Wednesday, December 12, 2007
Many Shell and Tube heat exchangers are provided in Chemical and Process plant for heat exchanging, heat recovery and integration for energy saving. There are many issues associate with Shell and tube heat exchanger such as corrosion, fouling & scaling, heat transfer efficiency drop, cleaning and maintenance, etc.One of the way to minimize and avoid above mentioned issues is applying protective coating on the tubes. The benefits are :
- CORROSION - Coating avoid corrosive contact with tube material and avoid corrosion. Extra corrosion allowance or corrosion resistance material is required. If severe corrosion occur, retubing may be required.
- FOULING & SCALING - Coating avoid sticky fluid contact with tube material and stay as fouling & scale.
- HEAT TRANSFER EFFICIENCY - Fouling & scaling will reduce heat transfer efficiency and more heat transfer area required. This will increases the heat exchanger capital investment.
- CLEANING & MAINTENANCE - Fouled heat exchanger shall be shutdown for cleaning and maintenance. In some event, chemical cleaning may be required. This increases heat exchanger operating and maintenance cost and also increases downtime and reduce plant availability.
- COST EFFECTIVENESS - In some configuration and operating condition, coating compare to corrosion resistance material, coating may turn out to be very cost effective.
Curran International (CI) is one of the heat exchanger tubing coating service provider. Edward Curran from CI has published an article in Chemical Processing.com.
On the other hand, there are disadvantages for coating. One of the major issue is the reliability of coating stay in tubing without dropping-off. Lost of coating layer may put the heat exchanger in unsafe operation without operator awareness and potentially lead to catastrophic consequence. This is an major issue alway debate till no conclusion and receive a lot of challenges.
What do you think about coating tubing ? Is any of your heat exchanger tubing coated ? Why not share you experience here ?
Related Topic
- Practical Design Tips for Heat Exchanger Design
- COLLECTION of Fouling Factor (FF) use in Heat Exchanger Design
- MultiChannel Heat Exchanger
- ECI – Operation & Maintenance Engineers - Don't miss FREE articles (>40) related to HX Fouling & Cleaning (Part 2)
- ECI – Operation & Maintenance Engineers - Don't miss FREE articles (>40) related to HX Fouling & Cleaning (Part 1)
Labels: Corrosion, Corrosion Resistance Material, Fouling, Heat Exchanger, Maintenance
Wednesday, August 8, 2007
- ECI – Operation & Maintenance Engineers - Don't miss FREE articles (>40) related to HX Fouling & Cleaning (Part 2)
- ECI – Operation & Maintenance Engineers - Don't miss FREE articles (>40) related to HX Fouling & Cleaning (Part 1)
- Do Not Overspecified Fouling Factor s for PHE
- Why Lower Fouling in Plate Heat Exchanger ?
- Heat Exchanger Fouling Mechanism, Prevention and Treatment
Fouling factor is generally used in the design to cater for heat exchanger deficiency resulted by fouling. TEMA has based on many years of experiences and experiments list out fouling factor for Shell & Tube Heat Exchanger for many services. Only TEMA subscribers are eligible to use this information. However, there are several reputable researchers & manufacturers have shared this information to the public. Following are the collection of fouling factors for different service.
- Engineering page
- Wolverine Tube
- Delta-T
- BayIndustrial
- GEO-center (Plate Heat Exchanger)
If you know some other site contain similar information, please kindly drop a note to me. I will park it here.
Labels: Fouling, Heat Exchanger, Heat Transfer, Plate Heat Exchanger, Shell-and-Tube Heat exchanger
Sunday, August 5, 2007
Last post <<ECI – Operation & Maintenance Engineers - Don't miss FREE articles (>40) related to HX Fouling & Cleaning (Part 1) >> has listed 3 articles.
1. Heat Exchanger Fouling & Cleaning - Fundamentals and Applications
2. Fouling During the Use of Seawater as Coolant - The Development of a User Guide™
3. Physical Water Treatment for the Mitigation of Mineral Fouling in Cooling-Tower Water Applications
This post i will only recommend some articles which are common to engineers in design & engineering and operation/maintenance in plant. I have left out other articles which are rather conceptual and research oriented. For those who are interested, please see HERE.
