ASM MET14_Debashis_Linde
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Transcript of ASM MET14_Debashis_Linde
Improving Furnace Atmosphere Circulation with High-Speed Gas
Injection SystemBy
Debashis RoyLinde India Limited
• Annual Sales (EURO):15 billion
• Employees worldwide: 55,000
• R&D spending (Euro): 9 million
• No. of patents: >2,800
• Global Presence:>100 countries
World’s leading gas company & Solution Provider for gases
Filling centre
Pipeline
Pipeline
On-site supply
Retailer
Transport of liquefied gas
Cust
omer
Cylinder
Bulk
Tonnage
Gases production plant
Gas Supply Capabilities
• Distortion and Quality Control
• Cost of Energy
• Environmental drivers
• Implementation of modelling and simulation technologies
• Problems with quenchant selection and use
• cost of Equipment
• Analysis Technique and Equipment
• Process optimization and Control
Key Challenges
An operation or combination of operations involving the heating and the cooling of
a metal or alloy in the solid state to attain certain desired properties.
The functions of furnace atmosphere— To prevent/reduce oxidation
— To achieve bright surface
— To adjust the surface chemistry of the components
Atmosphere gases used in Heat Treatment
Neutral
Gases
Active Gases
Reducing Oxidizing Decarburizing Carburizing Nitriding
Ar H2 H2O H2O CO NH3
N2 CO CO2 CO2 CxHy
He O2 O2
Why Heat Treatment & Why Furnace Atmosphere?
What is CARBOJET®
Inject small amount of gas with high velocity
Placed in one or several position on the furnace
Pit furnaces, Roller Hearth Furnace…
Annealing, carburizing, hardening …
Better gas convection in Heat Treatment furnaces
Improved furnace atmosphere homogeneity
Fan and inner retort can be removed
Increase heat transfer
Reduced energy/water consumption
Easy maintenance, No vibrations
What are the advantages of CARBOJET®?
CARBOJET® - General Idea
Principle – Atmosphere uniformity What kind of problems need to be solved
The CARBOJET® Solution
Evaporating or change of chemical
composition from the product
surface or addition of reactive or
inert gases have to be uniformly distributed to ensure the specified
heat treatment results.
In several heat treatment processes the atmospheric
gas convection is extremely low. This causes:
inhomogeneous composition of local atmospheres
uneven product quality, sooting, and problems in
heat and carbon transfer
Fan might help, but usually they cause other problems
due to air leakage and high service and maintenance costs
With high speed gas injection it is possible to move the furnace atmosphere and
create gas circulations, which improve the convection and increase the heat and
carbon transfer rates.
CARBOJET® - General Principles
Solution Description
The system consists of one or several
CARBOJET® high speed nozzles with
piping and flow train
The number of nozzles is adapted to the
furnace size and existing gas
consumption
Gas flows can be controlled manually or
through a CARBOFLEX® atmosphere
control solution
The specially designed nozzles are made
of heat resistant material to ensure a long
lifetime
All CARBOJET® systems are tailor-made to
optimally suit each customers needs
N2
CH3OH
NG
CH4
CARBOJET® - Solution Description
Added values:
Increased productivity due to faster
carburization processes
Homogeneous product quality due to
improved atmosphere mixing
Reduced soot formation and better
utilisation of carburising gases
Increased carbon transfer on material
surfaces due to forced convection
Savings on maintenance, energy and
water (e.g. no fans needed)
Better quality
Cost savings
Higher Productivity
CARBOJET® - Solution Description
m/s
CARBOJET® - Solution Description
• Test run to prove CARBOJET®
• 2 identical trials were prepared for
» conventional with fan (1200 rpm)
» fan off and special CARBOJET® lance
• Load: forging scrap 183 kg C15 (0.15 % C)
• Retort diameter 900 mm, height 3mtrs
• Carburising temperature 910 °C, C-pot. 1.0 %, 10h
30min
• Protective gas : 2.1 m3/h N2, 1.7 l/h methanol
• Process control with Lambda probe
• 4 thermocouples
• 12 test samples of which 6 were analysed
CARBOJET® - Customer Case Study Pit Furnace
•
Velocity (m/s)
With Fan CARBOJET with fan off
Empty furnace
CARBOJET® - CFD Simulation Pit Furnace
Fan with cylinder
m/s
Fan without Cylinder CARBOJET® without cylinder
CARBOJET® - CFD Simulation Pit Furnace
Temperature without CARBOJET®
Temperature difference min/max +/- 4°C
Temperature with CARBOJET®
Temperature difference min/max +/- 1°C
CARBOJET® - Customer Case Study Pit Furnace
Better homogeneity with CARBOJET®
Depth (mm) Homogeneity of %C
With FanWith
CARBOJET®
0 0.05 0.03
0.1 0.06 0.04
0.2 0.05 0.05
0.3 0.06 0.05
0.4 0.06 0.04
0.5 0.06 0.04
0.6 0.05 0.03
0.7 0.03 0.03
0.8 0.05 0.03
0.9 0.04 0.02
1 0.03 0.02
Average 0.049 0.035
Test Result• Faster Heating rate
• Temperature and case depth are more
uniform
• The lid construction can be simplified
• Savings for maintenance and energy
• Less soot formation
• Applicable with all different processes
The customer has introduced CARBOJET®
in all his furnaces.
