Founded in 1924, company OTTO JUNKER manufactures medium-frequency induction furnaces for melting, holding and casting ferrous and non-ferrous metals. The main production is located in Lammersdorf, Germany.

Close cooperation with the Technical University of Aachen, as well as the experience gained as a result of the supply of a large amount of equipment, form the basis for constant innovative developments.

Currently, the OTTO JUNKER group includes companies from Germany, UK, Netherlands, Spain, Czech Republic, USA and China, with more than 800 employees.

The technical and economic advantages of the medium-frequency OTTO JUNKER crucible induction furnaces are the reason for the growth of their widespread use in the foundry industry.

Economic characteristics:

  • Low power consumption
  • Low melting loss
  • High plant availability
  • Easy operation and maintenance
  • Low installation costs due to compact design
  • Minimum installation time due to pre-assembled units
  • Low labor costs due to melting automation

Technical characteristics:

  • Strict temperature and process control
  • High accuracy and repeatability of analyzes
  • High performance due to high power density
  • High flexibility / easy switching between different types and metal brands
  • Possibility of melting with and without swamp

A medium-frequency crucible furnace installation consists of:

Melting furnace including:

  • Furnace body with inductor
  • Tilting frame of the furnace (optional with a reverse tilting)
  • Hydraulic unit
  • Furnace pit protection
  • Operator panel
  • Exhaust hood hydraulically opening in two directions

Power section including:

  • Rectifier transformer
  • Frequency converter
  • Capacitor rack
  • Power cables

Process control systems, including:

  • Weighing system
  • Control cabinet
  • Melting processor JOKS
  • Optical Coil Protection (OCP)

Water cooling systems for the furnace and power section with air cooler / cooling tower

Auxiliary equipment, including:

  • Dust collection system
  • Loading device
  • Crucible push-out device

New efficient designs to lower melting costs

1. DUOMELT system

Smooth distribution of power of the frequency converter between two furnaces operating alternately

  • Full continuous use of 100% of rated power
  • Shorter downtime for higher productivity
  • Simultaneous melting, holding and pouring
  • Maximum flexibility

2. DUOCONTROL system

Switching the supply of 100% power between two furnaces operating simultaneously

  • Shorter downtime for higher productivity
  • Simultaneous melting, holding and pouring

This technology is based on changing the melting frequency to optimize the melting results. Such a process may include steps, starting with an increased frequency adapted to the grain size of the charge (250 Hz), then the frequency decreases automatically after the metal has melted, in order to increase the turbulence of the bath in the furnace to enhance the mixing effect and assimilation of alloying elements. If a smooth bath surface is required during the overheating phase, the frequency should increase (125 Hz).

Features of multi-frequency technology application:

  • Rapid melt of smal-lumpy material
  • Optimal chemical correction (carbon adjustment)
  • Minimal metal oxidation
  • Minimum melting loss
  • Reduced energy consumption per tonne of liquid metall
  • Optimal power consumption

4. Melting processor JOKS

Melting processor JOKS provide optimal process control and reliable monitoring of the entire melting process. JOKS provide automatic control of all functions and processes that are associated with smelting, exchanges data and information with higher-level control systems, and analyzes and records operating data.

Scope of functions includes:

  • Automation
  • Monitoring
  • Process documentation

The system can carry out the entire sequence of the process, from the preparation of the charge, loading and melting to analysis, correction and management of all auxiliary units and peripheral equipment.

Operating principle:

All actual data collected by sensors and PLC systems are compared with the specified parameters and set values for calculation and control.:

  • amount of energy for melting, holding and overheating;
  • sintering time;
  • temperature and cold start modes;
  • charge preparation;
  • analysis and correction of heat;
  • furnace data and safety functions.

Operation with JOKS

The main menu contains various subsections that the operator can select using a function buttons. At the same time, a brief description of the equipment status for continuous monitoring is displayed at the top of the window.

