RU78801U1 - LONG-TERM COMPARATIVE ELECTRODE ELECTRODE WITH STABILIZING BATTERY - Google Patents

Abstract

A long-acting reference electrode with a stabilizing backfill, containing a non-conductive casing, filled with an electrolyte from a saturated solution of copper sulfate in a mixture of water and ethylene glycol, a copper rod located in the central part of the casing, connected by a copper conductor to the electrode terminal, an ion-exchange membrane pressed by a perforated coupling to the casing, characterized in that the copper-sulfate reference electrode is placed in a water-permeable cover filled with a stabilizing backfill consisting of a mixture of bentonite hl ina and kieselguhr in a ratio of 9: 1.

Description

The technical field to which the utility model relates.

The utility model relates to corrosion protection of underground metal structures, in particular to non-polarizing long-acting reference electrodes and can be used to increase the durability of the electrodes.

State of the art

A non-polarizable reference electrode is known, containing a non-conductive housing with a coupling, filled with an electrolyte from a saturated solution of copper sulfate in a mixture of water and ethylene glycol, a copper rod located in the housing, an ion-exchange membrane, a potential sensor mounted on the housing, and the potential sensor equipped with a removable nozzle on the electrode housing at least two ion-exchange membranes are mounted, and the bottom of the sleeve mounted on the housing has perforations.

In the electrode, a removable nozzle is installed depending on the thickness of the insulation layer on an underground metal structure (see Pat. RU No. 2122047, class C23F 13/00, publ. 11/20/1988).

The disadvantage of this electrode is the low durability and stability of the electrode potential with seasonal changes in soil moisture.

Long-acting stationary copper sulfate electrodes of the type ENES and ESN-MS are known, consisting of a plastic case filled with an electrolyte in the factory, which does not freeze at ambient temperature to minus 40 ° С, a copper rod,

an ion-exchange membrane (one or two) with a protective grid, a safety tube with conductors from a copper rod and lugs. The electrodes are equipped with a potential sensor, which is a St3 plate 25 × 25 mm in size, mounted in a plastic socket mounted on the electrode body (see RD 153-39.4-091-01 “Instructions for the protection of urban underground pipelines from corrosion”. Appendix H, M. 4th branch of the Military Publishing House 2002).

The disadvantage of these electrodes is their low durability.

The closest in technical essence and the achieved positive effect and adopted by the authors for the prototype is a long-acting comparison electrode containing a copper rod located in a housing made of dielectric material, a ceramic porous diaphragm and an ion-exchange membrane. A potential sensor is mounted on the housing. The casing is filled with an electrolyte consisting of a saturated solution of copper sulfate in a mixture of water and ethylene glycol in a ratio of 3: 2-2: 1. The ion-exchange membrane was obtained by radiation grafted copolymerization of acrylic or methacrylic acid in an amount of 100-170% on a biaxially oriented polypropylene film (see ed. St. No. 1601199, class C23F 13/00, publ. 23.10.1990, “Long-acting comparison electrode" )

The disadvantage of this electrode is the low durability and stability of the electrode potential with seasonal changes in soil moisture.

Utility Model Disclosure

The objective of the proposed utility model is the development of tools to increase the durability of the reference electrodes.

The technical result that can be achieved using the proposed utility model is to obtain a reference electrode

long-term action, suitable for installation in the ground during the work on the electrochemical protection of underground metal structures from corrosion, which has a stable potential, extended service life and is not critical to the chemical composition and moisture of the soil in which it is installed.

The technical result is achieved by using a permeable cover filled with a stabilizing backfill consisting of a mixture of bentonite clay and kieselguhr, into which a non-polarizing long-acting reference electrode is immersed, containing a non-conductive case filled with an electrolyte from a saturated solution of copper sulfate in a mixture of water and ethylene glycol located in the central part of the case a copper rod connected by a copper conductor to the terminal of the reference electrode, an ion-exchange membrane pressed by a sleeve with rforatsiey to the body.

Placing the reference electrode in a water-permeable cover filled with a stabilizing backfill ensures that during the wet period of the year the soil moisture is accumulated in the stabilizing backfill, which is necessary to ensure reliable electrolytic contact with the soil in which the electrode is installed, while maintaining the electrolytic contact of the electrode with soil during the dry season due to previously accumulated moisture, in addition, the stabilizing backfill is an additional barrier to chemically active substances contained in gr HTE, can deplete the electrolyte and the replacement of the electrode during the ion exchange, thereby increasing the potential stability and durability of electrode.

