bushes as required and insulating springs and sleeves to allow the wire element to be inserted from one side of the frame and stretched thereacross in the appropriate number of passes before the further end of the wire is anchored into the frame. This is of great advantage when servicing an electrostatic air cleaning unit in the field since the service engineer need only take with him a number of spare ionizing elements already prefabricated in this manner and any that are found in the field to be damaged or beyond repair or requiring detailed cleaning can simply be removed by removing the wire from the opening and inserting into the frame a fresh element.

It will be appreciated that in order for this to be possible, the openings must be in the form of slots which open into one edge of the box frame so that the wire can be pushed into the slot from the said one edge of the frame during the initial threading up procedure and can also be removed from the frame in the same way, in reverse.

It will be appreciated that the insulating sleeves, springs and where required insulating bushes of an ionizing element which has had to be removed can of course be salvaged and used again with a fresh piece of wire. Since the latter is the only part which tends to get damaged or contaminated in use, the life of the bushes, springs and insulating sleeves can be virtually indefinite.

The invention will now be described by way of example with reference to the accompanying drawing.

In the drawing Figure 1 is a side view of an ionizing device for use in an electrostatic air cleaner, and Figure 2 is an end view thereof.

Detailed description of drawing As shown in the drawing an ionizing device comprises a frame having two longer sides 10 and 1 2 and two ends 1 4 and 1 6 between which is extended a continuous length of stretched conducting wire 18.

The two free ends of the wire are anchored by means of crimped enlargements 20 and 22 which prevent the wire from leaving insulating bushes 24 and 26 respectively located at opposite ends of the wire and held in position in the frame in slots which are shown in Fig. 2. The end view shown in Fig. 2 is that seen by viewing the left hand end of the frame as shown in Fig. 1 and the slot into which bush 24 is fitted is therefore the slot 28 shown in Fig. 2. The other slots in the end 14 are denoted by reference numerals 30 and 32.

The slots for the bushes at the opposite end of the frame 1 6 are similar to the slots 28, 30 and 32 and the open ends of the slots communicate with the same face of the frame as do the slots 28, 30 and 32 so that all the bushes can be inserted into their respective slots from the same side of the frame.

Intermediate bushes (which are similar to the bushes 24 and 26) are shown at 34, 36, 38 and 40 and in each case the wire 1 8 extends through the intermediate bush and passes in a loop generally designated 42 and 44 between adjoining bushes at opposite ends of the frame. Where the wire is so looped, it is protected by means of an insulating sleeve 46 and 48 and tension is imparted into the wire by means of coil springs situated between the ends of the sleeves 46 and 48 and the inner ends of the bushes 34 and 36 and 38 and 40 respectively. The coil springs are denoted by reference numerals 50, 52, 54 and 56 respectively.

The frame is strengthened by intermediate struts 58 and 60 which extend parallel to the members 10 and 1 2 between the opposite ends 14 and 16.

The wire 1 8 with all the bushes, sleeves and springs thereon can be removed entirely from the frame without breaking the wire or removing any of the bushes etc. and to this end can be treated and by making the frames of a standard size and using identical lengths of wire, the prefabricated spare part so formed can be used to fit any frame and used to replace broken or worn-out elements in the field.

In addition the pre-assembled units can assist in the manufacture and assembly of the ionizing devices at the manufacturing state.

In the embodiment shown in the drawing the frame is formed from aluminium strip, the bushes are formed from polytetrafluorethylene and the wire is .0008" diameter stainless steel. The springs for tensioning the wire are also conveniently formed from stainless steel and the insulating sleeves 42 and 44 are formed from polytetrafluoroethylene or similar plastics material.

It will be appreciated that where the frame is formed from electrically insulating material the electrical insulating bushes such as 24 etc. can be dispensed with or can be replaced by bushes formed from electrically conducting material. The bushes may of course be retained even though the frame is formed from electrically insulating material simply to provide a better location for the wire 1 8 as it passes through the sides of the frame.

Where the two opposite sides of the frame 1 4 and 1 6 are formed from electrically insulating material the transversely extending frame sections 10, 58, 60 and 1 2 may still be formed from electrically conductive material and in that event are electrically connected together by conductors (not shown) which can then be connected to earth in known manner.

Although not shown the sleeves 42 and 44 can be formed from convoluted hose typically formed from plastics or rubber or a composite rubber and plastics material and the natural resilience of such a hose used to tension the wire stretched between the sides of the frame.

CLAIMS (6 Sept 1979) 1. An ionizing device for an electrostatic air cleaner comprising an open-ended box frame two sides of which provide support for an elongate conductive ionizing wire, each of the sides having formed therein a plurality of openings through which the wire is passed, the wire extending between the two supporting sides of the frame and passing from first one side to the other and then back again and one end of the wire being anchored in one of the openings on one of the sides of the frame and the other end of the wire being anchored in another opening in the opposite side of the frame.

2. An ionizing device as claimed in claim 1 in which means is provided for tensioning the wire.

3. An ionizing device as claimed in claim 2 in which the means for tensioning the wire comprises one or more springs.

4. An ionizing device as claimed in claim 2 in which the means for tensioning the wire comprises resilient sleeves threaded on the wire as it extends between one opening and the next externally of the box frame.

5. An ionizing device as claimed in any of the preceding claims in which the frame is formed from electrically insulating material.

