EP0344074A2 - Removable ionisation chamber for a gas cleaner, especially of air - Google Patents

Abstract

The gas cleaner, especially of air, is of the type comprising a box structure provided with at least one inlet and with at least one outlet and containing an ionisation chamber which is profiled in order to ensure the aerodynamic guidance of the gas flow from the inlet to the outlet. It is characterised in that the ionisation chamber consists at least partially of a sheet of cardboard or a similar material stored flat and to be placed in the box structure so as to be able to be removed after folding and/or bending, the face 2 of this sheet which is to be situated on the inner side of the ionisation chamber being covered with a bare conducting material 3 such as aluminium not coated with an insulating product. <IMAGE>

Description

The present invention relates to air purifiers that are installed in premises in order to purify the atmosphere.

The known purifiers are of different types but all have a fairly poor performance due in particular to a poor design of the structure which provides for an air path which is poorly coordinated with the requirements of the electric field to be created in an ionization chamber.

The invention provides a new solution to the problem of air purification in rooms by proposing a rational structure which greatly improves the flow of air in the room and inside the purifier itself.

In addition, the invention relates to gas purifiers which contain an ionization chamber traversed by a taut conductive wire through which must pass a high voltage electric current (of the order of 10,000 volts) to create an electric field through which particles in suspension in the gas are ionized and are, therefore, biased towards the internal metal walls of the chamber on which they are deposited for their collection.

Existing devices are impractical because collecting dust requires either disassembly of the ionization chamber and cleaning out of the device, or intervention without disassembly, in which case there is a great risk of damaging the taut wire which is quite fragile. The person who acts must therefore take great precautions and rarely achieve complete cleaning. The cleaning operations are essential at regular intervals because the efficiency of the purification depends directly on the conductivity of the walls of the chamber and their yield. decreases as these walls become dirty. The difficulties of cleaning make these operations expensive for users who tend to space them out for reasons of economy, which obviously results in poor cleaning.

Furthermore, the need for the walls of the chamber to be conductive leads the manufacturers to produce the metal chamber. They are essentially smooth sheets, relatively thick and heavy to be robust, which requires the presence of holding and fixing members to avoid, in particular, the displacements, beats and vibrations due to the displacement of the pulsed gas by a wind tunnel.

The chambers are therefore very removable, in the strict sense of the word, but on condition of carrying out a real disassembly followed by a reassembly, and this requires the use of tools. Their price is such that they must be cleaned and not replaced.

Another disadvantage of metal ionization chambers comes from their origin itself: the sheets come from a rolling between smooth steel cylinders and the surface of their two faces is absolutely smooth. As a result, the dust which is attracted to the walls of the chamber is not well retained and on the contrary has a tendency to slip. Some fall into the bottom of the chamber and remain there until the next cleaning, but others are carried away by the outgoing gas stream, so that a correct purification at the origin becomes ultimately ineffective by repolution of the gas.

To be truly effective, the internal walls of the chamber should be rough during operation in order to effectively retain the deposited and smooth particles at the time of cleaning so that it is easy and complete.

These are two contradictory necessities and the invention provides precisely a new solution to this problem by making it possible to improve both the operation of the devices, their maintenance and the maintenance cost.

To this end the invention relates to a gas purifier, in particular air, of the type comprising a box provided with at least one inlet and at least one outlet and containing a profiled ionization chamber for guiding aerodynamics of the gas flow from the inlet to the outlet, characterized in that the ionization chamber is formed at least partially by a sheet of cardboard or similar material stored flat and which must be removably placed in the box after folding and / or bending, the face of this sheet which must be on the internal side of the ionization chamber being coated with a bare conductive material, such as aluminum not coated with an insulating product.

• - la feuille de carton ayant une face plus lisse que l'autre, le matériau conducteur est placé sur la face la moins lisse;
• - la feuille revêtue est marquée de lignes de rainage selon lesquelles elle doit être pliée et qui déterminent des parties spécifiques devant coopérer avec des éléments du caisson pour être maintenue en forme à sa place de fonction tout en étant interchangeable;
• - la feuille revêtue est marquée de deux lignes de rainage rectilignes transversales devant favoriser le pliage de la feuille vers l'extérieur selon deux marges, la feuille devant être cintrée vers l'intérieur pour que le revête­ment conducteur soit situé sur la face concave de la feuille quand celle-ci est mise en forme;
• - la feuille revêtue comprend une partie centrale devant être cintrée et solidaire de deux joues latérales délimi­ tées par deux lignes de rainage sensiblement alignées avec deux bords de la feuille, les joues éventuellement échan­crées devant être rabattues dans des plans perpendiculai­res à celui de la feuille avant cintrage;
• - chaque joue présente un bord libre courbe dont la forme correspond à la section que la feuille doit avoir à cet endroit après cintrage.

