The most beautiful analysis of the process of 1 ton steel shell hydraulic melting furnace

Steel melting furnace 1 ton hydraulic system, by a set of not less than 10 00KW dual frequency power supply and two steel 1t coreless induction melting furnace and auxiliary systems required for normal operation of the equipment.

A series resonant dual output power supply with two electric furnaces can work at the same time (commonly known as steel shell hydraulics ), that is, the output power can be distributed steplessly between the two furnace bodies, and the two furnace bodies can be simultaneously powered, one insulation , a smelt.

The power cabinet and furnace body use separate closed circuit circulating water systems, including closed circuit cooling towers. The rectifier transformer adopts a high-voltage electric drop to the input voltage suitable for the intermediate frequency power supply. The primary voltage is 10KV, and the second is DY11, d0 wiring . 3-phase 6-pulse or 6-phase 12-pulse rectification.

1 ton steel melting furnace includes a hydraulic set into the cabinet high-voltage line, a rectifier transformer station, a set of not less than 10 00kW frequency power supply, not less than 2 sets of 700 kW inverter, 2 sets 1t furnace, a cooling water jacket System 1 set of control system.

Melting furnace working mode:

1 ton steel melting furnace of a smelting furnace of hydraulic production, another set of the furnace equipment, with the single power 700kw.

One set of furnace body is smelted and produced, and the other set of furnace body is insulated at the same time. The melting power is 700kw and the heat preservation power is 300kw.

The two sets of furnace bodies are simultaneously smelted. 500kw per furnace

The main technical parameters 1 ton hydraulic steel smelting furnace:

1 ton steel melting furnace main hydraulic equipment technical description

The series resonant dual output IF power supply is housed in a closed cabinet. The incoming power supply is 660V, 3-phase 6-pulse or 6-phase 12-pulse rectification, 50HZ.

Cabinet

Cabinet body is made of cold rolled steel sheet is not less than 1.5 mm thick high strength. Opening the door makes it easy to access parts such as rectification and inverter. There are hooks on the top of the power cabinet for easy transportation and installation.

The components of the power cabinet are reasonably arranged, easy to maintain, and the wiring and wiring are in compliance with the specifications. It is convenient for maintenance personnel to easily access all maintenance points.

The copper bars are all set to reasonable water cooling as needed.

Isolation control room

A closed isolation control room is arranged at the upper part of the front door, and control components such as a main control board, a feedback board, and a control power supply are provided, so that the signal of the main control board can be conveniently observed.

The isolation control room does not require additional cooling.

Power receiving part

The circuit breaker adopts DW15 people's electric switch, which is composed of circuit breaker, voltage transformer and current transformer.

Rectifying section

Voltage feedback series type; the circuit adopts 6-pulse or 12-pulse circuit rectification mode, the incoming line voltage is 380v or 660v, and the rectifying part of the thyristor adopts the latest stacked heat sink assembly. The RC absorption branch at both ends of the thyristor can act as a buffer current sudden change when the thyristor switch is used. Each thyristor heat sink has a pressure indicating device.

Filter network

Reactor, leveling DC current, removing current ripple and preventing high frequency signals from entering the factory power supply line.

Filter capacitor. Filter capacitor is water cooled

The filter capacitor has an external discharge resistor that can be discharged within 5 minutes after the power is turned off.

The reactor is air core and water cooled .

Inverter part

The inverter circuit has two sets of series resonant inverter bridges, and the output power can be randomly and arbitrarily distributed between two series resonant inverter bridges.

The RC absorption circuit is connected in parallel across the thyristor to buffer the thyristor switch.

One power supply with two furnaces work at the same time, the power is distributed arbitrarily, one smelting one heat preservation, when it is needed for uninterrupted smelting, heat preservation, temperature rise, quenching and tempering at an accurate temperature, and maximally increase the amount of steel output.

Constant power output, power output is controlled by constant. During the melting process, when the load and temperature change, the load is always full power output, thus shortening the melting time.

Increase the power factor to ensure that the power factor is not less than 95% at any power.

The two furnaces share a transformer, and in any case the transformer reaches full capacity, reducing the capacity of the transformer.

The starting characteristics are good, and it can be started freely under full load and heavy load conditions, and the starting success rate is 100%.

Inverter capacitor bank

Two sets of series resonant capacitor compensation devices to meet the dual output, can simultaneously send power to the two furnaces. Capacitance capacitor mounted on the closed cabinet, the cabinet body is made of cold-rolled steel sheet is not less than 1.5 mm thick high strength.

