Filtration apparatus and filter washing method therefor

A filtration apparatus comprising:

• a casing that is partitioned into a fluid inflow chamber including a first port, through which a target fluid flows in from the outside, and a filtration chamber configured to filter the target fluid and including a second port through which a filtered fluid after filtration flows out to the outside;
• a filter element arranged in the filtration chamber and formed in a cylindrical shape with one end and another end to filter the target fluid guided from the fluid inflow chamber, which is connected to communicate with the one end, in such a manner that the target fluid passes in a direction from an inner circumferential surface toward an outer circumferential surface, and to block an outflow of the target fluid from the other end toward the second port;
• a backwashing mechanism that performs backwashing by drawing the filtered fluid in a direction from the outer circumferential surface toward the inner circumferential surface of the filter element;
• a high-pressure washing mechanism that performs high-pressure washing by injecting a high-pressure fluid so as to pass through the filter element in the direction from the inner circumferential surface toward the outer circumferential surface of the filter element;
• a rotary drive mechanism that includes, attached thereto, the backwashing mechanism and the high-pressure washing mechanism and rotates the backwashing mechanism and the high-pressure washing mechanism around an axial line of the filter element in an internal space of the filter element communicating with the fluid inflow chamber;
• a first discharge path that communicates with the internal space through the other end of the filter element and discharges a backwashing fluid generated by the backwashing when the filtered fluid passes through the filter element;
• and
• a second discharge path that communicates with the internal space through the other end of the filter element and discharges a washing fluid generated by the high-pressure washing, wherein
• the high-pressure washing mechanism includes:
• a movable cylinder that is movable in the direction of the axial line and is rotatable around the axial line;
• a piston rod including a piston portion, which is accommodated in the movable cylinder and is not movable in the direction of the axial line, and two fluid supply paths that supply the high-pressure fluid to a first fluid chamber and a second fluid chamber, which are partitioned in the internal space of the movable cylinder by the piston portion, from the outside, respectively;
• and a plurality of injection nozzles that are provided in the movable cylinder to inject the high-pressure fluid in a state in which one or more of the injection nozzles communicate with the first fluid chamber, and the other one or more of the injection nozzles communicate with the second fluid chamber, and the high-pressure washing mechanism is configured such that the movable cylinder is configured to reciprocate in the direction of the axial line by sequentially switching the fluid supply path that supplies the high-pressure fluid out of the two fluid supply paths, and
• an injection axial-line of the injection nozzle is inclined in a direction from a position of the injection nozzle toward a position of the other end of the filter element on the axial line with respect to a direction orthogonal to the axial line.

A filter washing method of a filtration apparatus,

• the filtration apparatus including:
• a casing that is partitioned into a fluid inflow chamber including a first port, through which a target fluid flows in from the outside, and a filtration chamber configured to filter the target fluid and including a second port through which a filtered fluid after filtration flows out to the outside;
• and
• a filter element arranged in the filtration chamber and formed with one end and another end in a cylindrical shape, the filter element being configured to filter the target fluid guided from the fluid inflow chamber, which is connected to communicate with the one end, in such a manner that the target fluid passes in a direction from an inner circumferential surface toward an outer circumferential surface, and to block an outflow of the target fluid from the other end toward the second port,
• the method comprising:
• performing backwashing by drawing the filtered fluid in a direction from the outer circumferential surface toward the inner circumferential surface of the filter element;
• performing high-pressure washing by injecting a high-pressure fluid so as to pass through the filter element in the direction from the inner circumferential surface toward the outer circumferential surface of the filter element;
• and
• rotating a mechanism for performing the backwashing and a mechanism for performing the high-pressure washing around an axial line of the filter element in an internal space of the filter element communicating with the fluid inflow chamber, during the backwashing and the high-pressure washing, wherein
• the mechanism for performing the high-pressure washing includes:
• a movable cylinder that is movable in the direction of the axial line and is rotatable around the axial line;
• a piston rod including a piston portion, which is accommodated in the movable cylinder and is not movable in the direction of the axial line, and two fluid supply paths that supply the high-pressure fluid to a first fluid chamber and a second fluid chamber, which are partitioned in the internal space of the movable cylinder by the piston portion, from the outside, respectively;
• and a plurality of injection nozzles that are provided in the movable cylinder to inject the high-pressure fluid in a state in which one or more of the injection nozzles communicate with the first fluid chamber, and the other one or more of the injection nozzles communicate with the second fluid chamber, and the high-pressure washing mechanism is configured such that the movable cylinder is configured to reciprocate in the direction of the axial line by sequentially switching the fluid supply path that supplies the high-pressure fluid out of the two fluid supply paths, and
• a moving speed of the movable cylinder is reduced by supplying some of the high-pressure fluids from one fluid supply path, which supplies the high-pressure fluid, out of the two fluid supply paths to the other fluid supply path.

A filter washing method of a filtration apparatus,

• the filtration apparatus including:
• a casing that is partitioned into a fluid inflow chamber including a first port, through which a target fluid flows in from the outside, and a filtration chamber configured to filter the target fluid and including a second port through which a filtered fluid after filtration flows out to the outside;
• and
• a filter element arranged in the filtration chamber and formed with one end and another end in a cylindrical shape, the filter element being configured to filter the target fluid guided from the fluid inflow chamber, which is connected to communicate with the one end, in such a manner that the target fluid passes in a direction from an inner circumferential surface toward an outer circumferential surface, and to block an outflow of the target fluid from the other end toward the second port,
• the method comprising:
• performing backwashing by drawing the filtered fluid in a direction from the outer circumferential surface toward the inner circumferential surface of the filter element;
• performing high-pressure washing by injecting a high-pressure fluid so as to pass through the filter element in the direction from the inner circumferential surface toward the outer circumferential surface of the filter element;
• rotating a mechanism for performing the backwashing and a mechanism for performing the high-pressure washing around an axial line of the filter element in an internal space of the filter element communicating with the fluid inflow chamber, during the backwashing and the high-pressure washing;
• discharging a backwashing fluid, which is generated when the filtered fluid passes through the filter element by the backwashing, through the other end of the filter element;
• and
• discharging a washing fluid, which is generated by the high-pressure washing, through the other end of the filter element, wherein
• the mechanism for performing the high-pressure washing includes:
• a movable cylinder that is movable in the direction of the axial line and is rotatable around the axial line;
• a piston rod including a piston portion, which is accommodated in the movable cylinder and is not movable in the direction of the axial line, and two fluid supply paths that supply the high-pressure fluid to a first fluid chamber and a second fluid chamber, which are partitioned in the internal space of the movable cylinder by the piston portion, from the outside, respectively;
• and a plurality of injection nozzles that are provided in the movable cylinder to inject the high-pressure fluid in a state in which one or more of the injection nozzles communicate with the first fluid chamber, and the other one or more of the injection nozzles communicate with the second fluid chamber, and the high-pressure washing mechanism is configured such that the movable cylinder is configured to reciprocate in the direction of the axial line by sequentially switching the fluid supply path that supplies the high-pressure fluid out of the two fluid supply paths, and
• the injection nozzle is inclined in a direction from a position of the injection nozzle toward a position of the other end of the filter element on the axial line with respect to a direction orthogonal to the axial line and injects the high-pressure fluid.