Piston pump for liquefied gas

Abstract

A fuel supply system for a vehicle uses a multi-piston LPG injunction pump which pumps fluid from a storage tank to an engine. The multi-piston pump uses the vehicle's pneumatic air system, wherein the pressurized air of this system alternatingly drives at least two pistons of the piston pump. Each piston moves through a pumping stroke and a return stroke wherein one piston moves through a pumping stroke, while the opposite piston moves through a return stroke. The pump includes barrier fluid chambers surrounding each of the pistons wherein during a pumping stroke of one piston, a first barrier fluid chamber associated with the one piston decreases in volume as the piston displaces through its pumping stroke. This reduction in volume of the barrier chamber drives the barrier fluid out of the first barrier fluid chamber into a second barrier fluid chamber associated with the second piston. By driving the barrier fluid into this second chamber, this pressurizes the second chamber and effects the displacing movement of the second piston through its return stroke as the barrier fluid chamber increases in volume through the movement of the second piston.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application asserts priority from provisional application 61 / 583,430, filed on Jan. 5, 2012 which is incorporated herein by reference.FIELD OF THE INVENTION[0002]The invention relates to a multi-piston pump and more particularly to a multi-piston liquid propane injection pump for a vehicle.BACKGROUND OF THE INVENTION[0003]In conventional diesel engines, it is known to inject liquid propane (LPG) into the fuel-air mixture in the fuel header or manifold of the engine. This is done to reduce emissions and increase performance of the vehicle. Typically, the vehicle would include an LPG tank and a pump which is in fluid communication with the LPG tank and pumps the LPG or other fluid into the engine manifold. In a known configuration, such a pump may be an in-tank, submersible turbine pump. However, such a configuration is known to have disadvantages associated therewith.[0004]It therefore is an object of the invention to overcome disadva...

AI Technical Summary

Benefits of technology

The invention includes a device that uses a barrier fluid to improve the performance of a piston. The device not only helps to move the piston but also provides lubrication to prevent leakage and damage to the seals. Additionally, the barrier fluid helps to dampen the tank pressure and prevents a vacuum from being created during the piston's motion. Overall, the device improves the efficiency and lifespan of the piston and reduces the risk of damage to the equipment.

Problems solved by technology

However, such a configuration is known to have disadvantages associated therewith.

This lubrication lengthens the life of the seals.

Additionally, the barrier fluid impedes the leakage of propane past the seals and to the environment.

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