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Reductions in dust, lower costs and improved measurement accuracy for your ingredients are just some of the advantages
In many plants that batch-blend bulk products, weigh batching is a manual, time-consuming operation in which ingredients are weighed individually before being discharged to a blender or some other process vessel. A significant number of such plants could benefit from the installation of an automated weighbatching system.
For small as well as large operations, an automated weigh-batching system can pay for itself fairly rapidly through increased productivity, increased accuracy for the measurement of ingredients (resulting in better product quality and lower feedstock costs), minimization of product losses and dust, and reductions in the cost of materials now purchasable in larger containers or volumes.
One of the strongest cases for an automated weigh-batching system is that it improves product quality by providing a more accurate and consistent mixture. In many plants that use manual methods, a common practice is to work with pre-weighed bags - for example, dumping ten 50-lb (23-kg) bags to add 500 lb (227 kg) of an ingredient. Problems associated with this method are that each bag may not contain exactly 50 lb of material, and that the worker may not empty the bag completely. Inaccuracies are compounded as more bags are used. Additionally, if an operator is required to manually count bags in order to achieve the proper weight, yet another chance for human error is present.
Gain-in-weight vs. loss-of-weight
There are two automated weigh batching methods: Gain-in-weight and lossof-weight. In the first arrangement, batch ingredients are generally conveyed in sequence into a hopper located above a process vessel, typically a blender or storage vessel. The hopper is set on load cells that transmit weight-gain data to a programmable logic controller (PLC) that starts the conveyor for each ingredient and then stops it when the preset weight for that ingredient is reached. Finally, the controller automatically charges the batch to the process vessel. In a lossof-weight system, the source of each ingredient (such as, a bulk bag unloader or preloaded hopper) is mounted on load cells that transmit weight-loss data to a controller that starts and stops each conveyor (or rotary airlock valve) to weigh each ingredient.
Determining the most suitable weigh-batching method...