AQUEOUS CHEMICAL LEAK DETECTION CABLE
Disclosed are aqueous chemical leak detection cables that provide protection to sensor wires by using a conductive polymer coating that is resistant to corrosion by aqueous chemicals. In addition, non-conductive, liquid pervious layers may surround one or more of the sensor wires to assist in preventing false detection of a aqueous chemical leak as a result of various non-liquid contaminants. The non-conductive, liquid pervious layer may comprise braided, non-hygroscopic, non-conductive fibers, or a continuous, non-conductive pervious coating.
The present application is a divisional application of U.S. application Ser. No. 12/777,462, filed May 11, 2010, by Donald M. Raymond, entitled “AQUEOUS CHEMICAL LEAK DETECTION CABLE,” which application is based upon and claims the benefit of U.S. Provisional Patent Application No. 61/177,594, entitled “AQUEOUS CHEMICAL LEAK DETECTION CABLE”, and filed May 12, 2009, by Donald M. Raymond. The entire content of the above-mentioned applications and the U.S. patent application Ser. No. 12/464,787, filed May 12, 2009, by Donald M. Raymond, entitled “Twisted Leak Detection Cable” (Attorney Docket No. RLET.09USU1) are hereby specifically incorporated herein by reference for all they disclose and teach.
BACKGROUND OF THE INVENTIONAqueous chemical fluid leaks can occur in commercial, industrial and residential environments. Aqueous chemical fluid leaks can cause serious damage to various types of components, especially components that are sensitive to aqueous chemical fluids. For example, certain types of aqueous chemicals are capable of dissolving insulation on wires. Other types of aqueous chemical fluids may have a corrosive effect on other materials, such as metal. Hence, early detection of aqueous chemical leaks can be very beneficial.
The process of detecting aqueous chemical leaks can employ the use of a detection cable that is connected to a monitor that provides an alarm upon detection of a leak. The alarm can be an auditory alarm and/or can communicate the alarm information through various communication devices. Monitors are disclosed in U.S. Pat. No. 7,212,009 and 6,144,209, and in the U.S. non-provisional application filed May 12, 2009, by Donald M. Raymond, entitled Twisted Leak Detection Cable” (Attorney Docket No. RLET.09USU1), which are specifically incorporated herein by reference for all they disclose and teach.
SUMMARY OF THE INVENTIONAn embodiment of the present invention may therefore comprise a method of sensing aqueous chemicals using a aqueous chemical leak detection cable comprising: providing a base member that is made from non-conductive polymer that is resistant to corrosion by the aqueous chemicals, the base member formed from two insulated lobes that are joined together to form two interstices on opposite sides of the insulated conductors; providing at least one conductor wire in at least one lobe of the base member; providing sensor cables that have a conductive polymer coating that is resistant to corrosion by the aqueous chemicals; providing a sensor wire in each of the sensor cables that is protected from the aqueous chemicals by the conductive polymer coating that is resistant to corrosion by the aqueous chemicals; placing the sensor cables in each of the interstices; twisting the base member so that the sensor cables are exposed to the surface along a length of the aqueous chemical leak detection cable; detecting the presence of the aqueous chemicals on the surface whenever the aqueous chemicals create a conductive path between the sensor cables such that the conductive polymer coating creates the conductive path to the sensor wires from the aqueous chemicals and simultaneously protects the sensor wires from corrosion.
An embodiment of the present invention may further comprise a aqueous chemical leak detection cable for detecting the presence of aqueous chemicals comprising: a base member that is made from non-conductive polymer that is resistant to corrosion by the aqueous chemicals, the base member comprising two lobes that are connected along a longitudinal surface to form two interstices on opposite sides of the base member; at least one conductive wire disposed in at least one of the lobes of the base member; two sensor cables that are disposed in the two interstices, the sensor cables having sensor wires and a conductive polymer coating that is resistant to corrosion by the aqueous chemicals and that surrounds the sensor wires to protect the sensor wires from corrosion by the aqueous chemicals, the two sensor cables and the base member being twisted together to form a helix so that the sensor cables are exposed to in different directions along the length of the aqueous chemical leak detection cable.