- Crystallisation Fouling Of Mixed Salts During Convective Heat Transfer And Sub-Cooled Flow Boiling Conditions.
- A Comparison of the Operating Characteristics of Two Cooling Water Systems using Chlorine and Chlorine Dioxide Biocides
- Analysis of Fouling Data Based on Prior Knowledge
- Challenges in Cleaning: Recent Developments and Future Prospects
- Fouling of Some Canadian Crude Oils
- Preheat Train Crude Distillation Fouling Propensity Evaluation by the Ebert and Panchal Model
- Retrofitting Crude Oil Refinery Heat Exchanger Networks to Minimise Fouling While Maximising Heat Recovery
- Chemical Cleaning of Oil Refinery Heat Exchangers -- The Need for a Joint Effort
- Analysis and Steps to Mitigate Heat Exchanger Fouling in an Aromatics Plant
- Fouling Characteristics of a Light Australian Crude Oil
- Development of a Data-Based Method for Performance Monitoring of Heat Exchangers
- Fouling Enhancement under Flow Boiling at Elevated Steam Qualities
- Improvements and New Developments in Self-Cleaning Heat Transfer Leading to New Applications
- The Practical Application and Innovation of Cleaning Technology for Heat Exchangers
- Fouling Mitigation Using Helixchanger Heat Exchangers
- ECI – Operation & Maintenance Engineers - Don't miss FREE articles (>40) related to HX Fouling & Cleaning (Part 1)
- What type of heat exchanger can be used to handle fluid with solid ?
- FAYF - Heat Transfer - Useful Heat Transfer Equation
- Do Not Overspecified Fouling Factor s for PHE
- Why Lower Fouling in Plate Heat Exchanger ?
- Heat Exchanger Fouling Mechanism, Prevention and Treatment
Labels: Cleaning, Fouling, Heat Exchanger
Saturday, August 4, 2007
ECI - Engineering Conferences International Symposium Series
Engineering Conferences International (ECI) is a global engineering conferences program, originally established in 1962, that provides opportunities for the exploration of problems and issues of concern to engineers and scientists from many disciplines. ECI is a not-for-profit partnership between the Engineering Conferences Foundation (ECF) and Polytechnic University.
If you are engineer working in plant and experiencing Heat Exchnager fouling problem...huh...here is the place where you may find your answer.
There are many FREE articles (>40) related to fouling and cleaning of Heat Exchanger available for download from ECI.
2. Fouling During the Use of Seawater as Coolant - The Development of a ‘User Guide’
3. Physical Water Treatment for the Mitigation of Mineral Fouling in Cooling-Tower Water Applications
[More]
Labels: Cleaning, Fouling, Heat Transfer
Saturday, July 21, 2007
Tubular Exchanger Manufacturers Association (TEMA) has developed a series of fouling factor for Shell and Tube (S&T). These fouling factor are generally higher than Plate Heat Exchanger (PHE), why not use S&T fouling factors to size PHE ?
Isn't this approach conservative and guarantee the performance ?
Reason being...
- Oversized Plate Heat Exchanger (PHE) required extra CAPEX and extra Space for oversized PHE
Tubulence minimise fouling tendencies in correctly sized PHE. Oversized PHE results low actual velocity and increase potential fouling and inefficient heat transfer
HTRI studies showed PHE fouling significant lower than Shell & Tube Heat Exchanger (S&T)...factor of 6.7
GUIDELINE : Do not oversized PHE more than 25% against required area.
Further reading :
- Do Not Overspecified Fouling Factor s for PHE
- Why Lower Fouling in Plate Heat Exchanger ?
- Heat Exchanger Fouling Mechanism, Prevention and Treatment
- PHE - Remove some plates, will pressure drop increase ?
