EGSB (Expanded Granular Sludge Blanket) is developed from the UASB. Due to good settling characteristics of granular sludge, EGSB can be used to expand sludge blanket when water flows up higher, while at the same time avoiding the loss of sludge. This means the concentration of mixed sludge as well as volume load is higher. One has to take care that more sludge is lost duet o the high up-flow velocity and intensive gas production. Therefore, the three-phase separator is used to enhance the solid-liquid separation. Biogas is led out from the sealed collector on the top.
The EGSB reactor makes full use of anaerobic granular sludge technology. It provides sufficient up-flow velocity for the reactor through the external circulation and ensures the expansion of granular sludge blanket, makes sure that the matters inside the reactor are fully mixed, and as a result improves the efficiency of the reactor. Wastewater of high concentration is pumped into EGSB from the bottom by the water distribution system and is then mixed with anaerobic granular sludge in the reactor. Most organics are converted into methane and the gas-liquid separation module separates methane, water and sludge. The biogas enters transport system from the top while the wastewater flows into the following processing system and anaerobic sludge returns to the sludge blanket.
Technical features are as follows:
1.External circulation system
2.Efficient separation module
3.High sludge concentration
4.High volume load