초록 ▼

A process of producing a multiple-layer filter medium comprising a porous support and a filtering layer formed on one of opposite surfaces of the porous support. The process includes the steps of: immersing the porous support in a liquid, to fill pores in the porous support with the liquid and there

A process of producing a multiple-layer filter medium comprising a porous support and a filtering layer formed on one of opposite surfaces of the porous support. The process includes the steps of: immersing the porous support in a liquid, to fill pores in the porous support with the liquid and thereby remove a gas from the pores; preparing a suspension containing particles to form the filtering layer; disposing the porous support such that the above-indicated one surface is exposed to a flow of the suspension, and partially defines a conduit through which the suspension flows; holding the other surface of the porous support under a first pressure lower than a second pressure acting on the above-indicated one surface, and effecting the flow of the suspension in contact with the above one surface for a predetermined time, to permit the particles in the flow to be deposited on the above one surface, thereby forming the filtering layer; draining the conduit of the suspension, and introducing into the conduit a gas having a third pressure higher than the first pressure, and to thereby remove aqueous components from the porous support and the filtering layer; and firing the porous support and the filtering layer.

대표청구항 ▼

A process of producing a multiple-layer filter medium comprising a porous support and a filtering layer formed on one surface of said porous support, comprising the steps of: providing a porous support having a plurality of pores filled with a gas; immersing said porous support in an aqueous liquid,

A process of producing a multiple-layer filter medium comprising a porous support and a filtering layer formed on one surface of said porous support, comprising the steps of: providing a porous support having a plurality of pores filled with a gas; immersing said porous support in an aqueous liquid, thereby filling said pores in said porous support with said aqueous liquid, so as to remove said gas from said pores; preparing a suspension containing particles of a ceramic powder for said filtering layer; disposing said porous support such that said one surface is exposed to a flow of said suspension, said one surface partially defining a conduit for the flow of said suspension; holding an opposite surface of said porous support under a first pressure lower than a second pressure acting on said one surface, and effecting said flow of said suspension in contact with said one surface for a predetermined time, to permit said particles to be deposited on said one surface and thereby form an unfired layer for said filtering layer; draining said conduit of the flow of said suspension, and introducing into said conduit a gas having a third pressure higher than said first pressure, and to thereby remove aqueous components from said porous support and said unfired layer of said particles; and firing said porous support and said unfired layer to produce the multiple-layer filter medium having said filtering layer.