Technical parameters and process analysis of 0.5 ton melting furnace

Basic configuration: two furnace bodies, one set of power supply, one set of compensation capacitors, and two sets of furnaces are operated separately. The tilting method is hydraulically reversed with a remote control box.

When designing the equipment, the user's on-site working status is considered to be continuous, and the furnace is frequently discharged. The equipment selection of this scheme ensures the user's output index and meets the user's overall requirements for the equipment: the equipment is durable and performance. Stable, safe and reliable.

1.2 Equipment technical requirements

Power rating	500KW
Power frequency	1000Hz
Power line voltage	3×380V
Power factor	The power factor of the furnace under any power operation is not less than 0.95
Melting rate	500KW/1T ≥0.65t/h
Release temperature	1650 ° C
Power consumption	≤ 580KW.h/t
Working noise	<85 decibels
Melting material:	Cast steel, cast iron

1.3 0.5 ton melting furnace smelting description:

The user's factory uses induction furnace melting, heating, heat preservation, quenching and smelting process.

1.3.1 Power Supply Selection:

In general, the smelting speed and the metal to be smelted are determined in advance. The required melting speed determines the required power. Based on experience, the following estimation principles are available.

The following is the recommended melting furnace rated power configuration (iron and steel)

Furnace capacity (T)	Power range (KW)
0.5-1	500-750
2	1000-1500
3/4	1500-2000
5	2000-3000
6	3000-4000
8	4000-5000
10	5000-6000

1.3.2 Selection of transformer:

Power supply (KW) × 1.25 = transformer (KVA) Note 1.25 is the safety factor;

1.3.4 Power rectifier design:

In order to reduce the harmonic pollution generated by the high-power IF power supply to the power grid, our company uses the series inverter technology on the intermediate frequency power supply. Therefore, to ensure that the intermediate frequency power supply operates under high power factor, the generated higher harmonics are within the allowable values of the utility grid harmonics specified in the GB/T14549-93 standard;

Comparison of characteristics of parallel and series circuits (table)

Project		Medium frequency power supply type
Project		(a) Parallel type	(b) tandem type	(c) series and parallel
Output voltage waveform		Sine wave	Rectangular wave	Sine wave
Output current waveform		Rectangular wave	Sine wave	Sine wave
Induction loop fundamental voltage		Inverter output voltage	Q× inverter output voltage	Inverter output voltage
Induction loop fundamental current		Q× inverter output current	Inverter output current	Q× inverter output current
DC filter		Large reactance	Large capacitance	Large capacitance
Anti-parallel diode		No need to	use	use
Thyristor	Du/dt	small	Big	small
Thyristor	Di/dt	Big	small
Commutation overlap effect		Series reactance and distributed inductance cause commutation overlap	no
Commutation failure protection		easily	easily	easily
Additional component		many	less	less
effectiveness		Low (about 90%)	Normal (about 95%)	High (90%)
Operational stability		Stable over a wide range	Stable over a wide range	Difficult to manufacture below 1000HZ
energy saving effect		difference	excellent	difference

Note: The quality factor of the Q-induction loop.

When designing an intermediate frequency induction furnace, the main circuit of the intermediate frequency power supply adopts a series circuit.

The main technical parameters:

A. Comprehensive parameters:
Equipment form:	Medium frequency melting furnace
Equipment use:	Used to smelt steel
Rated Capacity:	1T 0.75T
Maximum capacity	2t+10%
Operating temperature:	1650 ° C (steel)
Smelting material:	steel
Tilting method:	Hydraulic control
Maximum angle of the tilting furnace:	95 degrees
Hydraulic medium:	Machinery oil
Hydraulic station capacity	500L
Working pressure:	11MPa
Working noise:	<85 decibels
Furnace structure:	Steel shell
Way out:	Side outlet
Melting rate:	500KW/2T ≥0.65t/h
Melting power consumption	580kW.h/t
B. Electrical parameters:
Power supply	500KW/1T 0.75T
Number of rectifiers	6 veins
Inverter	SCR series
Rated frequency	500Hz
Line voltage	3×380
Transformer primary side line voltage	10KVA
Sensor voltage	1600V
Start success rate	100%
Power factor	Greater than 0.95
C. Closed cooling tower:
Inlet pressure	0.2-0.4MPa
Inlet temperature	5-35 ° C
Effluent temperature	<55°C
Cooling water flow	40mm ²
Equipment shape	2300mm1200mm2800mm
Water pump	5.5KW one use one

Description of the control principle of the 0.5 ton melting furnace :

Brief description of the operation of 0.5 ton melting furnace :

Waterway operation:

a. Before starting the machine, first check whether the valves of each waterway are open. Before starting the machine, first turn on the cooling water system.

b. Open the external circulating water system first, and observe whether the water pressure and temperature meet the requirements;

c. Open the inner circulating water system again, and observe whether the water pressure and temperature meet the requirements. If it does not meet the requirements, adjust it in time;

d. After all the cooling water is in normal circulation, the electric furnace can be started to smelt;

Control flow chart for intermediate frequency furnace:

0.5 ton melting furnace complete equipment range:

1 equipment range list :

Serial number	Device item name	Specification model	unit	Quantity	Remarks
1	Intermediate frequency power supply	KGPS-500/1	station	1
2	Furnace body	GW-1 GW-0.5	station	2	Leaky furnace alarm
3	Hydraulic system	10Mpa	set	2
4	Model	1T 0.5T	only	1	5mm
5	Compensation capacitor cabinet	KGPS-500/1	set	2	Includes: channel busbar
6	Furnace front console	LTL-C1	station	2	Includes: three color lights
7	Leakage alarm system	LT-BU-101	set	2	Contains: electrode for furnace body
8	Water cooled cable	SL-500	set	2	A total of 2 400 square
9	Pair of flanges, seals, connecting bolts, feet		set	1

XI. Main components supporting manufacturers and quotations:

Serial number	item name	Place of production
1	switch	Shanghai People's Electric Appliance Factory
2	Rectifier thyristor	Hubei Xiangfan Instrument Component Factory
3	Inverter thyristor	British Sima (domestic package)
4	Power meter voltmeter, frequency meter ammeter	Suzhou Instrument Research Institute
5	Capacitor	Shangyu Capacitor Factory
6	main control board	self made
7	Reactor	self made
8	Button, switch, indicator	Zhengtai
9	Wire loop	Luoyang Copper Material Factory Cold Extrusion Copper Tube T2 Copper
10	Yoke (with water cooling)	Gao Xi silicon steel sheet yoke