According to other characteristics of the invention:

• - the cardboard sheet having one side smoother than the other, the conductive material is placed on the less smooth side;
• - The coated sheet is marked with crease lines according to which it must be folded and which determine specific parts which must cooperate with elements of the box in order to be kept in shape in its place of function while being interchangeable;
• the coated sheet is marked with two transverse rectilinear creasing lines which have to favor the folding of the sheet towards the outside according to two margins, the sheet having to be bent inwards so that the conductive coating is located on the concave face of the sheet when it is shaped;
• - the coated sheet comprises a central part to be bent and secured to two delimited lateral cheeks ted by two crease lines substantially aligned with two edges of the sheet, the cheeks possibly indented having to be folded down in planes perpendicular to that of the sheet before bending;
• - each cheek has a curved free edge whose shape corresponds to the section that the sheet must have at this point after bending.

The invention will be better understood from the detailed description below made with reference to the accompanying drawing. Of course, the description and the drawing are given only by way of an indicative and nonlimiting example.

Figure 1 is a schematic sectional view of a sheet according to the invention.

Figure 2 is a plan view of a sheet according to the invention, seen from its smoother side.

Figure 3 is a schematic perspective view showing the sheet of Figure 1 bent and folded as it is when held in its place of function.

FIG. 4 is a plan view of a sheet in accordance with the invention, seen from its smoothest side and produced according to a variant different from that of FIG. 5.

Figure 5 is a schematic perspective view showing the sheet of Figure 8 bent and folded as it is when held in its place of function.

Referring to FIG. 1, it can be seen that a sheet according to the invention is made of cardboard and has a very smooth face 1 and a less smooth face 2. This difference may arise from the manufacturing method which provides that in during development, the fibers which are still wet constitute a very fragile and cohesive sheet which is supported by being placed on a carpet or other non-smooth support which communicates its surface irregularities to it, or which provides for the calendering of the sheet for the compress, one of the cylinders of the calender being polished so that the corresponding face 1 is smooth while the opposite cylinder has a rough surface, more or less regular, which provides a complementary surface on face 2. This can also come from a coating of face 1.

Generally, the face 1 being more noble, is chosen to receive a coating, in particular a thin aluminum sheet, because we are looking for the regularity and softness of the worked face. The rough and more or less voluntarily marked face 2 is disposed on the hidden side and is particularly suitable for coating adhesives.

Here, contrary to all practice, there is a conductive coating 3 on the rough face 2 in order to obtain a larger specific surface and a better attachment effect of the particles which it is desired to eliminate from the gas stream.

The coating 3 can be constituted by an aluminum sheet which will not have the glossy appearance which it has when it is well stretched or which it would have if it had been applied against the face 1. It therefore acquires, by using it thus, a new particular quality with regard to the retention of ionized particles, without losing at all its qualities of electrical conductivity.

This results in a better overall yield and a longer duration of effectiveness.

In FIG. 2, we see an example of a sheet constituted as said above with reference to FIG. 1 and having two transverse rectilinear creasing lines 4 and 5 which determine two margins 6 and 7. The new sheets are stored at flat and thus occupy little volume. They can be assembled in groups and possibly packed in boxes, with separators to protect the covering 3 against knocks and tears. When placing a new sheet, fold the margins 6 and 7 along the creasing lines 4 and 5 and bend the sheet together as shown in Figure 3, then put it in position in the usual scrubber box, which contains holding devices such as ribs, supports, guides and other supports which prevent the elastic return of the sheet to its original position and which ensure the continuity of the guiding of gas flow from the inlet to the outlet of the purifier, preventing leaks and harmful load losses.

With this embodiment, most of an ionization chamber is formed in which the gas to be purified arrives according to the arrows 1, under the edge carrying the margin 7 and leaves it according to the arrows 2, near the edge carrying the margin 6. It is because of the direction of movement of the gas flow that the high-voltage electric wire A is described as "transverse", the situation of which has been indicated schematically and since the creasing lines 4 and 5 are parallel to this thread A, they are also considered as "transverse".

Note that the sheet has free edges 8 and 9 which do not create sides to the ionization chamber. In this case, it is necessary to provide independent flanges, for example fixed or removable partitions in the box and these flanges can be given a higher profile corresponding to the curve that one wants to give to the sheet so that by placing it here on them and now there, we are assured of the precise profile desired. The sheet can be maintained by any means, in particular by a stirrup which is immobilized using the blocking resulting from the closure of the box by a cover or the like.

The sheet is advantageously made of cardboard, due to the excellent behavior of this material and its acoustic qualities which give the assurance that the operation of the device will be very silent. The cardboard also has the advantage of having a substantial thickness E and of being flexible. We can then use these mechanical characteristics to immobilize the sheet by a simple wedging or pinching of the margins 6 and 7. This is obviously not the case with the metal which is rigid, thin, slippery and noisy when it vibrates or when it taps another metal piece.

