A pulseback technique for cleaning and renewing a panel bed contractor suitable for chemical or physical treatment of liquid and granular material was investigated.

Free surfaces of quartz sand for the entry of water were provided by vertical support louvers. A pulseback technique was used to rid the liquid entry surface of the sand.

The pulseback consisted of a reverse transient flow of liquid across the panel bed of sand. The time of duration of the pulseback was a maximum of 100 milliseconds. The amount of sand removed from the panel bed was found to be related to the pressure drop across the panel bed and the duration time of the pulseback.

A description of the pulseback equipment, the pulseback data, and the correlation of the pulseback date are included.