A sludge dewatering system includes: a concentration apparatus that concentrates sludge while conveying the sludge on a top surface of a filter body; and a dewatering apparatus that subjects the sludge discharged from the concentration apparatus to pressure dewatering. The concentration apparatus includes: a filtering unit that subjects the sludge, which has been added with a first chemical agent, to gravity filtration; a chemical feeder that adds a second chemical agent to the sludge conveyed in the filtering unit; and a moving mechanism that moves the sludge, which has been added with the second chemical agent, in a direction intersecting a conveyance direction of the filter body.

A cylindrical filtration filter includes a cylindrical filter main body. The filter main body is constituted by at least two split filters. Each of the split filters has an arc shape in cross section. Each of the split filters includes a filter element for filtration and side frame bodies provided along side portions of the filter element. The side frame body of one of the two split filters adjacent to each other includes a first facing surface having an uneven shape. The side frame body of the other split filter includes a second facing surface having an uneven shape complementary to the first facing surface. The first facing surface and the second facing surface are fitted to each other when the filter main body is assembled.

A cylindrical filtration filter includes a cylindrical filter main body. The filter main body is constituted by at least two split filters. Each of the split filters has an arc shape in cross section. Each of the split filters includes a filter element for filtration and side frame bodies provided along side portions of the filter element. The side frame body of one of the two split filters adjacent to each other includes a first facing surface having an uneven shape. The side frame body of the other split filter includes a second facing surface having an uneven shape complementary to the first facing surface. The first facing surface and the second facing surface are fitted to each other when the filter main body is assembled.

A device is for separating a medium comprising a mixture of a solid portion and a fluid portion. The device has a filter arrangement with a displaceable filter element having a plurality of openings that allow the fluid to be disposed through the openings while maintaining the solid portion on the filter element. The device further has an inlet for feeding the medium to the filter element and an outlet for discharging the solid portion from the filter element after that the fluid has been separated from the solid portion. The device further has an obstruction has an elastic element extending towards a surface of the filter element and adapted to contact the surface while allowing the medium to be displaced from the inlet to the outlet.

A filtration device has a primary conveyer tank which is equipped with a first conveyer, a primary drum filter which rotates inside the primary conveyer tank, a secondary conveyer tank which is equipped with a second conveyer and a secondary drum filter which rotates inside the secondary conveyer tank. Liquid in the primary conveyer tank passes through a first opening to flow into the secondary conveyer tank. Clean liquid flowing into a first clean tank is supplied to a low-pressure-side supply system by a first pump. Super-clean liquid having been filtered by the secondary drum filter passes through a second opening to flow into a second clean tank, and then is supplied to a high-pressure-side supply system by a second pump.

A filtration device has a primary conveyer tank which is equipped with a first conveyer, a primary drum filter which rotates inside the primary conveyer tank, a secondary conveyer tank which is equipped with a second conveyer and a secondary drum filter which rotates inside the secondary conveyer tank. Liquid in the primary conveyer tank passes through a first opening to flow into the secondary conveyer tank. Clean liquid flowing into a first clean tank is supplied to a low-pressure-side supply system by a first pump. Super-clean liquid having been filtered by the secondary drum filter passes through a second opening to flow into a second clean tank, and then is supplied to a high-pressure-side supply system by a second pump.

A sludge condensing machine includes: a gravity filtration section conducting a gravity filtering to a sludge while conveying the sludge on an upper surface of a filtration body, and a movement mechanism, disposed at a downstream side of a sludge insertion position of the gravity filtration section, for reducing a dimension of the sludge in a width direction on the filtration body by moving the sludge in a direction intersecting a conveying direction that the sludge is conveyed by the filtration body.

A sludge condensing machine includes: a gravity filtration section conducting a gravity filtering to a sludge while conveying the sludge on an upper surface of a filtration body, and a movement mechanism, disposed at a downstream side of a sludge insertion position of the gravity filtration section, for reducing a dimension of the sludge in a width direction on the filtration body by moving the sludge in a direction intersecting a conveying direction that the sludge is conveyed by the filtration body.

A filtering apparatus includes a cylindrical filter including a cylindrical screen filter, a treated water nozzle including a nozzle port, a casing where the cylindrical filter is accommodated, the casing containing the nozzle port in the inside, a filtered water flow channel through which filtered water obtained by passage of water to be treated through the screen filter is guided to the outside of the casing, the filtered water flow channel being provided with a flow inlet provided in the inside of the casing, and a rotation mechanism that rotates the cylindrical filter with a central axis of the cylindrical filter. A distance between a centerline of the nozzle port along a direction of outflow of water to be treated and the central axis of the cylindrical filter is shorter than a radius of the cylindrical filter.

A filtering apparatus includes a cylindrical filter including a cylindrical screen filter, a treated water nozzle including a nozzle port, a casing where the cylindrical filter is accommodated, the casing containing the nozzle port in the inside, a filtered water flow channel through which filtered water obtained by passage of water to be treated through the screen filter is guided to the outside of the casing, the filtered water flow channel being provided with a flow inlet provided in the inside of the casing, and a rotation mechanism that rotates the cylindrical filter with a central axis of the cylindrical filter. A distance between a centerline of the nozzle port along a direction of outflow of water to be treated and the central axis of the cylindrical filter is shorter than a radius of the cylindrical filter.