Deep well anodes for electrical grounding

Abstract

Two related approaches are provided to controlling the relative permeability of ground water and gases developed in deep well anodic installations. The central metallic anode is encased and protected by a semi-permeable conductive cementaceous sheath, using as the sheathing material any of a number of compositions having the desired properties of permeability and conductivity. Alternatively, a conductive but impermeable anode is used in conjunction with a semi-permeable backfill material in a bore hole of a deep well anode installation, thereby achieving the same desired ends of controlling the relative permeability of water and gases in the installation.

Description

RELATED APPLICATION [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 643,149 filed on Aug. 19, 2003 and entitled CONDUCTIVE CONCRETE COMPOSTIONS AND METHODS OF MANUFACTURING SAME, which claims priority based on U.S. provisional patent application No. 60 / 404,129, filed on Aug. 19, 2002, both of which are hereby incorporated herein in their entirety, by reference.BACKGROUND OF THE INVENTION Electrical Grounding Techniques Generally [0002] Various electrical grounding techniques are utilized throughout the world for the prevention of electrical damage to buildings and equipment. Such grounding techniques find numerous applications in such diversified areas as power and telecommunication systems, electronic equipment, fuel storage tanks, industrial installations, commercial and residential buildings as well as buried equipment such as pipelines. The grounding techniques are also used to protect the buildings or equipment from a variety of electri...

AI Technical Summary

Benefits of technology

[0019] The principal objective of the present invention is to provide a deep well anode for electrical grounding in which the central metallic anode is encased and protected by a cementitious sheath and backfill affording sufficient permeability that by-product gases developed in use can escape at a rate which permits long-term operation of a cathodic protection system, while minimizing migration of groundwater. The sheath / backfill protection for the metallic anode according to the invention exhibits the attributes of:

[0026] With a view to achieving these advantageous properties and overcoming the aforementioned disadvantages of known deep well anodic installations, the present invention according to a first embodiment provides carbonaceous cementitious materials for forming a sheath for the central metallic anode in a deep well anode system which possess sufficient electrical conductivity while exhibiting a degree of permeability that allows by-product gases to migrate to the surface of the well while minimizing or eliminating the vertical flow of groundwater.

[0028] According to a second embodiment of the invention, the provision of a deep well anode system having the desired electrical conductivity in combination with a level of semi-permeability allowing by-product gases to migrate to the surface of the well, while minimizing or eliminating the vertical flow of groundwater is achieved by forming an impermeable conductive sheath around the central metallic anode, but using as the backfill in the well or hole a backfill material which itself is semi-permeable and conductive. The preferred backfill material to achieve this objective comprises a flowable granulated carbon such as coke breeze admixed with Type F fly ash, the latter having the surprising effect of reducing water permeability of the backfill to the selected degree. The anode is composed of a granular electrically conductive form of carbon compounded with a binding / sealing agent to render it impermeable. A preferred binding / sealing agent comprises from 10 to 40% of a long chain fatty acid and a metal oxide or hydroxide cross-linking agent such as quicklime or slaked lime.

Problems solved by technology

(v) cost of manufacture and use comparable to existing deep well anode electrical grounding systems.