Brief Description of the Drawings

In FIG. a copper sulfate non-polarizing long-acting reference electrode in a case with a stabilizing backfill is given, general view.

Utility Model Implementation

The long-acting comparison electrode in a waterproof permeable cover with a stabilizing filling consists of a non-conductive case 1 filled with an electrolyte 2, which includes distilled water, ethylene glycol and copper sulfate (CuSO ₄ 5Н ₂ О), while the content of copper sulfate should ensure saturation of the solution with the release of free crystals of CuSO ₄ 5H ₂ O. In the central part of the current-conducting housing 1 of the electrode, a copper rod 3 is strengthened, electrically connected by a copper conductor to terminal 7, and to provide ionic exchange In order to maintain tightness, a homogeneous ion-exchange membrane 4 is used, 13-60 μm thick, based on a biaxially oriented polypropylene film containing 150% radiation grafted with methacrylic acid, pressed by a sleeve with perforation 5 to the non-conductive housing 1, the reference electrode is placed in a waterproof permeable cover 6 filled with a stabilizing a backfill consisting of a mixture of bentonite clay and kieselguhr in a volume ratio of 9: 1. The composition of the backfill is due to the properties of the materials used, so bentonite clay is able to accumulate moisture in large quantities, and kieselguhr has high hygroscopicity and, when mixed with bentonite clay, provides its complete and uniform moisture saturation.

The long-acting reference electrode with stabilizing backfill is operated as follows.

Long-acting reference electrode, consisting of a non-conductive housing 1 filled with electrolyte 2, which includes distilled water, ethylene glycol and copper sulfate (CuSO ₄ 5Н ₂ О), while the content of copper sulfate ensures saturation of the solution with the release of free crystals of CuSO ₄ 5Н ₂ Oh, and in

the central part of the non-conductive housing 1 of the electrode is strengthened by a copper rod 3, electrically connected by a copper conductor to terminal 7, which provides ion exchange, and to maintain tightness, a homogeneous ion-exchange membrane 4 is used with a thickness of 13-60 microns based on a biaxially oriented polypropylene film containing 150 mg of radiation-grafted methacrylic acid %, pressed by a sleeve with perforation 5 to the non-conductive housing 1, while to increase the durability of the electrodes and the stability of their potential during the season SG changing soil moisture reference electrode is placed in water permeable cover 6 filled stabilizing backfill and as such is installed in the ground (not shown in FIG.), wherein the stabilizing filling consists of a mixture of bentonite clay and diatomaceous earth in a ratio of 9: 1. The composition of the backfill is due to the properties of the materials used, so bentonite clay accumulates moisture in large quantities, and kieselguhr has high hygroscopicity and, when mixed with bentonite clay, provides its full moisture saturation. During the wet season, moisture is accumulated in the stabilizing bed, which is necessary to ensure reliable electrolytic contact with the soil in which the electrode is installed, while maintaining contact due to accumulated moisture in the dry period. The chemical composition of the stabilizing backfill is neutral and is an additional barrier to chemically active substances contained in the soil, which can lead to depletion and replacement of the electrode electrolyte during ion exchange, thereby increasing the stability of the potential and the durability of the electrode.

Long-acting reference electrode with stabilizing backfill can be used as a long-term stationary electrode in the electrochemical protection systems of underground metal structures, in particular, pipelines to create electrolytic contact with the ground in determining the effectiveness

anticorrosive protection of these structures. Regarding the electrode, measurements are made of the potentials of the structure. Also, the electrode can be used as a potential source in the control system of automatic cathodic protection stations.

The proposed utility model in comparison with the prototype and other well-known technical solutions has the following advantages:

- increasing the durability of the long-acting reference electrode through the use of stabilizing backfill;

- increasing the stability of the potential with seasonal changes in soil moisture through the use of stabilizing backfill;

- increase the economic efficiency of the use of electrodes;

- environmental cleanliness when using long-acting reference electrodes.

Claims (1)

A long-acting reference electrode with a stabilizing backfill, containing a non-conductive case filled with an electrolyte from a saturated solution of copper sulfate in a mixture of water and ethylene glycol, a copper rod located in the central part of the body, connected by a copper conductor to the electrode terminal, an ion-exchange membrane pressed by a perforated sleeve to the body, characterized in that the copper-sulfate reference electrode is placed in a water-permeable cover filled with a stabilizing backfill consisting of a mixture of bentonite hl ina and kieselguhr in a ratio of 9: 1.