Filter plate and frame and method of making

#The present invention relates to a wrought single piece weld-free filter element, such as an inlet frame or an outlet plate. The plate or frame is hollow in the middle and is contiguous around its perimeter. Advantageously, the filter elements may be mounted in a filter press assembly at an angle to increase drainage.

#A horizontal-type filter press is known, for example, from U.S. Pat. No. 4,737,285 to Krulitsch et al, herein incorporated in its entirety by reference. In this patent, a horizontal-type filter press is disclosed which includes a plurality of filter elements supported on cross beams between a head and press cover. Filter aids disposed between the filter elements are moved by the filter press closing mechanism to seal the press edges located at each of the filter elements.

#Filter presses of this type are known for clarifying filtration, sterilizing filtration, or residue filtration of liquids. These types of filter presses are used in the chemical industry, pharmaceutical industry, beverage industries and other industrial applications.

#FIG. 1 is a plan view of a known inlet frame or outlet plate for a filter press assembly, having been manufactured by welding together four triangular pieces and four straight pieces and subsequently attaching two laterally extending ears by welding.

#FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1.

#FIG. 3 is a schematic illustration of the method of the present invention used for forming a plurality of filter elements from a plate or billet of metal or alloy by use of laser or water-jet technology, for example.

#In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

#FIGS. 1 and 2 are illustrative of prior art filter elements 20 such as an inlet frame or an outlet plate which make up the alternating components between a fixed head and a movable head of a filter press assembly. Traditionally, the filter element 20 was formed by interconnecting four triangular shaped sections 22a, 22b, 22c and 22d with four bar stock sections 24a, 24b, 24c and 24d by a series of welds 26. The support ears 28a, 28b are also welded to bar sections 24b, 24d, respectively, by welds 30.

#The use of filter presses in certain industries, such as the pharmaceutical industry for example, requires sterilization of component parts. As expected, a filter element as shown in FIG. 1, includes many pits and voids, particularly, at the welds 26. Therefore, to comply with the requirements of the pharmaceutical industry, extensive finishing of the frame element 20 is required.