초록 ▼

A method for softening a fluid containing hardness constituents, comprising the steps of: (a) mixing the fluid with sufficient amounts of a softening agent, and previously precipitated hardness constituents in a reactor to establish a softening reaction in the reactor for precipitating a substantial

A method for softening a fluid containing hardness constituents, comprising the steps of: (a) mixing the fluid with sufficient amounts of a softening agent, and previously precipitated hardness constituents in a reactor to establish a softening reaction in the reactor for precipitating a substantial portion of the hardness constituents contained in the fluid; (b) removing a portion of the fluid and precipitated hardness constituents from the reactor as a slurry and filtering the slurry through a cross-flow microfiltration module containing at least one elongated filtration tube, whereby substantially all of the precipitated hardness constituents are removed from the portion of the fluid exiting from the module as filtrate; and (c) returning at least a portion of the filtered out precipitated hardness constiuents exiting from the module to the reactor as the previously precipitated hardness constituents.

대표청구항 ▼

A method for softening an aqueous fluid containing harness constituents, comprising the steps of: (a) mixing the fluid with sufficient amounts of a lime-containing softening agent and previously precipitated hardness constituents including, calcium carbonate in a reactor to establish a lime softenin

A method for softening an aqueous fluid containing harness constituents, comprising the steps of: (a) mixing the fluid with sufficient amounts of a lime-containing softening agent and previously precipitated hardness constituents including, calcium carbonate in a reactor to establish a lime softening reaction in the reactor for precipitating a substantial portion of the hardness constituents including calcium carbonate contained in the fluid; (b) prior to any substantial settling of the precipitated harness constituents, removing a portion of the fluid and precipitated hardness constituents from the reactor as a slurry having a concentration of at least about 1%, by weight, of said precipitated hardness constituents, and filtering the slurry through at least one cross-flow microfiltration module containing at least one elongated microporous thermoplastic filtration tube, said tube having a pore size of from about 1 micron to about 10 microns and a filter cake of said precipitated hardness constituents at the inner wall thereof, whereby substantially all of the precipitated hardness constituents are removed from the portion of the fluid exiting from the module as filtrate; and (c) returning at least a portion of the filtered out precipitated hardness constituents exiting from the module as a slurry to the reactor as the previously precipitated hardness constituents.