Abstract: Methods, systems, and apparatuses are described to help manage oil return such as in a chiller system of a HVAC system. A refrigerant/oil mixture can be directed out of the evaporator into an oil return heat exchanger that is configured to help vaporize a refrigerant portion of the refrigerant/oil mixture. Superheat refrigerant vapor can be directed from a condenser into the oil return heat exchanger as the heat energy to vaporize the refrigerant portion in the refrigerant/oil mixture. The oil return heat exchanger can be positioned lower than the evaporator so that gravity can help the refrigerant/oil mixture to flow into the oil return heat exchanger.

Abstract: A system is provided to control fluid flow in a wastewater treatment system through wastewater level manipulation. The wastewater treatment system may include a wastewater treatment plant connected to a plurality of pump stations by a main. Each of the plurality of pump stations may include a wet well with a pump therein. The system may include a central server in communication with a sensor to sense a level of wastewater within the wet well. The pump may be automatically moved to an on position when the level of the wastewater in the wet well is at or above a first level and may be automatically moved to an off position when the level of the wastewater in the respective wet well is at or below a pump cutoff level. The central server may systematically manipulate the first level to selectively set the level of wastewater within the wet well.

Abstract: Reductions in energy consumption and maintenance requirements for operating a wastewater treatment plant are achieved by controlling the operation of pumps at pump stations along a force main in a systematic fashion. The operation of the pumps is controlled to manage the flow of wastewater along the force main to minimize energy consumption, to eliminate sediment, to manage peak pressures encountered by smaller pumps and to avoid septic conditions.

Abstract: Interruption in supervisory position control signals can cause problems with respect to actuators which upon loss of such control signals for the actuator will generally slew to a fixed idle position. In such circumstances a machine such as a gas turbine engine in which an actuator is associated will not sustain performance even though there is continued local power supply to the actuator. By utilizing a local controller which stores actuator response profiles for certain machine status stages through perturbation or marginal activation of the actuator an appropriate actuator response profile can be chosen and therefore sustaining control signals presented to the actuator to maintain machine operation.

Abstract: An apparatus for pumping liquids to a destination includes a pipe of a first cross-sectional area extending from the liquid to be pumped to the destination. A body having a cross-sectional area less than twice the first cross-sectional area also has an upper portion, a lower portion, an inlet in the upper portion and an outlet to the pipe in the lower portion, a gas injection port, and a normally open valve between the gas injection port and the inlet, closeable upon an injection of gas through the gas injection port. Gas injection apparatus injects gas through the gas injection port from time to time. When no gas is being injected, liquid may enter the upper portion of the body through the inlet and fall by gravity toward the outlet in the lower portion and the pipe. Upon injection of gas, the valve closes, trapping liquid in the body below the valve, and trapped liquid is forced out the outlet and into the pipe toward the destination.

Abstract: Apparatus for transferring metered quantities of a flowable bonding agent from a tank into a mixer of a sand core making machine has an upright tubular vessel into which the bonding agent is drawn from the tank by a suction pump and a pressure pump which transfers the accumulated bonding agent from the vessel into the mixer. The vessel contains a float which cooperates with sensors serving to generate signals for actuation or deactivation of the pumps and/or valves in the conduits connecting the vessel with the tank, mixer and the pumps. The bonding agent is kept out of contact with the pumps and out of contact with the valves in the conduits connecting the vessel with the pumps.

Abstract: In a diaphragm fluid pump which includes a diaphragm piston assembly assembled within a pump housing to form a pump chamber at one side thereof, the diaphragm piston assembly includes a diaphragm member secured in a fluid-tight manner at its outer periphery to the peripheral wall of the pump housing, and an operation rod connected at one end to the diaphragm member and at another end to a swingable end of a rocker arm to reciprocate the diaphragm piston assembly in an axial direction so as to produce a positive or negative pressure in the pump chamber. A pair of axially spaced upper and lower guide assemblies are mounted within the pump housing to slidably support the operation rod in its axial direction, and a support member is mounted on a lower end portion of the operation rod and slidably supported by the lower guide assembly, the support member being provided at its upper end with a receiver portion for receiving thereon the swingable end of the rocker arm.

Abstract: A device for controlling the performance of pumps, having a constant volume such as pneumatic pumps having a constant volume, comprises liquid level detectors, such as magnetic microswitches that cooperate with a magnetized float, and the detectors are adapted to control the filling and delivery operation of pumped liquid into and out of a pump body.The device may comprise three or more liquid level detectors and a timing device for the filling and/or delivery operation of the pump, at least one of said detectors being adapted to control said timing device and the other liquid level detectors being adapted to control the filling and delivery operation itself.

Abstract: For starting and stopping air injection, a pneumatic ejector for a liquid transport system typified by a municipal sewerage system is provided with an air release valve fitted with a limit switch as a control device.

Abstract: A pumping system intended especially for highly contaminated liquids uses an air pump for drawing liquid into or discharging the liquid from a vessel by creating respectively a vacuum or a pressurized condition within the vessel. A special valve device is provided for the system comprising an air filter in combination with a float-actuated, shut-off switch to preclude the entry of air or liquid-borne contaminants into the pump. The float-actuated switch is arranged to disable a prime mover used for driving the pump. An additional safety feature of the system comprises the provision of an intermediate float valve located between the pump and the valve device, to preclude the passage of liquid therebetween, the intermediate valve having a sight glass to detect leakage liquid and a drain cock to permit drainage of such liquid.

Abstract: A slurry pump including a pressure tank with an inlet and a lower outlet and having a pneumatically operated, inwardly opening closure at the inlet and a hinged, outwardly opening door at the outlet swingable between opened and closed positions. An external source of air under pressure hydraulically shuts the closure and pressurizes the tank, forcing a semi-liquid slurry such as liquid manure contained within the tank through the outlet and into a duct leading to a lagoon or the like. A slurry level sensor shuts off the supply of air to the tank when the slurry reaches a given level in the tank.