3) The basic requirements for the part of the waste heat boiler(1) Adopt a drum–type natural circulation boiler with large heat storage capacity;(2) In order to reduce the influence of particulate matter in the flue gas on the subsequent heating surface and stabilize the flue gas temperature, it is advisable to arrange the first enclosed by the water–cooled wall of finned tubes. And/or the second flue (if any); arrange the convective heating surface in the second or third flue;(3) For the dynamic characteristics of waste and reduce the corrosion of the superheater, the temperature of the flue gas at the convective heating surface should be appropriate control at no higher than 650˚C;(4) Slag catching pipes (also called pre–evaporators) should be arranged at the entrance of the convective heating surface; the heat exchange tubes of the convective heating surface should be smooth tubes and have an appropriate pitch;(5) Arrangement of evaporator and superheater in sections: a hybrid desuperheater is used between the two superheaters;(6) Economizers can be arranged in sections on the heating surface of the tail: the temperature of the demineralized water at the inlet of the economizer can be 130~140˚C or according to supplier's requirement;(7) The installation of the safety device of the waste heat boiler must comply with the relevant regulations of our country;(8) Special anti–corrosion materials should be used for the superheater;(9) Special attention should be paid to the ash removal measures on the heating surface of the waste heat boile