Abstract: A water heater supplies hot water at a variable flow rate, depending on demand, and at a substantially constant, controlled temperature. It comprises a heat exchanger formed with an inlet and an outlet whereby water can be supplied to and withdrawn from the heat exchanger in accordance with demand and means for passing a second fluid such as steam through the heat exchanger coil to heat the water. A temperature gradient is thus established in the water in the direction of its flow through the heat exchanger. A sense tube forms a substantially homogeneous mixture of different portions of the water, these portions being drawn from sampling points spaced apart along the temperature gradient and in relative proportions depending on the flow rate of the water through the heat exchanger. The temperature of the water in the sense tube is detected, and control means responds to the sensed temperature for controlling the rate at which steam is supplied to heat the water.

Abstract: A heat-reclaiming system is especially adapted for reclaiming heat from used laundry water. It comprises a heat exchanger providing for heat transfer from warm used laundry water to cold incoming water intended for use as fresh laundry water. The heat exchanger is formed with interior ducts and an outer shell. The interior ducts, preferably concentric coils hydraulically in parallel, define a space for the transport through the heat exchanger of the cold incoming water. The outer shell encloses the ducts, and the ducts and shell together define a space providing for the transport through the heat exchanger of the warm used laundry water. The flows of the warm and cold water through the heat exchanger are generally in opposite directions. Maximum heat-transfer efficiency is accomplished by simultaneously pumping both the shell and the duct sides of the exchanger at design flow condition and maximizing the log mean temperature difference across the heat exchanger.

Abstract: A fluidic device having a sensing nozzle remotely mounted from an emitter assembly and communicating with it through a connecting tube. An adjustable nozzle assembly, located within the emitter assembly, is movable with respect to an outlet and aligned orifice to provide a zero level output signal from the outlet for various lengths of connecting tube. The nozzle assembly is also adjustable to provide a range independent zero level output signal for different pressure level sensitivities. A test jack communicates with the outlet to monitor the output signal and provide for adjusting the zero level output signal.

Abstract: A high stability pneumatic pressure regulator is provided by the use of a movable vane and nozzle assembly to operate a valve plug and thereby change the regulator output pressure. Movement of the vane and nozzle assembly is initiated by an adjustable input member which changes the vane to nozzle spacing and subsequently causes the vane and nozzle assembly to move with the valve plug until the normal vane to nozzle spacing is restored. A feedback of the output pressure is used to balance the adjustable input member.