Fire Resistant Conveyor Belt（DIN-K）

According to various sources, fire-resistant conveyor belts, particularly those meeting the DIN-K standard, are essential for minimizing fire risks in environments such as coal mines, where flammable materials are prevalent. These belts effectively reduce the likelihood of ignitions caused by static discharge and help contain flames should a fire occur, thus protecting workers and property.

Application Background

The utilization of fire-resistant (or flame-resistant) conveyor belts (Standard: DIN-K/EN/JIS-K) in coal mining activities significantly contributes to mitigating the occurrence of both above ground and underground fires. The coal mining environment is complex, with coal dust and gas presenting dangerous factors. Additionally, the coal being transported is inherently flammable. In instances where electrical sparks are produced during transportation, the risk of fires increases substantially. Implementing fire-resistant conveyor belts reduces the possibility of electrostatic sparks during the coal transfer process. Even in the event that static sparks do arise, these belts possess high flame resistance, thereby prolonging the time before flames spread.

Globally, various flame-retardant standards exist to ensure safe operation, including Germany's DIN-K, Europe's EN (general/above ground) and EN (underground), ISO 340, the USA's MSHA 30, Japan's JIS-K, and Australia’s AS. It is crucial to clarify the specific fire resistance level needed for a particular application. When in doubt, consulting a professional is recommended.

Fire Resistant Capability Test

Testing protocols such as JIS/ISO/DIN involve subjecting six individual belt samples to an open flame until they burn. Upon removing the flame source, the duration for which the sample continues to burn is recorded. Following this, airflow is applied to the sample to ensure that no re-ignition occurs. The time taken for the sample to extinguish after the ignition source is removed is measured, with the standard requiring that the duration of visible flames be less than 15 seconds per sample, accumulating to a maximum of 45 seconds.

The pulley friction test is a significant factor differentiating the safety classifications of belts used above ground versus those used underground. For certifications, these tests must be conducted by an independent testing agency, ensuring no evidence of flame or glow is present during or after the trials. Typically, a PVC belt is employed, as its thermoplastic properties allow it to melt before reaching the critical temperature of 325°C; the SUNGDA maximum average lies around 260°C to 270°C.

Fire Resistant Conveyor Belt Carcass Types

Solid woven carcass: Composed of polyester and nylon filaments, this type is treated with PVC and plasticized to achieve high tensile strength, minimal elongation, and excellent impact resistance. It is primarily suited for underground coal mining applications.

EP carcass: This fabric consists of polyester in the longitudinal (warp) direction and polyamide in the latitude (weft) direction. It offers excellent flexibility and is suitable for medium to long-distance transportation in above-ground mining situations.

Steel cord carcass: Known for its superior tensile strength and excellent adherence of rubber to the steel cord, these belts are ideal for long-distance transport of materials.

Understanding Usage Environment

When selecting flame-retardant conveyor belts, assessing the customer’s operational environment is vital. Conveyor belts operate in diverse settings, ranging from dusty factory floors to hazardous environments like mines. Each setting imposes distinct demands regarding the flame-retardant properties of the belts. Therefore, a thorough analysis of these conditions, in conjunction with the anti-static and flame-retardant capabilities of the belt, is critical for ensuring safety and efficiency.

Types of Fire-Resistant Conveyor Belts

There are three predominant types of fire-resistant conveyor belts: fabric-layered, steel cord, and solid woven. The fabric-layered conveyor belt is the most widely used in coal mines, holding over 80% market share owing to its superior flame resistance, lightweight nature, and cost-effectiveness.

International Testing Standards

Understanding the applicable testing standards is essential when considering fire-resistant conveyor belts. Different standards like RMA and DIN offer varying criteria for testing and certifying conveyor belts.

Further Reading

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