Enameled Tube Preheaters

Air preheater is a heat exchange device that uses the waste heat from flue gas to heat the air required for boiler combustion. It’s generally set in the area with the lowest temperature flue gas temperature, recovers gas heat, reduces the exhaust gas temperature, and improves the boiler’s thermal efficiency. At the same time, the air required for combustion is preheated, that increases the initial temperature of the fuel and air, strengthens the ignition and combustion process, and reduces incomplete heat loss of the fuel, further improving the thermal efficiency of the boiler.  The working principle is: transfer the heat from flue gas to heating surface, then to the air, heating the air and increasing the temperature, thereby completing heat exchange and reducing the boiler exhaust gas temperature. Our company has rich experience in the design, production, installation, and operation of air preheater projects, especially develops and manufactures targeted enamel glazes based on the flue gas composition and operating characteristics of different types of boilers.

Air preheaters are divided into enameled tube preheaters, ordinary tube preheaters, Cowden steel tube preheaters, ND steel tube preheaters, stainless steel tube preheaters, etc.

The air preheater is at the rear heating surface of the boiler, no matter industrial boiler or power plant boiler, there is a common problem: severe low-temperature acid corrosion and ash blockage, which is particularly prominent when burning high-sulfur fuels, seriously affect the safety and economic operation of the boiler. Nitrogen oxides (NOx) is generated by the oxidation of nitrogen during the combustion process. It not only irritates the human respiratory system, harm animals and plants, destroy the ozone layer, but are also one of the main substances causing greenhouse effects, acid rain and photochemical reactions. The emission limits for NOx are becoming stricter globally, especially to the main sources of NOx gas emissions, including thermal power plants, waste incineration plants and cement plants. The impact of low-nitrogen combustion technology on the efficiency of boiler air preheaters:

(1)Heat loss

(2) Blockage in air preheater heat exchange elements, which increases the exhaust gas temperature

(3) Increased air leakage rate of air preheaters.

To address these challenges, we conduct technical research and develop a new generation of enameled steel tube air preheaters, which can minimize corrosion and ash blockage issues. With its scientific formulation, rigorous process, and reliable quality, this new generation has been adopted by numerous power plant customers in recent years. After extensive simulation tests and operational verification, we developed the scientifically formulated glaze and apply it to the surface of the rust-removed steel tubes, then dry and fire the tubes in parallel electric furnaces at a constant high temperature. The air preheaters using these enameled steel tubes has the advantage of exceptional wear and corrosion resistance, smooth surface that resists blockage, and low maintenance costs. To accommodate various boiler combustion methods, fuels types, and flue gas compositions, our company has developed a series of enameled steel tube air preheater products tailored to different media environments (based on corrosion and wear resistance levels):

1.Enameled steel tubes for chain-grate furnaces and other layer-fired boilers; 

2.Enameled steel tubes for circulating fluidized bed furnaces and pulverized coal furnaces; 

3.Enameled steel tubes for waste incinerators and biomass stalk furnaces; 

4.Enameled steel tubes for oil-fired boilers, coke oven gas furnaces, and other gas-fired boilers; 

5.Enameled tubes and enameled heat transfer components specifically for desulfurization and denitrification projects.

Our company can add an enamel tube air preheater in the flue according to the customer's actual needs and on-site conditions. Welcome to us for a solution.