Screw press apparatus

A screw press apparatus, comprising:

• a first frame;
• a second frame opposing the first frame;
• and
• a screw press comprising:
• an outside tube supported on the first and second frames, the outside tube comprising a cylindrical punched plate and a filtering screen fixed to an inner periphery of the cylindrical punched plate
• a screw shaft having a spiral screw blade projecting therefrom, the screw shaft being inserted through the outside tube and supported rotatably on the first and second frames;
• a supply pipe for supplying raw liquid into the screw shaft, the supply pipe being fixed to one end of the screw shaft supported on the first frame;
• and
• a cleaning pipe for ejecting cleaning water to wash the filtering screen, wherein
• the filtering screen is disposed between the first and second frames and has a plurality of fine filtering holes,
• the screw shaft and the filtering screen are configured to define therebetween a cylindrical space continuously extending from an upstream region at a side of the first frame to a downstream region at a side of the second frame,
• the spiral screw blade extends in the cylindrical space continuously from the upstream region to the downstream region,
• the screw shaft has an opening formed in a periphery thereof for supplying raw liquid from the supply pipe to the upstream region of the cylindrical space,
• the screw shaft and the filtering screen have a radial distance therebetween decreasing from the upstream region towards the downstream region,
• raw liquid supplied from the opening to the upstream region is pressurized and carried towards the downstream region by the spiral screw blade, while being separated into filtrate outflowing through fine holes of the filtering screen and solids to be discharged as a cake from the downstream region, and
• the plurality of fine holes of the filtering screen decrease in size gradually from the upstream region towards the downstream region, wherein
• the screw press apparatus further comprises:
• a drive for driving the screw shaft;
• a torque detector provided for the drive;
• and
• a control unit for controlling the drive in accordance with detected torque detected by the torque detector, wherein
• the control unit has a comparator and a controller,
• the drive comprises a variable speed motor,
• the comparator has a reference torque region set therein,
• the comparator compares the detected torque with the reference torque region, and when the detected torque does not reach the reference torque region, the comparator outputs a speed decrease request signal to the controller, and when the detected torque exceeds the reference torque region, the comparator outputs a speed increase request signal to the controller, and
• when the controller receives the speed decrease request signal, the controller controls the drive to decrease in speed, and when the controller receives the speed increase request signal, the controller controls the drive to increase in speed.

A screw press apparatus, comprising:

• a first frame;
• a second frame opposing the first frame;
• and
• a screw press comprising:
• an outside tube supported on the first and second frames, the outside tube having a filtering screen constituting a periphery thereof;
• a screw shaft having a spiral screw blade projecting therefrom, the screw shaft being inserted through the outside tube and supported rotatably on the first and second frames;
• a supply pipe for a continuous supply of raw liquid into the screw shaft, the supply pipe being fixed to one end of the screw shaft supported on the first frame;
• and
• a cleaning pipe for ejecting cleaning water to wash the filtering screen, wherein
• the filtering screen is disposed between the first and second frames and has a plurality of fine filtering holes,
• the screw shaft and the filtering screen are configured to define therebetween a cylindrical space continuously extending from an upstream region at a side of the first frame to a downstream region at a side of the second frame,
• the spiral screw blade extends in the cylindrical space continuously from the upstream region to the downstream region,
• the screw shaft has an opening formed in a periphery thereof for supplying raw liquid from the supply pipe to the upstream region of the cylindrical space,
• the screw shaft and the filtering screen have a radial distance therebetween decreasing from the upstream region towards the downstream region,
• during the continuous supply, raw liquid is continuously supplied from the opening to the upstream region and pressurized and carried towards the downstream region by the spiral screw blade, while being continuously separated into filtrate outflowing through fine holes of the filtering screen and solids to be discharged as a cake from the downstream region, and
• the plurality of fine holes of the filtering screen decrease in size gradually from the upstream region towards the downstream region, wherein
• the screw press apparatus further comprises:
• a pump adapted for the continuous supply of raw liquid;
• a supply path for interconnecting the supply pipe and the pump;
• a pressure detector provided in the supply path, for detecting an inlet pressure of raw liquid to the cylindrical space;
• and
• a control unit for controlling the pump in accordance with the inlet pressure detected by the pressure detector.

A screw press apparatus, comprising:

• a first frame;
• a second frame opposing the first frame;
• and
• a screw press comprising:
• an outside tube supported on the first and second frames, the outside tube having a filtering screen constituting a periphery thereof;
• a screw shaft having a spiral screw blade projecting therefrom, the screw shaft being inserted through the outside tube and supported rotatably on the first and second frames;
• a supply pipe for supplying raw liquid into the screw shaft, the supply pipe being fixed to one end of the screw shaft supported on the first frame;
• and
• a cleaning pipe for ejecting cleaning water to wash the filtering screen, wherein
• the filtering screen is disposed between the first and second frames and has a plurality of fine filtering holes,
• the screw shaft and the filtering screen are configured to define therebetween a cylindrical space continuously extending from an upstream region at a side of the first frame to a downstream region at a side of the second frame,
• the screw blade extends in the cylindrical space continuously from the upstream region to the downstream region,
• the screw shaft has an opening formed in a periphery thereof for supplying raw liquid from the supply pipe to the upstream region of the cylindrical space,
• the screw shaft and the filtering screen have a radial distance therebetween decreasing from the upstream region towards the downstream region,
• raw liquid supplied from the opening to the upstream region is pressurized and carried towards the downstream region by the spiral screw blade, while being separated into filtrate outflowing from fine holes of the filtering screen and solids to be discharged as a cake from the downstream region, and
• the plurality of fine holes of the filtering screen decrease in size gradually from the upstream region towards the downstream region, wherein
• the screw press apparatus further comprises:
• a cake discharge hole for the cake to be pushed therethrough out of the cylindrical space;
• an air cylinder fixed to the second frame;
• a presser connected to a shaft of the air cylinder and adapted for forward and backward movements to change an open degree of the cake discharge hole;
• a detector provided for the air cylinder for detecting the open degree;
• an air supply path connected to the air cylinder;
• a regulator valve provided in the air supply path;
• a pilot valve for changing a set air pressure of the regulator valve;
• and
• a control unit for operating the pilot valve in accordance with a detected value from the detector.