Power conversion function

Power conversion between the two furnace bodies is achieved by rotating the power conversion potentiometer on the panel. A furnace body is melted to melt the other furnace body. It can also be smelted in a furnace. The other furnace was shut down.

Control System

It is equipped with output voltage meter, output power meter, working frequency meter, input current meter, input voltmeter, DC voltmeter, DC current meter, phase display on the control panel, and inverter working display. The two furnaces can display the intermediate frequency voltage, power and operating frequency respectively to monitor and control the operating conditions of the two electric furnaces.

The circuit board contains all the necessary control and electronic logic components to respond instantaneously to the voltage, current and power of each induction coil and to generate thyristor trigger pulses.

The circuit board sets limits on the inverter to avoid damaging the thyristors and capacitors in the event of current or overvoltage.

Press the button to control the “Run” and “Disconnect” of the inverter.

Main power indicator, this indicator lights when the circuit breaker is closed to power the variable frequency power supply.

Complete protection and health monitoring system.

A current limiting reactor is required to delay the rising speed of abnormal current

A fuse is required to provide short circuit protection.

Ground/leak detector alarm (optional)

1 ton steel shell hydraulic melting furnace body

The furnace body is composed of a furnace shell, a fixed frame, a tilting furnace mechanism, an induction coil, a yoke, etc., and is additionally provided with a furnace lining material and a leaking furnace alarm device.

Furnace shell:

Hydraulic steel melting furnace 1 ton furnace shell is made of welded steel plate using the squirrel-cage frame structure, the furnace lining has a lower shell ejection mechanism mounting bracket. A contour yoke is provided in the furnace shell. The yoke shielding can reduce the leakage magnetic flux to prevent the furnace body from heating, improve the electric energy efficiency, support the induction coil at the same time, improve the strength, and can conveniently disassemble the coil and repair, observe and dissipate the coil when the yoke is not taken away.

Fixing frame:

The fixed hob adopts high-strength integral steel structural parts to ensure long-term work without deformation. The furnace platform is made of 10mm pattern steel plate, which can be kept flat and not deformed during long-term use, and the noise on the working platform of the furnace is <85dB.

Tilting mechanism (hydraulic plunger cylinder)

The tilting furnace adopts two inverted plunger hydraulic cylinders, and the hydraulic cylinder inlet port is directly connected to the speed limiting shut-off valve (flow control valve) to prevent the furnace body from falling sharply due to the rupture of the pipeline and the like, causing an accident. Manual speed control reversing valve control.

The two oil cylinders are connected in parallel, and there is no jamming at the same time. The furnace body rises and falls smoothly when the furnace is tilted. A high temperature resistant protective sleeve is required on the outside of the cylinder.

Induction coil (ie sensor)

The induction coil is made of TU1 type (purity of 99.97% electrolytic copper), wall thickness / 6mm extruded rectangular copper tube on a special mold, the pitch error is not more than 2mm, and the coil group needs to be relieved after welding. deal with.

The induction coil is made of high temperature resistant, high pressure insulation paint, which is dip coated and vacuum dried. The insulation grade is H grade. The induction coil passed the 12kg/cm3 water pressure withstand test before leaving the factory.

A stainless steel water-cooling ring is arranged on the upper and lower parts of the induction coil to ensure uniform heating of the furnace lining. A Faraday short-circuit ring is required at the upper and lower ends of the coil to fully absorb the leakage flux at the upper and lower ends to prevent the furnace body from heating up. The furnace body is connected to a large-section water-cooled cable, and the lead-out line is in the form of a side lead-out line.The coil pressing device is pulled down on the stainless steel rod.

Yoke

The yoke is laminated with Z11 high-quality crystal oriented cold-rolled silicon steel sheet, and its thickness is ≤0.3mm, which is clamped on both sides with stainless steel. The yoke has a contoured arc-shaped structure that is consistent with the outer diameter of the coil. After assembly, the bending degree is ≤ 4mm, and the deviation between the theoretical center line and the actual center line is ≤ 3mm. The yoke covers the area of the induction coil ≥60%. The yoke fixing method: the yoke is closely attached to the induction coil, and a high-voltage insulating layer is used in the middle, and the outer surface is screwed on the stainless steel plate on the back of the yoke.

The inside of the yoke stainless steel clamping plate needs a water-cooled radiator. When the electric furnace is in operation, the yoke temperature is kept at normal temperature to prevent the yoke temperature from rising and deformation, thereby strengthening the support of the induction coil and improving the strength of the furnace.

Furnace lining and bottom

A 12 to 25 mm permanent lining (refractory clay coating) is applied to the inside of the inductor, and then the lining material is kneaded inside the cement.

