Patent Application
20180221899
The present invention is directed to a system and apparatus for an electric pressure washer. Preferably, but not exclusively, the system of the present invention includes a heat exchanger in which the water is never heated in a tank or exposed to a heating element. In one embodiment, the heat exchanger of the present invention may be an in-cast type heat exchanger and may be combined with a plurality of other heat exchangers, which may vary in type. Preferably, the electric power washer present invention is able to heat pressurized water quickly and efficiently.
Frequently, electricity is used power a motor that turns a pump to pressurize the water and a separate heating element, which can be either gas or electric, is used to heat a tank of water. In many of the current electric pressure washers, the heat exchanger includes a heating element that is either a tank style heating element or an encased style heating element. A tank style heating element submerses a coil in a tank of hot water and the pressurized water then flows through the submersed coil. This requires the tank of hot water be initially heated to the desired temperature. These tank style systems are slow to heat the pressurized water, require a constant heating of the tank water, and thus are very inefficient.
The other current option is the encased element style of heating elements which has an element inside of a tube. The pressurized water flows through this tube and circulates about the heating element. This places the heating element in direct contact with the water. This encased element style of heating element presents many problems. For example, the minerals in the water are typically drawn to the element and form a scale which decreases the efficiency of the heating element while simultaneously increasing the maintenance requirements of the unit.
It is therefore desirable to have an electric pressure washer that overcomes one or more of the problems of the prior art and improves upon the state of the art.
Accordingly, it is an objective of the claimed invention to improve upon the state of the art.
Another object of the present invention is an electric pressure washing system which minimizes maintenance of the heating element in the unit.
Another object of the present invention is an electric pressure washer which is able to heat pressurized water at an improved rate.
Another object of the present invention is an electric pressure washer which provides higher temperature rises over an extended spray time.
Another object of the present invention is an electric pressure washer which minimizes scale buildup within the heat exchanger.
These and other objects, features, or advantages of the present invention will become apparent from the following specification, figures, and claims.
The present invention preferably includes a power washing machine where the power washing machine includes a base frame to which a plurality of panels may be secured. A plurality of heat exchangers are secured directly or indirectly to the base frame. At least one of the plurality of heat exchangers includes a heating element surrounded by a metallic body, which is an in-cast heating element. Within the metallic body water tubing is also incorporated. In this manner, the in-cast heating element is not exposed to water within the heat exchanger.
In one embodiment, the power washer apparatus of the present invention includes a base frame on which a first heat exchanger is secured, directly or indirectly. The first heat exchanger includes the in-cast heating elements surrounded by a body and water tubing travelling through the body, the water tubing including an interior through which fluid flows and an exterior. The in-cast heating element is located within the body and outside the water tubing interior. This arrangement prevents the buildup of scale or other deposits on the heating element.
The apparatus further preferably includes a pressure unit, which is generally comprised of an electric motor and a pressurizing pump. Tubing connects the pump to the heat exchanger and a gun is operatively connected to the heat exchanger to dispense pressurized fluid. The power washer apparatus may include a detergent system including a tank of detergent solution, a detergent metering valve, and a hose operatively connecting the detergent system to the gun.
In another embodiment, the present invention includes a second heat exchanger. Preferably, the second exchanger also includes an in-cast heating element. Alternatively, the power washer apparatus of the present invention can use multiple heat exchangers with a variety of heating elements, including an encased heating element, a tank style heating element, or an in-cast element style heating element. These heat exchangers can be arranged in series or in parallel.
In another embodiment, the power washer of the present invention further includes an unloader, a pressure regulating value, a thermostat, and other control systems to ensure proper operation of the power washer system.
The following drawings form part of the specification and are included to further demonstrate certain embodiments or various aspects of the invention. In some instances, embodiments of the invention can be best understood by referring to the accompanying drawings in combination with the detailed description presented herein. The description and accompanying drawings may highlight a certain specific example, or a certain aspect of the invention. However, one skilled in the art will understand that portions of the example or aspects may be used in combination with other examples or aspects of the invention and that the drawing and preferred embodiments are not to be limiting.
