Concrete mixing plant automatic control system

Contents

INTRODUCTION

1. Process Description

2. Building an Automation Functional Diagram

3. Calculation and selection of TSA

4. Electrical schematic diagram

5. Conclusion

LIST OF SOURCES USED

Project Description

Explanatory note to the course work on the discipline "Fundamentals of Automation and Automation of Industrial Processes" on the topic "System of Automatic Control of Concrete Mixing Plant": - s.: Fig., Table, ex., East.

Keywords: strain gauge, resistance, pneumatic cylinder, weight hopper, actuator, logic control device, control equipment, position sensors, elastic element.

This project contains a description of the process, a description of the functional diagram, the selection and calculation of automation circuits, a description of the electrical schematic diagram, a list of sources used .

The explanatory note is accompanied by 2 drawings of A2 format with functional and schematic diagrams, specifications.

Introduction

Currently, automation of construction production is based on an element base, which includes electronic, electrical, electromechanical, hydraulic, pneumatic and other devices.

Automation means the control of machines, units and technological processes with the help of automatic devices operating without human participation, i.e. equipping technological plants with automatic control, alarm, mechanism protection, control and regulation systems.

Automation of technological processes increases labor productivity, improves the quality of work and products due to more accurate compliance with technological regimes, reduces fuel, electricity and equipment wear.

Electrical Schematic Diagram Description

Press SB1 to start the mixing cycle. At that signal is generated for triggers DD1.1 and DD1.2. Relay-transistor device is actuated, and relay KV1 is actuated, the contact of which closes the power supply circuit of magnetic starter KM1.

At the same time, a signal is generated at the input of the timer, which is set to 300 seconds. After this time, a signal is generated from the timer, which resets the triggers, and the relay KV1 is turned off. Thus, the circuit of the magnetic starter KM1 is opened.

The timer uses the operation amplifier K140UD9 and the gate K1561LI4 to invert the signal.

The electric drive circuit provides for manual and automatic mode. In manual mode the vibration damper is started and stopped by SB3 and SB2 buttons respectively. In automatic mode, control is performed by contact KV1.

At operation of the magnetic KM1 actuator, its contact becomes isolated in a starting chain of the frequency A1 converter. Upon receipt of the signal, the frequency converter starts to rotate the motor.

The circuit provides protection against short-circuit currents - automatic switch QF1 and fuse FU1. Thermal protection of the engine is also provided - thermal relays KK1 and KK2. The electrical schematic diagram is shown on sheet A2 (sheet 2).

Conclusion

The issued course design considered the system of automatic control of the concrete mixing plant. Description is given of possible methods of mixing concrete mixture and selection of the most acceptable method. The selection of automation equipment, as well as electronic automation devices that meet the technological requirements of the plant was made. The design implementation of the devices and calculation of their parameters are given.

When designing the process of mixing the concrete mixture, the design provides for automatic and manual control of the circuit.

The course design presents the functional and schematic diagram of the installation.