Shaft furnace automation

Contents

Contents

Introduction

1 Process description. Characteristics of the main

process equipment

2 Mode card

3 Development of schemes of control, regulation, management, alarm system and protection

4 Selection of power type of instruments and automation equipment

5 Scheduled map

6 Selection of automation devices and tools

7 Calculation of regulator settings, selection of regulation law

8 Custom Specification for Automation Devices and Tools

9 Special part

List of used literature

Introduction

Automation of technological processes is a set of methods and tools designed to implement a system or systems that allow you to control the technological process itself without the direct participation of a person, or leave the right of the person to the most responsible decisions.

Automation of production involves the presence of reliable, relatively simple to device and control machines, mechanisms and devices.

What do you need mine type furnaces for? This is a type of industrial furnace that is designed for firing, hardening and heating. As blanks, both raw resources and lumped rocks, as well as loose masses, can be used. In particular, such aggregates work effectively with carbonate rocks and ore materials. With regard to metals, a shaft-type heat treatment furnace is suitable for servicing cast iron, aluminum and copper alloys. In order to efficiently use the capacity of such equipment, it is necessary to carefully calculate the amounts of material to be deposited. For example, the size of the lump material fraction may be in the range of 60120 mm. However, there are also industrial furnaces capable of receiving material with a diameter of more than 240 mm. This capability depends on the capacity of the camera and the performance of the unit. Even if the equipment can physically accept a large object, this does not mean that the chamber will properly treat it by thermal action. Therefore, initially, the power characteristics of the furnaces are compared with the qualities of the target material.

Process description. characteristics of basic equipment

A shaft furnace with an upwardly extended working space is a circular (cylindrical, conic) or rectangular shaft. The processed material is loaded from above, and the finished product is issued from below; gaseous products of fuel combustion move towards descending material. The shaft furnace is mainly used to produce metals from metal melting ores), firing refractory raw materials. Shaft type furnaces are also used for heat treatment of metal products.

Shaft furnace arrangement.

The basis of almost any shaft furnace is made up of four parts - loading and unloading blocks, as well as a chimney with a heat treatment chamber. Skip, cable and conveyor mechanisms are used to load the raw materials. The choice of design depends on two main parameters: first, the characteristics of the supplied material, and second, the operating conditions of the unit. For example, a skip system involves the use of a bucket with a reverse stroke and a winch, so it can be considered as a universal loading mechanism. The discharge device, which is supplied to the shaft furnace, also has several parts, but the main component is an intermediate container, sealing and dosing material. A flue duct in the form of branch pipes is used to remove exhaust gases, which are most often located in the rear of the furnace. In modern models, this system often has a complex design with filters and an automatic control system. As for the combustion chamber itself, which is supplied to the shaft furnace, the main process of processing the incoming raw materials takes place in it. Using the control panel, the user adjusts the parameters of its operation according to the requirements of the material manufacturing technology.

Principle of operation.

The function of such furnaces is based on the countercurrent principle, in which descending formations of raw materials are washed by oncoming gas flows. The treated material sequentially passes through several process sections, including a drying zone, heating, firing and cooling chambers. In some models, the firing chamber coincides with the area in which the fuel is burned. Hot gases are also formed here. An important value in the efficiency of the process is played by the structure in which the unit is made. If the mine furnace is calculated to work with large volumes of heterogeneous raw materials, then the distribution system comes to the fore in choosing the design. Most often, this function is performed by cones, due to which the automatic process of filling the furnace is carried out .

The advantage of mine furnaces.

The operational advantages of such furnaces are determined by structural features. Nevertheless, there are common advantages that have led to the widespread use of such aggregates. In particular, mine equipment for the production of bricks allows for the heat treatment of large volumes of clay raw materials at short intervals. The possibilities of working with metals, gas, bulk materials and even waste make it possible to talk about the versatility of such furnaces.

Selection of power supply for instruments and automation equipment

There are 3 types of power supply for devices and automation:

Electrical type of power supply

Pneumatic Power Type

Hydraulic type of supply

Electrical type of power supply

It is performed by alternating current of voltage 220V with frequency 50Hz

Electric circuit is divided into inner and outer parts. The internal part of the electric circuit includes the electric power source itself. The external part of the circuit includes connecting wires, consumers, choppers, switches, electrical measuring devices, that is, all that is connected to the terminals of the electric power source.

Advantages: implementation of any function, unified output signal, interchangeability of equipment, high speed, unlimited communication lines.

Disadvantages: Inability to use in fires and explosive processes, as well as in processes of conductive media.

Pneumatic Power Type

Performed by dry cleaned air, pressure 0.14 MPa

Pneumatic circuits are used to actuate pneumatic brakes and supply compressed air to the drives of the following devices and devices: electro-pneumatic power circuit and control circuits, and a number of others. These circuits include compressors, filters, air tanks, pressure regulators, check and blowdown valves, compressor valves, driver's cranes and auxiliary brake cranes, oil separators, and the like.

Advantages: the ability to realize any functions, high uniformity, can be used in fire and explosive processes and conductive media.

Disadvantages: limited communication lines and low speed

Hydraulic type of supply

Energy of incompressible liquid with pressure 392980 kPa is used

Advantages: great weekend efforts, the possibility of use in processes with aggressive environments.

Disadvantages: bulky and expensive equipment, limited communication lines, and the impossibility of use in fires and explosive environments.

The project "Shaft furnace automation" uses the electric type of power supply, since all instruments and automation equipment selected in the project are powered by electric current, voltage 220V, frequency 50Hz.