How to transform coal fired boilers into gas fired boilers
For industrial boiler fluidized bed gas boiler, whether it is changed into a circulating fluidized bed boiler or bubbling fluidized bed boiler, gas boiler manufacturer distributor is the key part of the fluidized bed boiler, a fluidized bed, but the orifices of high wind speed, wind resistance increased, especially more than 40 m/s, the resistance increased dramatically, fan high power consumption. The quality of fluidization, the stability of the combustion conditions, and the heat transfer of the bed have a great relationship with the structure rationality of the air distribution device.
Air distribution device generally adopts the hood type air distribution device. Because of the transformation of gas-fired boiler, the wind is evenly distributed in these parts, hood hole diameter than other parts selected bigger, the volume increases about 20%. At present, there are mainly two kinds of layout of fluidized bed boiler in our country. Most of the bubbling fluidized bed boilers are made of common models. Most of CFB boilers are equipped with water-cooled air chambers and water-cooled air distributor. The use of this kind of air distribution device is easy to be constructed, safe and reliable, and a lot of investment is less.
Now the brim of small diameter nozzle, its diameter is generally 40 to 50 mm, about 175 to 185 mm long hood, hood type air distribution device is composed of an air chamber, an air distributing plate, hood and protective layer. Air distribution uniform, hood on the grid plate according to the general layout of the equilateral triangle. Each nozzle opening 6 a 12, can be single or double row staggered arrangement. In the precombustion chamber oil ignition, Huo Feng indoor heat, insulation materials should be watered, the air distribution plate using I Cr18Ni9Ti steel, the thickness of 20 to 25 mm, a heat resistant nodular cast iron with high silicon production.
From the gas boiler orifices jet air speed as small wind speed, on the other hand, small wind speed is too low, in order to prevent the coal near the mouth due to the coal concentration caused bad fluidization and hypoxia phenomenon, the hole hole area also need to increase some. It is easy to cause coarse particle deposition and poor bottom fluidization, especially when the load is low, it often cannot be maintained. It is one of the main parameters of the design of the air distribution device. The larger the velocity of the small hole, the greater the impulse to the particles on the bottom of the bed. The stronger the disturbance, the better the fluidization of coarse particles. It will also operate stably at low load, and the load regulation range is large.
So, small wind Jian coal gas boiler should be based on the characteristics of cast iron and the bed material particle characteristics, load range and power consumption in terms of fan selection. In the bed around, because the barrier walls in the slag cooling pipe occupies several cowl position for a 10 mm 0 for coal particles generally select a hole velocity of 35 40m/s. For the coal with a particle of 0 to 8 mm, the wind speed of the hole is 30 35m/s. The speed of the coal with large real density is upper limit, and the lower density is limited.