JPS5816442B2 - Capacitive level detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacitive level detection device for detecting the thickness of an oil film floating on a water surface or seawater surface.

Conventionally, level detectors equipped with rod-shaped electrodes have been used to recover oil such as light oil and heavy oil spilled onto water surfaces such as lakes and seas. It has been difficult to detect and display changes in capacitance due to changes in capacitance.

Particularly on water surfaces with waves, the thickness of the oil film is thinner at the crests of the waves and thicker at the troughs, so the values measured by the conventional detectors mentioned above fluctuate from moment to moment, and the measured data is averaged. It was impractical because it required a lot of effort to convert.

The present inventor has discovered that it is possible to detect the thickness of oil on the water surface or seawater surface (hereinafter simply referred to as the water surface) or even minute changes in the thickness of the oil film. The present invention was achieved as a result of research into a device that can easily detect and display an averaged measurement value even when there is a minute change in the thickness of the material.

An object of the present invention is to provide a capacitive level detection device that detects the thickness of an oil film spilled on the water surface or a minute change in the oil film thickness, sends a signal to an oil recovery device, and controls the device. The goal is to provide the following.

The present invention has a large area, the entire area is covered with an electrically insulating material, and the lower part is held underwater by penetrating the thickness of the oil film by being installed on a floating device. It is equipped with a level detector connected to an electrode and a control device connected to the level detector, and takes advantage of the fact that the submerged part of the electrode is pulled up a distance close to its thickness by the buoyancy of the floating device. The present invention is a capacitance type level detection device for detecting the thickness of an oil film on a water surface, which is characterized in that it detects a change in capacitance occurring between a water electrode and an electrode.

In the present invention, the electrode is different from a vertically elongated rod-like body, and has a wide area of a horizontally spread band-like body, and the entire surface is covered with a film of an electrically insulating material. be.

This electrode is an electrode whose lower part is immersed to a desired depth just below the water surface with a thickness of oil film above the water surface, and the area of contact with the seawater is set to 100. It has been made possible to do so.

This increase in area is detected by averaging the capacitance changes from the oil film on the surface of water with waves (in general, the oil film at the crests of waves is thinner, and the oil film at the troughs is thicker). It is possible.

The shape of the electrode can be a plate shape such as a flat plate or a lattice shape, a ring shape such as a circle or an ellipse, or a shape with a wide surface area such as an American character shape or a spiral shape.

This electrode is different from conventional rod-shaped electrodes, and has a desired length that is penetrated through the oil film and the lower part is immersed in water, and has a horizontally long ring shape or a spiral shape. It is an electrode that has a wide area with a longer length (in the case of objects, etc.) and is formed in a shape that can detect minute changes in the thickness of the oil film.

The electrical insulating material coated on the electrode is selected from alkyd resin, phenolic resin, epoxy resin, silicone resin, urea resin, and other earth-based materials.The thickness of the coating film is adjusted to the desired sensitivity. The thickness can be adjusted as appropriate.

This coating film is necessary to keep the electrode surface always clean and to prevent corrosion of the electrode.

Floating devices are used for water or the interface between seawater, oil, and the atmosphere.
This is for holding the electrode vertically or at an angle, with the lower part of the electrode immersed under the water surface to the desired depth. When holding a ring-shaped electrode, a float is fitted inside the electrode to hold it. In this case, a level detector may be built into the floating device (see FIG. 3).

In addition, when holding a spiral-shaped, American-shaped, or plate-shaped electrode that cannot be directly attached to a hollow part, such as a ring-shaped electrode, two floats are used. A support frame is stretched over the floating device, and the electrodes are suspended from this frame to hold it (4th
Figure).

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of the present invention using ring-shaped electrodes, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a top view of FIG. 1.
FIG. 4 shows a side view of another embodiment of the invention using grid-shaped electrodes.

Figures 5 to T show side views of electrodes of various shapes used in the present invention, which are formed so that a wide area is in contact with water or seawater and oil, and Figure 5 shows a grid-shaped electrode. FIG. 6 shows an American-shaped electrode, and FIG. 7 shows a spiral-wound electrode.

In the figure, 1 is a ring-shaped electrode, 2 is a coating made of an electrode insulating material that covers the electrode 1 and protects the electrode, 3 is a floating device provided inside the ring-shaped electrode, and 3' and 3' are other than ring-shaped electrodes. 4 is a level detector provided inside the float 3, 4' is a float 3/, 3 is a float that supports the electrode from the outside with at least two floats that are homogeneous and the same shape. 5 is the ground (electrode) of the level detector 4;
' is the ground (electrode) of the level detector 4', 6 is the power connection cord, 7 is the control device connection cord, and 8 is the control device, which is equipped with an alarm, display, etc., and controls the oil recovery device. 9 is a water surface, 9' is a corrugated water surface, 10 is an oil film with a thickness of 1, 11 is a grid-shaped electrode, 12 is an American-shaped electrode, 13 is a spiral-shaped electrode (electrodes 11, 12, and 13 are all 14 is a connection cord between the electrode and the level detector, and 15 is a support provided if necessary.

According to the present invention, when oil spills on the water surface, the electrode is suspended in the water from the atmosphere through the oil film by the floating device, so that static electricity is generated between the water or seawater and the electrode, and between the oil-sealed electrode. By detecting changes in capacitance, the film thickness of spilled oil can be detected and the control device can be controlled.

If the level detector is set to activate an alarm or signal and an oil recovery device when the oil film thickness reaches a predetermined thickness, the control device is automatically activated.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a side view of the invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is a top view of FIG. 1, and FIG. 1 is an explanatory view of another embodiment of the present invention in use using a plate-shaped electrode according to the present invention, and FIGS. 5 to 7 are side views of electrodes of other embodiments of the present invention. In the figure, 1 is a ring electrode, 3 is a float, 4 is a level detector, 8
indicates a control device.

Claims (1)

[Claims] 1. In a capacitive level detection device that detects the thickness of an oil film on the water surface or sea surface, a level detector attached to a floating device that is connected to a power connection cord and a control device as well as grounded. A capacitance type level detection device, characterized in that an electrode is connected thereto, the area of which is a floor bundle and the entire area is covered with an electrically insulating material, which is held in water by penetrating the thickness of the oil film.