PCCC3 and SaskPower Symposium Regina Canada September 8-11, 2015
Managing Corrosion with Teflon®
Energy Efficiency, Environmental Protection Plant Availability Proven Technology for Flue Gas Cooler Applications Peter Dittmann, Director Produkmanagement Wallstein Thermal Technology Co., Ltd., Beijing/China Wallstein Ing. GmbH, Recklinghausen, Germany
VITA
1996 - Wallstein Service Co.
1989 - Wallstein Engineering Co.
Group History and Growth Strategy
- start in 1989
- turnover in 2014 approximately 30 Mio. Euro
- employees mid of 2015
125 in Germany
25 office in China /50 workshop China 2012 - Wallstein Thermal Equipment Ltd. / Tianjin China
2012 - Wallstein Saudi Arab Oger Ltd. / KSA
Wallstein Thermal Technology Manufacturing Ltd.
2011 - Wallstein Thermal Technology Ltd. / Beijing China
1998 - Wallstein Manufacturing Co.
Industries / Products
Waste to Energy
/ Biomass Plants
Power Plants Chemicals /
Petrochemicals
Climate /
Environment
Heat Recovery System (HRS)
Flue gas cooling for air-or boiler feed
water preheating
Leads to efficiency increase
Heat Displacement System (HDS)
Used for clean gas reheating by flue gas
cooling
Crossflow
Gas to gas heat exchanger
Gas Steam Preheater
Reheating of flue gases by the help of
steam and/or feed water
Preheater/Economizer
Air preheating / Flue gas cooling
Beginng at the 1980´s due to clean air act regulations in Germany FGD has been installed. Using rotating GGH for reheating the clean gas. Due to the leakage problems and the negative impact of the enviroment lekage free system are required. Cooler/reheater system liquid coupled with differnt material combination has been taken in operation. Most of them failed due to corrosion problems.
History
Starting Developing Reliable Materials
Test installation mainly in slip streams 1980 Wilhelmshaven Germany 1984 Schwandorf Germany 1984 Prunerov Czech Republic 1987 Maribor Slovenia 1992 Schwarze Pumpe East Germany 1995 Lippendorf East Germany
Material was already long time out of discussion, cleaning
needed to be tested because of this critical dust.
Material test with C.S. and C.S. lined materials Teflon shows the best results
Flake lined, vinylester lined different material without good results
Out of this Test
Installations in: Germany Czech Republic Thailand South Korea
Todays Installations: Poland Italy Canada China
All cooler with Fluoropolymer Tubing based on
Teflon®
Excellent Corrosion resistance
Cleanability due to the non stick surface effect
Cost effective
High service temperature up to 260°C
High flexural fatique strength
Stress cracking resistance High Hope stress values
Why Fluor Polymers Teflon® ?
This material offers many advantages like:
Design aspects: fly ashes acid formation online washing sytem corrosion resistant life time availibility
Cooling Flue Gases
Wall temperature below the acid dew point „condesation“
SO3, HCL, HF plus H2O forming critical mixture of acids ph values ≤1
175°C-130°C 347F - 266F
120°C-85°C 248F -185F
145°C 50°C 293F 122F
HRS Primary Air and Condensate/District Preheating
• Increase overall efficiency • Coal saving • CO2 reduction • Water consumption FGD • Heat recovery below the acid dew point • Corrosion resistant
Heat Recovery System with benefits
10 10
Gas Analysis
Lignite Hard Coal
Oil
N2 61.41 74.10 73.18 Vol. -%
O2 2.76 5.0 5.10 Vol. -%
CO2 12.7 13.10 11.90 Vol. -%
H2O 23.13 7.80 9.82 Vol. -%
Corrosive elements
SO2 4,920.0 2,224.0 5,448.0 mg/Nm3
SO3 40-100 10-40 165 mg/Nm3
HCl 37 68.5-425 mg/Nm3
HF 7 25-50 mg/Nm3
Dust 50 20 70 mg/Nm3
2530
35
20
4045
5055
6065
707580
100
120
140
160
180
200
1 10 100 1000 10000
Su
lph
uri
c A
cid
Dew
po
int
SO3 content V ppm
Sulphuric Acid Dewpoint in Flue Gases
Based on the SO3 content and water dew point in the flue gas
Sample: water content in flue gas 8,5%, water dew point 43
C SO3 20 ppm Remark: fly ash will drop the dew point
