Oil separators for parking lots, garages and car washes
Oil separators for service stations
Oil separator types
I. class with outflow load up to 5 mg / l and II. class with an outlet load of up to 100 mg / l.
Class I oil separators have a built-in coalescent filter and are used where meteoric and process wastewater is discharged into surface water or. into the environment.
II. class with an outlet load of up to 100 mg / l. Oil separators II. classes are used where meteoric and process wastewater is discharged into the sewer. The size of the separators is determined by the nominal number of NS, which is equal to the flow in l / s. Prior to installing the oil traps, make sure that the effluent does not exceed 35 ° C.
By-pass oil separators are used in car parks where there is a risk of incomplete wastewater treatment due to large tributaries, in contrast to car parks where the risk of spillage and high rainfall is low.
Formula for calculating the appropriate oil separator
Roto oil separator are used in combination with the mud separator and sample shaft. Therefore the entire chain consists of: mud separator – oil separator – sample shaft. In accordance with the norm, the nominal size is given by the formula:
Ns = (Qr + fx * Qs ) * fd
Ns – nominal volume in l/s
Qr – max. flow of rainwater in l/s
Qs – max. flow of wastewater in l/s
fx – retention factor, depending on the nature of release (Table I)
fd – density factor for the suitable light fluid (Table I)
Oil separator components
How a does an oil separator work?
Contaminated water with light liquids stays in the oil separator for some time. Due to the low specific gravity, the droplets are raised to the surface by means of a coalescent filter. Purified water drains through the drain from the oil trap. When the maximum amount of sludge and oil has accumulated, the sludge or oil is pumped out through the openings provided for this purpose.
Separation takes place as follows:
Wastewater flows from the surface into the inlet pipe of the oil separator.
The inflow hose is designed to disperse and calm the water.
Sedimentation takes place in the first chamber, solid particles are deposited at the bottom of the chamber.
Water that is still mixed with the oil flows through the coalescent filter. Due to the structure of the filter, the water flow slows down and the separation of water and oil begins. Small drops of oil begin to coalesce into larger ones, which further increases the volume of the drop. As the density of the oil is less than the density of the water, due to the increased volume, the oil droplets begin to rise to the surface of the second chamber.
Purified water flows into an outlet that is designed to retain oil. It is also possible to install an automatic shut-off valve at the outlet, which prevents spillage at the outlet in the event of an excessive amount of oil.