Abstract: Disclosed is method and apparatus for separating a light liquid component from a heavier liquid component. A holding tank holding a mixture of the light and heavy liquid has an outlet discharging into a separation tank. An underflow weir is provided in a separation tank adjacent the point of discharge to direct outflow beneath the surface underflow weir and the light liquid rises to the surface on the downstream side of the underflow weir to concentrate in a small vertical column in a portion of the separation tank to form an upper layer. A sensor in the separation tank senses sufficient light liquid in the vertical column and operates a removal pump to remove the light liquid from the vertical column. With removal of the light liquid, heavy liquid rises and the sensor senses the heavy liquid and stops the light liquid removal before the heavy liquid is also removed. Heavy liquid from the separation tank is recirculated, being directed across the surface of the holding tank in a downstream direction.

Abstract: A liquid level sensor for occluded water is provided to detect the surface water level as in a spray booth tank. The water level sensor may control the water level in the tank or it may be used to maintain a relatively constant outflow of water from the tank through a vertically movable weir. The weir is moved in response to changes in the liquid level detected by the sensor which includes an electronic signal sensor capable of detecting a level of a liquid relative thereto. The sensor is mounted in an elongated housing that has its lower end disposed in the liquid in the reservoir. The upper end of the housing is vented to the atmosphere to equalize the pressure between the interior thereof and the atmosphere ambient the housing. A flexible diaphragm is secured to the housing so as to seal the open lower end, and a substantially pure test liquid is held within the housing isolated from the liquid in the reservoir.

Abstract: A liquid level sensor for occluded water is provided to detect the surface water level as in a spray booth tank. The water level sensor may control the water level in the tank or it may be used to maintain a relatively constant outflow of water from the tank through a vertically movable weir. The weir is moved in response to changes in the liquid level detected by the sensor which includes an electronic signal sensor capable of detecting a level of a liquid relative thereto. The sensor is mounted in an elongated housing that has its lower end disposed in the liquid in the reservoir. The upper end of the housing is vented to the atmosphere to equalize the pressure between the interior thereof and the atmosphere ambient the housing. A flexible diaphragm is secured to the housing so as to seal the open lower end, and a substantially pure test liquid is held within the housing isolated from the liquid in the reservoir.

Abstract: A method and apparatus in which a water sludge suspension is initially separated from the water by skimming and then is conveyed to a dewatering station at which the sludge is oscillated or vibrated to separate mechanically the water from the solid sludge material. Preferably, at the dewatering station, the sludge is dropped a predetermined distance onto a sieve, the impact of the falling sludge producing a squeezing action on the sludge to initially exude the occluded water. The sieve, which is inclined, is then oscillated or vibrated to work the sludge to further exude water therefrom and to urge the sludge down the inclined surface of the sieve. After traveling to the bottom of the sieve, the sludge, now substantially dewatered, is received by a container for disposal.

Abstract: A sludge-separating apparatus including a separation tank for receiving a supply of liquid and sludge from an adjacent holding tank. A pump having an outlet disposed at the bottom of the separation tank transports suspended sludge from the adjacent holding tank to the separation tank. A baffle plate disposed in the separation tank adjacent the outlet deflects the suspended sludge entering therethrough toward the surface of the liquid held in the separation tank. A divider in the separation tank allows relatively sludge-free liquid to pass into one of the regions defined by the divider. A liquid return returns the sludge-free liquid to the holding tank. An automatic skimmer is associated with the sludge-containing region of the separation tank for skimming floating sludge and discharging the sludge over an upwardly inclined end panel.

Abstract: Sludge removal apparatus is provided for new or existing spray coating booths, degreasing tanks, phosphate tanks, plating tanks or the like to remove sludge from the surface of a liquid in the tank. Preferably, a sludge removal tank is disposed adjacent the water holding tank of the coating booth and communicated therewith through an inlet opening. Water jets in the holding tank are directed at the inlet opening creating a current which carries floating sludge to the removal tank. Preferably, air is entrained into water and aids in floating particles. The bottoms of the tanks are preferably swept by water to remove particles settling to the bottom of the tanks. A reciprocating skimmer pushes floating sludge from the sludge removal tank up an inclined beach and into a collection bin.

Abstract: Sludge removal apparatus is provided for new or existing spray coating booths, degreasing tanks, phosphate tanks, plating tanks or the like to remove sludge from the surface of a liquid in the tank. Preferably, a sludge removal tank is disposed adjacent the water holding tank of the coating booth and communicated therewith through an inlet opening. Water jets in the holding tank are directed at the inlet opening creating a current which carries floating sludge to the removal tank. Preferably, air is entrained into water and aids in floating particles. The bottoms of the tanks are preferably swept by water to remove particles settling to the bottom of the tanks. A reciprocating skimmer pushes floating sludge from the sludge removal tank up an inclined beach and into a collection bin.