Abstract: A filtering apparatus for indicating the degree of exhaustion of an adsorption filter which includes a mechanical filter and a pressure meter for detecting the difference in pressure between a point downstream and a point upstream of the mechanical filter to provide an indication of the degree of exhaustion of the adsorption filter. The mechanical filter may be an internal type filter or a surface filter and it may be either series-connected or connected in shunt with the flow path of the adsorption filter.

Abstract: The casing of apparatus for purifying water encloses a chamber and is formed with two orifices spaced from the chamber in opposite directions and communicating with the same for gravity flow of the water to be purified from one of the orifices through the chamber and out of the other orifice. Two electrodes spacedly mounted in the chamber for flow of the water therebetween are conductively connected to an electric battery in the casing by circuitry which causes current to flow between the electrodes through the water when the water and the battery satisfy proper conditions for the functioning of the apparatus, such conditions being indicated by a sensible signal. A compartment in the casing, sealed from the electrode chamber, encloses almost all the circuitry.

Abstract: A purification unit includes an electrolytic cell adapted to hold a body of water to be purified and provided with two electrically insulated electrodes, a pump supplying the water to be purified to the cell through a filter and driving purified water out of the unit, a power supply for supplying electrolyzing current to the electrodes, a control circuit which generates a sensible signal indicative of the operating conditions of the pump, the power supply, and the filter, and a housing which encloses the cell, the pump, the power supply, and the control circuit. The housing is partly received in a container for the raw water. The portion of the housing projecting from the container carries a discharge spout for purified water, a connector for an external source of current, and the signal display elements of the control circuit.

Abstract: An electrolytic water purification system operated from a battery includes an electrolytic cell which may purify water properly only when an applied voltage exceeds the battery output voltage. A power supply circuit energized by the battery furnishes the necessary higher voltage. An electrically driven pump is directly energized by the battery for pumping the water to be purified through the cell. The pump is automatically deenergized when the conductivity of the water or the available voltage is outside prescribed limits.