As also disclosed in
The non-conductive, aqueous chemical pervious layer 418, that is illustrated in
Hence, the various embodiments of the aqueous chemical leak detection cable disclose a cable that is capable of detecting aqueous chemical leaks, which uses a conductive polymer coating that surrounds sensor wires, and that are resistant to corrosion by aqueous chemicals and protects the sensor wires. In addition, a base portion includes feedback wires for communicating information to a monitoring system. Additional wires can be disposed in the lobes that can be used for communicating data and/or providing power. Non-conductive layers that are pervious to aqueous chemicals can also be used on one or both of the sensor cables to assist in preventing false detection of aqueous chemical leaks resulting from contaminants, especially solid contaminants. Braided, non-conductive fibers that are non-hygroscopic can be used for the non-conductive, liquid pervious layer. These braided fibers dry quickly because the non-hygroscopic properties. In addition, a continuous coating can be used of a continuous, non-conductive porous polymer that is pervious to aqueous chemical liquids. Both the braided fibers and the continuous, non-conductive porous polymer may be constructed of materials that have affinity to the materials of the base from which the insulative material of the lobes are formed. In this manner, the affinity between the materials helps to maintain the sensor cables in the interstices between the lobes. In addition, in the embodiments in which an optional, non-conductive, aqueous chemical pervious coating is not used, a conductive polymer material may be used that has affinity to the insultative material of the base, so that the sensor cables are maintained within the interstices between the lobes of the base.
The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.
Claims
1. A method of making an aqueous chemical leak detection cable for sensing aqueous chemicals comprising:
- obtaining a base member that is made from non-conductive polymer that is resistant to corrosion by said aqueous chemicals, said base member having two insulated lobes that are joined together to form two interstices on opposite sides of said insulated conductors, said base member having at least one conductor wire in at least one lobe of said base member;
- placing sensor cables in each of said two interstices that have a conductive polymer coating that is resistant to corrosion by said aqueous chemicals, said sensor cables having a sensor wire disposed in each of said sensor cables that is protected from said aqueous chemicals by said conductive polymer coating that is resistant to corrosion by said aqueous chemicals;
- twisting said base member to alternately expose said sensor cables along a length of said aqueous chemical leak detection cable so that said aqueous chemical leak detection cable is capable of detecting the presence of said aqueous chemicals on a surface when said aqueous chemicals contact said sensor cables and create a conductive path between said sensor cables resulting in said conductive polymer coating on said sensor cables creating a conductive path to said sensor wires.
2. The method of claim 1 wherein said process of obtaining a base member further comprises:
- obtaining a base member that has at least one conductive wire in each of said two lobes.
3. The method of claim 1 wherein the process of obtaining a base member further comprises:
- obtaining a base member that has more than one conductive wire in each of said two lobes.
4. The method of claim 1 wherein said process of placing sensor cables in each of said two interstices further comprises:
- placing sensor cables in at least one of said two interstices that have a non-conductive, aqueous chemical pervious layer surrounding said sensor cables that assists in preventing false readings from non-liquid contaminants.
5. The method of claim 4 wherein said process of placing sensor cables in at least one of said two interstices comprises:
- placing sensor cables in at least one of said two interstices that have braided, non-conductive, non-hygroscopic fibers surrounding at outer surface of at least one of said sensor cables that allows aqueous chemical liquids to pass through openings between said fibers while preventing non-liquid substances from contacting said conductive polymer coating on said sensor cables.
6. The method of claim 4 wherein said process of placing sensor cables in at least one of said two interstices comprises:
- placing sensor cables in at least one of said two interstices that has a continuous, non-braided, non-conductive, porous coating that surrounds an outer surface of said conductive polymer coating of at least one of said sensor cables and that is resistant to corrosion by said aqueous chemicals, and that allows aqueous chemical liquids to pass through openings in said porous coating while preventing non-liquid substances from contacting said conductive polymer coating on said sensor cables.
7. The method of claim 4 wherein said process of placing sensor cables in at least one of said two interstices comprises placing sensor cables that are surrounded by non-conductive, non-hygroscopic fibers that comprise poly-meta-phenylene isophthalamide.
Type: Application
Filed: Aug 3, 2012
Publication Date: Nov 22, 2012
Inventor: Donald M. Raymond (Fort Collins, CO)
Application Number: 13/565,949