For the reason of phosphate soil variety, operating conditions of pan filter have some difficulties so, it is necessary to change pans during one or two weeks. It causes some difficulties such as: system efficiency condition, interruption for changing, high cost of fences and tiredness of operational personnel. The objective of this project is finding a method that can put them again in service after two or three hours of interruption. After necessary investigations contractor suggested dense sulfuric acid that had a high efficiency in pans cleaning. But since using dense sulfuric acid was practically dangerous for operational personnel, the project was ended.