Reconstruction of DSV-10 electric furnaces with replacement of metal structures and introduction of microprocessor power regulator in conditions of Electric smelting shop 2 of ZMZ OJSC - Diploma work

Contents

Introduction

1 General part

1.1 Description of the Electric Steel Smelting Shop 2 of Zlatoust Metallurgical Plant OJSC

1.2 Structure and principle of operation of arc steel furnace DSV-

1.3 Description of the existing structure of the mechanism of movement of electrodes of the arc steel furnace DSV-

1.4 Disadvantages of the existing design of the mechanism of movement of electrodes of the arc steel furnace DSV-

1.5 Proposals for modernization of the mechanism of movement of electrodes of the arc steel furnace DSV-

1.6 Kinematic diagram of electrode movement mechanism

arc steel furnace DSV-

1.7 Description of electrohydraulic electrode movement mechanism

2 Special part

2.1 Power cylinder calculation

2.2 Calculation of hydraulic pump and determination of its operating mode

2.3 Piping Calculation

2.4 Calculation of hydraulic tank dimensions

2.5 Selection of operating fluid

2.6 Selection of distribution and control equipment

2.7 Calculation of pressure losses in the hydraulic system

2.8 Check calculation of hydraulic drive

2.9 Determination of hydraulic drive power

3 Organization of production

3.1 Description of the Department of Chief Mechanics of ZMZ OJSC

3.2 Description of Mechanical Service of Electric Steel Smelting Shop 2 of ZMZ OJSC

3.3 Procedure for Commissioning the Hydraulic Actuator

3.4 Rules of technical operation of electrode movement mechanism

4 Economics of production

4.1 Capital Implementation Costs

4.2 Cost effectiveness of introduction of electrohydraulic actuator of electrode movement mechanism

5 Occupational safety

5.1 Safety precautions during operation with hydraulic drive

5.2 Fire Safety Measures

5.3 Environmental protection measures

Literature

Appendix A - Assignment for diploma project

Appendix B - Abbreviations used in the text

Appendix B - LV Side

Appendix D - High Voltage Side

Introduction

The state of industrial and production funds of enterprises of leading industries is characterized by a low level of renewal of technological equipment (0.3%), the result of which is its moral and physical wear on 50..... 80% The only alternative way to ensure the quality and competitiveness of products is to upgrade the existing equipment fleet.

In the era of scientific and technological progress, each equipment and production technology must correspond to the world technical level. Zlatoust Metallurgical Plant OJSC is one of the leading iron and steel enterprises in the Southern Urals. To maintain and strengthen its position on the metallurgical products market, the Zlatoust Metallurgical Plant developed a comprehensive program for modernization, technical re-equipment and improvement of electric steel smelting production (reconstruction of existing equipment and commissioning of a new one), as more promising, with the subsequent withdrawal of the Martenovsky workshop and the construction of a new Electric Steel Smelting Workshop No. 4. As part of this program, the reconstruction of DSV10 electric furnaces installed in the Electric Steel Smelting Workshop 2 will be carried out. Electromechanical drive of electrode movement mechanism will be replaced with electro-hydraulic one.

The introduction of an electrohydraulic actuator (power controller) will allow:

- increase steel production in Electrostaleplavilny shop 2;

- Reduce energy costs for steel production;

- Reduce the cost of steel and increase its competitiveness accordingly;

1 General part

1.1 Description of the Electric Steel Smelting Shop 2 of Zlatoust Metallurgical Plant OJSC

The workshop is designed for smelting high-alloy stainless and special grades of steels and alloys, as well as fast-cutting and instrumental alloyed grades of steels.

The consumers of the workshop are the rolling and hammer shops of the plant.

The spread of ingots is 200, 500, 750 and 1000 kg, the possibility of casting ingots with a weight of up to 23 tons is provided.

Casting of steel - siphon, the possibility of casting from above is provided.

The annual productivity of the workshop is 100 thousand tons.

