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US 4,051,007 AGranted
Sacrificial anodes for cathodic protection
AssigneeNone recorded
InventorLudwig Hossle
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AssigneeNone recorded
InventorLudwig Hossle
Estimating the term…
Sacrificial anodes for cathodic protection systems wherein inner portions of a tank, at least partly filled with a liquid, are exposed to a corrosive inner environment and are protected against the corrosion by the provision of a consumable sacrificial anode, the material of which gradually migrates through the liquid to and is deposited on the inner tank portions, without an external voltage being applied, and wherein the inner tank environment also promotes detrition of the sacrificial anode. The invention with the anode with an inner metal tube, provides openings in the tube wall, preferably by perforation, so that the anode material normally constitutes a barrier between the tube interior and the tank environment, and obtains an indication of progressed detrition or consumption of the anode, at which point the consumable anode should be replaced for continued effective cathodic protection. A pressure difference is usually effected between the tank environment and the tube interior, either by pressurizing the tank, or by providing a source of pressure or vacuum in the system. A small slidable plunger is provided that gives visual, color-coded information on the progressed detrition or consumption of the anode material inside the tank.
A sacrificial anode for cathodic protection of inner portions of a tank and the like, at least partly filled with a liquid, which portions are exposed to a corrosive inner environment, to be protected against corrosion by the provision of the sacrificial anode that is consumed while its material gradually migrates through the liquid to and is deposited on the inner tank portions, in the absence of an external voltage being applied, and wherein the innter tank environment also promotes detrition of the sacrificial anode;
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto: monitoring…
Non-mechanical removal of metallic material from surface
Term ended 27 Sep 1994 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The invention relates to sacrificial anodes used for cathodic protection.
Known arrangements and anodes of this kind contain a body of anodic material having embedded therein a perforated metal tube, placed into a hermetically closed inner tank space. When the anode material is gradually consumed, as a result of its migration to the tank walls that act as the cathode, a signal indication can be obtained when the closed space reaches communication with the outside.
Such measures are not suitable to be used for automatically supervising and testing the integrity of the consumable sacrificial anodes, and particularly not in non-pressurized tanks, or when used in the soil. When the tank is not pressurized at all, so that only the static pressure of the medium or liquid is available, or if a pressure is available but small, e.g. as a result of an incomplete filling of the tank, there will be no indication or signalling, particularly at the end of a relatively long conduit that leads from the tank to an external test location.
Other objects and many of the attendant advantages of the invention, in all three of its major aspects, namely the method, the arrangement and the sacrificial anode itself, will be readily appreciated as the same becomes better understood by reference to the following detailed description, when considered with the accompanying drawing, wherein
FIG. 1 is a longitudinal, partly sectional view of a basic embodiment of the inventive sacrificial anode;
FIG. 2 illustrates in a perspective view an inner, partly perforated tube forming part of the anode of FIG. 1;
First the inventive sacrificial anode will be described with reference to FIGS. 1 and 2; the same or a similar construction may be used in the arrangement of FIG. 3, and to cooperate with the indicator portion shown in FIG. 4.
A body 2 of anodic material is shown, partly in section, including in the sectioned part an embedded metal bar 4 and, as a continuation of the latter, a metal tube which is identified with its various distinct portions, namely a perforated portion 6b, a smooth front end 6c which can extend out of the anode for connection to a conduit to be described later, and having a bore 6d therein; a weld 6a is shown at the tube end which joins the tube to the bar 4. This connection may be by way of welding, a suitable high-temperature and preferably non-corrosive glue, and the like. Only part of the embedded tube portion is perforated as shown at 8. It is important to note that the protruding portion 6c of the tube is not perforated.
As has been explained earlier, a plastic sleeve or jacket (not shown) may be applied to a portion of the body 2 of anodic material so as to slow down its detrition in that area, and to ensure foolproof operation, namely by allowing one of the perforations 8 to become communicative, and thereby to give an indication that the particular anode has been consumed to the extent of requiring replacement.