Siemens 7MH7300 Series, Руководство по эксплуатации

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Description
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SITRANS WW200 is a low-to-medium capacity weighfeeder for minor ingredient additives.
The unique weigh system applies live load directly to two platform load cells. An adjustable
mechanical shear gate profiles the material and fixes the correct material bed depth for a given
material application. The belt speed can be automatically adjusted to attain the correct feed
rate.
SITRANS WW200 comes with a weigh bridge, and speed sensor. An integrator and test
weights are required to complete the system.
3.1 Weighfeeder operation
Weighfeeders weigh bulk material while it is conveyed. An accurate rate of flow and totalized
weight measurement is received without interrupting the flow of material in process. A
weighfeeder can also control the rate of flow of the conveyed product.
In-motion weighing requires accurate transmission of the product load to load cells. The
resulting voltage signal corresponding to weight is transmitted to the integrator and becomes
one of the two inputs required for integration.
Unlike static weighing, in-motion weighing integration requires a second input: a pulse signal
proportional to the speed of the conveyor belt. Each belt speed sensor pulse represents a fixed
distance of belt travel.
Since the force measured by the load cell is represented as weight per unit length, it can be
multiplied by the distance of belt travel (one speed sensor pulse) to provide product weight for
that segment of the belt (lbs/ft x ft = lbs, or kg/m x m = kg).
Adding the samples provides total throughput weight of product across the scale. With proper
scaling and calibration, the total weight can be displayed in kilograms, pounds, short tons, long
tons, metric tons, or other appropriate units.
SITRANS WW200
Operating Instructions, 06/2018, A5E33560654-AC
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