Automatic hopper scales are mainly available as Electronic scales to obtain the target value of a single weighing, and as discontinuous totalizing scales to obtain the target value of multiple weighing. Structurally speaking, non-continuous cumulative scales have a feeding device, weighing module and unloading device, the bottom of the storage hopper is generally a large inverted conical shape, the material is discharged from the storage silo downward, due to the role of the material's self-weight, constantly overcome the internal and external friction resistance to downward mobility, the material in the descent process, the particles continue to be misaligned, extrusion and regrouping, and want to be close to the mouth of the particles, the particles of the squeeze friction intensified, need to add a vibrator, when the resistance is not sufficiently strong, the material will not be able to move, but the material will not be able to move. Need to add a vibrator, when the resistance is greater than the self-weight will form a shed material or bridge and other phenomena, so as to ensure the normal feeding. When the material level in the storage hopper is reduced, the upper layer of material is reduced, the lower layer of material particles between the extrusion pressure is reduced, the internal and external friction between the material particles is also reduced, the material flow rate of the discharge port is gradually accelerated. When the material is about to be emptied, the flow rate increases sharply, which will lead to over weighing, or even overflow from the weighing hopper. Therefore, in order to ensure accurate weighing, should be installed in the storage hopper level valves and material level meter, to reach the amount of material below the material level meter, the valve automatically closed.

In the storage hopper should be configured below the emergency gate, especially when the storage hopper is quite large, the bin can reach more than 40, then must be configured emergency gate. When the hopper scale or its subsequent equipment failure, should immediately cut off the material with the emergency gate. So that when there are maintenance personnel in the hopper scale or other equipment for maintenance, there will be no unknowing personnel or other circumstances of the equipment to start, thus ensuring the safety of maintenance personnel.

Outside the hopper scale to increase the shell to prevent the chemical dust flying, and attached to a dust-absorbing device for dust absorption, dust-absorbing device generates a negative pressure is generally in the 500Pa or so, when the negative pressure is too low, it can not play a very good effect of dust absorption, and when the negative pressure is too large, it will have an impact on the weighing, and even the material will be sucked away.

For the chemical industry, the more appropriate feeding door should be fan-shaped feeding door. In the switch to feed the door, the implementation of the cylinder only need to overcome the friction of the material in the fan to feed the door can be run quickly and reliably, can be better to complete the feeding process, and the fan to feed the door does not squeeze the material, there is no shutting down and crushed material. The size of the feed opening should be able to ensure that the hopper scale in the rated flow rate required for the work of the feeding rate, in this calculation and non-continuous cumulative scale of the size of the discharge opening.