STRAIGHT & FORMED TUBULAR HEATERS
Tubular heaters are the main heating source in most applications where electric heat is required. They are highly adaptable to the requirements of many applications. Tubular heaters can be used in their straight form or can be bent into various shapes. They can be used in free air, clamped to a surface, embedded, or cast into metals. Tubular heaters can provide heat up to 1500°F.
LAIYUAN HEATER tubular heaters use 80% Nickel 20% Chromium high grade coiled resistance wire as a heating core. This core is welded at both ends to pins that provide a cold section that varies in length depending on the application requirements. The coil-pin assembly is precisely centred inside a heavy gauge, oversized metal tube, and embedded inside a 96% pure, high-grade MgO insulating medium. This assembly is then compacted through a roll-reducing process that reduces the outside tube diameter to its final size and transforms the MgO matrix into a rock-hard solid that acts as an excellent heat transferring medium, as well as an electrical insulation with high dielectric strength. Finally, heaters are annealed inside a high-temperature furnace to eliminate internal stresses accumulated during the cold-forming roll-reducing process to make them soft. Heating elements are then formed into special shapes or supplied in their straight form. Proper electrical terminations are added to the final product.
APPLICATIONS OF TUBULAR HEATERS
HEATING MOLDS & PLATENS
IMMERSION INTO LIQUIDS
RADIANT & CONVECTION HEATING
EMBEDDED OR CAST INTO METAL
MOUNTING TIPS OF TUBULAR HEATERS
Tubular heaters expand when heated. At least 1% of element length should be considered as expansion and adequate clearance included in total design.
When a tubular heater is attached to a surface, the middle clamp screws should be tightened completely. However, the end clamp screws should be tightened enough to hold the heater down and allow for expansion at the same time. This procedure will prevent the tubular heater from getting detached from the surface during the heating cycle.
When tubular heaters are placed in grooves, the groove depth should be less than the heater diameter by 0.008”- 0.010”, in order to ensure proper clamping.
Insulating materials (if used) should never be in direct contact with heaters. An air gap should separate the heater sheath from the insulating material.
Tubular heater electric terminals should not be placed in vacuum or heated zones.
MOISTURE RESISTING SEALS
The MgO insulating medium inside a tubular heater is highly hygroscopic and can absorb moisture from its terminal ends. Moisture resisting seals are barriers that resist or stop moisture and contamination.
This seal is a silicone-based resin that is applied to tubular heater terminal ends. The seal penetrates a short length of the MgO insulation and transforms it into a moisture and contamination resistant medium suitable for temperatures below 390°F.
This is a silicone room temperature vulcanizing seal that can resist moisture and contamination for up to 450°F.
This is a liquid resin which is thermally cured to reach solid state. This moisture barrier is adequate for temperatures up to 250°F.