Bunker Loading Line Automation

Contents

Task

Summary

Introduction

Contents

1. Description of Process Train Operation

2. Analysis of control options and existing process line automation scope

3. Control System Requirements

4. Development of process line equipment control algorithm and its check for realisability

5. Development of structural control scheme for automatic operation of equipment

6. Development of complete schematic electrical diagram

7. Select Automation Tools

8. Description of operation of full schematic electrical diagram

9. Development of control board

Literature

Summary

This course project contains 30 sheets of typewritten text of the explanatory note with 12 tables and 13 figures. The graphic part is made on 5 A3 formats.

The note contains a description of the process of the loading line of the active grain ventilation hopper. During the course project, a circuit diagram of automatic and manual control was developed. Automation and protection tools are also selected.

Introduction

Automation of technological processes is one of the decisive factors for increasing productivity and improving working conditions. All existing and under construction industrial facilities are equipped with automation equipment to varying degrees.

Projects of the most complex productions provide for comprehensive automation of a number of technological processes.

Almost all design universities are developing automation projects, as well as training highly qualified specialists in this field.

The widespread introduction of automation tools became possible only after the implementation of integrated mechanization and electrification of agricultural production. In agriculture, a large organizational and research work has been launched to create automation systems, specific devices, which in the coming years will have a tremendous economic effect.

Automation of agricultural production increases reliability and prolongs the life of equipment, facilitates and improves working conditions, improves labor safety and makes it more adapted, reduces the use of labor and economic costs, increases the number and quality of products, reduces the process of erasing the difference between labor.

Automation in agriculture has its own characteristics. The main technological processes of agricultural production are continuously associated with biological processes. Violations of the biological regime lead not only to underperformance of the plan, but also to damage of residential vows (animals, birds, plants). Increased yields can be achieved by improving animal conditions and better effects on plants.

Control Diagram Requirements

Circuit diagram of grain active ventilation hopper loading line control:

control of the line in automatic and adjustment modes and their separation excludes the possibility of simultaneous control in several modes;

process signalling of process progress;

Stop of the noria drive motor must take place with a time delay to prevent it from starting under load.

Description of operation of full schematic electrical diagram

The electrical circuit can be conditionally divided into two parts: a power circuit supplying power to electric motors, and a control circuit. They are interconnected and work in normal mode in a coordinated manner. The control scheme provides for two modes: automatic and adjustment, their selection is carried out by the switch SA1. The power part is powered by three phase circuit breakers QF1... QF4, and the control circuit through single-phase is QF5.

Consider the operation of the circuit in the automatic mode, considering that in the initial state, the fan motor is operating, i.e. the coil of the magnetic starter KM4 is powered and its power contacts are closed. Blanking is in the lower position and contacts of SQ2.2 blanking position sensor are closed, SQ2.1 contacts are also open, which do not allow KM3 actuation.

The circuit drives the grain sensor in the hopper SL1, which, having closed its contacts SL1.1, energizes the coil of the magnetic starter KM1 (noria motor) and it drives all its contacts: power contacts are closed and voltage is supplied to the electric motor; contact KM1.1 is closed, which parallels contact SL1.1 and SL2.1 (which is normally in a closed state, and when the hopper is fully filled, it opens and does not allow the noria engine to turn on); contact KM1.3 is opened; contact KM1.2 is closed and voltage is applied to coil KM2. As a result, the contacts KM2 in the power circuit are closed and the winch motor is turned on, the plug begins to move upward. In this case, KM2.2 contacts open and exclude the possibility of activating KM3. When the plug reaches the extreme upper position, the limit switch SQ1 will be activated and its contacts will be opened, which will de-energize the coil KM2 and all contacts of this magnetic starter will return to the initial state. The winch motor will shut down and the plug will stop in the uppermost position.

When all grain from the litter pit is reloaded to the hopper, contact SL1.1 will open, and SL1.2 will close and supply voltage to the coil of time relay KT1, which will open its contacts with time delay and de-energize KM1. At the same time, KM1.3 contacts are closed and voltage will be supplied to KM3 magnetic starter. Which with power contacts will supply voltage to the winch motor, the plug will start moving downward. When the blanking position sensor comes into contact with grain, SQ2 will operate and its contacts SQ2.1 will de-energize KM3, and SQ2.2 will power KM4, the fan motor will start. The process of drying the grain will begin. If the grain humidity decreases to the required one, the humidity sensor will operate and open its contacts A and de-energize KM4, the fan will stop.

In the event that the hopper is fully filled during loading, the SL2 sensor will operate, its contacts SL2.2 will power the time relay coil and the noria will stop, and the SL2.3 contacts will power the HL5 light.

The HL1... HL4 light signalling indicates the state of the respective motors on or off.

In setup mode, all operations are performed manually using SB1... SB8 buttons.

The scheme provides protection against engine overload using heat relays KK1... KK4.