6. An ionizing device as claimed in any of claims 1 to 4 in which the box frame is formed from electrically conductive material and insulating bushes are threaded along the wire and anchored in openings in the sides of the box frame so that the wire extends therethrough to insulate the wire from the frame, and the anchoring of the wire is made by anchoring the wire to the insulating bushes at the opposite ends of the wire so that no conductive connection is made between the wire and the frame.

7. An ionizing device as claimed in any of the preceding claims in which the wire is anchored by crimping the end of the wire to form an enlargement thereof which is larger than the hole through which the wire passes in the frame or in an insulating bush in the frame.

8. An ionizing device as claimed in any of the preceding claims in which a bush is fitted in at least one of the apertures in the sides of the frame through which the wire extends, the bush having an adjustable member acting on the wire so as to effectively increase the path length over which the wire is extended upon adjustment, so as to allow the tension in the wire to be increased or decreased as required.

9. An ionizing device as claimed in any of the preceding claims wherein the wire is stainless steel tungsten.

1 0. An ionizing device as claimed in any of the preceding claims wherein the frame is of electrically conductive material and electrically insulating anchoring bushes are provided wherein the anchoring bushes are formed either from a ceramic material or from a plastics material.

11. An ionizing element for an air ionizing device comprising a length of wire having both ends enlarged by cimpring and having threaded thereon insulating bushes and mounting bushes, insulating springs and sleeves to allow the wire element to be inserted from one side of a frame into slots formed in the walls of the frame and stretched thereacross in an appropriate number of passes before the other end of the wire is anchored in a final slot in one of the walls of the frame.

1 2. An ionizing device constructed arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

CLAIMS (24 Apr 1980) 1. An ionizing device for an electrostatic air cleaner comprising a box frame openended at the front and back and having two side walls which provide support for an ioniz ing wire, each of the side walls having therein

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. replace broken or worn-out elements in the field. In addition the pre-assembled units can assist in the manufacture and assembly of the ionizing devices at the manufacturing state. In the embodiment shown in the drawing the frame is formed from aluminium strip, the bushes are formed from polytetrafluorethylene and the wire is .0008" diameter stainless steel. The springs for tensioning the wire are also conveniently formed from stainless steel and the insulating sleeves 42 and 44 are formed from polytetrafluoroethylene or similar plastics material. It will be appreciated that where the frame is formed from electrically insulating material the electrical insulating bushes such as 24 etc. can be dispensed with or can be replaced by bushes formed from electrically conducting material. The bushes may of course be retained even though the frame is formed from electrically insulating material simply to provide a better location for the wire 1 8 as it passes through the sides of the frame. Where the two opposite sides of the frame 1 4 and 1 6 are formed from electrically insulating material the transversely extending frame sections 10, 58, 60 and 1 2 may still be formed from electrically conductive material and in that event are electrically connected together by conductors (not shown) which can then be connected to earth in known manner. Although not shown the sleeves 42 and 44 can be formed from convoluted hose typically formed from plastics or rubber or a composite rubber and plastics material and the natural resilience of such a hose used to tension the wire stretched between the sides of the frame. CLAIMS (6 Sept 1979)

1. An ionizing device for an electrostatic air cleaner comprising an open-ended box frame two sides of which provide support for an elongate conductive ionizing wire, each of the sides having formed therein a plurality of openings through which the wire is passed, the wire extending between the two supporting sides of the frame and passing from first one side to the other and then back again and one end of the wire being anchored in one of the openings on one of the sides of the frame and the other end of the wire being anchored in another opening in the opposite side of the frame.

9. An ionizing device as claimed in any of the preceding claims in which the bushes are formed from a ceramic material or from a plastics material.

CLAIMS (24 Apr 1980)

1. An ionizing device for an electrostatic air cleaner comprising a box frame openended at the front and back and having two side walls which provide support for an ioniz ing wire, each of the side walls having therein

a plurality of slots open-ended to the front, in which slots are received bushes for passage of the wire, the opposite ends of the wire being anchored in two of such bushes and the wire being threaded through the remaining, intermediate bushes between its said opposite ends so as to form a planar array of wire electrodes at the front of the frame, the wire being looped between intermediate bushes on the exterior of the side walls to enable the wire electrodes to be tensioned by tensioning means acting on the exterior wire loops.

2. An ionizing device as claimed in claim 1 in which the means for tensioning the wires comprises one or more springs.

3. An ionizing device as claimed in claim 1 or 2 in which the means for tensioning the wire comprises a resilient sleeves threaded on the wire as it extends between one opening and the next externally in the box frame.

4. An ionizing device as claimed in any of the preceding claims in which the frame is formed from electrical insulating material.

5. An ionizing device as claimed in any of claims 1 to 4 in which the box frame is formed from electrically conductive material and the intermediate bushes are of insulating material and are threaded along the wire and anchored in openings in the sides of the box frame so that the wire extends therethrough to insulate the wire from the frame, and the anchoring of the wire is made by anchoring the wire to the insulating bushes at the opposite ends of the wire so that no conductive connection is made between the wire and the frame.

6. An ionizing device as claimed in any of the preceding claims in which the wire is anchored by crimping the end of the wire to form an enlargement thereof which is larger than the hole through which the wire passes.

7. An ionizing device as claimed in any of the preceding claims in which the bush has an adjustable member acting on the wire so as to effectively increase the path length over which the wire is extended upon adjustment, so as to allow the tension in the wire to be increase or decreased as required.

8. An ionizing device as claimed in any of the preceding wherein the wire is stainless steel or tungsten.