FR2527095A1 - Filter box for receiving filters - which can be readily subjected to standard inspection tests - Google Patents

Abstract

Box is claimed for receiving filters for materials in suspension and air guiding units which can be inspected at any time without interrupting service, as desired, with a testing fog for the "oil wire test" and a device for examining the seals of the filter mounting, checking for losses, or measuring pressure difference across the plane of the filter. The inspection groove for seal testing, in the form of a slot which is found in the filter box is formed by a fold in the shape of an angle and a U-shape, in the upper part of the box, and by a U-shaped frame placed and fixed directly above, closed all round, having flanges folded at right angles downwards. On the top is a U profile carrying a box for air input e.g. of triangular section with a tube entering the box at the side and a stop valve operated by hand or closing automatically. The inspection devices are arranged so that tests on the filter box can be simplified so that expensive alternatives presently used are made superfluous.

Description

 The invention relates to a new type of box for air filters, intended to receive filters for suspended particles and air guiding units and which can be controlled at any time, without interruption of service, as desired, with a test mist for the so-called "oil thread" test which consists in subjecting the box to an oil mist, a white wire coming out on the other side if the seal is not perfect and a device for checking the tightness of the filter assembly for checking for leaks, or regarding its state in terms of pressure difference.

 The filter housings corresponding to this preamble are well known and widely used, for example, in operating theaters, in hospital premises or in premises where the requirements relating to air purity or absence. germs are high.

 It is already known that, in order to fulfill the condition relating to the possibility of constant monitoring of filter housings in such areas of use, some of which are of a critical nature, control measures can be carried out during service. filters mounted in these boxes. This is to ensure that any bacterial contamination does not spread through free passages in the air filter or in the sealing elements, thus contaminating the premises.

 This is why the filter housings have control grooves which go around it and which apply tightly to the seals of the filter elements. These control grooves of the tightness checking device are passed from time to time in pressurized air to determine, using a pressure gauge, whether the drop in pressure in the system is due to a possible leak. . If the seals are not damaged, such a leak can be remedied by tightening the clamping device.

For safety reasons, before using
These types of premises, the filter elements are subjected to a clearly visible control mist, to see if
somewhere distinguishes from the halftones of smoke that come out of the filtering medium. Leaks thus detected in the filter medium are closed immediately at the place of use, or, if the damage is significant, the filters are changed on site. If the filter meets such an oiled wire test, it is in good condition and can continue to be used. In general, there are such test devices in the filter housings on the filter boxes outside.

 The object of the invention is to place control and testing devices of this kind on a filter housing already described, and to simplify them to such an extent that the currently usual expensive solutions become superfluous.

 This object is achieved, according to the invention, all on board thanks to the fact that the control groove in the form of a slot serving to check the tightness, inside the filter box, which it goes around, is formed by an angle-shaped and U-shaped folding in the upper part of the box, and by a U-shaped frame, with wings folded perpendicularly downwards, formed over its entire perimeter and placed directly above it. On the upper face of this ep U frame is placed and fixed an air inlet box, for example analogous to a triangle, which has a protruding lateral tube and a shut-off valve ac tioflné by hand or with closure automatic.

 According to another embodiment of the invention, the filter housing is provided, at the control groove in the form of a slit, from the outside, with a bent control tube, sealed, which passes through to at the slot of the control groove, the two vertical wings of the folded part of the upper U-shaped part of the box, while, in the U-shaped frame placed above, a tube for introducing the blast test mist is brought in from the outside. This tube has, either for the introduction of the test fog itself, or, for the test, as a variant, by means of a different pressure gauge, ii of suitable dimensions, with connections which can be closed. this tube acts, during the considered measurement of the pressure conditions, in combination with a bent pressure control tube which is located at the bottom of the box and which opens out inside the filter box.

 Another exemplary embodiment of the invention is characterized in that the filter box is alternatively equipped with a box-shaped cover added on top and with a bent connection pipe which joins it. Its downwardly folding inner lower wings form, together with the U-shaped folded part of the filter housing, a leak-tightness control groove that goes around it, while, if the cover added on top is removed, the U-shaped wing of the inner filter box making the folded turn downwards always constitutes a bearing edge for the seal of the filter elements.

