Abstract: In accordance with this invention, an improved filter resembling an envelope is disclosed. The filter envelope for the filter frame element includes an enclosure, the enclosure being constructed from planar first and second filter paper members lying atop one another. The first and second filter paper members each have a lateral, medial, base, and top sides, the lateral, medial, and base sides being connected to each other, respectively, to define the enclosure. The top side of the first member is not connected to the top side of the second member so as to define an opening in the enclosure to receive the frame. A closure is formed from a planar third filter paper member which is connected to a portion of the enclosure being proximate to the opening. The third filter paper member is movable between a first position and a second position, the second position being suited to close the opening.

Abstract: A filter holder assembly for use with an oil filtering pan in a food fryer filtration system to filter a contaminated cooking oil is provided with an adjustable sealing ring so as to accommodate filters of different thicknesses such as filter pads and filter paper. In one self-adjusting embodiment, the sealing ring is configured for vertical movement by way of a pair of pins operatively connected to the sealing ring and that are movable vertically within a corresponding pair of slotted hinge members. When a filter pad is used with this embodiment, the pins are urged against the hinge members such that pressure is applied to the sealing ring to form a positive seal. Alternative embodiments create a positive seal when either a filter pad or filter paper is used.