The Kinetic Water Pump

DOUBLE-ACTING KINETIC PUMP

 The Double-Acting Kinetic Pump shown schematically in Figure 5 has two pistons that move symmetrically opposite to each other so that vibration is reduced. Only half of the system is shown in the drawing.

During operation, steam inters at the center of the acceleration tube to force the left piston to the left, and steam flows through the steam channel to force the right piston to the right. Water ahead of the pistons is accelerated toward the ends of the acceleration tube. When the water strikes the check valves, it forces the check valves open, and some of the water flows into the compressed-air surge tank. The check valves are flapper-type valves that are spring loaded to keep them normally closed. The water continues to flow until the kinetic energy of the water and the piston is depleted.

When the right end of the left piston passes the steam exhaust pipe, the steam flows out to a condenser.

When the water and the piston stop, high-pressure air from the compressed-air surge tank flows through the air pipe and pushes on the end of the return cylinder, which is a hole formed in the center of the piston. The force on the end of the return cylinder accelerates the left piston to the right, and a similar system in the right piston accelerates the right piston to the left. This design allows for high flow rates of pumped liquid.

Details of the operation are not given in this document. Other, more advanced designs have been developed that are not included here.

Figure 5. This schematic shows the left half of the Double-Acting Kinetic Pump. The right half (cut off) is symmetrical with the left half except for the steam valve assembly.

INTELLECTUAL PROPERTY

 Extensive patent searches were made without finding any conflicting prior art. A number of patents were found that described pumps that used steam to pump a liquid (as in Figure 1), but they failed to utilize the heat in the steam with adiabatic expansion. That means that their energy utilization is roughly cut in half. Furthermore, their systems could not pump water to higher pressures than the steam pressure. For our Kinetic Pump, calculations show that we can use 200 or 300-psi steam to pump seawater to 1000 psi for reverse osmosis desalination.

Since the patent searches were favorable, a Patent Application was filed for the Kinetic Pump.

APPLICATIONS AND ADVANTAGES

 For RO desalination applications, the pump can be made to run 24 hours per day, if desired. Solar trough collectors often use high temperature mineral oil to collect energy as it runs through the collector. The oil can be used to generate steam in a heat exchanger. Some of the oil can run through a heat exchanger to store energy in a phase-change storage unit that provides energy at night to produce steam for the Kinetic Pump.

The great attractiveness of the Kinetic Pump in solar-powered desalination is that steam can be taken from a solar dish or solar trough and used to directly pump high-pressure seawater into an RO unit. For large systems in which there are many solar dishes or troughs and one central desalination plant, one Kinetic Pump can be placed adjacent to each solar collector so that the steam will not have to be piped long distances to the central plant, with attendant energy loss. Each Kinetic Pump would pump high-pressure seawater into pipes that lead to the central plant.

Besides pumping high-pressure water, this pump can pump hydraulic oils and other chemicals.

For electric power generation, since this method can produce high-pressure liquid efficiently, the pressurized liquid can then be directed into a Pelton Wheel turbine or a positive displacement engine that turns a generator to produce electricity. Since water turbines can be 95% efficient or positive displacement devices can be 85% efficient, the complete system would be efficient. This application would be attractive for small or large systems. The 30 Mwe SEGS power plant in the Mojave Desert , which uses solar trough collectors, performs at only 10.6% solar-to-electric efficiency. If we can develop a Kinetic Pump that runs at a temperature of 727 C (from Table I), we could achieve a theoretical efficiency of 43.1% (row 5 of the table). To be conservative, we multiply that by 80% and get 34.5%. With a 95% efficient high-pressure water turbine, the shaft power would be 33% efficient. Having a 95% efficient generator would yield a 31% over all thermal efficiency. If a solar dish is used that has 90% collection efficiency, the solar-to-electric efficiency would be 28%. That is 2.6 times as efficient as the SEGS plant. Going to higher temperatures would yield higher efficiencies.

Normally a hydraulic ram pump is considered to be a device which uses a low head of water to produce a small volume of higher head water. This Kinetic Pump can be used in the reverse sense. That is, high-pressure steam can be used to accelerate a long pipe full of water to produce a large volume of water at low head. Thus, a small volume of high-pressure steam can pump a large volume of low-pressure water.

During times in which the sun is shining weakly through high thin clouds, the steam pressure might be low, but the pump would still produce 70 bar water, although at a lower volume.

Introduction | Part 1 | Part 2 | Part 3 | Part 4