 Finally, it is also important, for the invention, that all the control tubes intended for the test mist or the leakage test, or for the differential pressure measurement, be housed, as well as the control rod. shut-off valve, in a sealed control box, placed separately on the side of the filter box or open from above into a U-shaped projection on one side of the filter box, projection formed directly by folding.

 According to another embodiment, the invention also consists in that the fixing of the four elastic clamping devices placed in the corners and the four fixing screws of the air guide units are supported by a frame in angles or in U-profiles which can be offset horizontally and which are either installed without fixing or can be folded down on one side, articulated in the form of a hinge, or in each case by a plug-in U-section, with two or four screws for each, while the filter element is also supported, when the filter is removed, by a leaf spring locking system screwed on both sides.

Embodiments will now be described, given by way of example, in no way limiting, with reference to the appended drawing in which;
Fig 1 is an elevational view of a prepier embodiment of a box for a filter according to the invention, of which
Fig 2 is an end view,
Fig 3 is an elevational view of a variant,
Fig 4 is a very schematic side view of fig 3.

 Figure 1 shows a filter housing.

By the superimposed mounting of a U-shaped frame and an air intake box used to receive filters for suspended matter and air guiding grids, it constitutes a complete filtering unit, which can be controlled during the service with means of control.

 the formation of the slot in the control groove 2, for checking the tightness of the seal of the filter element fitted, is done by itself thanks to the flap 3 in U turned inwards , in the upper part of the box for filter 4, and thanks to the U-shaped frame 5 placed on the box, with the wing 6 folded down, both being arranged suspended, parallel to each other, with a slit difference of about 2 to 2.5mm.

 On the filter box 1 and on the U-shaped frame 5, a separate air inlet box 8, for example, triangular, is fixed on the upper face 7 of the profile. It is provided with a lateral air intake pipe 9 which can be closed either by a rotary valve which can be closed or by a stop valve 10 controlled by hand or which can be opened or closed automatically for the when a control mist is blown into the filter element. This device can also be used to regulate the air flow.

 FIG. 1 shows, moreover, that the box 1 for the filter is provided, for supplying air to the groove 2 for checking the tightness, with a control tube 11, coming from the outside, bent and made waterproof, which crosses the two wings 12 in v of the upper flap 3 of the box up to the opening 2 of the slot. This tube is closed, entry side, by an instant closure 14.

 A pipe 13 for supplying air blowing from the outside passes through the 5-in-U frame placed on the box.

After the paraffin oil mist has been introduced by blowing, this pipe can be closed, at the bottom, by an instant closure 14.

 In addition, the lower box 15 of the filter is provided, below the filter element 21, with a control tube 16 of bent differential pressure. Combined with the upper supply air supply pipe 13 for the control mist, this tube 16 can also be used to measure the differential pressure on the filter element.

 FIG. 2 shows a side view of the filter box 1 with the air inlet cover 8, for example triangular, with the shut-off valve or throttle valve 10 in the pipe 9 and the linkage d actuation 22 as well as the control tubes 11, 13 and 16 which penetrate into the separate box 24.

 Figure 3 shows a variant of the filter box of Figure 1. In this case, the box 1 for filter is also provided, at its upper part, with a flap 3 and 6 in U, the wing 6 directed towards the bottom, which goes around, constituting the direct bearing edge for the seal of the filter element 20, as for the box 1 of FIG. 1.

 In FIG. 3, unlike what happens for the embodiment of FIG. 1, the air intake cover 17, which is not triangular but in the form of a box, constitutes with the sheet metal edge 19 directed downwards with the edge 2 of the filter housing 1, the slot in the control groove which goes around; the bearing surface 3 which goes around constitutes at the same time the connection surface between the cover 17 and the box 1. These two elements can be fixed to each other by screws, by # riveting or by spot welding. Additional pouring with liquid steel which solidifies can give the proper seal.

