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,Infrared 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 :
Blue Flame Mode:
Premix flows such that heat
If premix quantity is increased ,
intensity is in the range of 100500W/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.
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 = 1.05 to 1.1
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 â&#x20AC;&#x201C; 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 PreHeating Systems
Actual View of Circular Seam Gas IR Post- Heating Systems
Thank you