The dosing system consists of several parts such as cooling, safety, flour and production water supply, extrusion heating and extrusion head. Cooling system has frequency converter to control the flow of cooling water, which is usually not adjusted during the production process after adjustment. The safety system is mainly controlled by the safety relay, some safety switches such as guard limit etc. are connected to the safety relay, the output of the safety relay is sent to the PLC, once the safety switch is operated, it will stop the machine immediately and alarm on the HMI.

The supply of water for production is accomplished by the water pump, and the speed is controlled by the frequency converter. Flour supply is firstly driven by a motor on the top of the equipment to drive the reamer and then through the distributor controlled by the solenoid valve to send the flour to the two supply hoppers, the two supply hoppers are equipped with weight sensors on the hopper, when the weight of the flour in a hopper exceeds the set value, the distributor controlled by the solenoid valve automatically changes to the other hopper to supply, if the weight of the flour in the two hoppers exceeds the set value at the same time, then it will pause the supply of material to the hopper. After the flour enters into the hopper, two DC motors and controllers produced by BaldorelectricCo. will feed the flour into the chamber at a constant speed through the feeding mechanism, and the feeding setting will control the supply speed through the analog output point of PLC, and the speed of water supply and noodle supply should be according to the different products and match with the main machine.

Extruding and heating part in a long narrow cavity to complete, there are two screws in the cavity, the main motor drives the screw rotation, will join the cavity of the flour and water mixing and extrusion to the middle of the cavity extrusion head, by adjusting the main motor and add water and feed speed can be adjusted to the pressure in the cavity. The main motor is a 70KW DC motor, and the DC controller is the MENTOR series DC motor controller produced by British CT company. The chamber is divided into five units, each unit is measured by a temperature sensor and heated by a heating bar. In order to ensure the quality of the product, the temperature must be maintained at the appropriate temperature according to the different products.

The extrusion head is also equipped with heating rods and temperature and pressure sensors. To ensure product quality, the temperature and pressure here are strictly required for different products. Here there is also a cutter, driven by the motor, according to different products and spindle speed by the frequency converter to adjust the speed of the cutter.

The dosing control system consists of PLC, touch screen, actuator, and detecting elements. The computer is connected to the PLC via Ethernet to download programs and monitor the operation of the equipment. The touch screen communicates with PLC through Modbus485 communication protocol, displaying the running status of the equipment, and starting and stopping the equipment to set each running parameter and other operations. The actuator is responsible for the execution of the PLC instructions, the specific implementation of the corresponding action. The detecting element sends the status and parameters of the equipment to the PLC, and the original detecting and actuating elements are retained and the rest of the system is modified.

Automatic and manual control of dosing

1、Manual operation

The weighing and batching system sets the temperature setting value of each point and the upper and lower limits of the noodle hopper according to the process requirements on the touch screen, and sets the speed of the main shaft, the speed of water addition, the speed of noodle addition, the speed of the cutter and so on according to the parameters required in step 1. Automatic dosage system in turn start spindle, add water, add noodles, cutter, etc., to be stabilized according to the parameters required in step 2 step by step spindle speed, add water speed, add noodle speed, cutter speed, etc., and so on and so on and then go through step 3, step 4 step 5, and ultimately to achieve the technical parameters of the process requirements. To the end of production, the first step in accordance with the requirements of the parameters of step 4 to reduce the spindle speed, add water speed, add surface speed, cutter speed, etc., and then in turn in accordance with the requirements of step 3, step 2, step 1 of the parameters of the parameters gradually reduce the spindle speed, add water speed, add surface speed, cutter speed, etc., and finally back to the interface shown in Figure 3, turn off the equipment in turn.

2、Automatic operation

Manual operation is cumbersome, takes a long time, and requires high experience of the operator, so the customer requires the batching system to increase the automatic operation, and requires that the production formula can be stored, and after inputting it once, when the same product is produced next time, just call out the original formula and use it without re-entering it.

For this reason, the dosage system is designed with related HMI screen and related program. The automatic production interface firstly selects the recipe number, inputs the corresponding process parameters according to the process requirements, and then presses the store key, the CPU will send the current parameter values into the corresponding different memory areas according to the recipe number and save them, change the recipe number, input the process parameters of different products and press the store key. When producing a certain product, input the corresponding recipe number and press the activation key, the CPU will send the parameter value of the corresponding memory area into the storage area of the current parameter according to the recipe number and display it on the interface, press the auto start key, the equipment will gradually and automatically change the parameter setting under the control of the program, and finally reach the set value of the production parameter. At the end of production, press the automatic stop key, the equipment will gradually and automatically reduce the parameter settings under program control, and finally stop the equipment in turn.

The project has been completed, the manual operation completely reached the state before the transformation, the new automatic operation greatly facilitates the customer's operation and improve the production efficiency, get the customer's affirmation. The PLC, touch screen and other products of this transformation project are all products of GE intelligent platform, which are convenient and easy to use with reliable performance. Especially the PLC's PID regulation function and engineering unit conversion function, PID regulation is simple and convenient, high precision regulation, very good to ensure that the dosage system production process on the strict requirements of the temperature. In the change into a unit conversion, as long as you change the hardware configuration of the parameter settings, without the need to do in the program volume unit conversion. Therefore, the dosage system believes that GE intelligent platform automation products can provide excellent solutions in the transformation and manufacture of food machinery.