Descr i pt i on
HIGH EFFICIENCY, ANTI-FLUSH LIGHT
LIQUID SEPARATOR
Technical Field
This invention relates to a high efficiency separator with an anti-flush device for light liquids of specific gravity less than water. Interceptors are currently used within a drainage system to separate and retain accidental spillages of hydrocarbons.
Background Art
Within existing interceptors, separation takes place because of the difference in specific gravity between the hydrocarbons and the carrying liquid (usually water) The efficiency of current designs is limited as smaller globules of hydrocarbons, having insufficient buoyancy, can pass through the interceptor without separating from the carrying liquid. Also when the storage capacity of the interceptor is exceeded by either lack of maintenance or a significant spillage of hydrocarbons, then the hydrocarbons can discharge from the interceptor into the drainage system or receiving watercourse.
Disclosure of Invention
According to the present invention there is provided a light liquid separator comprising a storage tank with an inlet at high level connected to an inlet chamber with a high level outlet pipe connected at low level to an outlet chamber which is set below a valve chamber with a spherical specific gravity sensitive valve floating freely inside the valve chamber above an annular seat with a coalescing filter tube fitted around the valve chamber.
A specific embodiment of the invention will now be described with reference to the accompanying drawing in which figure 1 shows the interceptor with the removable valve chamber assembly in the working position.
The separator comprises a storage tank (12) with an inlet piped) at high level. This inlet piped) discharges into an inlet chamber (18) which reduces the velocity of the incoming liquid and promotes lamina flow.
A valve chamber assembly (13) is attached by sliding brackets(17) to a guide shaft (5) near to the outlet end of the storage tank (12). The sides of the valve chamber (16) have a series of large slots to allow the free passage of water. Around the outside of the valve chamber (16) a coalescing filter tube(2) is incorporated. A handle (11) extends from the top of the valve chamber assembly (13) to the top of the access turret (10) and has a locking device(15) at the top. At the base of the valve chamber assembly (13) is a tapered seat (7) against which a floating ball shaped valve(4) can seal. The floating ball shaped valve(4) is retained within the valve chamber (16) by a lid(9). The valve chamber assembly(13) sits on a tapered seat (3) set in the top of the outlet chamber (8). The outlet chamber (8) is connected to the bottom of the outlet pipe(6).
The high efficiency anti-flush light liquid separator will operate in the following manner : -
Water and light liquids (e.g. oil and or petroleum) will enter the storage tank(12) through the inlet piped), to the inlet chamber which will direct the incoming flow significantly below the natural liquid level inside the storage tank(12). The flow is introduced at such an angle as to cause the retained liquids to slowly rotate in a horizontal lamina flow. The velocity of the incoming liquid is reduced gradually thereby eliminating virtually all turbulence allowing previously collected light liquids to remain as a continuous layer floating on the surface of the water.
Suspended solids of a specific gravity greater than water will settle to the bottom of the storage tank(12) and be retained within the sediment area(14)
Any light liquid droplets will immediately begin to rise to the surface and join with any existing surface layer. The cleaner water at the base of the storage tank(12) will be pushed through the coalescing filter (2), through the slots in the side walls of the valve chamber assembly(13) into the valve chamber (16). From here the water will pass through the valve seat (7) into the outlet chamber (8) and thus to the outlet pipe(6).
Should any tiny droplets of light liquid still be in suspension when passing through the coalescing filter (2), they will coalesce into larger droplets until sufficient buoyancy is obtained to allow the droplet to float to the surface of the storage tank (12).
Inside the valve chamber (16) is a ball shaped valve(4) which has a specific gravity between that of a specified light liquid (e.g. oil or petroleum) and water. It will therefore float in water but sink in the light liquid. When there is a spillage of light liquid (e.g. oil or petroleum) then the layer of separated light liquid at the top of the tank will thicken and the boundary between the light liquid and the water will move down the tank.
As the light liquid descends, reaching the ball shaped valve(4), the ball shaped valve(4) will sink until it seals against the seat (7) at the base of the valve chamber assembly (13). This will then prevent any further discharge from the separator.
Should the separator not be maintained and the storage capacity of light liquid be exceeded then the ball shaped valve(4) will seal against the tapered seat (7) preventing further discharge and compelling the necessary maintenance to be carried out.
Periodically it may be necessary to examine or replace the coalescing filter(2) and the ball shaped valve(4) to ensure their continued efficiency. A provision has therefore been made for this maintenance to be conducted from above ground level by a guide shaft (5) which is attached, at the bottom, to the outlet chamber (8) and at the top, to the access turret (10). The valve chamber assembly (13) comprising the valve chamber (16), valve seat (7), ball shaped valve (4), lid (9) and coalescing filter tube(2) is attached to the guide shaft (5) with sliding bracket s ( 17). A long handle (11) projects upwards from the valve chamber assembly (13) to the top of the access turret (10). A mechanical catch (15) is positioned at the top of the guide shaft (5) which, when released allows the valve chamber asεembly(13) to be withdrawn from the storage tank(12). When the valve chamber assembly(13) is returned to it's working position, it seals against a tapered seat (3) on the top of the outlet chamber (6). The valve chamber assembly(13) is retained in position by resetting the mechanical catch (15).