Gas Analysis Influence on the Sulphuric Acid Dew Point
Results may be
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Corrosion started after some month of operation
Diffusion and Permeation after half a year operation
Nickel Base
S.S. Fluor polymer lined
Results may be
12
Carbon Steel after half a year of operation
13
Flue Gas Cooler General Arrangment around FGD
Elektrostatic Precipitator Flue Gas Desulphurisation
Flue Gas Cooler Installation
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HRS Flue Gas Cooler Installation
HRS Flue Gas Cooler Installation
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HRS Flue Gas Cooler Installation
HRS Flue Gas Cooler Installation
HRS Flue Gas Cooler Installation
Hubertusstraße 44 ▪ D-45657 Recklinghausen fon +49 (0)2361 1047-0 ▪ fax +49 (0)2361 1047-47
www.wallstein.de ▪ [email protected]
HRS Flue Gas Cooler Operation
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HRS Flue Gas Cooler Operation
HRS Flue Gas Cooler Operation
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Hubertusstraße 44 ▪ D-45657 Recklinghausen fon +49 (0)2361 1047-0 ▪ fax +49 (0)2361 1047-47
www.wallstein.de ▪ [email protected]
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HRS Flue Gas Cooler Operation
HRS Cooler in Operation
Companies:
DuPont in Neomurs Switzerland (actual Chemours ) Fluortubing in Utrecht Netherland and Wallstein Ing. in Recklinghausen Germany jointly developed a solution based on Teflon® AlWaFlon® Pressure Tubes for the Heat Exchanger application
Developing the AlWaFlon Pressure Tube
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Longterm Pressure Testing
Approved by: TÜV for AlWaFlon Pressure Tubes Approval: ASME Section VIII Div.I CC2795
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AlWaFlonTM is a Thermoplastic Modified Flouropolymer
Case XXXX
Use of PTFE Tubing Material for Flue Gas Heat
Exchanger Tubes-Section VIII, Division 1
Inquiry: May polytetrafluoroethylene (PTFE) be used for flue
gas heat exchanger tubes with water as the tube side fluid
and flue gas as the shell side fluid, in Section VIII, Division 1
construction? For the purposes of this Code Case flue gas
heat exchangers are used downstream of the boiler and
electrostatic precipitator in a power plant.
Reply: It is the opinion of the Committee that PTFE may be
used for flue gas heat exchanger tubes in Section VIII,
Division 1 construction provided the following requirements
are met:
1. GENERAL REQUIREMENTS
1.1 The virgin PTFE material shall have no fillers, additives
or pigments and shall be in compliance with ASTM D4895-
10 and shall be limited to the polymer with a classification
designation of either Type I Grade 4 Class B, or Type I
Grade 3 Class D. The PTFE material shall also have a
stretching void index of 50 maximum and a thermal
instability index of 7 maximum. The PTFE fine powder
material shall be certified by the materials manufacturer, and
a certificate of analysis shall be furnished to the vessel
manufacturer for each batch of finished material from a
production reactor.
ASME CC 2759 TÜV Approval
Reference Customers
Thank you for
your attention.
Flue gas cooler with tubes based on Teflon® fluorpolymer now in operation since more than 30 years.
HRS Primary Air Preheating
Wet Stack
or
Cooling
Tower
• Corrosion resistant • Increase overall efficiency • Coal saving • CO2 reduction • Water consumption FGD • Heat recovery below the acid dew point
Heat Recovery System with benefits:
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HRS Boiler Feed Water or Distict Heating
Heat Recovery System with benefits: • Corrosion resistant • Increase overall efficiency • Coal saving • CO2 reduction • Water consumption FGD • Heat recovery below the acid dew point
Wet Stack or Cooling Tower
Feed water and /or District Heating
