A common issue in self-serve car washes is high-pressure chemical dispensing. When the water supply line to the pump is fully open, soap and wax often fail to draw into the lines, affecting wash quality.
Interestingly, while pump cavitation is usually undesirable, we can use it to our advantage in this scenario.
Understanding Cavitation and the Venturi Effect
Cavitation occurs when pump pressure drops below the vapor pressure of the fluid, creating vapor pockets that can damage the pump. However, during this controlled process, a low-pressure zone is formed, enabling chemicals to be drawn into the system. This principle relates to the Venturi effect, where fluid pressure decreases as it flows through a constricted area, effectively facilitating chemical draw.
Steps for Proper Chemical Draw
Each pump should have its own ball valve for the water supply. Follow these steps to ensure effective chemical dispensing:
- Prepare the Gun: Activate the high-pressure soap or wax function and zip tie the gun trigger to keep it engaged.
- Adjust the Water Supply: Slowly close the ball valve for the water supply until the pump starts to cavitate, creating that low-pressure condition.
- Fine-tune the Valve: Gradually reopen the ball valve until cavitation stops, allowing chemicals to be effectively drawn into the system.
Conclusion
By using pump cavitation and the Venturi effect, you can optimize chemical dispensing in your self-serve wash bays. This not only enhances cleaning performance but also extends the life of your pump. For any questions or support regarding your self-serve system, feel free to reach out to us — all day, Every Bay!