The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 14, 2004
Filed:
Jan. 10, 2003
Ming-Shan Jeng, Hsinchu, TW;
Meen-Dau Hoo, Hsinchu, TW;
Juhn-Jie Chen, Hsinchu, TW;
Kuo-Hsiang Yang, Hsinchu, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
An airflow feedback control method and apparatus for fan filter unit (FFU) is proposed, which is designed for use with a fan filter unit that is widely used in semiconductor fabrication factories for dust-clearing purpose, for controlling the fan filter unit to generate a constant amount of airflow equal to a preset desired amount. The proposed FFU airflow feedback control method and apparatus is characterized by that it utilizes bell inlet as an airflow measuring nozzle and that airflow is used as feedback parameter to control the FFU, rather than utilizing motor speed as feedback parameter by prior art. This feature allows the fan filter unit to continuously generate a fixed amount of airflow equal to the preset desired amount even if there is a pressure change at the site of installation, thus lessening the problems of insufficient air change rate and sideward-going airflows.