Does the air coming out of the blower in a catalytic CO incinerator need to be preheated?
Thread Content
Does the air coming out of the blower in the catalytic CO combustion furnace need to be preheated? We don’t have a preheating system here; is it possible to arrange for the air to be preheated in a spare boiler before being fed into the CO combustion furnace? Could this help reduce the amount of fuel gas used? I wonder if anyone has done this before
Preheating the air reduces the heat energy required for heating, thereby increasing thermal efficiency; the air can be preheated before being fed into the furnace for combustion
The design of the blower outlet air in catalytic CO incinerators typically does not take preheating into account. The advantage of preheating is that it reduces fuel consumption; however, it also has certain disadvantages, such as the need to pass this air through an air preheater, which increases equipment costs and raises the pressure drop on the flue gas side. Furthermore, CO burners typically consume very little gas, as their primary purpose is to burn the CO in the flue gases; therefore, the amount of air used in this process is necessarily relatively small.
What you mean is that installing an air preheater will increase the capital cost of the equipment. Additionally, with an air preheater in place, the pressure at the outlet of the blower will inevitably rise, which in turn increases the cost of the blower. The savings in fuel gas are not proportional to the increased investment – is that what you mean?
The increased investment in blowers isn’t what I consider to be the main issue; what worries me more is the impact of the rising pressure drop on the flue gas side.
We use a high-temperature economizer to heat the exhaust steam, from which a stream of air is separated for heating and supplementary combustion; the purpose of this is to make use of the waste heat from the boiler in order to improve its thermal efficiency. If the process is convenient and it is possible to overcome the limitations posed by flue gas dew point corrosion, heating with the flue gas at the rear of the boiler can be considered; this approach can also reduce the water consumption of the desulfurization tower.
In that case, won’t the water temperature entering each drum decrease?