在下列情况应对风管进行保温：
The air duct shall be insulated in the following cases:
(1)由于冷、热损失过大，不保温，经济上不合理；
(1) due to the excessive cold and heat loss, it is not insulated and economically unreasonable;
(2)由于冷、热损失使介质温度达不到设计要求的温度；
(2) the medium temperature can not reach the design temperature due to cold and heat loss;
(3)由于热量损失，在风管内输送的气体温度降低到有可能在风管中或在随后的干式除尘器中结露或冻结；
(3) due to the heat loss, the temperature of the gas transported in the air duct is reduced to the extent that it is possible to condense or freeze in the air duct or in the subsequent dry dust remover;
(4)由于冷量损失，在风管外表面产生结露；
(4) condensation occurs on the outer surface of the air duct due to the loss of cooling capacity;
(5)由于输送高温气体，风管外表面温度过高(例如大于50℃)，会引起操作检修人员烫伤，或会引起煤气、蒸气、粉尘爆炸、起火的场合。
(5) due to the transmission of high-temperature gas, the temperature on the outer surface of the air duct is too high (for example, higher than 50 ℃), which may cause burns to the operation and maintenance personnel, or may cause gas, steam, dust explosion and fire.