From 2003, based on the technical experience from enclosed ground flare, Qiyao Energy started the technical R&D of open ground flare and made a great many combustion tests. Eventually Qiyao Energy developed a patent technology of independent intellectual property (patent No.: ZL201020529360.8).
Similar with the enclosed ground flare, open ground flare also adopts multiple burners and staging control principle and uses metal fence to reduce the influence of flame on the surroundings. Therefore, the open ground flare also has such environmental features as no smoke and light pollution, low heat radiation, low noise and etc.
Compared with enclosed ground flare, the open ground flare can adapt to much higher flare gas flow rate. As the scale of petrochemical plants is constantly increasing, more open ground flare will be applied in the future. The open ground flare consists of such main components as ground burner, pilot, igniter and metal fence. Based on the properties of various flare gas, the open ground flare can also take measures to improve the combustion process, such as steam and forced draft.
Compared with elevated flare system, the enclosed ground flare has such environmental features as no smoke and light pollution, low heat radiation, low noise and etc. In particular, the ground flare system can be arranged near the border of production plant and thus substantially reduces the land investment.
Typical case: Ningbo Heyuan project
This project is the first open ground flare with independent intellectual property in China. The flare system for Ningbo Heyuan Chemicals Co. Ltd (now Ningbo Fude) methanol-to-olefins project includes a HP open ground flare and a LP enclosed ground flare.
The design capacity of open ground flare is 1062t/h, and the design capacity of enclosed ground flare is 110t/h. The battery limit of the entire flare system is 170m×190m.
Typical case: Ningbo Fuji
A flammable gas venting system and flare system is provided for the propane resource comprehensive utilization project of NingboFuji Petrochemical Co,. Ltd to vent and burn the vent gas produced during the start-up, emergency and normal venting of the unit in a safe and reliable way and thus satisfy related environmental requirements.
The flammable gas venting network finally is divided into four streams before being connected to the flare battery limit:
---Ambient temperature HP flare: 800t/h;
---Low temperature HP flare: 60t/h;
---Ambient temperature LP flare (PSA): 3487kg/h;
---Ambient temperature LP flare (PP): 1890kg/h.