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 spray booth is provided with inexpensive, disposable pre-baffles which collect overspray thereon prior to the overspray reaching the filtering stages. The preferred disposable pre-baffles are made of paperboard and after being coated with overspray for a short period, e.g., one week, are easily detached and replaced. The paint on the disposable pre-baffles can be baked to convert the paint and the baffle from a hazardous to a non-hazardous waste. The pre-baffles may collect as much as 80% of the overspray, some of which may be collected and re-used, and reduces the amount of sludge, filter cleaning, chemicals used in the reservoir water, and the emissions. Thus, the overall savings easily overcome the expense of replacing the disposable pre-baffles.

Abstract: An air curtain conveyor protection system that prevents airborne particles from entering a slot through which the product support members extend from the conveyor mechanism housing into the product treatment booth. A continuous stream or curtain of high velocity air flows across the slot in the conveyor housing, exiting from an outlet or supply nozzle formed by a plenum on one side of the slot and entering into a suction nozzle formed on the opposite side of the slot by a second plenum. A fan or blower is associated with each plenum to force ambient air through the supply nozzle and to draw air through the suction nozzle. Ambient air flowing between the nozzles forms an air curtain across the slot to prevent ingress of the deleterious atmosphere in the product treatment booth into the conveyor housing.

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 spray booth includes an air cleaning apparatus providing an air intake beneath its floor, and provides air curtains along the interior surfaces of its side walls. The preferred air cleaning apparatus provides a first slot and water curtain through which air flows with the air velocity increased in the slot and then slowed down in a larger volume separation chamber. The direction of air and water flow are reversed several additional times with the air flowing through several additional water curtains. The water and air are discharged into a large precipitation chamber in which the water is collected and the air velocity is reduced very substantially before discharge through an air exhaust duct.

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: A spray booth that provides an improved, more uniform circulation of air past the operator and workpiece and a more effective cleaning of the air of oversprayed particulates. A plurality of water washes are utilized in the air cleaning section of the spray booth. The spraying section includes an open-faced front user portal with a grated flooring. The cleaning section includes three water washes. The first water wash underlies the grated flooring and has a spillway that slopes downward from the front of the portal towards the rear. The second water wash is disposed at the rear of the spraying section and includes a plurality of baffle surfaces that extend across the width of the spraying section from the ceiling toward the spillway, with the bottoms of the baffle surfaces and the surface of the spillway defining a space therebetween.

Abstract: A wet pump-less spray painting booth is provided that more efficiently removes overspray paint particles from the air and uses substantially less make-up water than prior designs of wet pump-less booths. In a rear air cleaning section of the booth, blower-generated air flow sucks water from a lower reservoir up through ducts into an upper plenum where the air and water impact against a splash plate, creating a turbulent mix of air and water. Water from the upper plenum drains through tubes to an upper reservoir and overflows the upper reservoir along a sheet, the bottom edge of which is spaced a substantial distance from the lower reservoir, creating a water curtain.

Abstract: Spray particles are removed in at least a 180.degree. surround of an article traversing an arcuate path in the interior of a spray booth. The booth includes a water wash extending vertically for a height greater than the work area and a spray area and preferably extends upwardly to the area of an overhead conveyor. Air flow is maintained at a substantially constant velocity to carry overspray particles into the water wash and away from the article and a water particle eliminator eliminates water particles from the cleaned air being discharged. The preferred booth comprises a plurality of adjacent units set at angles to each other to define a polygon of at least 180.degree. with a planar water wash means being provided in each unit. A conveyor protection device may be used which discharges positively pressure air from a housing about the conveyor with the air flow in the booth pulling this blown air away from the spray areas and booth portal and into and through the water wash.

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: In a booth in which articles are carried along a pathway for treatment with sprayed material directed through nozzles or the like at the pathway, apparatus is provided for positively rotating the conveyed articles to assure uniform treatment on all sides thereof. Article supports are connected to the conveyer, each having a first portion carried by the conveyer and a second portion rotatable relative to the first portion for holding an article. A toothed member on the second portion is positively engaged by and driven by links of a link belt to rotate the second hanger portion and the article held thereon.

Abstract: A spray booth is provided with an air cleaning system to remove airborne particles for use in heavy production applications where large amounts of paint are sprayed and in which large quantities of airborne particles are collected without a substantial reduction in air flow through the booth as would fall below desired minimum standard of air flow through the booth. Air flows through an open front face of the spray booth and across the piece being sprayed to a first water cascade means which has vertical water covered surfaces offset in the fore and aft direction to trap paint particles and which define vertical extending slots through which the air may pass. The air is deflected downwardly from the first water means across the top surface of a water reservoir at the bottom of a spray booth at which surface further paint particles are trapped. The air then directed upwardly through a downwardly directed water spray wash which traps more airborne paint particles.

Abstract: A protected conveyor for a spray chamber or spray booth is provided with a pressurized housing and an air curtain means which substantially isolates the conveyor from the deleterious fluids within the spray booth and substantially isolates the articles from droppings from the conveyor. More specifically, a blower supplies air under pressure to a plenum connected to a nozzle means which discharges a thin curtain of air transversely across a slot in the housing wall and transversely across depending conveyor hangers extending downwardly through the slot. The blower also supplies air under pressure to the housing to provide air discharge out of the housing slot. The transverse air discharge combines with and redirects the air discharge through the slot as common continued air movement transversely away from the conveyed articles and toward an external air exhaust from the booth. The housing, conveyor and air curtain means are formed in an inexpensive manner.