The industrial burner is used to mix or send fuel and air into burning equipment like the furnace, make the most of fuel and meet the requirement of processing and operation.
The burner for sulfur recovery unit mixes the acid gas or fuel gas with a certain content of air, burn the gas in the furnace, making them react with each other and provide the heat required for other equipment of the sulfur recovery unit. The common combustion furnace is a horizontal cylindrical furnace, and only one gas burner is arranged at the front end, and the gas combustion in the furnace is completed by the burner. Due to the particularity of this type of furnace and the extreme hazard of the operating medium, the sulfur furnace burner becomes the core and key to the safety and stability of operation. The performance of the burner directly affects the processing capacity and conversion efficiency of the entire unit.
Analytics of burner
To select a suitable and useful burner, we compare several types of burner for sulfur recovery unit. According to the mixture of fuel and air during combustion, we divide all burners into the premix burner and diffusion burner.
Premix burner
The premixed combustion is to premix the fuel and air into a combustible mixture in a certain ratio before combustion, and then eject it through a nozzle for combustion. The speed at which the combustion process takes place is entirely dependent on the speed of the fuel oxidation reaction. After the combustible mixture reaches the combustion zone, it can be burned in an instant and the flame is short. The air supply mode of the burner includes pressure mixing and ejector mixing, and it is suitable for combustion of industrial large energy heating devices. The burner also requires a special combustion chamber to maintain a stable high temperature in the combustion zone, complete the combustion process in the combustion passage, and its relative structure is complicated. Because there is high temperature smoke outside the combustion channel and the flame profile is not visible, it is called flame-less combustion.
The premixed burner has the advantages of high combustion temperature, high volumetric heat intensity (>30MW/m3), fast burning speed, small excess air, and complete combustion; the disadvantage is that the burner flame stability is slightly lower than that of the diffusion burner. It is easy to temper or blows off, and the structure is larger than the external burner. Because the combustible mixture does not necessarily form a stable flame in the high-speed air stream after ejecting from the fire hole and igniting.
Diffusion burner
Diffusion combustion refers to the simultaneous injection of fuel and air from two adjacent nozzles of a nozzle during combustion, and it is burning while mixing at the contact interface of the two, so that a clear flame profile can be seen. The speed of the diffusion combustion process mainly depends on the speed of fuel and air diffusion and mixing. When the nozzle structure is favorable for the mixing of the two gas streams, the combustion condition will be good, but otherwise isn’t contrary.
Diffusion combustion has good stability, simple structure, convenient operation and manufacture, no tempering, but low combustion temperature and low combustion intensity. Because it mixes while burning, the burning speed is slower than that of premixed combustion, and the flame is long, requiring a large furnace volume. When the excess air ratio is small or the mixing is poor, incomplete combustion is likely to occur. By improving fuel and airflow patterns, increasing gas flow rate, and setting high-temperature combustion passages, the strength of diffusion combustion can be appropriately increased, and the amount of excess air can be appropriately increased to ensure complete combustion. The air of the diffusion burner is supplied by a blower.
It is not difficult to find through the above description that the premixed burner and diffused burner are different, each has its own advantages. Therefore, the burner should be selected from the actual needs, and comprehensively considered to obtain the best comprehensive effect.
Features of burner for sulfur recovery unit
The burners for the sulfur recovery unit are usually tailor-made special burners, mainly include acid gas burners, online heat furnace burners, and tail gas incinerator burners, each has a different structure but they all have following features:
1.High strength
The special burner for the sulfur recovery unit has a large processing capacity and a high heat load. According to the amount of raw material processing and reaction conditions, the form of the burner is basically divided into two types, premixed burner, and diffused burner. Both have advantages and disadvantages, but all emphasize the high strength of the air and combustion process medium, and the high-intensity combustion makes the combustion medium and the air can get the most mixing, which is good for burning.
2.High temperature
The combustion temperature of the furnace of the sulfur recovery unit is generally between 1100-1400 ° C, and the combustion temperature of the online heat furnace and the tail gas incinerator is not lower than that. The higher the temperature, the more favorable the reaction is, but the excessively high combustion temperature will affect the long-term operation of the equipment. Therefore, the burner is not only required to meets the process, but the material should be also selected to prevent the burner from being damaged by high temperature radiation. This will ensure the safety and reliability of the combustion equipment.
3.High efficiency
The burners for the sulfur recovery unit have different positions in the process and different performance requirements. Each type of burner must be high performance and high efficiency.
4.High requirements for turkey design
The design of the burner should be based on the process requirements, and the optimized design matched with the furnace structure makes the whole combustion equipment an organic whole, which is compact in structure, consistent in material selection and excellent in performance.
5.The security and high degree of automatic control
Due to the hypertoxicity of the H2S, the process operation of the entire sulfur recovery unit is closed. As a positive pressure combustion equipment, the burner should be equipped with a series of safe operation control systems such as automatic purging, auto-ignition, flame detection, flameout protection, etc. The reliability of these systems will directly affect the normal operation and safety of the equipment.
Ruichang is a professional provider of complete EPC (Engineering Procurement Construction) solution of SRU for the petrochemical and coal chemical industry. Based on 30 years’ experience and more than 200 sets of applications. Our sulfur recovery unit has been proven by numerous clients. If you have any need, welcome to contact us!
