Pressure washer gun with chemical injection and foaming capabilities
A pressure washer spray gun includes a spray gun body configured to be fluidly coupled to a source of pressurized water, a chemical container coupled to the spray gun body, wherein the chemical container is configured to contain liquid chemical, a venturi including a converging section, a throat, and a diverging section, wherein the venturi is coupled to the body, and wherein the chemical container is fluidly coupled to the throat, an air inlet port formed in the diverging section and configured to fluidly couple the diverging section to a source of air, and multiple nozzles, wherein each nozzle has a different orifice diameter, and wherein only one nozzle at a time can be selected to provide a fluid output from the spray gun.
1. A pressure washer spray gun, comprising:
a spray gun body configured to be fluidly coupled to a source of pressurized water;
a chemical container coupled to the spray gun body, wherein the chemical container is configured to contain liquid chemical;
a venturi including a converging section, a throat, and a diverging section, wherein the venturi is coupled to the body, and wherein the throat directly connects the converging section to the diverging section;
a chemical injection port formed in the throat and fluidly coupling the throat to the chemical container;
an air inlet port formed in the diverging section and configured to fluidly couple the diverging section to a source of air; and
a plurality of nozzles, wherein each nozzle has a different orifice diameter, and wherein only one nozzle at a time can be selected to provide a fluid output from the spray gun.
2. The pressure washer spray gun of claim 1 , wherein, in operation, with a first nozzle having a first orifice diameter selected, a first back pressure is created at the venturi, thereby implementing a high pressure operating mode in which pressurized water flows through the venturi and flows through the first nozzle;
wherein, in operation, with a second nozzle having a second orifice diameter greater than the first orifice diameter selected, a second back pressure less than the first back pressure is created at the venturi, thereby implementing a chemical injection operating mode in which pressurized water flows through the venturi and draws liquid chemical into the throat, resulting in a combined fluid flow exiting the diverging section and flowing through the second nozzle; and
wherein, in operation, with a third nozzle having a third orifice diameter greater than the second orifice diameter selected, a third back pressure less than the second back pressure is created at the venturi, thereby implementing a foaming chemical injection mode in which pressurized water flows through the venturi and draws liquid chemical into the throat and draws air into the diverging section, resulting in a foaming combined fluid flow exiting the diverging section and flowing through the third nozzle.
3. The pressure washer spray gun of claim 1 , wherein the plurality of nozzles are included in a rotatable nozzle head, wherein the nozzle head is rotatable to select the desired nozzle.
4. The pressure washer spray gun of claim 3 , further comprising:
a wand attached between the rotatable nozzle head and the venturi to fluidly couple the venturi to the rotatable nozzle head.
5. The pressure washer spray gun of claim 4 , wherein the venturi is formed in a fitting attached between the spray gun body and the wand.
6. The pressure washer spray gun of claim 1 , wherein the plurality of nozzles comprises a plurality of individually replaceable nozzles.
7. The pressure washer spray gun of claim 1 , wherein the source of air is ambient atmosphere.
8. The pressure washer spray gun of claim 1 , wherein the venturi is formed in a fitting.
9. The pressure washer spray gun of claim 8 , wherein the fitting is attached to the spray gun body.
10. The pressure washer spray gun of claim 1 , wherein the spray gun body and the venturi are integrally formed as a single unitary component.
11. A pressure washer spray gun, comprising:
a spray gun body configured to be fluidly coupled to a source of pressurized primary fluid;
a fluid container coupled to the spray gun body, wherein the fluid container is configured to contain a secondary fluid;
a venturi including a converging section, a throat, and a diverging section, wherein the venturi is coupled to the body, and wherein the throat directly connects the converging section to the diverging section;
a chemical injection port formed in the throat and fluidly coupling the throat to the fluid container;
an air inlet port formed in the diverging section and configured to fluidly couple the diverging section to a source of air; and
a plurality of nozzles, wherein each nozzle has a different orifice diameter, and wherein only one nozzle at a time can be selected to provide a fluid output from the spray gun.
12. The pressure washer spray gun of claim 11 , wherein, in operation, with a first nozzle having a first orifice diameter selected, a first back pressure is created at the venturi, thereby implementing a high pressure operating mode in which pressurized primary fluid flows through the venturi and flows through the first nozzle;
wherein, in operation, with a second nozzle having a second orifice diameter greater than the first orifice diameter selected, a second back pressure less than the first back pressure is created at the venturi, thereby implementing a secondary fluid injection operating mode in which pressurized primary fluid flows through the venturi and draws secondary fluid into the throat, resulting in a combined fluid flow exiting the diverging section and flowing through the second nozzle; and
wherein, in operation, with a third nozzle having a third orifice diameter greater than the second orifice diameter selected, a third back pressure less than the second back pressure is created at the venturi, thereby implementing a foaming secondary fluid injection mode in which pressurized primary fluid flows through the venturi and draws secondary fluid into the throat and draws air into the diverging section, resulting in a foaming combined fluid flow exiting the diverging section and flowing through the third nozzle.
13. The pressure washer spray gun of claim 11 , wherein the plurality of nozzles are included in a rotatable nozzle head, wherein the nozzle head is rotatable to select the desired nozzle.
14. The pressure washer spray gun of claim 11 , wherein the plurality of nozzles comprises a plurality of individually replaceable nozzles.
15. The pressure washer spray gun of claim 11 , wherein the venturi is formed in a fitting.
16. The pressure washer spray gun of claim 15 , wherein the fitting is attached to the spray gun body.
17. The pressure washer spray gun of claim 11 , wherein the spray gun body and the venturi are integrally formed as a single unitary component.
18. A pressure washer spray gun, comprising:
a spray gun body including an inlet for receiving a pressurized fluid and a valve configured to be manipulated by a user to control discharge of the pressurized fluid;
a rotatable end including a plurality of nozzles, wherein the rotatable end can be rotated by a user, and wherein upon rotation, one of the plurality of nozzles is selected to discharge fluid from the pressure washer spray gun, wherein the plurality of nozzles each have a different sized effective opening;
a secondary fluid container coupled to the spray gun body;
a venturi provided between the inlet, the rotatable end, and the secondary fluid container;
an air inlet;
wherein when a first nozzle is selected, only the pressurized fluid flows through the first nozzle;
wherein when a second nozzle is selected, the pressurized fluid draws the secondary fluid into the venturi from the secondary fluid container, forming a combined fluid flow for discharge through the second nozzle; and
wherein when a third nozzle is selected, the pressurized fluid draws the secondary fluid into the venturi from the secondary fluid container, forming a combined fluid flow, and at least one of the pressurized fluid and the combined fluid flow draws air into the venturi through the air inlet, forming a foaming combined fluid flow for discharge through the third nozzle.
19. The pressure washer spray gun of claim 18 , wherein the venturi is formed in a fitting.
20. The pressure washer spray gun of claim 19 , wherein the fitting is attached to the spray gun body.