Resistance furnace repairs Precautions

Zhuanfeng:
1. Furnace wall longitudinal cracks between the blocks to stagger 1/3 to 1/2 brick length, does not allow vertical broken gap;
2. Each furnace wall 1m long must stay 5 ~ 6mm expansion joints at all levels staggered arrangement. After a covered brick expansion joints;
3. Roof cracks between the blocks is not greater than 1.5mm, and the bottom of the furnace wall brick joint is not more than 2mm, non-heating zone Zhuanfeng 4 ~ 5mm, brick brick furnace shell sewn 8 ~ 10mm.
Vault:
1. Premade circular wooden mold masonry, brick and standards by the wedge-shaped bricks with masonry;
2. Brick does not allow the lack of corners, brick arch foot slope must coincide with vaulted brick wedges;
3. Not allowed to have loose bricks, vaulted expansion joints should remain in the side wall junction, per meter 5 ~ 6mm.
Bottom:
1. Thermal insulation brick oven underlay flower format, fill vermiculite intermediate lattice;
2. Paving bottom seam must be wrong, a double metal underlay allow staggered.
Mortar:
1.1000oC above high temperature furnace clinker (0.9mm) mass fraction of 70%, raw material (0.9mm) mass fraction of 30%, plus the amount of sodium silicate and water
2.1000oC less in temperature, low temperature furnace clinker (0.9mm) mass fraction of 60%, the raw material mass fraction of 40%, plus the amount of water.
Heating elements:
1. Replacement heating element material, size, shape, heating elements should be the same as the original;
2. Greater than 1000oC welding high temperature furnace, the temperature DC arc furnace, furnace temperature acetylene - oxygen welding (neutral flame)
3. Nickel-chromium alloy with oxyacetylene welding (neutral flame);
4. Electrode selection R407 or R507. Oxyacetylene welding wire used to do the same electric wire;
5. After 600 ~ 700oC before welding preheat. After welding is best to stress at 600 ~ 700oC.