Hot water pressure washer

Abstract

A hot water pressure washer for delivering a high pressure stream of heated water. The hot water pressure washer includes an engine, a source of gas, a water heater, and a high pressure water pump. In one embodiment, the gas is one of liquefied natural gas, liquefied petroleum gas, gasoline, or propane. The water heater includes a gas input adapted to be coupled to an outlet of the source of gas and a water input adapted to be coupled to a source of water. The water heater includes a water heater inlet, adapted to receive gas from the source of gas, and a water heater outlet, adapted to provide a heated water to a spray wand. A high pressure water pump receives water from the water heater outlet and the water pump outlet provides the pressurized heated water to a spray wand.

1 . A pressure washer for delivering a high pressure stream of heated water comprising:
 a gas source, wherein the gas source includes an outlet to deliver a gas;   an engine adapted to be connected to the outlet of the gas source, wherein the engine includes an output shaft;   a water source connection adapted to be operatively connected to a source of water;   a water heater including a gas input adapted to be coupled to the outlet of the gas source and a water input adapted to be coupled to the water source connection, the water heater including a water heater outlet adapted to provide a heated water; and   a high pressure water pump including a water pump inlet adapted to be coupled to the water heater outlet, a pump actuator operatively connected to the output shaft of the engine, and a water pump outlet adapted to provide pressurized heated water.   
     
     
         2 . The pressure washer of  claim 1  wherein the engine is one of a liquefied natural gas engine or a gasoline engine, wherein the output shaft of the engine is driven by one of the liquefied natural gas or the gasoline. 
     
     
         3 . The pressure washer of  claim 1  further comprising a spray wand operatively connected to the water pump outlet, the spray wand including a hand operated valve having an on and off position, wherein the on position delivers a heated high pressure stream of water from the spay wand. 
     
     
         4 . The pressure washer of  claim 1  wherein the engine is a duel fuel engine coupled to the outlet of the gas source. 
     
     
         5 . The pressure washer of  claim 4  wherein the gas source is one of a liquefied natural gas or a gasoline. 
     
     
         6 . The pressure washer of  claim 5  wherein the water heater is an on-demand water heater and includes a heat exchanger operatively connected to the water source connection, and a gas burner directed toward the heat exchanger to heat water flowing through the heat exchanger. 
     
     
         7 . The pressure washer of  claim 6  further comprising a gas control valve having an on and off position and operatively connected to the gas source and to the burner, and a water flow switch having an on and off position and operatively connected to the heat exchanger. 
     
     
         8 . The pressure washer of  claim 7  further comprising a controller operatively connected to the gas control valve and to the water flow switch, wherein the controller actuates the gas control valve between the on and off positon and actuates the water flow switch between the on and off position. 
     
     
         9 . The pressure washer of  claim 8  further comprising a pressure regulator operatively connected to the water pump outlet wherein the pressure regulator controls a pressure of the pressurized heated water. 
     
     
         10 . The pressure washer of  claim 9  further comprising a frame having wheels, wherein the frame supports the gas source, the engine, the water heater, the high pressure water pump, and the controller. 
     
     
         11 . A method of delivering a high pressure stream of heated water from a high pressure washer, the method comprising:
 driving an output shaft of an engine with a gas;   delivering the gas to a water heater to heat water;   pressurizing the heated water with a high pressure water pump, wherein the high pressure water pump pressurizes the heated water in response to the driving the output shaft of the engine; and   delivering the pressurized heated water to a spray wand in response to actuation of a hand operated valve.   
     
     
         12 . The method of  claim 11  wherein the engine is a duel fuel engine. 
     
     
         13 . The method of  claim 11  wherein the engine is one of a liquefied natural gas engine or a gasoline engine. 
     
     
         14 . The method of  claim 13  wherein the delivering the liquefied natural gas to the water heater includes delivering the liquefied natural gas from a portable propane tank. 
     
     
         15 . The method of  claim 14  further comprising delivering the liquefied natural gas to the engine from the portable propane tank. 
     
     
         16 . A pressure washer for delivering a high pressure stream of water from a spray wand comprising:
 a gas source, wherein the gas source includes a portable propane tank having an outlet to deliver a propane gas from the propane tank;   a gas engine coupled to the outlet of the gas source, wherein the gas engine includes an engine actuator driven by combustion of the propane gas;   a water source connection adapted to be operatively connected to a source of water;   a water heater including a gas input adapted to be coupled to the outlet of the gas source and a water input adapted to be coupled to the water source, the water heater including a water heater outlet adapted to provide a heated water;   a high pressure water pump including a water pump inlet adapted to be coupled to the water heater outlet, a pump actuator operatively connected to the engine actuator, and a water pump outlet adapted to provide pressurized heated water; and   a frame including a first shelf and an second shelf, wherein one of the propane tank and the gas engine is located on the first shelf, and the other of the propane tank and the gas engine is located on the second shelf.   
     
     
         17 . The pressure washer of  claim 16  wherein the high pressure water heater is an on-demand water heater and is located on one of the first shelf, the second shelf, or another shelf. 
     
     
         18 . The pressure washer of  claim 17  further comprising a hood, wherein the hood is located on the frame and covers at least a portion of the propane tank and the gas engine. 
     
     
         19 . The pressure washer of  claim 18  wherein the propane tank includes a hand wheel for releasing the gas from the propane tank, and the hood includes an opening to provide access to the hand wheel. 
     
     
         20 . The pressure washer of  claim 16  wherein the engine is a duel fuel engine.