Hopper scales are used for weighing product streams for packaging, dosing, dispensing and yield monitoring in batches. The unit consists of a hopper, weighing cell and weighing instrument. It is an ideal automatic weighing device for the modernization of bulk materials, mainly divided into totalizing hopper scales and loss-in-weight feeding scales.

Hopper scales realize material level control by weighing, the material can be liquid or granular solid. Usually 3 or 4 force sensors are used. The weight of the material is converted into an electrical signal by the force sensors and amplified by the amplifier in the measuring circuit for display, recording and data processing. It has automatic zeroing and weighing data processing functions.

Explosion-proof batching machine is a very important process in the chemical production process of electronic scales, mainly to complete the weighing and proportioning of the main material and various ingredients. After the batching of the former system will be formed by the base powder through the spiral scale and conveyor sent to the premixer and the raw materials mixed by the conveyor sent to the finished product warehouse. The post-batching realizes the measurement of the flow of the conveyed materials.

The dosage machine is mainly a weighing instrument, PLC as an auxiliary control system, computer human-machine interface to display the proportioning parameters (formula) and monitor and record the real-time data. In automatic control mode, by clicking the "Start" button of automatic dosage in the pre-dosage process screen or the "Start" button of the pre-dosage control cabinet, the weighing instrument opens the weighing valve of the electronic scale according to the set recipe. If the system detects that the dosage valve of a scale is not closed, an alarm occurs and the scale enters the pause state. Each scale has an advance quantity according to the weighing speed. When the control instrument detects that the weighing weight of the scale reaches the set value, the advance quantity will be subtracted and the control instrument will close the feeding valve. The amount of advance can be corrected manually or automatically, so that the control instrument can control the dosage scale to reach the set target value every time the dosage accuracy.

Weighing and batching machine puts the weighed raw materials into the reactor in a certain order, and at the same time turns on the stirring and heating, the control process is completed by the weighing instrument and PLC together. The weighing instrument controls the dosing range, and the weight reaches the target value which is automatically completed by the PLC control valve, and there are two control modes of fixed order and programmable program for the dosing. In the fixed order mode, the discharge order of all kinds of raw materials is fixed and cannot be changed. In programmable mode, the feeding order of various raw materials can be set according to the recipe on the human-machine interface.

Measuring and batching machine gives the control current of pump according to the ratio value, PLC outputs 4-20mA to control the pump and pump frequency converter, so that the flow control of discharging material is PID regulation, and according to the ratio of process requirements, the corresponding tracking flow is calculated and transmitted to PLC. PLC gives the control current of 4-20mA to control the frequency converter of the auxiliary material scale, so that the corresponding flow of the batching material is controlled in the range of the tracking flow most. The premixer, distribution screw machine and the umbrella fan are equipped with on-site shoulder and stop buttons, which are converted by remote control and connected to the central control room. The start-stop control of the equipment can be realized through the start-stop button on the lip distribution cabinet, or the start-stop button on the human-machine interface after the distribution process can also be manipulated. It can also realize the start/stop control by controlling PLC.

The mixing and dosing machine sets up the interface to display the instantaneous weight, the material level, the use status and the dosage sequence of the various materials. Complete the production record of batching process, including the pre-matching report of each shift, recording the weight, time and pot number of each material scale, and the post-matching report recording the amount of genuine and inferior products produced in each shift, the total amount of genuine and inferior products produced every day, and the instantaneous weight of the batching scale can be viewed from the interface of history curve. The alarm interface can display the valve closing and alarm signals such as feeding timeout and discharging timeout.

The weighing device of the automatic batching machine adopts a spiral weighing bin, and the materials stored in each bin are not exactly the same. Under the bin is a frequency-controlled broadband feeder, and the materials flow to the weighing bin through the spiral, and then to the mixing mixer, and there are three weighing modules in each weighing scale and connected to a junction box, and the signals are transmitted to the weighing instrument through the junction box, and then the analog signals and pulse signals are transmitted from the weighing instrument to the PLC, and then the PLC processes the signals and outputs DO signals to the computer to monitor and control the operation. The PLC processes the analog and pulse signals and outputs the DO signals to the computer for monitoring and control, and the PLC transmits the commands from the computer to the weighing instruments for processing.

Weighing hopper machine detects and samples the weight of material in the metering hopper by the controller, and stops feeding when the weight of material in the metering hopper reaches the upper limit value set for dosage. It reads the main totalization, instantaneous flow rate, set flow rate, weighing instrument status and other related data from the weighing instrument. Weighing instrument status display (zero state, interval state, running state or alarm state), online monitoring and management by computer, with high requirements on weighing speed, weighing accuracy, system compatibility and expandability.