A screw press apparatus, comprising:

• first and second frames in opposition to each other;
• an outside tube having a screen on a peripheral surface thereof, the outside tube being supported on the frames;
• a screw shaft having a spiral screw blade, the screw shaft being inserted through the outside tube and supported rotatably on the frames;
• a supply pipe for supplying raw liquid into the screw shaft, the supply pipe being fixed to one end of the screw shaft supported on the first frame;
• and
• a cleaning pipe for ejecting cleaning water onto the screen, wherein
• the screen is disposed between the frames and has a plurality of fine holes,
• the screw shaft and the screen define a cylindrical space continuously extending from an upstream region at a side of the first frame to a downstream region at a side of the second frame,
• the screw blade is projected from the screw shaft into the cylindrical space and continuously extends from the upstream region to the downstream region,
• an opening for supplying raw liquid from the supply pipe to the upstream region of the cylindrical space is formed in the screw shaft,
• a relative distance between an outer peripheral surface of the screw shaft and an inner peripheral surface of the screen decreases from the upstream region towards the downstream region,
• raw liquid fed from the opening to the upstream region is pressurized and carried towards the downstream region by the screw blade, while being separated into filtrate allowed to outflow through the fine holes of the screen and a cake allowed to move in the cylindrical space to be discharged from the downstream region, and
• sizes of the fine holes of the screen decrease gradually from the upstream region towards the downstream region, wherein
• the screw press apparatus further comprises:
• a cake discharge hole for a cake to be pushed therethrough out of the cylindrical space;
• an air cylinder fixed to the second frame;
• a presser connected to a shaft of the air cylinder and adapted for forward and backward movements to change an open degree of the cake discharge hole;
• a detector provided for the air cylinder, for detecting the open degree;
• an air supply path connected to the air cylinder;
• a regulator valve provided in the air supply path;
• a pilot valve for changing a set air pressure of the regulator valve;
• and
• a control unit for operating the pilot valve in accordance with a detected value from the detector, wherein
• the control unit has a comparator and a controller,
• a standard open degree is set in the comparator,
• the comparator compares the detected value with the standard open degree, and when the detected value exceeds the standard open degree, the comparator outputs a pressure increase request signal to the controller, and when the detected value does not reach the standard open degree, the comparator outputs a pressure decrease request signal to the controller, and
• when the controller receives the pressure increase requests signal, the controller increases the set air pressure of the regulator valve, and when the controller receives the pressure decrease signal, the controller decreases the set air pressure of the regulator valve.

A screw press apparatus, comprising:

• first and second frame in opposition to each other;
• an outside tube having a screen on a peripheral surface thereof, the outside tube being supported on the frames;
• a screw shaft having a spiral screw blade, the screw shaft being inserted through the outside tube and supported rotatably on the frames;
• a supply pipe for supplying raw liquid into the screw shaft, the supply pipe being fixed to one end of the screw shaft supported on the first frame;
• and
• a cleaning pipe for ejecting cleaning water onto the screen, wherein
• the screen is disposed between the frames and has a plurality of fine holes,
• the screw shaft and the screen define a cylindrical space continuously extending from an upstream region at a side of the first frame to a downstream region at a side of the second frame,
• the screw blade is projected from the screw shaft into the cylindrical space and continuously extends from the upstream region to the downstream region,
• an opening for supplying the raw liquid from the supply pipe to the upstream region of the cylindrical space is formed in the screw shaft,
• a relative distance between an outer peripheral surface of the screw shaft and an inner peripheral surface of the screen decreases from the upstream region towards the downstream region,
• raw liquid fed from the opening to the upstream region is pressurized and carried towards the downstream region by the screw blade, while being separated into filtrate allowed to outflow through the fine holes of the screen and a cake allowed to move in the cylindrical space to be discharged from the downstream region, and
• sizes of the fine holes of the screen decrease gradually from the upstream region towards the downstream region, wherein
• the screw press apparatus further comprises:
• a cake discharge hole for the cake to be pushed therethrough out of the cylindrical space;
• an air cylinder fixed to the second frame;
• a presser connected to a shaft of the air cylinder and adapted for forward and backward movements to change an open degree of the cake discharge hole;
• a detector provided for the air cylinder for detecting the open degree;
• and
• a control unit for controlling the drive in accordance with the detected value from the detector.