Cathode Protection Rectifier

Nature has endowed each metallic substance with a certain natural energy level or potential. When two metals having different energy levels or potentials are coupled together, current will flow. The direction of positive current flow will be from the metal with the more negative potential through th

Project Title

Cathode Protection Rectifier

Project Area of Specialization

Electrical/Electronic Engineering

Project Summary

Nature has endowed each metallic substance with a certain natural energy level or potential. When two metals having different energy levels or potentials are coupled together, current will flow. The direction of positive current flow will be from the metal with the more negative potential through the soil to that which is more positive. Corrosion will occur at the point where positive current leaves the metal surface. When this current flows through the soil indiscriminately .The current may contact and follow a buried metallic structure such as a pipeline, but wherever it leaves that structure to return to its origin, corrosion will occur. 

Cathodic Protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell.It reduces corrosion by minimizing the difference in potential between anode and cathode. This is achieved by applying a current to the structure to be protected (such as a pipeline) from some outside source. When enough current is applied, the whole structure will be at one potential; thus, anode and cathode sites will not exist. 

Cathode Protection is a secondary defence against corrosion of Metal objects which are submerged into the ground or sea water. It is mostly used in projects that have been build for long life duration. It protects the metal surface/object by making it the cathode of an electrochemical cell.It reduces corrosion by minimizing the difference in potential between anode and cathode. This is achieved by applying a current to the structure to be protected (such as a pipeline) from some outside source. When enough current is applied, the whole structure will be at one potential; thus, anode and cathode sites will not exist. 

Cathodic protection is commonly used on many types of structures, such as pipelines, underground storage tanks, locks, and ship hulls.

The most effective corrosion protection system for buried and submerged structures involves a good coating and a Cathodic Protection.

Project Objectives

The main objective of this project is to insure that it provide a required current supply to the structure through which we can prevent it from corrosion. Some of the main objective that can be achieve by this projects are:

• Providing a current source for structure to prevent it from corrosion.
• Controlling the current flow to the structure.
• Monitoring the potential difference of structure. 
• Reduce operational monitoring costs significantly
• Monitor pipeline CP levels on a daily basis automatically
• Respond immediately to a potential corrosion hazard automatically 
• No need for constant manual monitoring 
• Reduce lone working and the need to access remote sites
• Demonstrate best practice to Regulators
• Reduce environmental emissions / carbon footprint from survey vehicles

A critical part of design calculations for cathodic protection systems on existing structures is the amount of current required per square foot (called current density) to change the structure’s potential to -0.85 volt. The current density required to shift the potential indicates the structure's surface condition. A well coated structure (for example, a pipeline well coated with coal-tar epoxy) will require a very low current density (about 0.05 milli ampere per square foot), an uncoated structure would require high current density (about 10 milli amperes per square foot). The average current density required for cathodic protection is 2 milli amperes per square foot of bare area.

Project Implementation Method

The whole Cathode Protection system is divided into two sub systems.

1: Rectifying Unit.
2. Control Unit.

 In Rectifying Unit, a rectifier is present that consists of SCRS’s. Note that the firing angle of the SCRs are very essential for the project. This is where Control Unit comes into play. The Control Unit, which consists of a MicroController, checks the soil resistivity as a feedback and fluctuates the firing angle accordingly. This plays an important role as it leaves any human intervention. 

The most important parameters are Soil Resistivity and the Current density. The latter here is dependant on Soil Resistivity and will be changed by altering the Firing angle of the Rectifier. 

Benefits of the Project

• Prevents Rusting in Metal pipes that are submerged underground
• No need for manual surveillance 
• No need to change the pipe after few years rather just need two change the sacrificial anodes
• Best for Humid areas (such as Karachi)

Technical Details of Final Deliverable

Cathode Protection Rectifiers output Voltage, Current and overall Power depends on the Soil Resistivity and other enviormental Conditions in which CP rectifier is Working.

Our CP Rectifier would automatically adjust to these readings and change the output Voltage and Current accordingly.

Our Range for Voltage and Currents are as follows:

Current: 6 Amps
Voltage: 50-60V

Final Deliverable of the Project

Hardware System

Core Industry

Petroleum

Other Industries

Core Technology

Others

Other Technologies

Sustainable Development Goals

Industry, Innovation and Infrastructure

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com