Position: Typical process weighing applications and solutions include batching/blending, reactor, and mixing vessels where two or more "ingredients" are combined to produce a final product. Although actual processing varies greatly from product to product and company-to-company, the usual procedure entails adding each ingredient to the process vessel separately, based upon recipe designated weight values. Once all essential ingredients are present in their predetermined quantities, processing is initiated by adding a catalyst, beginning a motorized mix/blend interval, or both. Precision processing requires systems that remain insensitive to side and end loads introduced by integral process weighing equipment (motors, mixers, etc.) and thermal expansion caused by the vessel heating.
System Solutions
Vishay BLH and Vishay Nobel, with thousands of system installations world wide, bring over fifty years of engineering expertise to you and your process weighing application (see our extensive list of case studies at left). Experienced application and service engineers give you much more than a list of products to choose form, they design, install, and maintain weight based processing systems that work predictably with your PLC/DCS control infrastructure.
Application Requirement
A single process weigh batching system is required to handle multiple batch recipes combining water, two or three powders, and up to six other liquid ingredients involved in paint production. Individual ingredients, stored in separate tanks, feed into a single ten-ton mixing tank with seven tons of tare weight.
Customer Concern
All recipe ingredients must be conveyed flawlessly to a single batch/blend vessel with a high-powered agitator. Resultant batch quality cannot be diminished from recipe to recipe.
Vishay Solution
Vishay Nobel connected all seven ingredient vessels (six for liquids and one to batch the powders) to TAD 3 Indicators equipped with batching software. All TAD 3 Indicators were connected to a supervisory DCS System via RS 485 Modbus RTU communication.
The DCS system handles all recipe formulation by downloading ingredient data parameters to each of the TAD 3 batching controllers/indicators. Batching of each ingredient is done locally by the TAD 3 indicators into the mixing tank. KIS-1 Load Cells weigh the mix tank contents precisely while rejecting the torque side load introduced by the agitator. Batch weighing process results are fed back to the DCS System from another TAD 3 that controls the mixing tank.
Precise repeatability from recipe to recipe is maintained by KIS-1 and TAD 3 technology.
