A reverse osmosis filtering module includes: a purified water discharge pipe in which a purified water discharge path is formed, and which has a communication hole that is formed on an outer periphery thereof and communicates with the purified water discharge path; a reverse osmosis filtering part including a reverse osmosis filtering member in which a purified water flow space is formed, and which is wound around the purified water discharge pipe such that the purified water flow space communicates with the communication hole; a first flow channel formation cap provided at one side and having an inlet hole; and a second flow channel formation cap provided at the other side of the reverse osmosis filtering part and having an outlet hole.

The present invention provides a hollow fiber membrane module that can effectively resolve the accumulation of suspended solids within the membrane module, lower running costs, and also operate stably. The present invention relates to a hollow fiber membrane molecule provided with: a cylindrical case having a first end and a second end in the direction of height; a plurality of hollow fiber membranes accommodated within the cylindrical case; and a first potting part accommodated within the cylindrical case and attaching the plurality of hollow fiber membranes together such that the end parts of the plurality of hollow membrane fibers at a first end side of the cylindrical case are open. The hollow fiber membranes are porous hollow fiber membranes having a breaking strength of 23 MPa, and the hollow membrane module has a membrane area per unit volume of 800-3700 m.sup.2/m.sup.3. The filling fraction for the hollow fiber membranes in a cross-section orthogonal to the direction of height of the cylindrical case is 25-38%.

Raw liquid is fed along a raw liquid and drain liquid mixing line to a liquid purification device. Drain liquid is fed along a recirculation line to be mixed with raw liquid. After a set period of time, the liquid purification process is interrupted to flush the liquid purification device by a liquid to remove contaminants built up on the inside surface of the liquid purification device. Downstream of the liquid purification device, the liquid is discharged at high speed into a drain. Prior to flushing, the purification process is interrupted at least once for a time sufficient to enable disruption of a polarized layer of contaminants. A mixture of raw liquid and drain liquid is used as the liquid medium for flushing such that less raw liquid is used for flushing and the service life of the water purification device increases.

A water purifier and a filter for the water purifier are provided. The water purifier includes a raw water flow path formed to bring in raw water from the outside, a purified water flow path connected to the raw water flow path for the raw water to flow in a first direction, a filter located in the purified water flow path to filter the raw water, a bypass flow path branched from the purified water flow path for the raw water to bypass the filter and connected to the purified water flow path on a downstream side of the filter in the first direction, a washing flow path branched from the bypass flow path and connected to the purified water flow path on a downstream side of the filter in the first direction, and a drain flow path connected to the filter to guide the raw water flowing into the filter to a second direction. The filter includes a raw water inlet through which raw water flowing in the first direction is introduced, a purified water outlet through which purified water filtered is released, and a drain outlet through which wash water having washed the filter is discharged.

A novel multi-stage reverse osmosis system is proposed that allows for following benefits a) reduction in pressure-loss while achieving optimum cross-flow velocities and therefore reducing energy consumption of 4-10%; b) increased flux balance between stages resulting in reduced fouling of the first stage; c) disruption of scale forming conditions resulting in reduced scaling of the last stage; d) reduction in scale potential of the concentrate valve; e) reduction in downtime for CIP by proactively disrupting scaling or fouling through several innovative methods; f) ease-of and effectiveness-of CIP with reduced number of valves and g) to keep system operational via isolation of the last stage for maintenance while the keeping remaining system in production mode. All the above improvements are achieved with process-flow and operational characteristics defined in the Specifications and Claims.

A reverse osmosis filtering module includes: a purified water discharge pipe in which a purified water discharge path is formed, and which has a communication hole that is formed on an outer periphery thereof and communicates with the purified water discharge path; a reverse osmosis filtering part including a reverse osmosis filtering member in which a purified water flow space is formed, and which is wound around the purified water discharge pipe such that the purified water flow space communicates with the communication hole; a first flow channel formation cap provided at one side and having an inlet hole; and a second flow channel formation cap provided at the other side of the reverse osmosis filtering part and having an outlet hole.

A water treatment system is provided. The system includes a prefiltration unit for filtering the untreated water in fluid communication with a source of untreated water. The prefiltration unit produces a prefiltered water from the untreated water. A pump in fluid communication with the prefiltration unit can selectively increase the flow rate of the prefiltered water in a first line, the first line in fluid communication with a membrane element. The membrane element produces a permeate and a retentate from the prefiltered water, the permeate being imparted with a lower concentration of solutes than the retentate. A tank in fluid communication with the membrane element and the prefiltration unit stores prefiltered water from the prefiltration unit and the permeate from the membrane element. One or more valves regulate the flow of prefiltered water and the permeate, and one or more sensors can measure characteristics of the prefiltered water.

A tangential filtration device, particularly for fluid food products, includes a tangential filter arranged essentially vertically and provided with a plurality of filtering membranes having a longitudinal extension and arranged essentially vertically, an inlet for the product to be filtered, an outlet for the retentate and an outlet for the permeate. The inlet for the product to be filtered is disposed at the lower portion of the tangential filter so that the filtering membranes are longitudinally crossed, from the bottom upwards, by the product to be processed. The device further includes a pump, a cleaning apparatus, and a collection area.

The present invention provides a hollow fiber membrane module that can effectively resolve the accumulation of suspended solids within the membrane module, lower running costs, and also operate stably. The present invention relates to a hollow fiber membrane molecule provided with: a cylindrical case having a first end and a second end in the direction of height; a plurality of hollow fiber membranes accommodated within the cylindrical case; and a first potting part accommodated within the cylindrical case and attaching the plurality of hollow fiber membranes together such that the end parts of the plurality of hollow membrane fibers at a first end side of the cylindrical case are open. The hollow fiber membranes are porous hollow fiber membranes having a breaking strength of 23 MPa, and the hollow membrane module has a membrane area per unit volume of 800-3700 m.sup.2/m.sup.3. The filling fraction for the hollow fiber membranes in a cross-section orthogonal to the direction of height of the cylindrical case is 25-38%.

There is provided a method for cleaning a ceramic filter which can shorten an operation time required to clean the ceramic filter. The method for cleaning the ceramic filter includes: reducing a pressure of a space on a secondary side of the uncleaned ceramic filter, while supplying a cleaning medium to a space on a primary side of the uncleaned ceramic filter, thereby passing the cleaning medium through the ceramic uncleaned filter, so that the uncleaned ceramic filter is cleaned.