Supercritical fluid apparatus and pressure control method used in supercritical fluid apparatus
AssigneeShimadzu Corporation
InventorMichiaki Owa
Life of this patent
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Abstract
A supercritical fluid apparatus includes a solvent supplier that supplies a solvent, a pressure control device provided in a flow path for a solvent supplied by the solvent supplier, and a controller that controls the pressure control device. The controller includes a first controller that increases a pressure in the flow path, puts the solvent in a supercritical fluid state and maintains an environment for execution of a predetermined process by controlling the pressure control device, and a second controller that sets an intermediate target value for a pressure in the flow path and controls a pressure in the flow path in order to get the pressure to reach the intermediate target value, when ending the environment for execution of a predetermined process.
Claims10
A supercritical fluid apparatus comprising:
- a solvent supplier that supplies a solvent;
- a column provided in a flow path for a solvent supplied by the solvent supplier;
- a pressure control device provided further downstream than the column in the flow path;
- a controller that controls the pressure control device;
- and
- a pressure sensor that detects a pressure in the flow path, wherein
- the controller includes
- a first controller configured to increase the pressure in the flow path including the column, put the solvent in a supercritical fluid state and maintain an environment for execution of a predetermined process by controlling the pressure control device, and
- a second controller configured to set an intermediate target value for the pressure in the flow path including the column and feedback-control the pressure control device based on a difference between the intermediate target value and a pressure value obtained by the pressure sensor to lower the pressure in the flow path toward the intermediate target value to protect the column, when ending the environment for execution of a predetermined process.
A pressure control method used in a supercritical fluid apparatus including a column provided in a flow path for a solvent supplied by a solvent supplier, including the processes of:
- increasing a pressure in the flow path, putting the solvent in a supercritical fluid state and maintaining an environment for execution of a predetermined process by controlling a pressure control device provided further downstream than the column in the flow path;
- and
- setting an intermediate target value for the pressure in the flow path including the column and controlling the pressure in the flow path using feedback-control of the pressure control device based on a difference between the intermediate target value and a pressure value obtained by a pressure sensor to lower the pressure in the flow path toward the intermediate target value to protect the column, when ending the environment for execution of a predetermined process.
Dependencies are inferred from the claim text.