The weighing mixer is composed of weighing module, weighing transmitter, Siemens S7-200PLC, vibration feeding frequency converter, conveying and lifting trolley frequency converter, unloading motor, limit switch, proximity switch and upper industrial control computer (IPC). In the production of raw material mixer, the batching process as a whole can be divided into four main production links such as quantitative setting, weighing, blanking, mixing conveying and unloading of four kinds of materials, involving production equipment: material bin, hopper scale, vibration Feeder, lifting conveyor, blanking and unloading device. Dosing process: From the raw material field, different materials are transported to the 4 material silos in the feeding system, and 4 vibration feeders will quantitatively drop the materials into the hopper scale according to a certain ratio. Mixed material conveying process: The feeding system adopts inclined bridge type feeding, which mainly has three parts: inclined bridge, skip truck and hoist. When the batching is finished and the material handling conditions are met, the feeding door at the lower end of the hopper scale is opened, and the mixed material falls into the conveying trolley from the hopper scale, and the trolley is sent to the dividing bin on the top of the furnace through the hoist, and the unloading gate at the bottom of the dividing bin is opened, and the mixed material is finally sent to the mixing machine.

The raw material mixer includes a mixing system and a transport control system, and the mixing system is set to two control modes, namely manual control and automatic control, and the automatic control mode includes single step and continuous mode. Manual operation is mainly used in system debugging, maintenance or when the PLC fails. The automatic control mode is the normal working mode of the mixing system. In the automatic operation, according to the production requirements, the ratio of 4 kinds of materials is input through the keyboard on the host computer, and the target value of the fast allocation of various materials and the standard set value are calculated by the host computer. When the target value of the fast allocation of No. 1 material is less than the standard set value, the PLC issues high-speed instructions. Make the 1# vibration feeder work at high frequency, the 1# material is quickly dropped into the hopper scale to improve the feeding efficiency, and the net weight of the 1# material is displayed on the upper computer in real time. When the material reaches the set fast batching target value, the inverter switches to the smaller vibration frequency and slow vibration feeding; When the weighing value is less than the standard set value of No. 1 material (if the difference is outside the tolerance range), PLC will automatically start the point to correct, and No. 1 material will continue to batching to ensure the batching accuracy; If the difference is within the tolerance range, the PLC will output a stop signal, the vibration feeder stops running, and the 1# vibration feeding ends. Enter 2# vibration feed at the same time. The batching process for No. 2 to No. 4 materials is the same as the batching process for No. 1 materials, until the four materials are finished, the batching cycle of a batch is completed.