Method of dehumidifying and drying powdered or granular material and system for dehumidifying and drying powdered or granular material

A method of dehumidifying and drying powdered or granular material using a system for dehumidifying and drying powdered or granular material, said system comprising a drying hopper for storing therein and drying a powdered or granular material, a dehumidifying unit equipped with an absorbing body therein, and a circulation route having a processing gas supply route and a processing gas dehumidifying route that interconnect said drying hopper and said dehumidifying unit, a processing gas being repeatedly circulated for dehumidifying and drying by being returned to said dehumidifying unit from said drying hopper via the processing gas dehumidifying route after being heated by a heater and allowed to pass through said drying hopper,

• said processing gas supply route being configured to connect a downstream side of said absorbing body of said dehumidifying unit and an upstream side of said heater of said drying hopper such that processing gas
• dehumidified and processed by said dehumidifying unit is supplied toward said drying hopper;
• said processing gas dehumidifying route being configured to connect a downstream side of said drying hopper and an upstream side of the absorbing body of said dehumidifying unit such that gas passing through said drying hopper is supplied toward said dehumidifying unit;
• said method comprising the following process;
• a dehumidifying process in which the processing gas exhausted from said drying hopper is dehumidified with said absorbing body in said dehumidifying unit by allowing the processing gas to pass through said absorbing body;
• a heating regenerating process in which a heating gas is allowed to pass through said absorbing body for its own reuse after said dehumidifying process;
• and
• a cooling regenerating process in which a cooling gas is allowed to pass through said absorbing body for its own reuse after said heating regenerating process;
• whereby the flow amount of the processing gas to pass through a bypass route, which interconnects midway of the processing gas supply route and midway of the processing gas dehumidifying route and supplies a part of dehumidified processing gas supplied to said heater and said drying hopper through said processing gas supply route without passing through said heater and said drying hopper, is adjusted depending on the temperature in an upper part of said drying hopper under the condition that the total circulation amount of the processing gas circulating in said circulation route, including the amount of the gas passing through the bypass route, is substantially kept a predetermined amount, and thereby performing control of increasing or decreasing the flow amount of the processing gas to supply to said drying hopper.

A system for dehumidifying and drying powdered or granular material comprising a drying hopper for storing therein and drying a powdered or granular material, a dehumidifying unit equipped with an absorbing body therein, and a circulation route having a processing gas supply route and a processing gas dehumidifying route that interconnect said drying hopper and said dehumidifying unit, a processing gas being repeatedly circulated for dehumidifying and drying by being returned to said dehumidifying unit from said drying hopper via the processing gas dehumidifying route after being heated by a heater and allowed to pass through said drying hopper,

• said processing gas supply route being configured to connect a downstream side of said absorbing body of said dehumidifying unit and an upstream side of said heater of said drying hopper such that processing gas dehumidified and processed by said dehumidifying unit is supplied toward said drying hopper;
• said processing gas dehumidifying route being configured to connect a downstream side of said drying hopper and an upstream side of the absorbing body of said dehumidifying unit such that gas passing through said drying hopper is supplied toward said dehumidifying unit;
• said system comprising:
• a bypass route with a regulation valve for supplying a part of dehumidified processing gas supplied to said heater and said drying hopper through said processing gas supply route without passing through said heater and said drying hopper, said bypass route interconnecting midway of the processing gas supply route and midway of the processing gas dehumidifying route;
• a temperature sensor provided in the processing gas dehumidifying route, for detecting the temperature of the processing gas exhausted from said drying hopper;
• said dehumidifying unit comprising:
• a dehumidifying process zone for dehumidifying the processing gas exhausted from said drying hopper, so constructed as to allow said processing gas to pass through said absorbing body;
• a heating regenerating zone so constructed as to allow a heating gas to pass through said absorbing body for reuse of said absorbing body after the processing gas is dehumidified;
• a cooling regenerating zone so constructed as to allow a cooling gas to pass through said absorbing body for reuse of said absorbing body after said absorbing body is regenerated by said heating gas;
• and an inlet and
• an outlet for introducing and passing the processing gas, said heating gas, and said cooling gas into and out of said dehumidifying process zone, said heating regenerating zone, and said cooling regenerating zone, respectively, and
• a control means for controlling open or close operation of said regulation valve provided in said bypass route depending on the temperature detection signal from said temperature sensor under the condition that the total circulation amount of the processing gas circulating in said circulation route, including the amount of the processing gas passing through said bypass route, is substantially kept a predetermined amount.

A system for dehumidifying and drying powdered or granular material comprising a drying hopper for storing therein and drying a powdered or granular material, a dehumidifying unit equipped with an absorbing body therein, and a circulation route having a processing gas supply route and a processing gas dehumidifying route that interconnect said drying hopper and said dehumidifying unit, a processing gas being repeatedly circulated for dehumidifying and drying by being returned to said dehumidifying unit from said drying hopper via the processing gas dehumidifying route after being heated by a heater and allowed to pass through said drying hopper,

• said processing gas supply route being configured to connect a downstream side of said absorbing body of said dehumidifying unit and an upstream side of said heater of said drying hopper such that processing gas dehumidified and processed by said dehumidifying unit is supplied toward said drying hopper;
• said processing gas dehumidifying route being configured to connect a downstream side of said drying hopper and an upstream side of the absorbing body of said dehumidifying unit such that gas passing through said drying hopper is supplied toward said dehumidifying unit;
• said system comprising;
• a bypass route with a regulation valve for supplying a part of dehumidified processing gas supplied to said heater and said drying hopper through said processing gas supply route without passing through said heater and said drying hopper, said bypass route interconnecting midway of the processing gas supply route and midway of the processing gas dehumidifying route,
• a temperature sensor provided in said drying hopper, for detecting the temperature in an upper part of said drying hopper;
• said dehumidifying unit comprising:
• a dehumidifying process zone for dehumidifying the processing gas exhausted from said drying hopper, so constructed as to allow said processing gas to pass through said absorbing body;
• a heating regenerating zone so constructed as to allow a heating gas to pass through said absorbing body for reuse of said absorbing body after the processing gas is dehumidified;
• a cooling regenerating zone so constructed as to allow a cooling gas to pass through said absorbing body for reuse of said absorbing body after said absorbing body is regenerated by said heating gas;
• and
• an inlet and an outlet for introducing and passing the processing gas, said heating gas, and said cooling gas into and out of said dehumidifying process zone, said heating regenerating zone, and said cooling regenerating zone, respectively, and
• a control means for controlling open or close operation of said regulation valve provided in said bypass route depending on the temperature detection signal from said temperature sensor under the condition that the total circulation amount of the processing gas circulating in said circulation route, including the amount of the processing gas passing through said bypass route, is substantially kept a predetermined amount.