1.1.2 Composition of shop areas

Workshop consists of - main building and powder preparation department

The total length of the workshop is 156m and the width is 84m.

The main building has four spans in width:

a) Charge span - designed for preparation and sorting of iron scrap (charge).

The width of the charge span is 22m, the length is 156m, the height to the head of the crane rail is 9m.

The charge span stores magnetic materials, ferroalloys, as well as bulk materials (ore, lime, melting spar, etc.) and scrap metal (scrap of rolling and hammer production).

Ground closures are constructed to store all materials on the ground. In the end part of the span there is a storage of electrodes.

Two normal gauge railway tracks are laid in the charge span. One path is laid at the exterior wall of the building, along the closures. The second is a dead end, located at the end of the span, on the side of furnace No. 15.

To transfer self-unloading trays with a charge in the furnace span, two transverse railway tracks equipped with self-propelled bogies with a carrying capacity of 25t are laid between the columns. For weighing of bogies with charge two scales of railway type with carrying capacity of 30 t are installed.

Two bridge magnetic grab cranes with lifting capacity of 10t and one with lifting capacity of 16t are installed in the span.

b) Furnace span - designed for smelting steels and alloys..

The width of the furnace span is 18m, the length is 156m, the height to the head of the crane rail is 14m .

In the furnace span there are three 10-ton arc steelmaking furnaces (DSV10), two 20-ton cranes, a multi-loading crane with a lifting capacity of 1.5 tons, benches of arches, frames, two drying furnaces (for drying ferroalloys and auxiliary materials), two rolling pedestals and a 5-ton furnace located on preservation.

c) Casting span - designed for casting of steels and alloys into molds..

The width of the casting span is 18m, the length is 156m, the height to the head of the crane rail is 14m.

For steel casting, two trolley conveyors are installed in the span, on which steel is cast and pallets with poured molds are transferred to the auxiliary span to remove ingots from the molds and prepare molds, pallets and other casting equipment for melting.

In the span there are two bucket drying stands and two bucket heating stands (horizontal and vertical), three 30-ton cranes, as well as AKOS (complex steel treatment unit), consisting of: Bucket-Furnace (AKP) unit and Oxygen Steel Refining Vacuum (VKR) unit, which is a modern equipment of the Electro-Steel Smelter Workshop 2.

e) Auxiliary span - for annealing and storage of ingots.

The width of the casting span is 24m, the length is 156m, the height to the head of the crane rail is 9m.

In the auxiliary span there are two annealing furnaces, eight pits for cooling ingots, two 10-ton and one 15-ton cranes.

1.1.3 Description of the process flow of the workshop

The process of the Electric Steel Smelting Shop 2 is as follows:

- preparation of charge

- steel is smelted in arc steelmaking furnaces DSV10;

- casting into steelmaking ladles;

- after casting, ladles with liquid steel are fed for treatment to the complex steel treatment unit (ACOS), where steel is saturated with special additives, as well as burning of harmful impurities with argon and oxygen;

- after treatment on the automatic control system, the ladle with steel is supplied to the vacuum chamber of the vacuumizer for further treatment and production of high-quality steel

- finished steel from ladles processed at ACOS is poured into molds on two steel-grinding ditches;

- ingots after removal from molds are either immediately supplied to Rolling shop 1 for rolling at mill "1150," or sent to the section of ingots cooling, after which they are sent to the cutting compartment or to the Molotov workshop.

3.2 Description of Mechanical Service of Electric Steel Smelting Shop 2 of ZMZ OJSC

The structure of the mechanical service of the Electric Steel Smelting Shop 2 of ZMZ OJSC is shown in Figure 5.

The mechanical service of the electric steelmaking workshop consists of the deputy head of the workshop for mechanical equipment, who gives all orders to the mechanics of the workshop, and also reports to him the head of the design bureau and the engineer of the design second category. The workshop mechanic is subordinate to senior foremen for the repair of crane equipment of the workshop, the repair of equipment of the electric steel smelting department, and the repair of AKOS equipment. Senior craftsmen are subordinate to foremen, as well as duty and repair personnel.

