GSL Separator Design
Slope of the separator bottom from 45 – 60oFree surface in the aperture between the gas collectors: 15 – 20% of reactor area.Height of separator from 1.5 – 2 m
The baffles to be installed beneath the gas domes should overlap the edge of the domes over a distance from 10 – 20 cm
Construct material: In the anaerobic conditions of an UASB reactor, there is a risk of corrosion in two main situations:
Some H2S gas can pass the GSL separator and accumulate above the water level in the top of the reactor. This will be oxidized to sulphate by oxygen in the air to form biogas loading is less than 3.0 m/h then adopt 0.3 m as top width.
If the biogas loading is greater than 3.0 m/h, calculate the top width required. Generally, top width of 0.3 to 0.7 m can be adopted in design with maximum of 1.0 m. When even with maximum top width, if biogas loading is greater than 3.0 m/h reduce the height of GLS separation device to 20% and repeat the earlier steps of GLS separator design, with fresh number of domes. Even with reduction in height of GLS separator if these checks are not satisfying, provide additional layer of gas collector dome. When two or more layer of gas collectors are used the height of each layer can be 15 to 20% of the overall reactor height, with minimum height of each layer as 1.2 m and maximum up to 1.5 to 2.0 m. The fresh biogas collection per dome is to be worked out and further steps are repeated until all design conditions are satisfied.