How do they differ from ordinary steam boilers?

Waste heat boilers differ from ordinary steam boilers primarily in their purpose, design, and operation. Here are the key distinctions between the two:

1. Heat Source:

   • Waste Heat Boilers: Waste heat boilers are specifically designed to recover heat from industrial processes that would otherwise be wasted. They utilize exhaust gases, flue gases, or other waste streams from various industrial processes as their primary heat source. The recovered heat is then used to generate steam or hot water for additional processes or power generation.
   • Ordinary Steam Boilers: Ordinary steam boilers are designed to generate steam from a primary fuel source, such as coal, natural gas, or biomass. They rely on combustion of fuel to produce heat, which is transferred to water to generate steam. Unlike waste heat boilers, ordinary steam boilers do not utilize waste heat streams as their primary heat source.

2. Design Considerations:

   • Waste Heat Boilers: Waste heat boilers are engineered to withstand the corrosive and high-temperature conditions associated with industrial waste streams. They typically feature robust materials, corrosion-resistant alloys, and specialized heat transfer surfaces to maximize heat recovery efficiency and durability.
   • Ordinary Steam Boilers: Ordinary steam boilers are designed to meet specific requirements based on the type of fuel, steam pressure, and desired steam output. They are typically constructed using materials suitable for high-pressure steam generation and combustion chamber designs optimized for efficient fuel combustion.

3. Operating Conditions:

   • Waste Heat Boilers: Waste heat boilers operate under varying and often challenging conditions, depending on the characteristics of the waste heat stream. They may encounter fluctuations in temperature, flow rate, and composition, requiring careful design and control measures to ensure optimal performance and safety.
   • Ordinary Steam Boilers: Ordinary steam boilers operate under more controlled conditions, with fuel combustion regulated to maintain stable steam production. Operating parameters such as fuel flow, air-to-fuel ratio, and combustion chamber temperature are closely monitored and adjusted to achieve desired steam output and efficiency.

In summary, while both waste heat boilers and ordinary steam boilers are used to generate steam, their distinct designs, purposes, and operating conditions set them apart. Waste heat boilers are specialized for recovering heat from industrial waste streams, while ordinary steam boilers rely on combustion of primary fuel sources to generate steam.