Should the water coming out of the deaerator be fed into the boiler or the economizer?
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RT, I would appreciate advice from the experts here. I am currently installing a SZL 15-ton steam boiler, and the manufacturer has provided a economizer and a deaerator as part of the setup. My question is: should the deaerated water be fed directly into the boiler or first into the economizer? If it goes directly into the boiler, then does the softened water first go to the economizer for heating before proceeding to the deaerator? How is it generally handled in conventional industrial boilers?
The softened water is pumped to the deaerator using a deoxygenation pump, and the boiler feed pump sends the water from the deaerator to the boiler. The economizer is part of the boiler; in all boilers, the water first passes through the economizer before entering the boiler, and part of the steam produced is then used to deoxygenate the softened water in the deaerator
Having a economizer means it’s an advanced economizer; otherwise, what’s the need for an economizer?
If it is heated with an advanced economizer, doesn’t that require raising the flue gas temperature? Deoxygenated water is 104°C
Under normal circumstances, the water enters the boiler directly after passing through the economizer at 104°. However, if you want to save energy, you can let the water pass through the economizer first, which will result in a much lower flue gas temperature. The cast-iron economizer can be used in this way; there’s no need for steel pipes. Because oxygen corrosion is very severe
The temperature of the flue gas after passing through the economizer is generally around 320°C, while the temperature of the flue gas after exiting the economizer is usually around 200°C. The temperature of the water coming out of the deaerator generally does not exceed 105°C; it can therefore be heated using the economizer. Only by removing some of the heat from the economizer through heating can the temperature of the flue gas falling to 200°C, thereby meeting the boiler’s requirements regarding flue gas emission temperatures
Softened water--------Deaerator--------------Feed pump------------- economizer--------------Steam drum
The water coming out of the deaerator is first sent to the economizer for further heating, thereby saving fuel.