The bottom structure satisfies the requirement of removing the furnace lining by using the lining pushing mechanism.

Leakage alarm device

It is necessary to set the lining thickness detecting device: when the lining thickness detecting device is working normally, the work indicator lights up and the warning light goes out. When the furnace lining has a low resistance phenomenon or the induction coil has a short circuit to the ground, the alarm lamp lights up and the buzzer sounds an alarm.

The detection device has a self-test button and a reset button. When the device is normal, the self-test button is pressed, the alarm lamp is lit, and the buzzer alarms. Press the reset button to cancel the alarm and resume the detection device to work again. The button below the reset button and the self-test button is used to break the bottom electrode. When the detecting device is in normal operation, the button can be used to initially determine the cause of the alarm. The detecting device can judge the change of the lining.

Output copper row and water cooled cable

The output copper row is made of high quality T2 copper bars with a purity of 99.9%. The copper busbar is connected to the variable frequency power supply and the furnace water-cooled cable.

The water-cooled cable is made of high-quality T2 material multi-strand copper stranded wire. The jacket is made of American Gates carbon-free hose or high-strength flame-retardant rubber tube. The joint needs to be cold-formed to ensure good contact and strong tensile strength.

The water-cooled cable and the induction coil must be connected to ensure better electrical conductivity, no deformation under high temperature working environment, good contact, long service life, impermeability > 10kg/cm ² , convenient and quick to replace, easy to repair.

Model

The boring die is made of ≥8mm steel plate and can be pulled out at any time as the furnace melts or the slab is finished.

Furnace lining quick ejection mechanism

The lining ejector mechanism is used for quickly removing the waste lining, and needs to be composed of a pushing block, a pushing cylinder and an operating mechanism. The pushing block is installed under the lining and can be connected to the pushing cylinder through the pushing hole at the bottom of the furnace body. When the old lining is required to be pushed out, the furnace body can be tilted by 90°, and the pushing mechanism is connected with the fixing part of the bottom of the furnace, and the furnace is operated. The old lining can be pushed out by the handle.

Smelting furnace table operation cabinet

Instrumentation and operational control devices are mounted on the panel. Install the operation switch, button, signal indicator and instrument indication on the operation console. The main function is to manually operate and stop the smelting furnace system. This panel has a hinge that can be opened for easy maintenance inspection. There are mainly the following components.

The power meter, voltmeter shows the electric furnace voltage and frequency meter, as well as the required transmitter, voltage transformer, current transformer, used to monitor and control the operating conditions of the two electric furnaces.

Press the button to control the "run" and "disconnect" of the inverter

Main power indicator, this indicator lights when the circuit breaker is closed to power the variable frequency power supply.

The main console outlet mode is in front of the platform, and the terminal blocks are arranged in the console panel.

The hydraulic device is mainly composed of two parts: a hydraulic pump station and a hydraulic console.

Hydraulic power station

The hydraulic pumping station is used to provide power to the cylinder of the tilting cylinder lining out of the mechanism cylinder. It needs to adopt a dual-machine dual-pump unit (one set of work, one set of spare), and has a pressure regulating device, oil returning and oil suction filtering device. The hydraulic cylinder requires a protective cover to ensure that the cylinder rod is not contaminated by dust and splash metal.

Hydraulic console

The hydraulic console is mounted on the table to control the tilting of the furnace (in the range of 0 to 95 degrees) and the lining. The operation console is operated by manual hydraulic valve. The work should be reliable, stable, without impact and creeping. The speed can be adjusted and can stay at any position.

Hydraulic station control cabinet: (1 set)

A control device is installed in the cabinet to provide power and control for the motor of the hydraulic pump station .

The main electrical components selected ABB, Siemens, Chint brand.

Smelting furnace dust removal device (optional)

During the smelting process of the smelting furnace, due to the preheating, melting and overheating of the metal charge, the movement of the furnace gas, the addition and lowering of the charge, and the damage of the refractory material, the cupola is made due to chemical action, thermal action and mechanical action. The flue gas emitted from the melting furnace contains a large amount of harmful gases (such as SO2, CO, HF, etc.) and solid harmful substances, which are not only harmful to humans, but also have great harm to the natural environment. The successful experience of smelting furnace waste gas, special recommended to the user bag filter, choose oil-proof waterproof polyester needle felt, take reasonable cleaning technology, control the flue gas temperature of the dust removal system, will make the system run resistance, dust removal effect Good, long life of the bag and low operating costs. The three are organically and reasonably matched, and the dust removal system achieves environmentally-friendly emission targets in a stable and reliable manner.