Supplementary Fired Waste Heat Boiler Design Supply & Site Supervision Service

Supplementary Fired Waste Heat Boiler Design Supply & Site Supervision Service

SMDERI has been engaged in research and development on waste heat boiler for catalytic cracking unit in oil refinery industries for more than 40 years and obtained numbers of patents. Based on his strong R&D ability and engineering experience, SMDERI provides design, fabrication, engineering, technical supervision and EPC contract service for the new-built project & upgrade reconstruction of various types of waste heat boilers.

Supplementary Fired Waste Heat Boiler

Dependent on the production process, the flue gas from some production unit may contain such flammable gas composition as CO, and the Supplementary Fired Waste Heat Boiler is to recover the physical enthalpy and heat value of flammable flue gas compositions (such as CO) and produce steam or hot water as required by the owner. It recovers both the physical heat energy and the chemical energy of the flue gas and handles the toxic and harmful gas in the flue gas, which is both environment friendly and energy saving.

Work Flow: The work flow is described below based on flue gas flow and steam-water flow.

* Flue gas flow:  When discharged from the production plant, the hot flue gas first flows into the water   seal drum and then is connected into the adiabatic chamber of the supplementary fired waste heat boiler through flue gas duct. The burner located at the lower part of the adiabatic chamber heats the flue gas to the temperature where the flammable gas may be treated. The hot flue gas after treatment out of the adiabatic chamber successively flows through the convective section, superheater, evaporizer, economizer, and finally the emission duct. The heating surface of waste heat boiler supplied by SMDERI is designed as modules in order to minimize site installation work and reduce the installation time.

* Steam-water flow:  

Feedwater system: The medium pressure deaerated water from external supply is heated at the feedwater preheater before it is delivered to the low temperature economizer. Hot water from the low temperature economizer flows to the feedwater preheater to discharge heat there before it flows into the high temperature economizer. The flow is medium pressure deaerated water→ feedwater preheter→ low temperature economizer→ feedwater preheater→ high temperature economizer→ hot water for external consumer or steam drum.

Evaporization system: Saturated water is delivered to the convective section and evaporizer through different process pipelines, where it is heated and vaporizes. Then the steam-water mixture enters steam drum through the process piping. In this way, the convective section, evaporizer and steam establishes an evaporization system of natural circulation.

Steam system: Saturated steam produced at the steam drum, together with those from external supply, is connected to the inlet header of low temperature superheater. It is superheated there before it flows into the high temperature superheater. The superheated steam from the outlet header of high temperature supereheater is piped to the medium steam network of the plant.