Abstract: Spraying apparatus for cleaning filter plates embodies a support frame which is mounted for movement beneath the filter plates and is adapted to align with each space formed between adjacent filter plates to be cleaned. A spraying unit is mounted for pivotal movement on the support frame selectively to a lowered position beneath the filter plates and to a raised position extending upwardly into the space between adjacent filter plates. A spray dispenser carried by the spraying unit moves within the space to apply spray to the adjacent vertical surfaces of the filter plates being cleaned.

Abstract: Apparatus for protecting aquatic life carried by water passing through a vertical traveling band screen unit having inwardly opening screening baskets. Each basket carries a longitudinally extending, inwardly projecting baffle adjacent its trailing side with the portion thereof adjacent the basket being imperforate. The area along the length of each basket at the inner side of the baffle is imperforate and defines with the baffle a pocket for receiving water and aquatic life carried thereby upon upward movement through the water and is adapted to discharge the water and aquatic life carried thereby upon movement of the pocket to a predetermined elevation. A low pressure stream of water transfers the aquatic life from the pocket to a discharge trough located inwardly of the screening unit.

Abstract: A process and apparatus for the thermal destruction of solid fuel material in a gravity-type multiple hearth furnace having groups of two or more superimposed hearths. Solid fuel is fed to the upper hearth of each group of hearths. Auxiliary fuel is selectively burned in the lower hearth of each group of hearths to maintain the discharge temperature of the exhaust gas flowing from each said upper hearth above the ignition temperature of said gases so that each group of hearths is operated as a combined drying and burning zone. Preheated air for combustion is introduced into the lower hearth of the lowermost group of hearths so that oxygen available for combustion increases as the solid fuel moves downwardly. Ash is removed from the lower hearth of at least the lowermost group of hearths.