US2675920A

US2675920A - Filter cartridge with elastic rings

Info

Publication number: US2675920A
Application number: US226438A
Authority: US
Inventors: Muller Jacques
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-05-16
Filing date: 1951-05-15
Publication date: 1954-04-20
Anticipated expiration: 1971-04-20
Also published as: DE905970C; DE855394C; GB712841A; CH301790A; GB687705A; FR1017959A

Description

April 20, 1954 .1. MULLER FILTER CARTRIDGE WITH ELASTIC RINGS Filed May 15, 1951 /M W I l INVENTOR JACQUES MULLER I ATTORNEYS Patented Apr. 20, 1954 UNITEDv STATES PATENT OFFICE FILTER CARTRIDGE WITH ELASTIC RINGS Jacques Muller, La Garenne-Colombes, France Application May 15, 1951, Serial No. 226,438 Claims priority, application France May 16, 1950 3 Claims.

This invention relates to filter cartridges of the kind comprising a stack of filter discs in which the adjacent odd and even discs are clamped together in pairs successively and alternately at the outer and inner edges, between outer and inner perforated spacing rings. In other words, the first disc is clamped against the second disc at the outer edge between two outer rings, the second disc is clamped against the third disc at the inner edge between two inner rings, and the third disc is clamped against the fourth at the outer edge between two outer rings and so on. This arrangement, known per se, provides a succession of alternating outer and inner filter cells which communicate respectively through perforations in the spacing rings with a chamber surrounding the cartridge, and with an axial conduit in the cartridge. The outer and inner spacing rings are guided respectively by concentric perforated tubular casings which are substantially rigid. 7

The object of the invention is to improve the spacing rings in such a manner as to obtain a better clamping of the filter discs, improved sealing at their outer and inner edges, greater ease of maintenance, and facility for the rapid assembly of the discs without requiring skilled labor or special attention.

The invention will be better understood from the following description of a preferred embodiment, illustrated in the accompanying drawings in which:

Figure 1 is a vertical axial sectional view through the filter cartridge mounted in a casing;

Figure 2 is a diametric sectional view of an inner spacing ring;

Figure 3 is a similar view of an outer spacing ring; r and Figure 4 is a fragmentary diametric sectional View of a pair of spacing rings showing a modification of the shape of the elastic portion of the ring."

The filter cartridge is composed of a stack of annular filter discs I, 2, 3, 4, etc. for example of sheet metal, paper, other fiexible material, or any combination of these. The discs are aligned on a central perforated tube 5 which is preferably rigid. The stack is surrounded by a perforated tubular envelope 6 which preferably is also rigid. The envelope 6 is centered on the axis of the tube 5 by means of two slightly conical rigid annular discs or flanges i, 8 provided at the ends of the cartridge and which fit exactly in the annular space. Their shifting outwardly is prevented by the fact that they bear against the inturned edges of the envelope and the outturned edges of the tube. Thus, as has been stated above, the odd discs I, 3 etc. and the even discs 2, 4 etc. are clamped successively and alternately in pairs at their outer and inner edges between outer and inner spacing rings 9, H), H, [2 etc. The first or lowest outer ring 9 bears against the outer edge of the flange l. The inner edge of the first or lowest filter disc I is clamped between the flange 1 and the first or lowest inner ring it. This first disc I is clamped to the second disc 2 at the outer edge between the two consecutive outer rings 9 and i l, the second disc 2 is clamped to the third disc 3 at the inner edge between the consecutiv inner rings 10 and [2, the third disc 3 is clamped to the fourth disc A at the outer edge between the outer edge I I, and the following and so on. If the conicity of the fianges l, 8 is made such that the outer rings 9 and l l are spaced axially by one-half pitch relatively to the inner rings [0 and I2, it will be seen that there is formed a succession of outer and inner filter cells it, Hi, I5, 16 with the outer and inner cells alternating with each other. The cells are formed by the filter discs having a slightly conical shape and being placed alternately with their convex and concave faces opposite each other. Through the perforations in the rings 9, H and in the envelope 6, the outer cells l3, l5 communicate with the space surrounding the cartridge. By means of the perforations in the rings l0, l2 and in the tube 5, the inner cells M, It communicate with the central conduit of the cartridge. The latter is mounted in the usual manner between the plate I! and a base It of a cover member. Sealing between the outer space and the central channel is provided by gaskets I9, 20. v

For the spacing of the filter discs, there are employed according to the present invention, rings of elastic material of V cross section or preferably of U cross section, i. e. general channel shaped cross section, with diverging wings or flanges symmetrical relative to a perpendicular plane passing through the axis of the ring inter' mediate its ends as shown in Figures z'ande, These rings have on the outer face of their flanges a small peripheral fold or bead 2|, of the shape shown at Figure 2 or similar. The perforations ar formed in the cylindrical wall or in the base of its peripheral groove.

