Development, design and manufacture of heat transfer convection thermal furnaces on the basis of the high temperature industrial fans designed by OJSC "VNIIMT"
Fig. 1 Thermal furnaces equipped with a high temperature circulation fans
Intensification of heating and cooling processes in convective furnaces due to high speed gas atmosphere blowing along the processed materials in workspace, in order to improve furnace productivity and product quality.
Increasing convection furnaces productivity and quality of products obtained, is currently largely limited by technical capabilities of existing industrial heat-proof fans. The main problems hindering the efficient operation of such devices are:
- the lack of performance and drop pressure, generated by heat-proof fan;
- the lack of reliability and short lifetime heat-proof fans;
- inability to use centrifugal fans as reversing devices in furnaces with a periodic change in the direction of gas atmosphere moving without regulatory and closing valves.
The use of industrial heat-proof fans designed by OJSC "VNIIMT" when engineering new convective heat transfer type furnaces and systems and upgrading existing ones.
The use of industrial heat-proof fans designed by OJSC "VNIIMT" in convective furnaces results in:
- significant increase in quality of products due to a steady flow of heat transfer agent during the heat treatment process;
- increase in convective type furnaces performance by 15-20% due to intensification of heating or cooling processes;
- increase in fans lifetime by 30-50% due to the latest design of impellers and bearing assemblies used in heat-proof fans;
- reduce in power consumption by 5-8% due to high efficiency of the fan;
- lowering temperature gradient non-uniformity of long workpieces (e.g., pipes) through the organization of a patented OJSC "VNIIMT" reverse gas flow system without using valves - reversible centrifugal and axial fans.
High-temperature industrial fans for thermal furnaces
OJSC "VNIIMT" develops, manufactures and supplies high-temperature industrial fans and heat proof exhausters in gastight design to move various gaseous environments (air, endothermic gas, carbon dioxide) with the temperature up to 900°C. This force-draft equipment can also be used as remote circulatory fans for heat transfer type furnaces.
Fig.2 Furnace high-temperature fans
High temperature fan (exhauster) consists of the following parts: a frame, a stand, a chassis with a heat resistant impeller, a built-in shaft cooling air system, a spiral case (volute) with thermal insulation, an electric motor, a belt joint (V-belt drive) . After the inlet and outlet pipelines are connected the fan (exhauster) is ready for operation. The fan (exhauster) parameters are adjusted by changing the rotating speed of the heat proof impeller using the electric drive frequency control. OJSC "VNIIMT" also has the ability to manufacture high-temperature impellers according to customer's drawings or to develop new designs of impellers with required parameters.
Fig.3 High temperature centrifugal impellers for thermal furnaces operating at 550˚C
Fig.4 Heat proof axial impellers for thermal furnaces operating at 400 ˚C
Parameters of high temperature industrial fans designed by OJSC "VNIIMT" used in thermal furnaces
up to 80000 m3/h
Total pressure at NTP
up to 10000 Pa
Maximum temperature of the pumped gas atmosphere
Maximum temperature of the pumped gas atmosphere in heat-treatment furnaces with protective blanket (endothermic gas, hydrogen etc.)
Shaft and bearing parts cooling system
built-in air system
OJSC “VNIIMT” carries out the following types of works:
- Design and supply of jet-circulation devices (jet cooling units) for cooling stripes and rolled metal (pipe) in catenary and pusher-type furnaces with protective atmosphere.
- Design and supply of water-cooled section (water cassions), equipped with built-in heat transfer intensification system for catenary and pusher-type furnaces with protective atmosphere.
- Design and supply of gas-dynamic obturators (inlet and outlet valves) for catenary furnaces where metal stripes are thermally treated in protective atmosphere.
When the equipment is designed, our experts make gas dynamics, aerodynamic, strength and thermal calculations based on the finite element method with the help of modern computing devices.
Research institute of metallurgical heat engineering – OJSC "VNIIMT"
Studencheskaya St. 16, Yekaterinburg, 620137, Russia.
Head of Laboratory Vladimir Kalganov
Tel/Fax +7 343 383-75-69
Email: firstname.lastname@example.org , email@example.com