I. Mechanical and Electrical Dual Interlocks

• Mechanical Interlock: The furnace door is equipped with a sturdy mechanical locking mechanism (such as spiral compression type, clamp quick-opening type, etc.), which requires specific tools or operations to physically lock or open. This fundamentally prevents accidental opening.

• Electrical Safety Interlock: A limit switch (or proximity switch) is installed at the mechanical locking point. Only when the furnace door is completely physically locked in place, pressing this switch, will the control system receive the "door closed" signal.

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II. Interlock Logic: Safety First

• Startup Interlock: As long as the "door closed" signal is not received by the PLC, the equipment's heating system and vacuum system absolutely cannot start. The operation interface will clearly prompt "furnace door not closed."

• Interruption Interlock: During equipment operation (heating or when the furnace is in high-temperature/high-pressure/vacuum state), if the furnace door is forcibly opened abnormally, the system will immediately trigger an emergency shutdown:切断 heating power, close the vacuum pump, open the safety valve, and simultaneously emit audible and visual alarms.

• Cannot Open with Power/Pressure: It is this precise logic that ensures the furnace door cannot be opened through normal procedures when the equipment is powered on or the furnace interior is in an unsafe state, fundamentally ensuring operator safety.

• The above technical article is exclusively written by Yuanhang Industrial Furnace Company. Reproduction is prohibited.