The deputy head of the workshop for mechanical equipment is carried out directly by the work manager. Systematically analyzes the safety of operational and repair works. Ensure serviceable maintenance and repair of units and equipment, consider and coordinate slinging diagrams, storage maps and cargo transportation routes, routing diagrams for equipment repair. Organizes and monitors safe performance of high-risk equipment. He takes part in the development and organizes the workshop for work in spring - summer and autumn - winter conditions. Organizes the execution of orders, orders for the plant, pre-descriptions and instructions of higher authorities. Participates in plant and workshop management meetings; in commissions.

- upon acceptance in operation completed by construction (installation) reconstruction or after major and ongoing repairs, equipment;

- on certification and periodic inspection of knowledge of workers and ITR on safety procedures.

The senior master directly manages the work on the site. There is control over the organization of safe work by craftsmen and foremen. Compliance with the requirements of orders for the mill with the instructions and instructions of the higher and controlling authorities.

Before the start of the shift, the foreman gets acquainted with the work of the equipment over time, get acquainted with the entries in the logs of the on-duty fitters for acceptance and delivery of shifts and downtime records. Ensuring control and execution of personal and subordinate operating safety instructions and position of work order - admission. Must correctly and in a timely manner issue equipment repair documentation .

3.3. Procedure for Commissioning of Hydraulic Actuator

The use of structurally complex hydraulic equipment with precision friction pairs in hydraulic drives poses increased requirements for its operation and maintenance. The inconsistency of operating conditions and requirements leads to a violation of the operability of hydraulic equipment, a decrease in the reliability and productivity of machines, and sometimes a failure. Often, breakdowns of the hydraulic drive occur at its first start, therefore, it is necessary to observe the following strictly defined procedure for commissioning the hydraulic drive:

1) fill the tank with oil. The oil to be poured shall be as specified in the manual and its quality shall be pre-controlled;

2) check compliance with safety requirements;

3) loosen the adjusting screw of the safety valve;

4) check the position of working bodies and distributors, which provides pressing of working bodies to stops .

5) by short-term starting of the electric motor (1... 2 с) check the correctness of the pump rotation direction (specified in the pump manual);

6) check the presence of pressure when the pump unit is switched on;

7) eliminate external leaks;

8) during operation at low pressure check the stroke of all working elements and release air from hydraulic motors and pipelines through specially provided devices or loosen tightening of pipelines connections in upper points of the hydraulic system;

9) by means of safety valve set normal operating pressure in the hydraulic system. After checking the operating pressure, the pressure gauge must be disconnected from the hydraulic system (using special switches) and make sure that its arrow returns to zero elevation;

10) if there is an increased level of noise or foam on the oil surface in the tank, check the sealing of the pump shaft, the tightness of the suction and drain pipelines, as well as the oil level in the tank;

11) perform adjustment of hydraulic drive units; ensure smooth movement of hydraulic cylinders, violation of which can be caused by the following reasons: increased friction in cylinder seals or working member guides, skew of cylinder axis relative to guides, presence of air in cavities, insufficient pressure of safety valve adjustment, insufficient back pressure in drain cavity. In the process of adjustment and adjustment of the hydraulic drive, check the correctness of the hydraulic interlocks providing the necessary sequence of the mechanisms (for example, first clamping the workpiece, and then turning on the supply), as well as protection from an accident in case of disturbances in the hydraulic system (accidental pressure drops, disconnection of one of the pumps, etc.).

