China wholesale Molybdenum Flat Bar - Molybdenum heat shield – WINNERS

Product Description

Molybdenum heat shield

As the heat insulation component in the vacuum furnace, the biggest function of the heat shield is to block and reflect the heat in the furnace. Therefore, high-purity, accurate size, smooth surface, easy assembly, and reasonable design of heat shields are very important.

Molybdenum heat shields are generally produced and processed with 0.5-1.2 mm molybdenum sheets. Generally, there are 4-6 layers. The inner layer of the furnace is made of high-temperature molybdenum TZM material with a thickness of 1.2 mm. Molybdenum strips are used to separate the layers with a space of 7mm. ​Other molybdenum heat shields are made of 0.5-0.8 mm MO1 material. 

The heat shield is generally fastened with molybdenum bolts or riveted with molybdenum sheets. Of course, we can also provide these accessories. Please contact us.

Design points of metal heat shield

●Thermal properties of materials

The maximum temperature of the selected metal material should be greater than the environmental working temperature, and the thermal deformation of the metal should be small. When the temperature is higher than 900°C, tungsten, molybdenum and tantalum sheets are generally used. Below 900°C, stainless steel sheet is generally used.

●Material blackness

Choose low blackness material, surface reflection effect is better, higher surface finishes.

●Material thickness

The thickness of the heat shield should be as thin as possible. Molybdenum is generally 0.2 ~ 0.5mm. Stainless steel plate is generally 0.5 ~ 1mm.

●Material price

Under the condition that the working temperature is satisfied, the material cost should be considered, and the cheaper material should be selected.

●Determining the number of layers of heat shield

With the increase of the number of layers, the heat loss decreases, the cost increases, the structure is complicated, and the vacuum degree is more difficult to meet working requirements. Increasing to three layers to increase about 8%. The number of layers is not the better, and it should be considered comprehensively. The working temperature is 1000℃, and up to six layers can be used.

●Spacing between each heat shield

The spacing should be minimized. The thermal effect of increasing the distance is not large. If the spacing is too small, the two insulation plates will be connected together due to thermal deformation. Reduce the spacing, generally around 10mm.

●Connections between layers

Each layer of heat shield should be connected, and the contact area of the connection should not be too large, which will reduce the thermal efficiency. Use bushings and washers to connect each layer.

●Maintenance of the heat shield

The heat shield should be designed to be easily disassembled, and the thermal expansion and contraction properties of the material should also be considered.

●The distance between the first screen and the radiating surface

Generally 50~100mm

●The distance between the outermost screen and the circulating water wall

Generally 100~150mm

Order Information

Inquiries and orders should include the following information:​

☑ Drawing of the Molybdenum isolation screen
☑ Material of the screen (W, Mo, Ta or SS304)
☑ Quantity

*In general, please provide relevant drawings so that we can quote quickly. Of course, if you may have some technical problems. Please describe them to us in detail so that our engineers can help you more efficiently.
Please contact us if necessary. (Whatsapp: +86 156 1977 8518)