Flange Preheating Tunnel Oven

The Flange Preheating Tunnel Oven is an industrial furnace system specially designed for continuous heating or preheating of metal flanges. It adopts a tunnel-type structure and uses conveying systems such as conveyor belts, roller conveyors, or push-rod mechanisms to continuously transport flange components through the heating zones, achieving the required process temperatures for welding, forging, thermal assembly, or coating preparation.

Core Applications

1. Preheating Before Welding

Used to preheat high-carbon steel and alloy steel flanges before welding.

Reduces the cooling rate during welding and helps prevent:

Welding cracks

Thermal stress concentration

Structural defects

2. Thermal Assembly Process

Utilizes the principle of thermal expansion.

The flange is heated to expand its inner diameter, making it easier to achieve interference fitting and secure assembly with:

Pipes

Shafts

Other mechanical components

3. Forging and Rolling Processes

Used for overall controlled heating before:

Flange forming

Forging

Precision machining processes

to improve material forming performance and processing quality.

4. Pre-Coating Heating and Drying

Used before:

Surface coating

Anti-corrosion treatment

to preheat flange surfaces and improve coating adhesion and durability.

Applicable Standards

GB/T 10067.1

Basic Technical Requirements for Industrial Electroheat Equipment

Specifies general technical requirements for industrial electric heating equipment design and manufacturing.

GB/T 10066.1

Test Methods for Electroheat Equipment

Provides testing and performance verification methods for industrial heating equipment.

JB/T 4311

Performance Evaluation of Batch and Continuous Resistance Furnaces

Defines performance evaluation requirements for resistance heating furnaces.

TSG 11

Safety Technical Regulations for Boilers

Applicable when the equipment involves related gas-fired or steam heating systems.

Main Features

1. Continuous Production Operation

The tunnel structure enables continuous flange feeding and heating, providing:

High production efficiency

Stable heating cycles

Compatibility with automated flange manufacturing lines

It is suitable for large-volume industrial production.

2. Precise Temperature Control

The equipment adopts:

Multi-zone independent temperature control

Optimized internal thermal circulation system

to ensure uniform heating of flange components and minimize temperature differences throughout the heating process.

3. Energy Saving and Environmental Protection

The furnace features:

Good sealing performance

Thick thermal insulation layers

Reduced heat loss compared with traditional batch box furnaces

Continuous operation also improves thermal utilization efficiency and reduces energy consumption per unit product.

4. Intelligent Operation Control

The system is usually equipped with:

PLC control system

Touchscreen interface

Temperature curve recording function

Production data export capability

allowing accurate process monitoring and traceability.

FAQ

Q1: What heating methods are commonly used in flange preheating tunnel ovens?

A:The main heating methods include:

Electric heating (resistance heating wires or infrared radiation tubes)

Natural gas/LPG combustion heating

Electric heating provides more precise temperature control and is suitable for applications requiring strict temperature accuracy. Gas heating is generally more economical for large-size flange preheating applications with high heat demand.

Q2: What is the typical preheating temperature range?

A:The preheating temperature depends on the specific process requirements.

For welding preheating applications, the temperature is generally around 150°C–400°C.

For forging processes, the heating temperature may exceed 1000°C.

The equipment can be customized according to flange material, size, and production process requirements.

Q3: How does the equipment prevent flange surfaces from being scratched during transportation?

A:The conveying system usually adopts:

High-temperature-resistant stainless steel mesh belts

Chain conveyors

Special ceramic roller conveyors

For precision flanges, customized tooling fixtures can be designed on the contact surfaces to minimize mechanical damage and ensure product quality.

Q4: Is the energy consumption of this type of furnace high?

A:The tunnel oven has high thermal utilization efficiency due to continuous operation.

Compared with traditional box furnaces that frequently open doors for loading and unloading, continuous tunnel operation can reduce energy consumption per unit output by approximately 20%–30%, especially in large-scale production environments.

Q5: Does the equipment require a large installation area? What are the factory requirements?

A:Because of its longitudinal tunnel structure, the equipment is usually relatively long, typically ranging from 5 meters to 20 meters depending on production capacity and heating requirements.

The installation site should provide:

Sufficient longitudinal space

Proper exhaust ventilation systems

Stable electrical power supply or gas supply

Suitable foundation and equipment layout conditions