The wings or flanges of the inner rings are directed inwardly and those of the outer rings are directed outwardly with variation if necessary. The advantages of this construction are the fol lowing:

The assembly consisting of the stack of filtering discs and spacing rings is compressed in the axial direction for assembly and is held in this state by the flanges l, 8 which are themselves held at their outer edges at the ends of the envelope 6 and tube 5 by flaring the latter as shown. In the course of the axial compression, the elastic generally conical wings or flanges of each ring are caused to approach each other in such manner as to lie in a plane perpendicular to the axis of the cartridge, as shown in Figure 1. However, due to their elasticity they have a permanent tendency to separate one from the other and thus to maintain the clamping of the filter discs without it being necessary to provide any other means for this purpose. It is necessary to maintain a close contact between the edges of the discs of each pair to prevent direct passage of the liquid being filtered towards the interior or towards the exterior of the cells through leaks which might result from slight irregularities in the rings. The effects of any such irregulari ties are eliminated due to the elastic deformation of the wings. The folds or heads 2! con tribute of the sealing action by penetrating into the thickness of the filter discs.

It should also be noted that due to the axial compression of the cartridge and the flattening of the conical wings of the spacing rin s, the beads of each of these wings describes the arc of a circle, inwardly against the inner rings and outwardly against the outer rings, and having for center the angle of joining with the bottom of the groove of the ring. As a result, there is an increase in the diameter of the outer beads and a decrease in diameter of the inner beads. Referring to Figure 1, it is easy to understand the effect produced on the filter discs. The beads which may be considered as being hooked to the edges of the filter discs, exert on them the traction both towards the interior and towards the exterior whereby the discs are stretched. Therefore, it is not necessary to provide other stretching means nor to insert the filter discs between woven or perforated reinforcements adapted to prevent their excessive bending and their permanent deformation under the action of the pressure of the filter liquid.

In the form of invention shown in Figure 4, the wings have a greater radial dimension and have a somewhat corrugated effect which renders them more flexible and yet lightly grips the portions of the filter discs adjacent their peripheries. In other words, the fianges are provided with concentric grooves in their surfaces.

It will be understood that without departing from the principles of the invention, the rings may have a transverse section different from that shown in the drawing. The essential thing is that each spacing ring, made of elastic material, shall have diverging flattened wings symmetric with respect to a plane perpendicular to the axis of the ring and directed outwardly on the outer rings and inwardly on the inner rings so that any other system of assembly by screw thread means may be provided instead of the clamping.

I claim:

1. A filter cartridge comprising a stack of substantially conical alternately inverted filter discs contacting each other in pairs at their flat outer and inner peripheral margins, perforated spacing rings of channel shaped cross section made of yielding material inserted between the successive pairs of outer contacting margins of the filter discs, perforated spacing rings of channel shaped cross section made of yielding material inserted between the successive pairs of inner contacting margins of the filter discs, each spacing ring having two lateral diverging and yielding flanges symmetrical with respect to a plane at right angles to the axis of the ring and directed towards the exterior of the outer rings and towards the interior of the inner rings.

2. A filter cartridge comprising a stack of substantially conical alternately inverted filter discs contacting each other in pairs at their fiat outer and inner peripheral margins, perforated spacing rings of channel shaped cross section made of yielding material inserted between the successive pairs of outer contacting margins of the filter discs, perforated spacing rings 'of channel shaped cross section made of yielding mater'al inserted between the successive pairs of inner contacting margins of the filter discs, each spacing ring having two lateral diverging and yielding flanges with a lateral annular bead on the outer face thereof and symmetrical with respect to a plane at right angles to the axis of the ring and directed towards the exterior on the outer rings and towards the interior in the inner rings.

3. A filter cartridge comprising a stack of substantially conical alternately inverted filter discs contacting each other in pairs at their fiat outer and inner peripheral margins, perforated spacing rings of channel shaped cross section made of yielding material inserted between the successive pairs of outer contacting margins of the filter discs, perforated spacing rings of channel shaped cross section made of yielding material inserted between the successive pairs of inner contacting margins of the filter discs, each spacing ring having two lateral diverging and yielding, somewhat annularly corrugated flanges symmetrical with respect to a plane at right angles to the axis of the ring and directed towards the exterior on the outer rings and towards the interior in the inner rings.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,216,646 Mautz Oct. 1, 1940 2,372,865 Taylor Apr. 3, 1945 FOREIGN PATENTS Number Country Date 489,860 Great Britain Aug. 4, 1938 531,427 Great Britain Jan. 3, 1941 880,629 France Jan. 6, 1943