 In FIG. 3, we can also see on the face 26 of the box, a projection 25 in a U shape. It is used to house monitoring and execution devices for the described control process and for the passage of the control tubes 11, 13 and 16 as well as of the draw rod 22 with adjusting nut, which is used to actuate the shut-off valve. oblique 23 in the part 18 with flange tubing routed to the casing 1 by folding.

 In FIG. 3, another detail of the drawn representation is characterized in that the fixing of the four clamping devices 27 placed in the corners and the fixing screws 28 of the air guide units 29 are supported by a frame 30 in U-shaped angle bars which can be offset horizontally, which is xis in place without fixing or can be folded down on one side, articulated in the manner of a hinge, or each by a plug-in section 30 in U with, in each case, two or four screws, while the filter element 21 is also supported by a locking device 31 with leaf springs placed on two sides, which supports it when this filter element 21 must be replaced during maintenance.

 Figure 4 is a simple side view of Figure 3, which is used to make the representation geometrically clearer.

 The advantage of the present invention lies essentially in the fact that there are considerable variations from the prior art, in order to be able to constantly monitor the filter element placed in the filter box, before or during the service.

Claims (5)

REVEIYD # CATIONS  1. Housing (1) for filter intended to receive filters for suspended matter and air guiding units (29), which can be controlled at any time without interruption of service, as desired, with a mist of es  said Bai pour test / tu fildhuile "and a device for checking the tightness of the filter assembly, for checking relating to leaks, or as regards its state in terms of pressure difference, characterized in that the test groove (2) for sealing, in the form of a slit, which is located in the box (1) of filtra geetaifat the tower, is formed by a bend (3) in the form of an angle and a U in the upper part (4) of the box and by a U-shaped frame (5), placed and fixed directly above, closed all around, having wings (6) bent at right angles downwards, on the top (7) of the profile in U of which an air inlet box (8), for example analogous to a triangle, is placed and fixed and which has a lateral tube (9) which protrudes and a shut-off valve (10) actuated by hand or self-closing.  2. Air filter housing according to claim 1, characterized in that the housing (1) is provided, at the control groove (2) in the form of a slot, from the outside, with a control pipe (iî ) bent and sealed, which crosses the two vertical wings (12) of the folded part (3) in a U from the upper part of the box to the slot (2), while a tube (13) for introduction blowing test mist is introduced from outside into the U-shaped frame (5) placed on the top, a tube which,  either for the actual introduction of the fog of  test, either for the alternative test procedure, using  a differential pressure gauge, is of appropriate dimensions  and has closable connections (14), which  tube (13) acting, if necessary, during the measurement  temporary pressure conditions, in combination with  a bent pressure control tube (16) which is  ve in the lower part of the box (15) and which opens inside the box (1).  3. Box for air filter according to one of claims 1 and 2, characterized in that the box (1) is provided in a variant with a cover (17) in the form of a box placed above and a tube ( 18) of connection which joins it by bending, of which the inner lower wings (19) formed by folding, directed downwards form, at the same time as the folded part (3) in U of the box (1), a groove (a ) tightness control which goes around, while, if the upper cover (175 is removed, the inner wing (6) in U folded down, and which goes around, always constitutes in all case a bearing edge (20) for the seal of the filter elements (21).  4. Air filter box according to one of claims 1 to 3, characterized in that all the control tubes (11, 13, 16) used for the introduction of the control mist or for the leak test , or else the differential pressure e ~ sure, are housed, as well as the actuating bar (22) of the shut-off valve (23), in a sealed control box (24), arranged separately on the side of the box (1) or open from above into a U-shaped projection (25) on one face (26) of the box.  5. Housing for air filter according to one of rew vendications 1 to 4, characterized in that the fixing of the four elastic clamping devices (27) placed in the corners and the four fixing screws (28) of the guide units air (29) are supported by a frame (30), in angles or in U-profiles, which can be horizontally offset and which is either put in place without fixing, or can be folded on one side and articulated in the manner of a hinge, or each by a plug-in U-shaped section (30) having in each case two or four screws, while the filter element (21) is also supported, when the filter is removed, by a locking system (31) with leaf springs screwed to the side.