Top Mounted Single Coal Slurry Burner For Long Term Stable Operation

Top mounted single coal slurry burner for long term stable operation

The top mounted single coal slurry burner is also used for coal slurry gasifier. Different from the opposite four burners type, it is a single burner mounted at the top of the gasifier. The structural sketch is shown in the figure below.

The coal slurry burner has 4 channels, with oxygen channel in the center and then coal slurry channel, outer oxygen channel and cooling water channel accordingly. The cooling water channel is divided into cooling water in & out channels to form a circulation at the burner head to improve the cooling process of burner head and prevent it from damages owing to high temperature.

Before the burner starts operation, usually conventional burner is used to increase the reactor temperature to the desired value to ignite the coal slurry. The cooling water is supplied at the same time. Then coal slurry and oxygen is delivered into the high temperature reactor for reaction. When the burner is ignited, the reactor pressure is gradually increased to the value desired by gasification reaction. Now the burner starts normal operation.

Compared with conventional 4-channel arrangement, the coal slurry burner developed by SMDERI has made major improvement to the cooling water structure. The cooling water channel combines water jacket with water coils. Water jacket is used at the end face to enhance the cooling to end face by forced cooling of whirls. In addition, the end face uses thin wall structure to improve the effective heat exchanger. A heat resistant coating is sprayed to the surface to greatly improve the resistance to high temperature.

Flame arresting device is provided inside the water jacket to prevent backflow of hot flue gas. As the cooling water pressure is lower than the gasifer pressure, if the end face is burnt and damaged, hot flue is apt to flow back to the pipelines along the cooling water return line. In this case, if the monitoring system or valve does not act promptly, there might be explosion hazard. A flame arresting device is provided to effectively prevent hot flue gas backflow and create enough time for the system to react and thus prevent major hazard.

The entire burner is mainly constructed with constructed with stainless steel and nickel-based alloy steel, and special material of high crystal phase grade is used for cooling channel at the burner head to resist high temperature thermal stress, which contribute to a prolonged service life.