A proportioning valve for a reverse osmosis system that controls the production of product water by the differential pressure across the purification membrane. By sensing increasing tank pressure to actuate the proportioning valve, the flow of waste water is restricted. Placement of seals within the cavity of the valve, as well as placement of waste water inlet and outlet ports, protects tension components that provide reverse tank pressure from waste water exposure. A needle valve assembly responsive to an actuating assembly that senses tank pressure removes the need for an inlet tank water port while restricting water flow.

A heat power management system is disclosed for an alternating current (AC) power controller for use with portable reverse osmosis water purification systems requiring precise control of a heating action for an internal water heater coupled with energy savings and the reduction of AC line disturbances. The heat power management system is designed to operate with various international electrical systems while protecting such system from excessive current draws.

A reverse osmosis desalination system has a combined displacement pump and displacement pressure recovery motor that propagate feed water with a structurally fixed recovery rate and structurally stabilized volume flow through continuously alternating discharging and recirculation intervals. Thereby enabled is an instantaneous discharge of the entire feed water concentrate and unmixed replacement with low salinity source water that intermittingly and effectively flushes the reverse osmosis membranes. This in turn provides for high recirculation peak salinity and recovery rate that are simple and reliably controlled without impairing membrane longevity.

A reverse osmosis desalination system has a combined displacement pump and displacement pressure recovery motor that propagate feed water with a structurally fixed recovery rate and structurally stabilized volume flow through continuously alternating discharging and recirculation intervals. Thereby enabled is an instantaneous discharge of the entire feed water concentrate and unmixed replacement with low salinity source water that intermittingly and effectively flushes the reverse osmosis membranes. This in turn provides for high recirculation peak salinity and recovery rate that are simple and reliably controlled without impairing membrane longevity.

A control system has a water purification module and a control module. The water purification module has a preliminary filter and a reverse osmosis filter. The control module regularly controls the purification and the drainage of the water purification module, and solves the problem that the TDS value of the water on both sides of the reverse osmosis membrane is too high after the water purifier is on standby for a period of time. The control system regularly drains high concentration water on both sides of the reverse osmosis membrane to improve water purification efficiency.

A control system has a water purification module and a control module. The water purification module has a preliminary filter and a reverse osmosis filter. The control module regularly controls the purification and the drainage of the water purification module, and solves the problem that the TDS value of the water on both sides of the reverse osmosis membrane is too high after the water purifier is on standby for a period of time. The control system regularly drains high concentration water on both sides of the reverse osmosis membrane to improve water purification efficiency.

A method of predicting membrane fouling in a reverse osmosis process includes collecting information relative to the reverse osmosis process being performed over a predetermined period of time, the collected information including a process factor and a water quality factor, the process factor including a produced water flow rate; calculating a salt removal rate and a pressure drop based on the collected information; normalizing the produced water flow rate, the salt removal rate, and the pressure drop; generating a prediction equation using normalized values of the produced water flow rate, the salt removal rate, and the pressure drop values; and predicting membrane fouling through the generated prediction equation to determine a chemical cleaning time. Process and water quality factors are normalized to temperature and/or flow rate, and the prediction equation uses the normalized factors. Both short-term and long-term predictions are made for chemical cleaning time and membrane module replacement time.

A method of predicting membrane fouling in a reverse osmosis process includes collecting information relative to the reverse osmosis process being performed over a predetermined period of time, the collected information including a process factor and a water quality factor, the process factor including a produced water flow rate; calculating a salt removal rate and a pressure drop based on the collected information; normalizing the produced water flow rate, the salt removal rate, and the pressure drop; generating a prediction equation using normalized values of the produced water flow rate, the salt removal rate, and the pressure drop values; and predicting membrane fouling through the generated prediction equation to determine a chemical cleaning time. Process and water quality factors are normalized to temperature and/or flow rate, and the prediction equation uses the normalized factors. Both short-term and long-term predictions are made for chemical cleaning time and membrane module replacement time.

A method for filtering a dairy product is used in a filter system that includes at least one pump loop having a pump and a filter, with the pump being arranged to feed a feed product to the filter for filtering the feed product and outputting a permeate product and a retentate product. The method includes supplying the feed product to the pump at a feed pressure, during a first operational mode in which the feed pressure is below a first predefined threshold, controlling the pump to operate at a first power that is within a first percentage range of a maximum rated power of the pump, and during a second operational mode in which the feed pressure is above the first predefined threshold, controlling the pump to operate within a second percentage range of the maximum rated power which is higher than the first percentage range.

A method for filtering a dairy product is used in a filter system that includes at least one pump loop having a pump and a filter, with the pump being arranged to feed a feed product to the filter for filtering the feed product and outputting a permeate product and a retentate product. The method includes supplying the feed product to the pump at a feed pressure, during a first operational mode in which the feed pressure is below a first predefined threshold, controlling the pump to operate at a first power that is within a first percentage range of a maximum rated power of the pump, and during a second operational mode in which the feed pressure is above the first predefined threshold, controlling the pump to operate within a second percentage range of the maximum rated power which is higher than the first percentage range.