An energy efficient a drying system and process using heated, dry air. The system includes an air inlet, a heat pump evaporator unit, a heat pump condenser unit, a drying unit, a heat exchanger unit, a fan, and air channels for transport of airflow from the air inlet through the system. The fan causes air to flow into the air inlet through the heat pump evaporator unit and to maintain an airflow through the system. The heat pump evaporator unit is configured to use a refrigerant to absorb heat from air that flows into the system through the heat pump evaporator unit. The heat pump condenser unit is configured to release the heat absorbed at the evaporator to the airflow. The heat exchanger unit is arranged to transfer heat from the airflow leaving the drying unit to the cold, dehumidified air flowing from the heat pump evaporator unit.

A production method includes a surface-crosslinking step of heating a mixture of a surface-crosslinking agent and a particulate dried polymer obtained with an acid group-containing unsaturated monomer as a main component. A moisture content of the particulate dried polymer is not greater than 15% by mass. A heating device including a rotary container and a plurality of heating tubes that are located within the rotary container, extend in an axial direction of the rotary container, and rotate together with the rotary container, is used in the surface-crosslinking step. The heating device includes a means for introducing and discharging a gas into and from the rotary container.

A production method includes a surface-crosslinking step of heating a mixture of a surface-crosslinking agent and a particulate dried polymer obtained with an acid group-containing unsaturated monomer as a main component. A moisture content of the particulate dried polymer is not greater than 15% by mass. A heating device including a rotary container and a plurality of heating tubes that are located within the rotary container, extend in an axial direction of the rotary container, and rotate together with the rotary container, is used in the surface-crosslinking step. The heating device includes a means for introducing and discharging a gas into and from the rotary container.

This invention relates to a rotary dryer with multi-drying chambers which is developed and improved for drying materials such as cassava chip, paddy, corn, various crops, longan, fertilizer, biomass and mining industry with better drying efficiency. The rotary dryer with multi-drying chambers according to this invention comprises a base frame, a drive assembly installed on the base frame, in which the drive assembly comprises a motor and a plurality of rollers, a drying chamber assembly having a moist material inlet part at one end and a dried material outlet part at the other end, in which the moist material inlet part and the dried material outlet part are installed on the rollers of the drive assembly, a moist material inlet assembly capped to the moist material inlet part and installed on the base frame, a dried material outlet assembly capped to the dried material outlet part and installed on the base frame and a housing encompassed the drying chamber assembly and installed on the base frame, characterized in that the drying chamber assembly comprises a plurality of drying chambers formed from an axial core, a plurality of drying chamber partition walls installed around the axial core and a plurality of drying chamber enclosure walls fixed to the plurality of drying chamber partition walls, in which a plurality of material flow control assemblies is provided in each of the plurality of drying chambers.

This invention relates to a rotary dryer with multi-drying chambers which is developed and improved for drying materials such as cassava chip, paddy, corn, various crops, longan, fertilizer, biomass and mining industry with better drying efficiency. The rotary dryer with multi-drying chambers according to this invention comprises a base frame, a drive assembly installed on the base frame, in which the drive assembly comprises a motor and a plurality of rollers, a drying chamber assembly having a moist material inlet part at one end and a dried material outlet part at the other end, in which the moist material inlet part and the dried material outlet part are installed on the rollers of the drive assembly, a moist material inlet assembly capped to the moist material inlet part and installed on the base frame, a dried material outlet assembly capped to the dried material outlet part and installed on the base frame and a housing encompassed the drying chamber assembly and installed on the base frame, characterized in that the drying chamber assembly comprises a plurality of drying chambers formed from an axial core, a plurality of drying chamber partition walls installed around the axial core and a plurality of drying chamber enclosure walls fixed to the plurality of drying chamber partition walls, in which a plurality of material flow control assemblies is provided in each of the plurality of drying chambers.

Provided is an indirectly heating rotary dryer which has achieved enhanced energy-saving performance by reducing heating tubes non-contacting with material to be dried and reducing power required for rotation even when a hold up ratio is increased. Specifically provided is an indirectly heating rotary dryer having four partition walls 16 extended respectively along an shaft center C in an inner space of a rotating shell 10 at angle intervals of 90 degrees in the vertical and horizontal directions. The four partition walls 16 partition the inner space of the rotating shell 10 at a lateral section of the rotating shell 10 into four approximately-sector-shaped small spaces K respectively extended along the shaft center C. Heating tubes 11 are aligned in the rotating shell 10 in three lines extended respectively in parallel to the shaft center C of the rotating shell 10. The heat tubes 11 heat and dry the material H to be dried by supplying heated steam to the heating tubes 11 and performing heat exchange with the material H to be dried in the rotating shell 10.

Provided is an indirectly heating rotary dryer which has achieved enhanced energy-saving performance by reducing heating tubes non-contacting with material to be dried and reducing power required for rotation even when a hold up ratio is increased. Specifically provided is an indirectly heating rotary dryer having four partition walls 16 extended respectively along an shaft center C in an inner space of a rotating shell 10 at angle intervals of 90 degrees in the vertical and horizontal directions. The four partition walls 16 partition the inner space of the rotating shell 10 at a lateral section of the rotating shell 10 into four approximately-sector-shaped small spaces K respectively extended along the shaft center C. Heating tubes 11 are aligned in the rotating shell 10 in three lines extended respectively in parallel to the shaft center C of the rotating shell 10. The heat tubes 11 heat and dry the material H to be dried by supplying heated steam to the heating tubes 11 and performing heat exchange with the material H to be dried in the rotating shell 10.

In one aspect, a filter disk for a device for dewatering sludge includes a screening plate. The screening plate has a plurality of openings for the passage of liquid and is substantially circular. Additionally, the filter disk has a supporting structure for supporting and/or stiffening the screening plate, wherein the supporting structure has at least one annular section.

To provide a drying method for terephthalic acid and a horizontal rotary dryer allowing easy performance of mass processing of the terephthalic acid and enabling size reduction by improving drying performance of the dryer. In a method of drying terephthalic acid by using a horizontal rotary dryer, a rotating shell is rotated to make a critical speed ratio defined by expression 1 and expression 2 become 17 to less than 80% to dry the processing material,

Vc=2.21D1/2 Expression 1

=V/V c.Math.100 Expression 2 wherein Vc indicates a critical speed (m/s) of the rotating shell, D indicates an inside diameter (m) of the rotating shell, indicates the critical speed ratio (%) of the rotating shell, and V indicates a rotation speed (m/s) of the rotating shell.

To provide a drying method for terephthalic acid and a horizontal rotary dryer allowing easy performance of mass processing of the terephthalic acid and enabling size reduction by improving drying performance of the dryer. In a method of drying terephthalic acid by using a horizontal rotary dryer, a rotating shell is rotated to make a critical speed ratio defined by expression 1 and expression 2 become 17 to less than 80% to dry the processing material,

Vc=2.21D1/2 Expression 1

=V/V c.Math.100 Expression 2 wherein Vc indicates a critical speed (m/s) of the rotating shell, D indicates an inside diameter (m) of the rotating shell, indicates the critical speed ratio (%) of the rotating shell, and V indicates a rotation speed (m/s) of the rotating shell.