Given the low weight and flexibility of the sheet, it is no longer necessary to provide fixing members. because we understand that a simple setting is sufficient to avoid vibrations, shocks and other small displacements and that there is practically no fear of noise during the operation of the device.

When the apparatus is in working order, the ionization chamber is formed by the sheet in the position of FIG. 3. The gas, which can be the air of premises for example, is sucked by the entry by means turbines and it is guided by deflectors at the entrance of the chamber, that is to say under the edge formed by the creasing line 5. It is thus pulsed in the electric field generated between the wire A and the conductive face of the sheet, namely the coating 3. The particles and dust are ionized and are plated on the coating 3 which retains them all the better as its surface is not very smooth. The purified air leaves the ionization chamber in the vicinity of the edge of the sheet formed by the creasing line 4 and leaves the device.

The sheet is continuously charged with dust when the device is operating and, after a certain period of time which can be a few days or a few weeks, the sheet is as "saturated", that is to say that the electric field becomes less intense because the conductivity of the coating 3 attenuates as and when the dust accumulates and the roughness offered to these dusts so that they cling to it dulls by filling the hollows.

According to the invention, the box of the apparatus is opened, the sheet is removed, it is replaced by another new taken from the stock and shaped as in FIG. 3.

The worn leaf is discarded.

The price of the new sheet is low enough and the intervention time is short enough that the repair operation is significantly less expensive than the cleaning that is currently required. In addition, the replacement of one sheet by another can be so simple that one can consider entrusting it to the user himself, thus avoiding the displacement of qualified personnel.

In FIG. 4, a variant is shown according to which the new sheet presented flat is integral with two lateral cheeks 10 and 11 determined by rectilinear creasing lines 12 and 13 substantially aligned with the free edges 14 and 15 of the sheet.

The shaping of this sheet is done by first folding the cheeks 10 and 11 along the creasing lines 12 and 13 inward, namely towards the face 2 carrying the coating 3, and then bending the whole sheet as shown in FIG. 5. To obtain the desired curve with simplicity, it is possible to give the cheeks 10 and 11 with curved edges 16 and 17 so that after folding the cheeks 10 and 11, the edges of the sheet are 'apply on the curved edge. It is easy to provide the interior of the box so that the shaped sheet can be placed and maintained there, including the cheeks 10 and 11, without using fixing means. Nevertheless, it is possible as a precaution to keep the cheeks 10 and 11 in the folded position for example by means of adhesive tape.

The margins 6 and 7 are also provided here, but by providing for the presence of cheeks, these can be combined with holding means which would make the creasing lines 4 and 5 and the margins 6 and 7 unnecessary.

It is noted that the cheeks 10 and 11 each have a notch respectively 18 and 19 which allows them to best adapt to the shape of the interior of the box and to the presence of elements such as deflector, turbines etc. in order to avoid leaks and pressure losses as much as possible.

Claims (6)

1- Purifier of gas, in particular air, of the type comprising a box provided with at least one inlet and at least one outlet and containing a profiled ionization chamber to ensure aerodynamic guidance of the gas flow from the inlet to outlet, characterized in that the ionization chamber is constituted at least partially by a sheet of cardboard or similar material stored flat and having to be placed in the box in a removable manner after folding and / or bending, the face (2) of this sheet which must be on the internal side of the ionization chamber being coated with a bare conductive material (3), such as aluminum not coated with an insulating product. 2- purifier according to claim 1, characterized in that the cardboard sheet having one side (1) smoother than the other (2), the conductive material (3) is placed on the less smooth side (2). 3- Purifier according to claim 1, characterized in that the coated sheet is marked with crease lines (4 and 5 - 12 and 13) according to which it must be folded and which determine specific parts (6 and 7 -10 and 11 ) must cooperate with elements of the box to be kept in shape at its place of function, while being interchangeable. 4- purifier according to claim 3, characterized in that the coated sheet is marked with two transverse rectilinear creasing lines (4 and 5) to promote the folding of the sheet outwardly along two margins (6 and 7), the sheet to be bent inward so that the conductive coating (3) is located on the concave face of the sheet when it is shaped. 5- purifier according to claim 3, characterized in that the coated sheet comprises a central part to be curved and integral with two lateral cheeks (10 and 11) delimited by two crease lines (12 and 13) substantially aligned with two edges (14 and 15) of the sheet, the cheeks (10 and 11) possibly indented to be folded in planes perpendicular to that of the sheet before bending. 6- Purifier according to claim 5, characterized in that each cheek (10-11) has a curved free edge (16-17) whose shape corresponds to the section that the sheet must have at this location after bending.

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