The following definitions and introductory matters are provided to facilitate an understanding of the present invention.
Numeric ranges recited within the specification, including ranges of “greater than,” “at least,” or “less than” a numeric value, are inclusive of the numbers defining the range and include each integer within the defined range.
The singular terms “a”, “an”, and “the” include plural referents unless context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicate otherwise. The word “or” means any one member of a particular list and also includes any combination of members in that list.
One example of the present invention is shown in
A flow diagram of the present invention is shown in
Next, the water travels past the flow valve 112 and into the water inlet 122 of the heat exchanger 120. The heat exchanger 120 is shown in
The heating elements 144 of the heat exchanger 120 are never exposed to the water that travels through the high pressure piping 126. This prevents the water from contacting the heating elements and minimizes any potential scale buildup. It also enables the water to be heated rapidly. After the water is heated, it exits the heat exchanger 120 through outlet 124. The water then travels through additional high pressure tubing 106 past a thermostat 138. The thermostat is operatively connected to a control system which will turn on the heat exchanger 120 if the temperature is too low and, correspondently, turn off the heat exchanger 120 if the temperature gets too high.
The heated water then flows past the detergent system 148. If no detergent is desired, the water will flow through a t-valve 134 and past the detergent metering valve 150 to the gun 160. If detergent is desired, the detergent system 148 will take the liquid detergent solution 156 and incorporate it into the water stream. This is done by allowing the detergent solution 156 to travel through a detergent strainer 154 through a detergent hose 152 and into the detergent metering valve 150, where it is joined with the high pressure heated water flow. The water flow is dispensed by the user through the gun 160. As shown in more detail in
As shown in more detail in
An example of one embodiment of a plurality of heat exchangers is shown in
As shown further in
From the outlet 124, the heated pressurized water travels through a variety of high pressure hoses 126 and a variety of connecters 146, which may include nipples 128 or other connecters such as t-connectors or elbow connectors. The water passes a thermostat 138 which will turn off the heat exchanger 120 if the water gets too hot or turn on the heat exchanger 120 if the water gets too cold. The water then travels through additional high pressure hoses 126 to reach the outlet assembly.
An alternative arrangement is shown in
In operation, a pressurized water source, such as a garden hose connection, is connected to the power washer assembly 10 and into the water inlet 20. When the water is turned on, water will flow through a water strainer 22 and into the high pressure pump unit 80. An unloader can bypass the water when the trigger gun is closed. To protect the pump from heated water during this bypass stage, a heat pump valve will preferably open at or above 125 degrees Fahrenheit or at or above 52 degrees Celsius, allowing the heated water to escape. The heat dump valve automatically resets when the water cools. Attached to the pump is a pressure switch that controls the time/delay shut down feature.
After the high pressure water exits the pump, it enters a safety system which protects the operator from danger. The safety system contains a flow switch which must signal that water is flowing before it allows the heaters to turn on. From there, the water flows through the heat exchanger inlet where it is heated when the heat exchanger switches are on. As the water exits the heat exchanger outlet, it passes an adjustable thermostat which senses the water temperature and shuts off the heat exchangers if the water gets too hot. If the unloader fails to bypass water, or the heat exchanger remains on when the trigger gun is closed, the safety relief valve will relieve and allow water to exit safely. During normal operation, the trapped pressure in bypass mode may be lowered by the pressure regulating valve which will relieve a small amount of water into the bypass loop. This will lower the trap between the unloader and the gun.
The heated water then flows through the high pressure hose and to the trigger gun assembly which allows the operator to control the water supply. When the trigger gun is open, the water flows through the adjustable pressure dual lance and exits the nozzle. In this manner, an electric pressure washer is provided that operates in a safe and efficient manner and accomplishes the objects of the present invention.
It will be appreciated by those skilled in the art that other various modifications could be made to the pressure washer apparatus and system as described above without parting from the spirit and scope of this invention. All such modifications and changes fall within the scope of the claims and are intended to be covered there by.
