Skimming device for use on a liquid surface

Claim 2

Apparatus for skimming oil from the surface of a body of water comprising a paIr of spaced floats having a central buoyancy chamber of substantial depth and stabilizing chambers of less depth than the central buoyancy chamber extending laterally from the buoyancy chamber, a horizontal upwardly opening overflow trough extending between and supported by the floats, the opening in said overflow trough being narrow and of substantial length and at substantially the level of the bottom of the stabilizing chambers, said overflow trough tapering downward toward its lower end, a flexible drain line connected to the lower end of the overflow trough, a sump connected to the outlet end of the flexible drain line, a discharge line extending from the sump, a pump in the discharge line, the capacity of the pump exceeding the rate at which liquid flows into the trough whereby the liquid level in the trough is maintained below the opening, a control valve in the discharge line downstream of the pump, a bubbler line extending downwardly into the overflow trough and opening therein near the lower end of the trough, a gas supply source connected to the bubbler line, and means responsive to the pressure in the bubbler line for sending a signal to the valve to reduce the opening of the valve when the liquid level in the trough drops and increase the opening of the valve when the liquid level in the trough rises.

Claim 3

Apparatus for skimming a liquid immiscible with water and having a lower density than water from the surface of a body of water comprising a pair of spaced-apart floats; an overflow trough having a narrow elongated horizontal opening along its top supported by and between the floats with the opening slightly below the surface of the low-density liquid: said floats comprising a central buoyancy chamber of small horizontal cross-sectional area and substantial depth and stabilizing chambers of substantially larger horizontal cross-sectional area than the central buoyancy chambers extending laterally from the upper portion of the buoyancy chambers, the bottom of the stabilizing chambers being at substantially the level of the horizontal opening in the trough; a flexible drain line connected to the lower end of the trough; said trough having a narrow cross section and tapering from the ends of the opening downwardly to the flexible drain line whereby the volume of the trough is small relative to the volume of the floats and a small change in the volume of liquid in the trough causes a substantial change in the liquid level in the trough; a discharge line into which liquid from the drain line flows; valve means in the discharge line; and control means supported in the trough below the horizontal opening and responsive to the vertical distance from the horizontal opening in the trough to the liquid level in the trough to increase the opening in the valve means as the distance decreases and reduce the opening in the valve means as the distance increases.

Claim 4

Apparatus for skimming a liquid immiscible with water and having a lower density than water from the surface of a body of water comprising a pair of spaced-apart floats; an overflow trough having a narrow elongated horizontal opening along its top supported by and between the floats with the opening slightly below the surface of the low-density liquid: said floats comprising a central buoyancy chamber of small horizontal cross-sectional area and substantial depth and stabilizing chambers of substantially larger horizontal cross-sectional area than the central buoyancy chambers extending laterally from the upper portion of the buoyancy chambers, the bottom of the stabilizing chambers being at substantially the level of the horizontal opening in the trough; a flexible drain line connected to the lower end of the trough; said trough having a narrow cross section and tapering from the ends of the opening downwardly to the flexible drain line whereby the volume of the trough is small relative to the volume of the floats and a small change in the volume of liquid in the trough causes a substantial change in the liquid level in the trough; a discharge line into which liquid from the drain line flows; valve means in the discharge line; and control means supported in the trough below the horizontal opening and responsive to the vertical distance from the horizontal opening in the trough to the liquid level in the trough to increase the opening in the valve means as the distance decreases and reduce the opening in the valve means as the distance increases.