5. Optical system for coil protection OCP (Optical Coil Protection)

OCP represents a new generation of a system for measuring and monitoring the temperature in the working area of the furnace using fiber optic sensors. Due to their measuring characteristics, such sensors are particularly well suited to measuring without interference on crucibles in induction melting furnaces.

Thus, OCP is a unique monitoring system, which the first makes it possible to determine the temperature field in an induction furnace, regardless of the type and design of the refractory.

Physical principle of operation

Based on the optical fiber, the system uses a quantum-mechanical effect, called “Raman scattering” effect (Raman effect) to measure temperature. The system delivers laser radiation with a suitable wavelength and modulation frequency to the optical fiber. This laser radiation is scattered by the binding electrons of the structure along the entire length of the fiber and is determined in the form of a backscattering spectrum.

This spectrum contains Raman lines, the intensity of which is functionally dependent on the vibration of the solid-state structure of the fiber, which in turn depends on temperature. The new, patented “optical radar method” makes possible the local determination of such lines, as well as the measurement of the accurate temperature profile with high resolution around the circumference of the crucible in a real time.

Coil Protection Functions OCP

  • Visualization of temperature, as well as temperature difference over a period of time in the immediate vicinity of the inductor.
  • Сrucible lifetime estimation
  • High temperature difference alarm
  • Reaching a set maximum temperature alarm

A RGD type filling furnace consists of a cylindrical furnace tank with a filling hole and a siphon-type discharge chute, and also includes a stopper mechanism. Easily replaceable inductor with flange mounting at the bottom. The filling hole and the discharge chute can be angled +/- 90 ° or 180 ° to each other. The casting furnace is mounted on a double trolley in order to be able to move along and across the molding line and, thus, approach for pouring to the gate funnels, which can be located in different parts of the mold.

Application area:

  • Flask molding lines
  • Flaskless molding lines
  • Instalations for the production of high quality copper anodes
  • Centrifugal Casting Machines
  • Casting in intermediate ladle

The regulation of the metal level in the exhaust chute of casting furnaces RGD type is carried out due to:

1. Float system

A ceramic float is immersed in liquid metal. When the level of the bath changes, a change in buoyancy is detected, and the casting pressure is adjusted so that the metal again reaches the set level.

2. Laser system

Non-contact determination of the level of the bath occurs through a laser system. The set metal level remains constant by adapting the casting pressure.

3. Protective electrodes

These electrodes limit the maximum allowable metal level in the discharge chute. When the electrodes come into contact with the liquid metal, an instantaneous safety discharge occurs, as a result of which the liquid metal flows back from the discharge chute to the furnace tank.

Economic aspects of the use of casting furnaces OTTO JUNKER RGD type

  1. reduced rejects due casting
  2. no residual cast iron and increased bucket efficiency
  3. increased productivity due to optimum use of the molding machine
  4. the casting process is carried out independently of the melting shop
  5. labor cost savings
  6. improved working conditions

Catalogs and documents

  • Брошюра “1_Junker_cистема управления JOKS” Download .pdf/ 3.42 Mb
  • Брошюра “2_Junker_книга” Download .pdf/ 7.75 Mb
  • Брошюра “3_Лазерное устройство контроля футеровки LLP_Каталог” Download .pdf/ 1.41 Mb
  • Брошюра “4_Junker_загрузочные машины” Download .pdf/ 825.73 Kb
  • Брошюра “5_Junker_плавка цветных металлов” Download .pdf/ 4.84 Mb
  • Брошюра “6_Junker_оптическая защита катушки OCP” Download .pdf/ 2.7 Mb
  • Брошюра “7_Junker_вакуумные печи” Download .pdf/ 1.79 Mb
  • Брошюра “8_Junker_печи типа MFT SC cтандарт компакт до 6 т” Download .pdf/ 3.63 Mb
  • Брошюра “10_Junker_индукционные_печи_общая_брошюра” Download .pdf/ 1.64 Mb
  • Брошюра “1_Junker_cистема управления JOKS”_(ColorsConverted) Download .pdf/ 10.64 Mb

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