CARBOJET® - Customer Case Study Pit Furnace
Sennestahl GmbH in Bielefeld, Germany•Two pit furnaces for several Heat Treatment processes
•Installations were made on August 2005 and January 2006
•With CARBOJET® it was possible to operate the pit furnaces
without fans Significant savings on maintenance costs
D. Holzenbecher, production manager of Sennestahl:“Broken ventilators are now history. I’m very convincedthat this technology is a success in our rough, non-stop
operation. The heating elements, retorts and brick lining
suffer less frequent damage. We’ve already seen a
noticeable reduction in maintenance costs.
These cost savings wouldn’t been possible without the
introduction of CARBOJET ®.”
CARBOJET® - Customer Case Study Pit Furnace
High speed nozzles are installed through the furnace
wall, roof, cover., bottom
Gas flow is usually controlled with a control system
(CARBOFLEX®, CARBOTHAN, …)
Possible also to control the flow manually with a
simple flow meter (not best practice)
Very little maintenance needed since there are no
moving parts and the nozzles are heat and wear
resistant
Nozzle details (position, angle, amount) and gas flow
has to be defined separately for each furnace
High-speed nitrogen is the main gas component and it
is usually accompanied with methanol. It is possible
also to add propane, ammonia or natural gas with the
jet.
CARBOJET® Solution Package
MHP Mannesmann Präzisrohr GmbH in Brackwrede, Germany
Two Roller Heart Furnaces for carbon steel tube annealing
First furnace equipped with CARBOJET® in 2005
CARBOFLEX® control system and in-situ endogas generators
CARBOJET® - Customer Case Roller Hearth Furnace
Benteler AG, Germany
CARBOJET® on Roller Heart Furnaces for carbon steel tube annealing
Improved atmosphere homogeneity
Reduced soot formation and better utilisation of gases
CARBOJET® - Customer Case Roller Hearth Furnace
Heating Zone
Each red arrow represents a CARBOJET® Lance. N2 amount: 10 Nm³/h and per Lance.
CARBOJET® - Customer Case Roller Hearth Furnace
With CARBOJET®
Without CARBOJET®
CARBOJET® - CFD Simulation Roller Hearth Furnace
• Manufacturing of electric connecters
• Increases productivity by 15%
• More homogeneous atmosphere
• Less soft spots
• More precise atmosphere control
• Longer life of the retort
CARBOJET® - Customer Case Rotary Retort Furnace
Furnaces where CARBOJET®® used successfully Roller hearth furnaces
Walking beam furnace
Rotary retort furnaces
Pit furnaces, etc
Furnaces where CARBOJET®® can work
Batch furnaces without a fan
Rotary hearth furnaces
Mesh Belt furnaces
SQF, etc
HT processes suitable for CARBOJET®®
Annealing, Carburising, Carbo-nitriding,
Hardening, Nitriding, Nitrocarburising…
CARBOJET® - Suitable Furnaces And Processes
• Low maintenance costs –The elimination of problematic mechanical fans
• Reduced down time - No down time required for mechanical fan maintenance.
• Infinite turndown – CARBOJET® nozzles can be turn on and off at will
• Compositional flexibility – Quick change of atmospheres and the application of
different gases.
• Improved quality – less scrap due to better control of the atmosphere
• Improved consistency - Due to uniform distribution of the furnace atmosphere
• Other major benefits –Heating elements, retorts and brick lining suffer less
frequent damage.
CARBOJET® - Feedback from Customers
• “CARBOJET® Roller Hearth Furnace“ at several companies
• Jansen (CH), Benteler (x2), Zollern, MHP(x2), Poppe & Potthoff(x2), Železiarne Pobrezova (SK).
• Satisfied customers, quality improves, costs savings, higher productivity
• “CARBOJET® Rotary Furnace” (x3) at Weidmüller with measurable results!
• Productivity increases by 15% in tool carburizing after installing CARBOJET®
• “CARBOJET® Pit Furnace” (x2) at Sennestahl, Sandvik (SK) with promising results
• The pit furnace fan could be replaced with CARBOJET®
• “CARBOJET® Cooling Zone” Železiarne Pobrezova (SK), installation at Jansen (CH)
• More than 10% faster cooling rate
CARBOJET® - References
Since 2005, Linde has successfully commissioned 100+ CARBOJET® installations in
practically different types and sizes of heat treatment furnaces, with Process
Performance Guarantees.
Linde’s CARBOJET® injection solutions have proven to deliver
– Improved quality and consistency of product
– Improved furnace atmosphere homogeneity
– Reduced maintenance cost and energy cost
– Improved temperature uniformity
– Reduced soot formation
Results from Successful Use of CARBOJET®
CARBOFLEX®
ACS: Control System CARBOJET® CARBOTHAN®
HYDROFLEX®
Non-Ferrous Annealing Ferrous annealing Brazing
CRYOFLEX®
FRIOFLEX®
SINTERFLEX®
ACS: Control System SINTERFLEX SH SINTERFLEX MIM
LINDE Product Families for Heat Treatment Applications
Thank youfor your kind attention
Creating Customer Value as a Solutions Provider
Debashis RoyMob: 9004061367