Boiler Inspection and testing using Eddy Current Probe (NDT)

Defect detection in industrial boiler is an important issue in industry, because its potential use in industry to produce steam etc. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials. The purpose of this project is to

Project Title

Boiler Inspection and testing using Eddy Current Probe (NDT)

Project Area of Specialization

Electrical/Electronic Engineering

Project Summary

Defect detection in industrial boiler is an important issue in industry, because its potential use in industry to produce steam etc. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials. The purpose of this project is to present an eddy current based testing method for defect detections in industrial boilers. The application of fault detection and diagnosis methods will play a great role in early identification of faults and selecting the most suitable fault tolerant scenario without losing the services.

An alternate magnetic field is produced by a solenoid and eddy currents are generated in the material under test., defects were induced by cracks machined in work pieces made of metal. In this aspect an ECT probe is preferred for the inspection of industrial boilers. Different fault scenarios are simulated on the identified model in order to validate the observer based fault detection.

The fault detection method is applied to identify the behaviour of material. This is one of the most widespread electromagnetic technique (NDT) used for the inspection of conducting materials. This system provides the recorded data to the LCD output for effective control at a lowered cost, so as to reduce the time-consuming process of manual inspection instead of shutting down the controlling system and to avoid the sudden burst of boiler. This eddy current testing system is able to detect, localize and characterize failures in electrically conductive materials.

Boilers are considered as the base of the most of real industries such as power plant generation and petrochemical industry, and other industries. So, it is essential to improve performance and safety related issues for a safe and efficient operation. The main challenge faced is the cost of the testing equipment and successful visualization of the fault/data. Our objective is to overcome these challenges and lower the cost to a range where effective testing equipment is readily available at a cheaper rate for local industries.

Project Objectives

The core objective to design this system will examine the regular inspection of conductive materials at industrial level and to make it much easier and possible that the propose equipment will be able to perform material inspection as per the material type and provides the output according to the defects.

This system allows the remote testing without dismantling the material from its location and it also saves the time and cost of dismantling the job and enables the testing throughout the period no need to wait for the year end when the plant is shut off for yearly maintenance.

The system will be able to locate the crack on the surface. The equipment will be tuned to asses’ different materials. The proposed solution is to implement such a multi-tasking Eddy Current based device which will be able to operate at maximum frequency and can detect defects or flaws of different type of materials, data acquisition system is used to fetch the data from the job by which the visualization of the defect is possible on the HMI.

Overall expected output is an equipment or product that can effectively help to detect the fatigue/cracks/faults of industrial materials, ultimately resulting in risk-free environment if that un-inspected material gets busted.

That’s how ECT system gets completed, our objective is to design a device which will be able to extract defect data from any type of material.

Project Implementation Method

The proposed eddy current system based device for inspecting the conductive materials and boilers is based on modules, these modules are discussed under with their functionality.

There are three major modules of this ECT system are:

• Self-Oscillated circuit
• Test Coil circuit (ECT Probe)
• Controller circuit

Eddy current probe is surface probe type, usually a spring mounted flat probe or a pointed pencil type probe,

allows to determine the location of crack or any defect.

Eddy current probes used to meet specific inspection requirements. There are many different types of probes available that can be designed to match the contours of a part or shaped to fit into a fixture for fast and accurate inspections.

A MOSFET based oscillator basically converts the unidirectional current flow of a DC source into an

alternating waveform, which is of certain frequency, as per the instructions received from the microcontroller.

The Esp32 WROOM Kit microcontroller will be used as the controlling component of system.

It will be responsible for taking analog inputs from the Probe (test coil) and displaying it on the LCD (HMI of ECT system/Data acquisition system) screens.

It will be responsible for activating the oscillator to provide input signal to eddy current probe.

It will also be interfaced via guided/unguided channel for PC interfacing to transmit the data.

A finest data acquisition system is under design that will be used as the User interface to visualize the real time defect analysis on that HMI. Once the microcontroller is programmed, then it will automatically fetch real time data on database and then visualization system. Graphical display of distorted waveform (after detection of any defect or flaw) will occur with some changes in frequency and amplitude in pre set threshold values. And, that’s how system will be able to identify a particular point of defect of which surface part come under inspection.

Benefits of the Project

This system can detect the cracks and faults of conducting materials, especially for industrial boilers,

• Locally designed equipment local maintenance available.
• Can inspect variety of material gauges and sizes
• No installation cost
• Time saving solution
• No need to replace or move the boiler or conducting material for inspection.
• Increased safety due to more number of inspections could be done
• Most extensively used NDT for inspecting electrically conductive materials at very high speeds.
• This proposed model is cost effective.
• Graphical visualization of defect or flaw. (butterfly plot/polar plot as well as sinusoidal plot).

Technical Details of Final Deliverable

The final deliverable equipment or device will be the package that is consisting of two things a probe and a device.

Eddy current probe is used to inspect the job while device process the results and provides output, the device is composed of some circuitry along with the micro-controller and has a graphical display of 7 inches where the results of inspection can be seen.

The deliverable project is portable, easy to handle and it can be taken anywhere easily.

The device will operate ay certain frequency and Vpp will 20V depending upon the type of materials and the features of that material.

As available equipment in market which are being used for eddy current inspection, are still limited to certain frequency and limited types of materials can be inspected but it is tried to make it more diversified equipment.

Probe inputs

• 8 probe inputs

Frequency range

 1 KHz to 2 MHz

Generator output/coil drive

 Up to 20 Vpp

Purposed system is totally industrial based project that directly target the maintenance and inspection of metal-

type and risky materials that may be in terms of cracks and other faults.

This designed model is making possible the real-time inspection which is not possible to inspect in manual testing.

If some further advancements are made, it can be done to improve the accuracy in locating the fault and measuring geometric characteristics of the fault such as width and depth. It can also be made the evaluation of subsurface cracks by using other excitation frequencies to control the currents depth of penetration.

Final Deliverable of the Project

HW/SW integrated system

Core Industry

Manufacturing

Other Industries

Petroleum

Core Technology

Others

Other Technologies

Internet of Things (IoT)

Sustainable Development Goals

Industry, Innovation and Infrastructure, Responsible Consumption and Production

Required Resources

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