Abstract: A dishwasher has a housing (10) with a wash chamber (20) and a top wall (204) with a non-planar surface (214;214?) facing downwardly into the wash chamber, the surface having portions (216,218; 226,228) facing downwardly and facing in different horizontal directions (H1,H2; HX,HY,HP,HQ). Nozzles (402) mounted within the wash chamber spray a liquid upwardly within the wash chamber. The surface portions redistribute the upwardly-sprayed water in horizontal directions to provide a more uniform washing action. A portable dishwasher may have a fresh water reservoir (422) and a used water reservoir (430) mounted in the housing beneath the wash chamber. The used water reservoir may be removably mounted in the housing so that the user can remove used wash water by removing the used water reservoir. The portable dishwasher can be used at a location remote from a sink.

Abstract: A heater for heating a conductive liquid includes a two-dimensional array of rod-like electrodes (22, 122, 322, 422, 522) extending parallel to one another, an electrical power supply having a plurality of poles, and power switches to connect different ones of the electrodes to different poles so that current flows between the poles through the liquid. The array desirably includes outer electrodes defining the boundary (24, 424) of the array and inner electrodes disposed within this boundary. The array may have regular or irregular spacings between the electrodes. The array can provide numerous different connection schemes to vary the electrical resistance between the poles and thus vary the heating rate. The array can be arranged to provide substantially equal currents through three poles of a three-phase power supply.

Abstract: An ohmic heater for heating a conductive fluid has a plurality of electrodes mounted to a structure with spaces between the electrodes. The electrodes (14) are selectively connect to poles (38, 40) of a power supply, so that some electrodes are connected to the poles and others remain isolated from the poles. Shunting switches are provided for connecting two or more of the isolated electrodes to one another. The shunting switches allow formation of a large number of different connection schemes having a variety of different electrical conduction paths through fluid in the spaces and a variety of resistances between the poles with relatively few electrodes and spaces.

Abstract: A flowmeter for measuring flow of a conductive liquid includes a structure (20, 220) defining a flow path, electrodes in the flow path and electrodes (34a, 34b, 234a, 234b) exposed within the flow path. An electrical circuit (40, 240) applies a voltage between the electrodes so that an electrical current flows along a conduction path between the electrodes within a liquid flowing in the flow path. Means such as temperature sensors (56, 58, 256, 258) are provided for determining a value representing a temperature rise in the liquid passing through a sensing region of the flow path which encompasses at least a part of the. A monitoring circuit (60, 207) determines a value representing the flow rate based on the value representing the temperature, rise the voltage and the current. The flowmeter may be incorporated in an ohmic heater and elements of the ohmic heater may serve as elements of the flowmeter.

Abstract: An ohmic heater has a structure (20) defining a flow path extending in a downstream direction (D), a first pair of electrodes (34a,34b) and a second pair of electrodes (36a,36b). The electrodes of each pair are adjacent one another in the downstream direction but spaced from one another in a direction perpendicular to the downstream direction; the pairs of electrodes are spaced apart from one another in the downstream direction. An electrical circuit (40,42,44,46,48,50) is operative to apply a voltage (i) between the electrodes (34a,34b) of the first pair; or (ii) between the electrodes (36a,36b) of the second pair; or (iii) between at least one electrode (34a) of the first pair and at least one electrode (36b) of the second pair, and may vary the applied voltage. The heater can meet varying conditions such as changes in conductivity of the liquid flowing through the heater.

Abstract: A liquid heating system includes an instantaneous heater (18) having an inlet (20) connected to a reservoir (62). The outlet (22) of the heater is connected to fixtures (72) which use the heated liquid, and is also connected through a return connection (30) to the reservoir. In an idle mode, a pump 40 draws liquid from the reservoir (62), so that the liquid circulates through the heater and back to the reservoir. A controller (52) actuates the heater to heat the liquid to a first setpoint temperature, so that the liquid in the reservoir stabilizes at the first setpoint temperature. In a supply mode, some or all of the heated liquid flows from the outlet to the fixtures (72). Cold liquid is admitted from a supply (60) to the reservoir, and cold liquid desirably also is supplied to the heater inlet along with liquid from the reservoir, so that the heater inlet receives a combination of these.

Abstract: A dishwasher has a housing (10) with a wash chamber (20) and a top wall (204) with a non-planar surface (214;214?) facing downwardly into the wash chamber, the surface having portions (216,218; 226,228) facing downwardly and facing in different horizontal directions (H1,H2; HX,HY,HP,HQ). Nozzles (402) mounted within the wash chamber spray a liquid upwardly within the wash chamber. The surface portions redistribute the upwardly-sprayed water in horizontal directions to provide a more uniform washing action. A portable dishwasher may have a fresh water reservoir (422) and a used water reservoir (430) mounted in the housing beneath the wash chamber. The used water reservoir may be removably mounted in the housing so that the user can remove used wash water by removing the used water reservoir. The portable dishwasher can be used at a location remote from a sink.

Abstract: An ohmic heater for heating a conductive fluid has a plurality of electrodes mounted to a structure with spaces between the electrodes. The electrodes (14) are selectively connect to poles (38, 40) of a power supply, so that some electrodes are connected to the poles and others remain isolated from the poles. Shunting switches are provided for connecting two or more of the isolated electrodes to one another. The shunting switches allow formation of a large number of different connection schemes having a variety of different electrical conduction paths through fluid in the spaces and a variety of resistances between the poles with relatively few electrodes and spaces.

Abstract: An ohmic heater for heating a conductive fluid includes electrodes (14) and spaces (20) between the electrodes. A controller (52) selectively connects the electrodes to a power supply (36) during a succession of actuation intervals so as to form conduction paths, each including two live electrodes connected to different electrical potentials, and the fluid in one or more spaces. The controller models fluid passing through the spaces as a series of finite elements moving through the spaces. Before each actuation interval, the controller estimates the expected results of actuating various possible conduction paths, including the estimated temperature of the fluid in the conduction paths and the estimated currents passing through the live electrodes. The controller selects a set of conduction paths for which the estimated results meet a set of constraints, and actuates only the selected conduction paths during the actuation interval.

Abstract: A liquid heating system includes an instantaneous heater (18) having an inlet (20) connected to a reservoir (62). The outlet (22) of the heater is connected to fixtures (72) which use the heated liquid, and is also connected through a return connection (30) to the reservoir. In an idle mode, a pump 40 draws liquid from the reservoir (62), so that the liquid circulates through the heater and back to the reservoir. A controller (52) actuates the heater to heat the liquid to a first setpoint temperature, so that the liquid in the reservoir stabilizes at the first setpoint temperature. In a supply mode, some or all of the heated liquid flows from the outlet to the fixtures (72). Cold liquid is admitted from a supply (60) to the reservoir, and cold liquid desirably also is supplied to the heater inlet along with liquid from the reservoir, so that the heater inlet receives a combination of these.