Continuous High-Temperature Roller Kiln

I. Scope of Application

The continuous high-temperature roller hearth kiln is a highly efficient firing solution characterized by high throughput and low energy consumption. While traditionally utilized in the architectural ceramics, sanitaryware, and daily-use ceramics industries, its application scope has expanded significantly in recent years to include lithium battery materials, rare earths, magnetic material raw materials, electronic powders, and electrical ceramic components. This advancement is largely attributed to the development of advanced roller materials—specifically the emergence of recrystallized silicon carbide (ReSiC) rollers—which enable the furnace temperature to reach up to 1200°C. For investments requiring high-volume production, the roller hearth kiln stands as the premier choice.

This kiln is suitable for the large-scale drying and firing of products operating below 1200°C. Typical applications include: advanced ceramic materials, electronic components, powder metallurgy, ultra-pure alumina powder, catalysts, magnetic materials, rare earth oxides, alumina, zirconia, lithium cobalt oxide, lithium manganese oxide, ternary lithium-ion materials, cobalt oxide, pearl pigment, ultra-pure powders, petroleum catalysts, glass crystallization, lithium battery materials, sodium battery materials, chemical powders, ceramic substrates, magnetic material raw materials, rare earths, electronic powders, and electrical porcelain parts.

II. Technical Overview

1. Kiln Length: Determined based on the customer's required production capacity.

   
   

2. Heating Elements: High-temperature resistance wire or silicon carbide rods.

   
   

3. Temperature Range: Operating range from 200°C to 1300°C, offering wide adjustability.

III. Kiln Features

1. Atmosphere: Capable of operating in air or nitrogen environments.

   
   

2. Materials: The furnace chamber utilizes new-type materials ensuring a pollution-free process.

   
   

3. Energy Efficiency: Adoption of new refractory materials results in approximately 30% energy savings compared to traditional refractory structures.

   
   

4. Loading Method: Materials are loaded into saggers, which are placed on the rollers for conveyance. Saggers are arranged in double rows and double layers within the kiln.

   
   

5. Internal Atmosphere: Air. Note that the material may release small amounts of waste gas (e.g., water vapor) during the firing process.

   
   

6. Atmosphere Control: Exhaust pipes are installed in the preheating and firing sections to accelerate the removal of various waste gases from the kiln.

IV. Main Technical Parameters & Requirements

4.1 Rated Temperature: 200–1300°C. Operating Temperature: 1200°C (adjustable).

4.2 Rated Power: Determined by furnace chamber size and required temperature.

4.3 Holding Power: Dependent on feed speed and exhaust volume.

4.4 Power Supply: 3 Phase, 380V AC.

4.5 Heating Zones: Determined by furnace length.

4.6 Control Points: Twice the number of heating zones.

4.7 Heating Method: Top and bottom heating; constant temperature zones controlled separately for top and bottom.

4.8 Heating Elements: High-temperature resistance wire or silicon carbide rods.

4.9 Control Accuracy: ≤ ±1°C.

4.10 Cross-section Temperature Difference (Constant Temp. Zone): ≤ ±5°C.

4.11 Sagger Size (L×W×H): 300 × 300 × 90mm (Purchaser to prepare; customizable).

4.12 Approx. Overall Dimensions (L×W×H): Varies according to furnace size.

4.13 Conveying Speed: 800—4500 mm/h; Common speed: 2000mm/h (adjustable).

4.14 Speed Regulation: Variable Frequency Drive (VFD).

4.15 Reference Furnace Dimensions (L×W×H): Customizable upon request.

V. Roller Hearth Kiln Control System

Temperature Control: Employs PID (Proportional-Integral-Derivative) automatic control. The system features automatic temperature rise/regulation, PID auto-tuning, and zero-crossing triggering. The actuating component is a bi-directional thyristor (SCR), offering advantages such as no mechanical contacts, silent operation, long service life, and minimal interference with the power grid. Controls are centralized and display is intuitive.

Control Panel: Features an intuitive, visually clear layout. Each heating zone's temperature control system is equipped with corresponding alarm devices, specifically overtemperature alarms. Each zone also has an independent circuit breaker for convenient operation and maintenance.

Thermocouples: Utilize insertion-type thermocouples. Spare thermocouple insertion ports are provided. When not in use, these ports should be sealed with refractory fiber to prevent heat loss from the furnace chamber. The control system is designed to operate reliably under rated conditions, supporting continuous 24/7 operation. Custom designs are available per user requirements.

VI. Roller Hearth Kiln Body Structure

6.1 Furnace Lining: The side walls are constructed with mullite lightweight standard bricks using wet laying. The insulation layer is composed of lightweight fibrous material.

6.2 Preheating/Binder Removal Zone: Equipped with adjustable exhaust ports.

6.3 Furnace Body Design: Features easily detachable side panels (with handles) and a protective top cover, ensuring an aesthetically pleasing exterior.

6.4 Cooling System: To reduce the product exit temperature (approx. 90°C), a water-cooling jacket is installed in the cooling zone. The system includes alarms for water overtemperature, overpressure, under-pressure, or water flow stoppage.

VII. Mechanical Drive Section

7.1 Drive Unit: Utilizes a helical gear drive system (Origin: Guangdong). The main drive unit is installed on the right side of the kiln (viewing from the entrance). Powered by 1 variable frequency drive (VFD) motor (Origin: Jiangsu), enabling adjustable speed. The speed adjustment range is 120 mm/min to 700 mm/min.

7.2 Drive Structure: The drive mechanism serves as the power source for moving products through the kiln. Its smooth and reliable operation directly impacts product quality. The system consists of a VFD motor driving a gear transmission, engineered according to mechanical design principles.

7.3 Drive Tubes (Rollers): Constructed from materials such as silicon carbide tubes, stainless steel tubes, or alumina ceramic tubes. (Selection or customization is based on specific temperature requirements and furnace chamber dimensions).