US2068511A - Filter - Google Patents

Description

Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE FILTER Application July 15, 1935, Serial No. 31,361

2 Claims.

This invention relates to improvements in filters and more particularly to means for assuring proper drainage for vacuum filter chambers or compartments.

In rotary vacuum filters it is the general practice to provide at the periphery of the drum a plurality of compartments or chambers having fluid tight bottoms and sides, except for drainage outlets, an openwork backing sheet or wire stretched over the tops of the compartments, and filter cloth over said backing wire. If the backing wire be forced down too close to the bottom of a suction compartment, the drainage through this compartment will be interfered with or destroyed, and the efiiciency of the filter will be impaired accordingly. For avoidance of such interference with drainage, use has heretofore been made of drainage devices, usually of wire, that are placed in said compartments to support the backing wire. Such drainage devices in prior use have, however, been comparatively easily crushed or deformed, for example by the dropping of a tool thereon or in the event of the stepping thereon by a person engaged in repairing the filter.

The principal object of the present invention is to provide novel and advantageous drainage devices which will be free of the aforesaid defects. In preferred embodiments of the invention, such drainage devices are made of relatively thin plates of corrosion-resisting metal formed, as by stamping, with raised portions to support the backing wires or sheets, and with perforations adapted to provide free drainage through the compartments. Preferably the raised portions of the drainage plates are provided by corrugating the plates, and the perforations are so arranged as to provide drainage passages not only through the tops of the ridges and bottoms of the intervening valleys or depressions, but also at points intermediate said tops and bottoms.

One great advantage of the drainage devices of the present invention is that they are strong enough to stand any ordinary rough usage without substantial damage.

Other objects, features and advantages will appear upon consideration of the following description and of the drawing, in which Fig. 1 is a fragmentary elevational view of a rotary suction filter drum embodying the present invention, parts being broken away to show the underlying structure;

Fig. 2 is a section taken along the line 2-2 of Fig. 1;

Fig. 3 is a perspective view on a larger scale of the drainage plate illustrated in Figs. 1 and 2;

Fig. 4 is a plan view of a second form of drainage plate;

Fig. 5 is a section on the line 55 of Fig. 4; and 5 Fig. 6 is a plan view of a third form of drainage plate.

Referring to Figs. 1 and 2, the reference character I0 designates a rotary suction filter drum having a peripheral wall H, preferably of cylin- 10 drical form, ends I2 of such diameter as to extend outwardly beyond the cylindrical wall I], and dams or partitions 13 extending from either head l2 to the other thereby dividing the channel between the heads into a series of com- 15 partments.

Extending over the tops of the partitions l3 and from end to end of the drum, is a foraminous backing sheet, or backing wire, l4 and outside of the backing wire is a filter cloth I5 which 20 may be of wire, cotton or any other suitable material. Preferably the arrangement is such that, although extending outside of the partitions l3 and of the backing wire [4, the filter cloth 15 does not project above the channel walls formed 25 by the drum ends I2. At the bottom of each of the compartments, the cylindrical wall of the drum I0 is provided with one or more openings or outlets 15a connected with a suitable vacuum producing means by means of pipes 15b. 30

Installed in each compartment between adjacent partitions I3 is a drainage plate 16, preferably of corrosion resisting material such as bronze, constituting an embodiment of the present invention. This drainage plate I6 is cor- 35 rugated, each of the ridges ll being formed with a relatively long and straight incline at one side and a shorter, steeper and. substantially straight incline at the other side, and the valleys or depressions l8 being narrow at their bottoms. 40 The perforations IS in the drainage plate may be of any suitable shape and size, but as illustrated in Fig. 3 each perforation is in the form of an elongated slot starting near the bottom of the long inclined side of one ridge I1, and extending 45 to the bottom of such long side, up the short side of the next ridge and partially down the long side of said next ridge. It will be evident that this form of drainage plate will not interfere to any substantial extent with the drainage and at the 50 same time will resist very strongly any force tending to deform it. Each drainage plate l6 may be secured in'- place in any suitable manner as by means of screws threaded into the cylindrical Wall. 55

The second form of drainage plate [6a, illustrated in Figs. 4 and 5, is very similar to the drainage plate l6 of Fig. 3 but has rounded ridges Ila and rounded depressions 18a and the slots or perforations [9a. are rounded at their ends In Fig. 6, there is illustrated a third form of drainage plate lBb which difiers principally from the other forms of plates by the shape of its perforations l9b which are round and arranged in sets of three rows, one row in a depression or valley and the other two rows on an adjacent ridge.

Although, as illustrated, the bottoms of all the compartments are parts of a cylindrical casing and the drainage plates are curved accordingly, it should be understood that the bottoms of the compartments may be of other shapes and the drainage plates may be changed accordingly. Also the present invention may as well be applied to a filter in which the liquid to be filtered is introduced to the interior of the drum, as to the illustrated form of drum which is designed to be partially submerged.

It should be understood that various changes may be made and that certain features may be used without others without departing from the true scope and spirit of the invention.

Having thus described my invention, I claim:

1. In a vacuum filter comprising an open top compartment having vacuum connections and filtering means stretched across the top of said compartment, a drainage plate in said compartment supporting said filtering means, said drainage plate having corrugations providing alternate ridges and valleys and elongated slots each starting on one side of one of said ridges and extending over the crest of the ridge, down the other side thereof to the bottom of the next valley and part of the way up the side of the next ridge.

2. In a vacuum filter comprising an open top compartment having vacuum connections and filtering means stretched across the top of said compartment, a drainage plate in said compart ment supporting said filtering means, said drainage plate having corrugations providing valleys and intervening ridges each formed with a relatively long straight incline at one side and a steeper relatively short straight incline at the other side of the ridge, said drainage plate also having slots each beginning at a point part way up the long incline at one side of a ridge and extending over the top of the ridge, down the short incline of this ridge to the bottom thereof and part way up the long incline of the next ridge.

WILLIAM RAISCH.

Images