GAS FUEL ROTARY KILN For Sale

Gas Fuel Rotary Kiln Introduction

Gas-fueled rotary kiln (gas rotary kiln) is a gas-fueled rotary kiln equipment, mainly using natural gas, liquefied petroleum gas (LPG), coal gas (such as coke oven gas, blast furnace gas, generator gas) and other gaseous fuels as heat source. According to the type of gas, the combustion devices used in gas-fueled rotary kilns include gas burners, LPG burners and natural gas burners. The number of burners used and the installation layout are basically the same as those for oil-fired rotary kilns. Compared with oil or coal-fired rotary kilns, gas-fueled rotary kilns have more advantages in combustion efficiency, environmental performance and automation control, and are widely used in cement, metallurgy, chemical industry, environmental protection and other industries.

Analysis of Different Types of Fuel in Gas-Fired Rotary Kiln

Gas rotary kiln can use a variety of gas fuels, different fuels in the calorific value, combustion characteristics, environmental protection, cost and so on there are significant differences, directly affecting the rotary kiln operating efficiency and economy.

Natural gas (NG)
High calorific value, but not as high as liquefied petroleum, high flame temperature (above 1900°C), suitable for some natural gas-rich countries and high temperature calcination (e.g. cement clinker). Compared with coal-fueled rotary kilns and oil-fueled rotary kilns, natural gas can effectively increase the kiln’s combustion utilization, and improve and reduce the environmental pollution caused by combustion products. However, the cost of gas supply in remote areas is high and the price fluctuates greatly.

Liquefied petroleum gas (LPG)
Relatively high calorific value, flame temperature up to 2100 ℃, suitable for high heat demand process, as long as there is a transformer equipment, it is very convenient to use. It can be transported in high-pressure storage tanks and is suitable for areas without piped natural gas. However, the cost is higher than natural gas, and it is usually used as a back-up fuel or for small kilns. Moreover, it requires special storage tanks and pressure reduction equipment, and safety management is very important. LPG is smokeless, ashless and residue-free, and is cleaner than oil and gas.

Coal Gas：

Low calorific value of coal gas, unable to obtain higher flame temperature alone:

• Coke Oven Gas (COG)：High hydrogen content (55%~60%), fast combustion speed, strong flame radiation ability. Low cost, suitable for coking plant supporting rotary kiln. However, it has low calorific value and needs to be matched with combustion aid or oxygen enrichment technology.
• Blast furnace gas (BFG)：Free by-product of iron and steel plant, very low running cost, low sulfur content, less dust. However, it has very low calorific value (3~4 MJ/m³), needs combustion and high CO content, and has poor safety.
• Producer gas (PROG)：It can be produced by coal gasification and has a wide range of fuel sources. Low calorific value (5~6 MJ/m³), poor combustion efficiency. Containing tar and sulfur, easy to block the pipeline, poor environmental protection, has been gradually eliminated.

Gas Fuel Rotary Kiln Advantages

The oil rotary kiln with oil mist combustion reaction is fast, and the heating process is fast, which is conducive to shorten the cold and hot process of the rotary kiln, and can effectively shorten the heating time. In addition, oil rotary kiln has the following obvious advantages.

Reducing powder sticking to the wall and improving powder performance
The oil rotary kiln has been improved in the following aspects: increasing the kiln tube inlet temperature, increasing the intensity of kiln ventilation, and disturbing the powder in the kiln by using a percussion hammer.

Very good powder consistency
The consistency of the product depends on the degree of adhesion of the powder to the wall of the kiln tube. Since the oil-fired rotary kiln solves the problem of powder sticking to the wall very well, the powder consistency produced during the pre-firing process of the powder is very good.

High production capacity
Fuel rotary kiln is a large rotary kiln equipment. The production capacity of one oil-fired rotary kiln is equivalent to that of 2-3 electrically heated rotary kilns, with an annual output of 3,600 tons. The oil-fired rotary kiln also saves land and reduces maintenance.

Mature technology, simple operation
Oil burning technology is mature, with a stable control system and relatively low technical requirements for operators. The ignition and shutdown process is faster than coal-fired kiln, which is suitable for intermittent production or commissioning stage.

Simple equipment structure and low maintenance cost
No need for crushing, conveying and other supporting systems of coal-fired kilns, fewer equipment failure points, less maintenance workload.

Special Design of Gas Rotary Kiln Combustion System

The combustion system of gas rotary kiln mainly consists of gas burner, gas ignition system, flame detection system, air chamber, transition tube, nozzle, nitrogen purge/release device, fixed frame, combustion fan and other components. The design of the combustion system of a gas-fired rotary kiln directly affects its combustion efficiency, temperature control accuracy, pollutant emission and operational stability. Compared with coal/oil-fired system, gas combustion system has unique design in flame regulation, low-NOx combustion, intelligent control and so on.

The characteristic design of the gas rotary kiln combustion system focuses on high efficiency, cleanliness and intelligent control. The new gas rotary kiln burner is also equipped with an ionization electrode flame monitor machine and an emergency shut-off valve to ensure that the safety and energy efficiency are both up to the standard and to provide a decarbonized solution for high-temperature industries.

Multi-fuel compatible system
Using dual-fuel backup design of main fuel (e.g. natural gas) and backup fuel (e.g. LPG or diesel) to prevent gas source interruption. Natural gas is mixed with coke oven gas to balance calorific value and cost.

Safety control design
Equipped with emergency shut-off valve and leakage monitoring to automatically cut off gas supply when gas pressure is abnormal or kiln temperature exceeds the limit.
Methane sensor (natural gas) or CO sensor (coal gas) is installed along the pipeline. When the gas leaks, an interlocking alarm system is formed, and when the leakage concentration exceeds the standard, the exhaust air is started and the machine is shut down.

Anti-tempering design
Flame detector (UV/IR probe) as well as minimum flow control are installed at the burner head to close the gas valve immediately when flame out to avoid low speed gas backfire.

Gas Fuel Rotary Kiln Technical Parameters