Hopper Scales – find manufacturers and suppliers

Hopper scales, the scales for free-flowing bulk goods

Hopper scales are used to automatically weigh those goods that are poured into the scale. The scale frame is a stable welded construction made of stainless steel and is equipped with a shut-off flap at the entrance, the so-called "inlet", and with a bottom discharge flap in the lower part. Both flaps are pneumatically operated. Load cells are responsible for exact weighing. Substances such as sugar, grain, flour, etc. are suitable for this purpose. This is why these scales are also called bulk or hopper scales. The weighing range is between 10 t/h and 400 t/h. Of course, hopper scales are available in high-performance versions, with capacities ranging from 3,000 kg to 600 t/h. Hopper scales are also available in duplex design with a capacity of 1,000 t/h. The level can be used for measuring and dosing liquids, e.g. as a molasses scale for sugar syrup. The hopper sizes depend on the bulk material. Hopper scales, including pre- and post hoppers, are installed in the material flow or the loading paths of the silos so that the bulk material can be weighed immediately during "pouring". In this way, the production process does not have to be interrupted. Hopper scales are used for the most part in the ports of the world, such as in Hamburg.

How accurate are hopper scales?

These scales achieve an accuracy of approx. 0.25 %. Error limits of 0.10 % are possible, which is very important, especially when weighing grain. The more accurate the adjustment, the lower the loss.

What are the differences between hopper scales and are upgrades possible?

Upgrades are generally always possible, but depend on the circumstances and requirements. Hopper scales are available in both mechanical and electrical versions. In any case, an upgrade brings an increase in performance as well as the possibility to connect to digitalisation and thus to logistics systems. In accordance with the MID Directive, manufacturers can put legal-for-trade hopper scales into operation throughout the EU without involving the Weights and Measures Office. Approval for verification is therefore relatively straightforward. Official recalibration is only necessary after two years. Of course, manufacturers also offer maintenance services. In addition, hopper scales have three or more load cells as well as several load cells for better weighing.

Advantages of hopper scales

These scales are individually adaptable, Loss-In-Weight is a matter of course and, in addition, they can be combined with a volumetric dosing system, as is common for cement.

What is meant by "Loss-In-Weight" measurement technology?

In this process, material of sometimes fluctuating density is drawn off from the containers. The measuring method is used to constantly readjust the draw-off during the batching process so that the mass flow is kept constant. The prerequisites for this, however, are controllable discharge elements, such as rotary valves and screw conveyors.