FR2667021A1 - FILTER FOR PURIFYING AIR FROM AN AIR CHANNEL TO THE COCKPIT OF A MOTOR VEHICLE. - Google Patents

Abstract

The invention proposes a filter for purifying the air supplied by an air channel to the passenger compartment of a motor vehicle, the filter being preceded, on the incoming air side, by a metal grille which can be connected to an electric voltage pole. So that the filter which retains gaseous impurities in the air can be regenerated quickly before reaching its maximum absorption capacity, the filter (5) has at least one layer of activated carbon (12), and the grid ( 14) consists of a resistance wire which heats up greatly when an electrical voltage is applied, the heat thus produced being delivered to the passing air flow (A), and transmitted to the activated carbon layer ( 12), in a distributed fashion.

Description

Filter to purify the air supplied by an air channel to the passenger compartment of a

  motor vehicle The present invention relates to a filter for purifying the air supplied by an air channel to the passenger compartment of a motor vehicle, the filter being preceded, on the incoming air side, by a metal grid.

  which can be connected to an electrical voltage pole.

  Such a filter is known from the German patent application DE-A 63 764; it is made there in the form of a filter f in, which is

  preceded by a coarse filter and followed by a filter retaining the components

  toxic health The fine filter has, both on the incoming air side and on the outgoing air side, a grid fixing the filtering material, each grid being connected to a pole of an electrical voltage source, so

  benefit from an additional electrical separation effect.

  A filter retaining the toxic and odorous components of the air-

  does not present, like other filters separating pulp particles

  verulent, only a limited absorption capacity, and it must therefore be replaced or regenerated at given time intervals.

  object of the invention is to indicate a simple means for a filter to

  containing gaseous impurities from the air, the absorption capacity of which is at least partially exhausted, is quickly returned to a state of availability for absorption, with simple means and a low

  cost, so that the replacement time can be delayed.

  For a filter of the type mentioned in the introduction, the invention achieves this object by the fact that the filter has at least one layer of activated carbon, and the grid consists of a resistance wire,

  which can be placed at an electrical voltage and then warms strongly

  ment, and that the heat thus produced is delivered to the passing flow of a

  and transmitted to the layer of activated carbon, in a distributed manner.

  Admittedly, we already know from the German patent DE-C 35 17 105 that in order to separate toxic and odorous components from the air, we

  can use a filter with a charge of activated carbon, and

  heat the filter by electric heating elements in order to obtain better desorption; but the heating elements, consisting of individual heating bars, are embedded in the

  charge of activated carbon and rotate together with the rotary filter

  tif, so that the zone engagement of the heating elements,

  which are in the desorption flow, is difficult to configure

  which cannot be guaranteed that the layer of carbon

  active, preceding on the incoming air side the external heating elements

  laughs, will reach a temperature triggering a process of desor-

sufficient.

  According to an exemplary embodiment of the invention, the grid consists of a multiplicity of wires, which extend parallel to each other and which are mutually connected, at the two ends, by respective collecting wires provided with an electrical connection, of

  so that the surrounding layer of activated carbon, usually embedded

  placed in a non-woven mat, receives satisfactory support.

  But the grid can also be formed by a wire extending in

  meanders, both ends of which have an electrical connection

  trique This embodiment is distinguished by a warming

  particularly uniform layer of activated carbon.

  According to an additional configuration of the invention, the grid

  may constitute a wall delimiting the filter and, when replacing

  placement of the filter, be deposited together with the latter The filter is thus stabilized In this context, it is advantageous to make the electrical connections in the form of plug-in connectors or couplings, the electrical connection with the respective complementary element being effected then automatically when

installation of the filter.

  An economical arrangement, meeting the requirements, is obtained if the grid constitutes a wall delimiting the filter, which remains

  in the air channel when replacing the filter.

  The electric current for the heating of the grid can be provided by the battery or the alternator of the vehicle, and / or by an external source of electric current, the latter possibility

  of power supply being mainly used when the

  automobile vehicle is in a workshop to carry out

inspection work.

  According to a simple embodiment of the invention, the order

  the grid heating can be given by an or-

  switching gane which can be operated at will But the order

  the grid heating can also be given automatically

  matically at predetermined time intervals, preferably during stopping times of the motor vehicle In both triggering modes, it is expedient that the heating is only switched on for a fixed duration The predetermined time interval between two processes of reheating is preferably a function of the duration

  filter service; in embodiments with contour filter-

  level or swivel in the non-use position, it must be taken into account

  in determining the length of service for periods of non-use

use of the filter.

  So that the contamination of the passenger compartment remains low, the air leaving the filter is, at least during the period of heating of the grille, directed directly towards the outside, bypassing the passenger compartment. This can be obtained while preserving the air flow direction, by providing a valve which, when the flow towards the passenger compartment is isolated, releases an opening opening out through

  example in the engine compartment.

  The passenger compartment will also not be contaminated if we pass

  air through the filter, possibly with the support of a blower

  floating heating, against the prevailing air flow

  during adsorption operation This can be done without modifying

  specification of the air flow path if, during the desorption phase, the heating fan rotates with an opposite direction of rotation,

  The following description describes in more detail an example of realization

  tion of the invention using the accompanying drawings, in which:

  FIG. 1 is a greatly simplified side view of an arrangement

  heating sitive fitted with a filter binding the gaseous substances no

  cives and odorous, FIG. 2 represents a first example of embodiment of a grid configuration, and FIG. 3 represents a second configuration of grid, in

form of meanders.