12) connect the electrical automation system and adjust the automatic cycle. Operation of hydraulic motors in automatic cycle must strictly correspond to equipment operation cyclogram. When setting up the automatic cycle, the accuracy of the operation of the electrical control system for the sequence of switching on the distributors, the reliability of the interlocks are worked out, the time of each transition, the values ​ ​ of the moves, the nature of the dynamic processes are finally adjusted and specified;

13) if during adjustment it is established that the average sound level of 85 dBA allowed in accordance with GOST 12.1.00383 for permanent workplaces in production premises is exceeded, it is necessary to take measures to reduce it. First of all, you should pay attention to the quality of the pump and the presence of air in the hydraulic system;

14) after operating the hydraulic drive in an automatic cycle for 4... 5 h, determine the steady-state oil temperature in the tank, which should not exceed 55 "C. If there is overheating, first of all, reduce power losses in the hydraulic drive. (check the operation of unloading devices, eliminate excessive reserves of suppression and flow), and then pay attention to the functioning of oil coolers (presence of cooling air flow in air or water in water heat exchangers; the amount of oil passing through the heat exchanger; serviceability of temperature controllers and correctness of their adjustment).

15) establish a filtering system. After several hours of operation of the actuator, check the degree of contamination of the filters and, if necessary, clean or replace the filter elements.

3.4 Rules of technical operation of hydraulic drive of electrode movement mechanism

Maintenance is a regulated, regularly carried out set of preventive measures that ensure serviceability of hydraulic drives during their operation.

Maintenance is an integral part of the system of scheduled preventive repair of machines, which should connect technical maintenance and repairs in one complex. Components of maintenance of hydraulic drives are:

- continuous monitoring of the state of the working fluid and all other parts of the system, carried out with the help of sensory organs - visually, by ear and by touch, and checking the readings of devices in order to detect deviations from the norm, the reasons for their appearance and taking prompt measures to eliminate them;

- periodic comprehensive check of the working fluid properties and condition, as well as check of the state of the most fail-safe components of the hydraulic drive for their timely replacement or repair (immediately, if their real state requires it, or in a planned preventive order);

- a one-time complete revision of the hydraulic drive, usually performed no more than once a year, accompanied by cleaning of the hydraulic tank and oil cooler, replacement of the working fluid, replacement, if necessary, of the main hydraulic units and adjustment of the control equipment.

Hydraulic drive maintenance shall be performed by specially trained personnel.

The personnel serving the hydraulic drive is divided into operational and repair. The duties of the operating personnel include the maintenance of the drive during the operation of the equipment. The duties of the repair personnel include periodic monitoring of the serviceable operation of the drive and troubleshooting.

When the actuator is on, the power cabinet door shall be closed.

Repair works on the drive are permitted only with complete removal of voltage and pressure from the drive elements.

All equipment shall be subject to periodic inspection and inspection.

Periodically, but at least once every two years, it is necessary to check the accuracy of the readings of electrohydraulic devices by comparing their readings with the readings of reference devices.

Pipelines shall be inspected daily. In case of leaks, perform tightening of nuts or repair of connections (at removed pressure.

Inspect seals daily, tighten them in a timely manner, make minor repairs.

Monitor filter contamination once per shift. In case of contamination replace the filter elements.

Recharge the gas part of the microaccumulators to the required operating pressure in a timely manner.

At least 2000 hours of operation, it is necessary to perform a physical and chemical analysis of the working fluid: determine the kinematic viscosity of the liquid at + 400C, the content of mechanical impurities. The analysis results are entered in the aggregate log. Take operating fluid from the tank for analysis in steady-state mode of drive operation and during operation of equipment mechanisms.

During normal operation it is necessary to replace the working fluid if its physicochemical properties do not meet the passport standards. When replacing the operating fluid, the internal cavities of the tank must be cleaned of dirt.

During operation in the log of the duty repair officer it is necessary to record the current preventive repair works and works on elimination of emergency faults that lead to and do not lead to equipment downtime.

All works carried out during major and ongoing repairs, as well as repair works resulting from major accidents, must be included in the aggregate log.

When replacing faulty electrohydraulic equipment, it is necessary to remove the power pressure, close all valves, turn off the voltage, repair the faulty unit or replace it with a spare one.