The heating system is a core functional module of a crack sealing machine. Its working principle and technical features are as follows:

I. Basic Components of the Heating System

1. Heat Source Unit

• Diesel Burner (Mainstream Configuration):

• Power: Typically 15-50 kW

• Flame temperature: 800-1200°C

• Electric Heating System (Small Equipment):

• Uses resistance heating tubes

• Power: 3-10 kW

• Gas Burner (LPG/CNG):

• Environmentally friendly option

2. Heat Transfer Medium

• Direct Heating Type: Flame directly acts on the bottom of the material tank.

• Thermal Oil Circulation Type (Mid-to-High-End Models):

• Closed-loop circulation system

• Operating temperature: 150-280°C

3. Temperature Control System

• PT100 Temperature Sensor (Accuracy: ±1°C)

• PLC Intelligent Temperature Control Module

• Dual-Channel Temperature Monitoring (Material temperature + Heating medium temperature)

II. Working Process

1. Preheating Stage

• Direct Heating Type:

• Radiant heating of the tank bottom (Thermal efficiency: ~65%)

• Thermal Oil Type:

• Oil pump drives thermal oil circulation (Thermal efficiency: ~85%)

• After burner ignition, heat is transferred through:

• Radiation (direct heating)

• Convection (thermal oil circulation)

2. Temperature Stabilization

• PID Controller adjusts burner output.

• Over-Temperature Protection automatically cuts off fuel supply.

• When material reaches set temperature:

• Standard asphalt: 160-180°C

• Modified asphalt: 180-200°C

3. Insulation Stage

• Maintains working temperature within ±5°C fluctuation range.

• Agitator operates simultaneously (Speed: 15-30 rpm).

III. Performance Comparison

IV. Safety Protection Mechanisms

• Triple Temperature Protection:

• Over-limit alarm (>220°C automatic shutdown)

• Flame monitoring & flameout protection

• Thermal oil pressure monitoring

• Emergency Systems:

• Manual pressure relief valve

• Overheat automatic exhaust device

V. System Advancements

• Fuzzy control algorithm for precise temperature adjustment.

• Ceramic fiber insulation layer reduces heat loss (<8%).

• Modular design for easy maintenance (quick burner disassembly).

Note: Actual performance is affected by ambient temperature, material moisture content, etc. In winter, preheating time may need to be extended by 30-50%.