  According to Figure 1, a motor vehicle 1 simply suggested is provided with a heating device 3 mounted in front of the passenger compartment 2 and which has, in addition to a heating heat exchanger 4, a filter 5 Of not shown, an evaporator could

  in addition to being planned, in order to obtain an air conditioning installation.

  When the motor vehicle 1 is used in an atmosphere free of harmful substances or poor in harmful substances, the outside air flows against the air flow designated by arrows "A" between the windshield 6 and the engine cover 7, towards an intake

  of air 8 retaining coarse impurities, which is followed by a separation

  water bypassing the filter 5, and with the possible support of a heating blower 10, the air reaches the heating heat exchanger 4, then divides and flows towards the passenger compartment 2 by of

  outlet openings 11 placed at different heights.

  When the motor vehicle 1 is used in an atmosphere rich in harmful substances, the air passes through the filter 5 which has, in order to adsorb the harmful components of the air, several layers of activated carbon 12 which are mounted one at a time. the rest of the others, in

  being for example fixed on a nonwoven In this context, the pas-

  operation wise with bypassing the filter during operation

  filtration can be caused by valves not shown, de-

  triggered by a sensor placed on the air inlet side.

  Since the adsorption capacity of the activated carbon layers 12 is exhausted after a certain time, it is necessary to interpose desorption phases at intervals, so as not to have to replace

  prematurely the filter 5 by leaving it from the air channel 13 from above.

  In order for the desorption process to proceed quickly, it

  it is necessary to reheat and sweep the layers of activated carbon

  tif In order to be able to supply the necessary heating energy, a grid 14, made up of a resistance wire, precedes the air side

  entering the first layer of activated carbon 12.

  According to FIG. 2, the grid 14 has a multiplicity of

  wires 15 extending parallel to each other, which are mutually re-

  linked at both ends by a respective collecting wire 16, each

  collecting wire 16 being provided with an electrical connection 17 The fi

  gure 3 represents another embodiment of the grid 14 A wire 18, the two ends of which 19 each have a connection

  electric 17, has a meandering shape.

  Figure 1 shows that a line 20 leaves each connection 17 and leads to a switching device 21, which is supplied by the

  on-board network via a battery 22 or an alterna-

  tor 23 of the vehicle In a manner not shown, it is also possible, for example during an intervention in the workshop and in order to save the battery 22 of the vehicle, to bring current from the outside when carrying out 'a desorption process So

  to activate the heating current of the grid 14, we can action-

  ner a switching device 24 placed in a favorable place in the passenger compartment It is however better that the desorption process takes place automatically, and is triggered by a device suggested in 25 Reheating, of limited duration, s advantageously performs during downtime of the motor vehicle 1, or during use in an atmosphere free of harmful substances or poor in harmful substances The air flowing on the grid 14 heats up and delivers heat to the layers activated carbon 12,

  so that the desorption process takes place in an accelerated

  The air which leaves the filter 5 during the regeneration phase is directed towards the outside atmosphere in order to avoid contaminating the passenger compartment 2, which can be obtained, in a manner not shown, by an appropriate channeled guide. and a simultaneous closure of the outlet openings 11 The same effect is obtained at a lower cost by reversing the direction of rotation of the heating fan 10 during the desorption operation, so that the air flow follows the suggested pattern by the arrows "A" Compared to the possibility cited first, the grid 14 is then not disposed on the side of the filter 5 which is turned towards the air intake 8, but

on the opposite side of the filter 5.

Claims (8)

  1 Filter to purify the air supplied by an air channel to the passenger compartment of a motor vehicle, the filter being preceded, on the incoming air side, by a metal grid which can be connected to a voltage pole electric, characterized in that the filter (5) has at least one layer of activated carbon (12), and the grid (14) consists of a resistance wire, which can be placed at an electric voltage and then heats up strongly, and in that the heat thus produced is delivered to the passing air flow (A), and transmitted to the layer of   activated carbon (12), distributed.   2 Filter according to claim 1, characterized in that the grid (14) consists of a multiplicity of wires (15), which extend parallel to each other and which are mutually connected, at both ends, by respective collecting wires. (16) equipped   an electrical connection (17).   3 Filter according to claim 1, characterized in that the grid (14) is formed by a wire (18) extending meanders, of which   the two ends (19) have an electrical connection (17).   4 Filter according to any one of the preceding claims,   characterized in that the grid (14) constitutes a boundary wall   tion of the filter (5) and, when replacing the filter (5), is removed together with the latter.   Filter according to any one of the preceding claims,   characterized in that the grid (14) constitutes a boundary wall   tion of the filter (5), which remains in the air channel (13) when replacing filter cement (5).   6 Filter according to any one of the preceding claims,   characterized in that the electric current for heating the grid (14) is supplied by the battery (22) or the alternator (23)   of the vehicle, and / or by an external source of electric current.   7 Filter according to any one of the preceding claims,   characterized in that the order for switching on the heating of the grid (14) is given by a switching member (24) which can be operated at will.   8 Filter according to any one of the preceding claims,   characterized in that the order in which the heating of the   grid (14) is automatically given at pre-   determined, preferably during downtime of the motor vehicle mobile (1).   9 Filter according to claim 7 or 8, characterized in that at least during the heating period of the grid (14), the air leaving the filter (5) is directed directly outwards, bypassing the passenger compartment (2).   Filter according to claim 9, characterized in that   passes air through the filter (5), possibly with the support   from a heating blower (10), against flow   air prevailing during adsorption operation.