An Overview on Gas Infrared Heating Systems

30/07/2010

Kerone (Brief History)

Began in 1976, grew with 34 yrs of experience in the Heating Industry.

An ISO 9001-2008 Company

Kerone provides customized solutions in the field of heating.

Specialize in : Industrial heating Equipments, Automation systems,Infra-red Equipments ( Gas fired and electrical), Process control systems.

Exports to developed countries like US, UK, Germany, Australia,etc.

Have a widespread customer base in other applications like auto manufacturing, paper&board, paper/ plastic conversion, rubber, plastic, leather, textiles, glass, food, consumer products and general engineering.

What is Infrared (IR) ?

IR is a part of Electromagnetic Spectrum

Invisible

Travels at the speed of light

Can be directed

Can travels in Vacuum

No medium like Air is required to heat a

substance

Industrial heating: wavelength begins at 0.7µ up

to 10µ

Spectral Distribution of Energy for various of

IR sources

SW: 1800 - 2200 °C

FMW: 1200 - 1800 °C

MW: 750 - 1200 °C

LW: up to 650 °C

Advantages of IR heating

High energy efficiency

Improved quality due to non-contact heating

Fast response of the Emitters

Faster heat (Shorter time cycle)

Space Saving

Controllability and Control accuracy

Flexibility

MFB Gas IR Burners

Proposed for L&T (HED)

MFB (Metal Fibre Burners)

Unbreakable, very high life

Short heat-up and cool-down time (3- 4 secs)

Uniformity of radiation

Flexibility of Shape

Thermal & Mechanical Shock proof

Types:

MFB cloth 100 - Low Density 1.5 Kg/m2 , blue flame application

Sintered Mat 200/ Knitted Mat 250 - medium Density 2.5Kg/m2,

Radiant application

MFB Consists of..

Special alloy mat of Low Thermal mass

SS304 Plenium body

Thin perforated sheet supporting the mat

Diverters are used for equal distribution of premix

Gas entry is either from back or from side

Sintered Mat Burner

Knitted Mat 250,high density 4Kg/m2 is

used for consistently high temperature

applications.

Mat can be welded between housing and

flange

Rest of the construction is same as the

MFB design as described in previous

slide.

MFB Operation

Burner can be fired in 3 directions: up, down & sideways with some CARE

Vertically it can be fired with no loss of uniformity till a heated length of 1000mm.

Atmospheric firing :

Inexpensive, Less modulation Capacity.

Possible only if pressure of 120 mbar is available.

Firing Gas-Air Premix:

Requires Paraphernalia, higher modulation range and can work with Low pressures. (typical 20 - 40 mbar)

For long term reliability – addition of Gas train is required.

Important Note – Gas Combustion

Composition of Gas is the most Important parameter in designing a safe system.

Installation is set for a particular type of gas.

Variation in this can cause safety hazards.

Eg: Butane used in a system designed for propane or natural gas, flashback or explosion can occur.

Chemistry of Combustion

Generally CO2 and H2O are formed as byproducts of combustion of

hydrocarbons.eg..

CH4 + ½ O2 = CH3OH

CH3OH + ½ O2 = HCHO*+H2O

HCHO = CO+H2

H2 + ½ O2=H2O

CO + ½ O2=CO2

* This is formaldehyde. If the mix hits cold wall, the process stops here.

This is why formaldehyde smell is observed in a poorly designed

heat exchanger.

Gas : Air

λ = stoichiometric ratio = 1 if air is just

adequate for combustion

λ > 1 if air is excess

λ < 1 if gas is excess

Flame Modes

Radiant Mode : Premix flows such that heat

intensity is in the range of 100-500W/m2.

Most of the Combustion takes place within the burner surface.

This heats the surface, glows and transfers the heat in radiant form. This is Infrared mode.

Surface temp. is highest at 1050 ºC.

λ = 1.05 to 1.1

Blue Flame Mode: If premix quantity is increased ,

the burner cools down due to excess nitrogen flow.

Combustion takes place outside the burner. This is blue flame mode

Here the heat transfer is in convection mode.

Intensity is as high as 20MW/m2

λ = 1.1 to 1.2

Efficiency in Radiant Mode

At Lower intensities – higher combustion within surface

Around 125KW/m2 – radiant efficiency is highest ( approx 55 -60 %)

Below 100KW/m2 – Flame cannot be sustained.

Efficiency is high in face down position, it can be increased in any position by adding a grid in front.

MFB Gas IR Burners – Flexibility in

Design

Advantages of MFB Burners over

convection Gas Burners

Operates at low Gas pressure

Low Pressure drop

Low CO/NOX emissions, clean Heating

Homogeneous combustion with Modulation rate

Energy efficient

Safest design because of the flashback arrestors, much

safer than the household connections

Noise-free combustion, below < 500 KW/m

Tour to Gas IR Burners

GAS IR BURNER SYSTEM

FOR LONG SEAM WELDING

GAS IR BURNER SYSTEM

FOR LONG SEAM WELDING

GAS IR BURNER SYSTEM

FOR CIRCUMFERENTIAL SEAM WELDING

GAS IR BURNER SYSTEM

FOR CIRCUMFERENTIAL SEAM WELDING

PORTABLE CONTROL PANEL/GAS TRAIN

TROLLEY OF BURNER HEATING SYSTEM

(PLC Controlled)

Actual View of Circular Seam Gas IR Pre-

Heating Systems

Actual View of Circular Seam Gas IR Post- Heating

Systems

Thank you