Bitumen storage tank electric heating technology makes asphalt transportation more efficient

Asphalt transportation urgently needs "green" transformation

The railway transportation mode of asphalt is high-temperature liquid loading. The temperature of asphalt in the tank gradually decreases with the transportation time. Due to the characteristics of the asphalt medium itself, the viscosity of asphalt increases, the fluidity deteriorates, and even condenses into a solid state. After the transport vehicle arrives at the station, it cannot be directly unloaded. It needs to be heated to a certain temperature before the unloading operation conditions are met.

At present, the heating method of domestic railway asphalt tank cars is flame heating. The tank body has a built-in fire tube. The high-temperature flue gas generated during the combustion process uses a burner to heat the asphalt in the tank through the fire tube.

This open flame heating method has simple equipment and easy operation, but there are problems such as low heating efficiency, uneven heating of asphalt, serious burning of heating sleeves, easy blockage of fire tubes, uncontrollable flame temperature, and high operation risks. In particular, the large amount of flue gas generated during the heating process causes serious environmental pollution.

Since the 1950s, the Soviet Union, Japan, Europe and the United States and other countries have begun to study electric heating methods and equipment, and gradually applied them to oil-sticking equipment such as oil tankers in the 1960s, and then promoted and applied them. Relevant companies in the United States have applied electric heating technology to innovate asphalt storage tanks. The electric heating technology used is mainly radiant tube type, with coils or electric heating tubes inside the radiant tube.

In countries and regions with relatively developed roads such as Europe and Japan, electric heating has become a standard configuration for asphalt mixing plants. As the country's efforts in environmental protection and safety management are becoming increasingly stringent, the exhaust gas and waste emissions generated by the fuel flame heating of existing asphalt tank trucks have begun to be strictly controlled at most unloading points. Under the pressure of environmental protection, it is urgent to improve the heating system of railway asphalt tank trucks to meet environmental protection requirements and better serve the asphalt transportation market.

"Original" technology is urgently needed to break through difficulties

Taking into account the needs of asphalt railway transportation and environmental protection requirements, it is necessary to solve technical problems such as using electricity as the energy source for heating, achieving zero flue gas emissions and zero environmental pollution during the heating process; being able to solve the problem of uneven heating of asphalt, controlling the temperature during the heating process, and ensuring the quality of asphalt products; the electric heating system is safe and simple to operate, and convenient for maintenance and repair.

Key technologies for electric heating of asphalt storage tanks mainly focus on the research of heat transfer characteristics of asphalt media, design of components of electric heating devices, matching of electric heating systems with railway asphalt tank cars, and intelligent control technology of electric heating. We master the key core technologies of electric heating, break through the technical bottleneck of electric heating of railway asphalt tank cars, and improve the environmental performance and safety and reliability of vehicle heating and unloading.

The development of asphalt tank cars strictly follows the product design and development process, and has passed the design scheme review and prototype vehicle technical review organized by China National Railway Group Co., Ltd. The prototype vehicle has undergone body static strength tests, vehicle impact tests, electric heater modal tests, loading and unloading and heating performance tests, etc. The test results all meet the requirements of relevant standards and specifications, ensuring that the product quality meets the design requirements. Asphalt tank cars are at the domestic advanced level.