Venturi type chemical dilution systems also known as a “clicker mixes” are an effective way for blending liquid chemicals and managing chemical dilution. They operate according to the theory of differential pressure. Water pressure is higher when it enters the venturi than when it leaves. The suction port on the side of the venturi experiences a vacuum due to the difference between the entry and exit pressures. The vacuum will be stronger and the mixing will be more effective the greater the difference. Based on this, there a few points to keep in mind when buying, installing or calibrating venturi type chemical dilution systems.
While there are many different makes and models of dilution systems available, they are quite similar. The key ideas to consider here are the number of chemicals in use and how you intend to clean with the diluted usable product that will be available from the dilution station. Generally these types of dilution systems are able to dilute between one and four chemicals through a single unit and vary between bucket filler models with a higher flow rate or bottle filler units with a slower flow rate and a thin spout that fits inside the top of a poly sprayer bottle for spray and wipe applications. Bucket filler models have a longer outlet pipe that allows a user to fill a large bucket on the floor, compared to a bottle filling units that fill a spray bottle while being held below the unit. Four product dilution units are able to connect to four different chemicals, that can be selected using a dial on unit to select the chemical of choice.
The SEKO ProMax 14lt per minute bucket filler and the SEKO ProMax 4lt per minute bottle filler are my preference for factories, production areas, abattoirs and restaurants alike. ProMax units from SEKO are easy to install, requiring three small holes drilled. The units come with the screws and plugs needed to mount the backplate to most walls, including isowalls. The units clicks simply to the backplate once mounted. A standard water tap point is required to feed water to the dilution system via a standard washing machine type hose. It’s recommended that the waterpoint be a maximum of two meters away from where the unit will be installed. It is also important that the tap is a dedicated connection for the dilution system as contantly disconnecting and reconnecting the water source can effect the accuracy of dilution. Up to four drums of concentrate chemical stand below the unit to be tapped for dilution. The non return filters and weights common with these systems are important and assist with not allowing anything back into the drum of concentrate and keep the filter at the bottom of the drum for better suction when drums are near empty. It’s also important to note that the concentrate chemical drums should never sit higher than the dilution system on the wall as it will cause chemical leakage inside the units.
Chemical dilution ratios are achieved by inserting coloured tips “jets” into the inlet pipe of the unit before joining the chemical suction pipe to the unit. The tips have different sized holes based on your dilution requirement and can often achieve ratios between 5:1 and 800:1 with ultra lean tips. While four product systems can handle various products from high to low ph, stronger acid based chemicals can sometimes effect other detergents if diluting through the same unit. Water pressure is also worth considering as venturi based dilution requires 2 bars of pressure in most cases to function optimally. In cases of large factories that sometimes have fluctuation in their water pressure throughout the day, we can carefully set the dilution tips to allow for some mild fluctuation in dilution in order to ensure dilution remains within spec for food production and healthcare facilities that have to pass stringent audits and provide evidence of testing diluted chemical for efficacy. Once installed, a simple test of adding 1lt of concentrate to the chemical suction pipe and a large enough bucket or drum on the other end will allow you to test how much solution you get out for 1lt of concentrate going in. We check all chemicals added in this way to determine if the tips used are giving us the required ratios. This can be logged and signed off regularly to track the accuracy of dilution over time. Another way to test the diluted product is using test strips to test achieved PH or QAC strength in the case of common food grade disinfectants. More advanced solutions like conductivity measurement and titration tests are also available.
While realativly simple by design a well installed and correctly set up dilution system that remains un-tampered, can be a fit and forget solution to businesses looking to save costs through over usage or food producers needing to remain compliant and effective in their food safety and HACCP plans.
To find out more about the SEKO range of dosing and laundry dosing equipment contact ryan@safic.co.za