Processing Magazine

Unit Controls Valves, Pumps to Ensure Exact Dispensing of Predefined Batch Quantities

May 17, 2011

The RA33 Batch Controller provides precise sensing and dispensing of liquids into a container or process vessel in food, chemical, pharmaceutical, oil and gas and other process industry applications. It monitors flow, temperature and density; controls valves and pumps; and dispenses the exact amount requested by the programmed recipe. The controller can work with a single valve and pump in automatic or manual mode, or with two valves for two-stage batching. Two RA33 controllers can work together for batch mixing of two ingredients. The RA33 calculates the exact volume to be dispensed based on an analog or pulse signal from a flow sensor and its built-in temperature/density compensation functions. For example, mineral oils can be corrected according to the ASTM D1250-04 standard. The volumes of other media can be corrected using expansion coefficients, or the volume can be converted to mass by measuring the density. The RA33 makes an automatic after-run correction for constant and extremely accurate results, and advanced error diagnostics detect leakage, fill deviation and "no flow" conditions.