Effects of liquid temperature and viscosity on Venturi injectors

The effect of chemical temperature change on the injection flow rate of a V enturi injector was evaluated. The percent change inflow rate corresponding with changes in temperature should be quantified because Venturi injectors are connected to chemical ranks at various temperatures due to radiative a nd convective heat transfer Water CAN17 (calcium ammonium nitrate), UAN32 ( urea ammonium nitrate), soybean oil, and Orchex(R) were injected from a the rmal reservoir into a PVC pipeline with a Venturi injector Both CAN17 and U AN32 are soluble in water, while soybean oil and Orchex oil are insoluble. The injection flow rate for the four chemicals and water was measured over a range of pressure differentials between the upstream and downstream side of the Venturi, and over a range of chemical temperatures, The viscosity of water was less than 1.5 mPa.s. The viscosity of the other four chemicals r anged from 3.1 mPa.s to 121 mPa.s. The injection flow for water with low vi scosity, did not change significantly with temperature. However the injecti on rate for the four chemicals was correlated with temperature and viscosit y If the chemical tank temperature variation is 20 degreesC during the day, then the injection flow rate variation would be in the range of 50% for so ybean oil, 30% for Orchex(R), 10% for UAN32, and 5% for CAN17, insoluble ch emicals had much higher injection rates than soluble chemicals at the same viscosity Because the injection rate for Venturi injectors is temperature d ependent, and flow increases as chemical temperature increases, the increas ed cost of chemicals, environmental contamination, and crop loss might be g reater than capital and maintenance savings.