US 8,803,039 B2Granted

Heating unit, substrate processing apparatus, and method for heating fluid

AssigneeTokyo Electron Limited

InventorsHideaki Sato, Hiromi Hara

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Abstract

In a heating unit, based on a required output amount Q, a control part 50 performs: (A) when the required output amount Q is not more than a predetermined set value, a control in which none of the heating devices 24a is continuously kept on throughout a heating cycle, and all or one or more heating devices 24a are controlled in a periodically divided manner; and (B) when the required output amount is larger than the predetermined set value, a control in which all or one or more heating devices 24a are continuously kept on throughout the heating cycle, and all or one or more heating devices 24a among the remaining heating devices 24a are controlled in the periodically divided manner during this heating cycle. At this time, a difference between the maximum number and the minimum number of the heating devices 24a that are simultaneously kept on during the heating cycle is made not more than 1.

Claims14

Dependent claims

A heating unit configured to heat a fluid, the heating unit comprising:

at least three heating devices respectively configured to heat the fluid;
and
a control part configured to control ON/OFF of each of the heating devices;
wherein:
the control part is configured to calculate a required output amount of the heating unit such that a temperature of the fluid heated by the heating unit can be maintained at a predetermined temperature, and calculate a period of a heating cycle based on the required output amount;
and
the control part is also configured to select one control mode from a plurality of control modes based on the required output amount of the heating unit and configured to perform the selected control mode in the heating cycle, the control modes including:
(A) a first control mode to be selected when the required output amount is not more than a predetermined set value in which none of the heating devices is continuously kept on throughout the heating cycle, and at least two heating devices are controlled in a periodically divided manner during the heating cycle with a heater on time of each one of said at least two heating devices only partially overlapping with a heater on time of another one of said at least two heating devices, and with a difference between the maximum number and the minimum number of the heating devices that are simultaneously kept on during the heating cycle being maintained at not more than 1;
and
(B) a second control mode to be selected when the required output amount is larger than the predetermined set value in which at least one heating device is continuously kept on throughout the heating cycle, and at least two heating devices among the remaining heating devices are controlled in the periodically divided manner during the heating cycle with a heater on time of each one of said at least two heating devices only partially overlapping with a heater on time of another one of said at least two heating devices and with a difference between the maximum number and the minimum number of the heating devices that are simultaneously kept on during the heating cycle being maintained at not more than 1.

7 more elements

A method for heating a fluid by means of a heating unit including a plurality of heating devices respectively configured to heat the fluid, the method comprising:

calculating a required output value such that a temperature of the fluid heated by the heating unit can be maintained at a predetermined temperature;
calculating a period of a heating cycle based on the required output amount;
selecting one control mode from a plurality of control modes based on the required output amount of the heating unit;
and
performing the selected control mode in the heating cycle, the control modes including:
(A) a first control mode to be selected when the required output amount is not more than a predetermined set value in which none of the heating devices is continuously kept on throughout the heating cycle, and at least two heating devices are controlled in a periodically divided manner during the heating cycle with a heater on time of each one of said at least two heating devices only partially overlapping with a heater on time of another one of said at least two heating devices and with a difference between the maximum number and the minimum number of the heating devices that are simultaneously kept on during the heating cycle being maintained at not more than 1;
and (B) a second control made to be selected when the required output amount is larger than the predetermined set value in which at least one heating device is continuously kept on throughout the heating cycle, and at least two heating devices among the remaining heating devices are controlled in the periodically divided manner during the heating cycle with a heater on time of each one of said at least two heating devices only overlapping with a heater on time of another one of said at least two heating devices and with a difference between the maximum number and the minimum number of the heating devices that are simultaneously kept on during the heating cycle being maintained at not more 1.

4 more elements

Dependencies are inferred from the claim text.