Which of the following is a common feature of an atmospheric fluidized bed boiler?

In an atmospheric fluidized bed boiler, a uniform bed temperature is a crucial feature due to the operation of the fluidized bed itself. The process involves suspending solid particles—such as sand or ash—within an upward flow of air, creating a 'fluidized' state. This uniformity in temperature is important because it ensures consistent combustion and minimizes variations that could lead to inefficient fuel utilization or increased emissions. The design allows for good mixing of the fuel particles, leading to efficient heat transfer and overall improved combustion efficiency.

Other aspects, such as combustion air pressure and temperature, vary based on operational requirements and design specifications. The choice of fuel, including whether coconut shells are used, can depend on regional availability and the specific capabilities of the system but is not a defining trait of atmospheric fluidized bed boilers. Thus, uniform bed temperature stands out as a key characteristic inherent to the operation of these boilers.