The solution for a dosing furnace is completely dry installation with INSURAL* precast shapes and high insulating backing materials - huge energy savings, no sintering, low density index of the melt immediately and easy cleaning, say Arndt Fröscher, Foseco Europe and Jens Ohm, Foseco Germany.
Target: Quicker Availability
A market analysis amongst Foseco customers showed clearly, that there is a strong need for optimisation in terms of cleaning and avoidance of corundum growth. To solve these problems, extended trials with different INSURAL recipes have been made.
Foseco now offers a completely dry installation with INSURAL precast shapes which provides a number of benefits:
- Installation in the foundry is possible
- No sintering process needed
- The desired density index of the melt can be achieved much quicker
- The growth of corundum is reduced to a minimum
- Easy cleaning
- Huge energy savings
To the precast shapes belongs a launder, which holds the molten metal and two roof plates, two heating element plates and six tubes for the heating elements. All elements will be assembled without plaster or glue. Untrained operators could undertake the installation within 65-70 working hours (depending on circumstances). There is no need for special tools.
The area of the heating elements with separated plates and tubes is no longer sensible for cracks. The changing of heating elements is simplified.
The INSURAL precast shapes are installed together with a high insulating backing material. High insulating plates are installed on the inside of the steel shell. The gap between the plates and the INSURAL piece is filled with a high insulating bulk material. The heating is separated with plates.
As no plaster is in use, parts of the backing materials can be reused in the following installation.
After the installation, the furnace can be switched on and is ready to use after achieving the desired working temperature.
The huge time saving just in this step is clearly shown in fig.1. Depending on the quality requirements, the density index of the melt plays an important role.
Due to the dry installation, the required density index can be achieved much quicker than usual.
The use of the INSURAL material provides a minimised corundum build-up and easy cleaning due to its non-wetting ability.
An alloy change in the furnace is possible at any time. The only need is a cleaning process with only one flushing batch.
As INSURAL has a good insulating property, it is the basic material for the concept.
A case study shows that a dosing furnace with a capacity of 650kg can be heated up to 720°C within eleven hours.
Measurement of the power consumption shows the reduced energy requirement (up to 17 per cent).
The heating element stays on the lowest level for 98 per cent of the time (positive for low corundum growth). This fact also reduces the energy consumption in the standby stage (on weekends etc.).
Another case study with a dosing furnace with a capacity of 1050kg shows an energy saving of approximately 80kW/h per day. This high values is obviously caused by the high melt temperature of 780°C.
Summary
The installation with INSURAL precast shapes provides a number of benefits:
- Possibility of quick installation on site
- No need for sintering
- No hydrogen pick-up
- Minimised corundum growth
- High energy saving
- Easy cleaning
Contact: Paul Jeffs, UK technical manager, Vesuvius UK Limited - Foseco Foundry Division, Tamworth, Staffordshire B78 3TL UK. Tel: +44 (0) 1827 289999, email: [email protected] web: www.foseco.com
* INSURAL is a Trade Mark of the Vesuvius Group, registered in certain countries, used under licence.
For copies of the figures with this article refer to the printed version in the December 2016 issue.