Volumetric dosing offers a simple and economical way of dosing bulk solids in the required volume.
Mechanical conveyors always convey a defined volume. This can be calculated easily: A discharge screw conveyor for example where the intake area is always filled at 100% has a fixed volume inside the screw conveyor blades.
Depending on the speed of rotation the result is a conveyed volume in m³/h. This conveyed volume is determined and set up during commissioning. When the flow behaviour of the bulk solid changes the conveying capacity will also change without even being detectable.
In addition, a precise tonnage is often required. In this case volumetric dosing is less suitable as the conveyed weight varies with the bulk density.
For gravimetric dosing we have to distinguish between continuous and batch dosing.
Continuous gravimetric dosing differs from volumetric dosing by the fact that the speed of conveying (e.g. rotation speed with a screw conveyor) is individually adjusted. The upstream container is equipped with weighing cells and decrease in weight over time results in a precise conveying capacity in t/h.
The conveying capacity is monitored by the weighing cells and can be adjusted at a precision of ±2%/10 min with this system if necessary.
At gravimetric batch dosing the destination container is equipped with weighing cells. The dosing is done into containers with the attached discharge element until the required weight is reached. Depending on the required accuracy we can work with coarse and fine flows. This enables us to achieve batch precision of ±0.5%.
We would be happy to advise you on which dosing system is best suitable for your application!