Labels: Fouling, Heat Exchanger, PHE, Plate Heat Exchanger
Wednesday, June 27, 2007
"Heat exchangers are a significant part of many industrial processes that involve energy exchange. Most of these heat exchangers become fouled with use. The United Engineering Foundation, which hosts a conference every three years on the fouling problem, estimates that the cost of heat exchanger fouling is 0.4 % of global Gross Domestic Product (UEF, 2001). This high cost has lead to frequent study of the fouling problem, including numerous books and conferences on the subject (Somerscales and Knudsen, 1981; Melo et al., 1988; Bott, 1995). Much of this work has focused on particular industries. Crude oil processing, dairy and food processing, and nuclear reactor cooling are all industries that have conducted a large amount of research aimed at understanding and mitigating fouling."Read this Thesis for details...
Particulate Fouling of HVAC Heat Exchanger
Particulate fouling of HVAC heat exchangers can lead to negative energy and indoor air quality impacts. This work investigated the mechanisms and consequences of particle deposition on fin-and-tube heat exchangers.
Please constantly do heat exchanger maintenance to minimise OPEX.
Further reading
- Predicting and Accounting for Heat Exchanger Fouling
- Why Lower Fouling in Plate Heat Exchanger ?
- Heat Exchanger Fouling Mechanism, Prevention and Treatment
Labels: Fouling, Heat Exchanger, HVAC
Tuesday, June 26, 2007
Have you ever seen or heard about SELF CLEANING HEAT EXCHANGER ?
Self Cleaning heat exchanger operating concept is mainly base on fluidization concept. It commonly used for severe fouling service. It has been proposed in 1970s and used for seawater application.
Self Cleaning heat exchanger operating concept is mainly base on fluidization concept. It commonly used for severe fouling service. It has been proposed in 1970s and used for seawater application.
KLAREN
, one of supplier for SELF CLEANING HEAT EXCHANGER...Further reading
Labels: Fouling, Heat Exchanger, Self Cleaning
Monday, June 25, 2007
An article on Heat exchanger Fouling for designer & Operator...
Predicting and accounting for heat exchanger fouling
Here are some insights into the design, operation and research issues associated with Heat Exchanger fouling.
Here are some insights into the design, operation and research issues associated with Heat Exchanger fouling.
T. REG. BOTT, UNIVERSITY OF BIRMINGHAM
Further reading...
- Why Lower Fouling in Plate Heat Exchanger ?
- Heat Exchanger Fouling Mechanism, Prevention and Treatment
- PHE - Remove some plates, will pressure drop increase ?
- ALFA LAVAL - Plate technology and Designing Plate & Frame Heat Exchanger
- KOCH HTC - Special Heat exchanger provider...Twisted & Helical tube Heat exchanger
- GEA - Brazed Plate Heat Exchanger
Benefit from this post...buy me some sweets...
Labels: Fouling, Heat Exchanger, Plate Heat Exchanger
Sunday, June 24, 2007
I have been knowing lower fouling factor in Plate Heat Exchanger for many years. However, i don't understanding the main reason until i read this article...
This article has briefly discussed types of fouling, fouling factor used in Shell and Tube Heat Exchangers for common fluids, why lower fouling factor in plate heat exchnager (PHE) and, design consideration to reduce effects of fouling....(From BAY INDUSTRIAL)
For those who involves in plant operation, please read this...
"According to Pritchard and Thackery (Harwell Laboratories), about 15% of the maintenance costs of a process plant can be attributed to heat exchangers and boilers, and of this, half is probably caused by fouling. Fouling can be very costly in refinery and petrochemical plants".
Please ensure upstream filter / strainer constant maintain...
Further reading...
If you benefit from this post...buy me some sweets...hehe...
Labels: Design, Fouling, Heat Exchanger, Plate Heat Exchanger
Friday, June 22, 2007
Heat exchanger fouling has been a headache problem which can not be avoided...however many of us may not aware of it mechanism, preventiona and treatment....
The article presented six (6) distinctive different mechanism causing Heat Exchangers Fouling e.g. Crystallization, Sedimentation, Chemical reaction & Polymerization, coking, Biological growth and corrosion. This article will only focus on particulate fouling.It discusses particulate fouling mechanisms, prevention and treatment. This article also presented Prection Model for Particulate Fouling by Kern & Seaton.
by Reza Hashemi and Robert L. Brown, Jr., Pall Corporation
If you benefits from this post...buy me some sweets...hehe
Labels: Corrosion, Fouling, Heat Exchanger
