Candle insertion type filter and application

The invention provides a candle insertion type filter and application, the candle insertion type filter comprises a shell, the shell is internally provided with a filter element bin, the filter element bin comprises an upper cover plate and a lower cover plate which are connected with the shell in a sealed mode, at least two filter elements are arranged between the upper cover plate and the lower cover plate in a sealed mode, and the two ends of each filter element are communicated with a liquid inlet; a rotatable flushing structure is arranged on the filter element bin and is used for communicating one end of the filter element with a drain outlet and selectively closing the other end of the filter element so as to perform combined cleaning on the filter element. The candle insertion type filter disclosed by the invention can be used for sequentially carrying out combined cleaning including direct flushing and back flushing on the filter element, so that high-efficiency cleaning of impurities with different