Automation of a Flour Mix Preparation Unit (A/S Rīgas dzirnavnieks)

Used controller: Siemens S7-315.

Used visualization program: Siemens WinCC.

1.Goal of Project

Task of the Project: To perform automation of flour mix preparation unit at Joint Stock Company "Rigas Dzirnavnieks".

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Fig. 1. - Flour mix preparation unit

Goal of the Project: To change control of the management system of the production to one operator.



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Fig. 2. - Hall Operation station OP-8

2.Stages of the Project

The execution of the project can be divided into following stages:

  • Formation of the technological diagram of the devices (cooperation with technological company "Agroproff");
  • Development of list of devices to be managed;
  • Management principles forming the basis for recipes;
  • Preparation of work plan;
  • Structural diagram of the automation;
  • Electrical design (Diagrams of control panel and assembly);
  • Ordering and procuring component parts (management system, sensors, etc.);
  • Algorithm of the management system work;
  • PLC programming (programmable controller S7-315);
  • SCADA programming (visualization on software package WinCC base);
  • Assembly of control board;
  • Testing of the management system before delivery to the Contracting authority;
  • Delivery of the control board to the object;
  • External installation of electrical devices at the object;
  • Testing of the management system at the object;
  • Staff training and submission of project documentation to the Contracting authority;
  • Putting into operation.

3.Production Technology

Production consists of the following parts:

  • Group of devices for loading of different flour types;
  • Group of devices for dosing of main components (Scale W1);
  • Group of devices for dosing additional components (Scale W2);
  • Group of devices for dosing micro-components 1 (MD1);
  • Group of devices for dosing micro-components 2 (MD2);
  • Group of devices for transportation to the mixer;
  • Mixer (Swiss company "Buhler");
  • Group of devices for transportation of the product to a warehouse, to packing unit, to car loading;
  • Group of devices for aspiration./li>

Product's recipe is the basis of the flour mix preparation. Recipe for preparation of the mix is chosen from recipe bank (not less than 100 recipes). System allows saving and editing recipes. The amounts of components in a recipe can be up to 6 basic components, up to four additional components, up to two micro-components and one hand component. Size of a portion (kg), number of portions and dispatch route can be determined in a recipe.

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Fig. 3. - Production technological scheme




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Fig. 4. - mixer production unit




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Fig. 5. - Microdosimeter

4.Management system

Management system consists of:

A.Management system of Mill. It consist of:

  • Management system server;
  • Programmable controller Mill (S7-414);
  • Programmable controller Silo (S7-414);
  • Programmable controller Pack (S7-414);
  • Operator control station OP1..OP7.

B.Operator control station OP-8 with installed software package WinCC (client part)

C.Programmable controller S7-315 for mixer mill management S7-315

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Fig. 6. - Production control system structural scheme

Group management of the devices, including management of frequency transformer and micro-dosing management device, is done through PLC "Profibus" network. For the purpose of saving money and increasing safety certain sectors use AS-I interface modules. To format information on the weight Siemens-Siwarex module is used.

Internet through Router device is used to ensure remote observation and adjustment of software and operating modes.

Production process starting with preparation of raw materials and ending with unloading of finished products at the warehouse can be controlled by one operator

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Fig. 7. - Control cabinet mounting example

5.PLC program

Control software is developed on the basis of Siemens Step7 software.

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Fig. 8. - Illustration of device control algorithm in PLC S7-317 software

6.SCADA program

Visualization of the production process and management system is developed on the basis of the WinCC (Siemens) software.


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Fig. 9. - Operator station OP8: mixing process visualization screen.




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Fig. 10. - Operator station OP8: current recipe of mixture




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Fig. 11. - Operator station OP8: equipment configuration


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