In some heat exchangers fouling occurs rapidly, in others the equipment may operate for long periods, perhaps several years, before a problem becomes apparent. C4 fouling of heat exchanger surfaces springerlink. Poorly controlled cooling tower water can cause significant fouling issues in all heat exchangers in the closed loop circuit. These materials have no special anti fouling properties. Fouling can occur inside the tubes or outside the tubes. Retrofitting crude oil refinery heat exchanger networks to minimise fouling while maximising heat recovery, b. The fouling materials can consist of either living organisms biofouling or a. Pdf fouling of heat exchangers hamza shafiq academia. This biological fouling is best controlled via quality water treatment at the cooling tower. The initial weights of the heat exchangers were documented. It is only in recent years that the problem of heat exchanger fouling. The fouling problem exists in more than 90 percent steinhagen r, 1993 of heat exchangers. Evaluation of sodium hypochlorite for fouling control in. Fouling investigation of brazed plate heat exchangers.
Online cleaning technique for mitigation of biofouling in heat. Heat exchanger fouling and estimation of remaining useful life. Bott, fouling of heat exchangers and its mitigation with special reference. The problems that restrict the efficient operation of equipment are described and the costs, some of them hidden costs, that are associated with the fouling of heat exchangers are discussed. The plate heat exchangers contained 10stainlesssteel plates aisi 316l.
Heatexchanger fouling can be reduced by proper heatexchanger design, by. A large part of the text is devoted to the use of chemical and other additives to reduce or eliminate the problem of fouling. Heat exchanger fouling of course reduces the opportunity for heat recovery with its attendant effect on. Copper and steel in contact in sea water 158 fouling o f heat exchangers copper plates large cathode represent small anodes and cause severe corrosion attack around the rivets. Influence of fouling on heat exchanger effectiveness in a polyethylene plant 6. Use features like bookmarks, note taking and highlighting while reading fouling of heat exchangers chemical engineering monographs book 26. To the output losses listed above, one needs to add the cost of downtime required to inspect, clean, and repair the components millions of dollars per. In addition to the operational costs, also the capital cost increases because the heat exchangers have to be designed in larger sizes to compensate for the heat transfer loss due to fouling. Some simple concepts and models of the fouling processes are presented as part of the introduction to the subject. Fouling of heat exchangers 9780444821867, 9780080531908. A large amount of fouling in the flow areas of the heat exchangers could be seen for some.
However, fouling is a selffulfilling prophecy and the selection of fouling factors or excess area must be done carefully. In this work, experimental study and numerical simulation on heat transfer and pressure drop characteristics where performed at the shell side of a helically baffled heat exchangers. As a result of fouling, there is a possibility of deterioration in product. Fouling science and technology, kluwer academic publishers, dordrecht, the netherlands, pp. Fouling of heat exchangers is a serious issue as it reduces heat transfer efficiency and increases pressure drop and hence affects the economy of processing plant mullersteinhagen 1993, toyoda et al. Fouling factor is a numerical allowance for possible coating of the tubes by dirt or precipitate in the heated or cooled fluid. Sep 02, 2015 in the end when there are no data or other information available, it is necessary to revert to empiricism, i. Much depends on the particular fluid and the conditions under which the exchanger operates. In fact, fouling has been recognised for a in fact, fouling has been recognised for a long time, and research on heat exchanger fo uling was. Several brazed plate heat exchangers were used in this study. What is a fouling factor in shell and tube heat exchangers. Fouling, not only for preheat exchangers of crude distillation units, but also for other units, is one of the most serious operating problem and source for energy loss in oil refineries.
Fouling resistance an overview sciencedirect topics. The plates were separated using equidistantly spaced cfc gaskets 3. Pdf 20 fouling of heat transfer surfaces semantic scholar. Heat exchanger fouling of course reduces the opportunity for heat recovery with its. After the specified time period of running oncethrough lake water through the heat exchangers, the exchangers were taken off line. A biofouling model applied to the development of biofilms in heat exchangers is presented. There are many textbooks devoted to heat transfer and the design of heat exchangers ranging from the extreme theoretical to the very practical. Bott, fouling of heat exchangers, chemical engineering monographs 26. Fouling, the unwanted accumulation of generally solid material on heat. Advice on the selection, design, installation and commissioning of heat exchangers to minimise fouling is given. Chemical cleaning of oil refinery heat exchangers the need for a joint effort, himanshu m. By many, fouling is considered the single most unknown factor in the design of heat exchangers.
Biological fouling often presents as a dark green to brownish slime on the surface of the plate. Heat exchanger fouling and cleaning vii, july 1 6, 2007, tomar, portugal fouling monitoring and cleaning optimisation in a heat exchanger network of a crude distillation unit andrea heins 1, ramon veiga 1, carlos ruiz 2, andres riera 2 1 argentinean technology center cta repsol ypf. One of the difficulties faced by designers and operators of heat exchangers is anticipating the likely extent of fouling problems to be encountered with different flow streams. Fouling and scaling issues in heat exchangers and condensers. Heat exchanger fouling and estimation of remaining useful life tutpol ardsomang1, j. Fouling of heat exchangers chemical engineering monographs. The worldwide costs, associated specifically with crude oil fouling in preheat trains were equated to around 20% of all heat exchanger fouling mullersteinhagen. The consequences of fouling accumulation include not only the economic loss, but heat transfer efficiency degradation, high flow resistance and pressure drops, and increased safety hazards, such as. In many instances, particularly where the velocity is high enough, particle deposition is not a problem in respect of heat exchanger fouling see chapter 7. Another large section is designed to give information on both online and offline cleaning of heat exchangers. Cleaning of heat exchangers is discussed in more detail in the cost of fouling 19 production.
Bott, school of chemical engineering, the university of birmingham, edgbaston, birmingham b15 2tf. Fouling of heat exchangers chemical engineering monographs book 26 kindle edition by bott, t. Fouling is the accumulation of unwanted material on solid surfaces to the detriment of function. Since it is the fouling resistance that is under scrutiny an obvious choice of experimental method involves the determination of changes in heat transfer during the deposition process. In some situations however, the deposition of particulate matter does represent an operating difficulty, but. Save up to 80% by choosing the etextbook option for isbn. Bott fouling of heat exchangers chemical engineering monographs. Fouling and scaling issues in heat exchangers and condensers the problems related to heat exchanger fouling and scaling and their economic and environmental impact are commonly known as fouling and include both organic deposits as well as inorganic deposits also referred to as scaling. Bott fouling of heat exchangers chemical engineering. Apr 23, 2016 delplace f, leuliet jc, bott tr 1997 influence of plate geometry on fouling of plate heat exchangers by whey protein solutions.
Fouling of heat transfer surfaces occurs in most chemical and process industries, including oil refineries, pulp and paper manufacturing, polymer and fiber production, desalination, food processing, dairy industries, power generation and energy recovery. Filters, membranes and heat exchangers are especially sensitive to it, but the accumulation of deposits can take place on any surface when the conditions are favorable. These metals are considerably more expensive and have much lower thermal conductivities than copper and carbon steel. An overview of fouling encyclopedia of desalination and water. The basis for subsequent operations will be equations 2.
Bott this unique and comprehensive text considers all aspects of heat exchanger fouling from the basic science of how surfaces become fouled to very practical ways of mitigating the problem and from mathematical modelling of different fouling mechanisms to practical methods of heat exchanger cleaning. Tube heat exchanger an overview sciencedirect topics. For other types of heat exchangers, excess heat transfer area is often used. Generally speaking, heat exchangers are liable to fouling. General references on or related to heat exchangers. In fact, fouling has been recognised for a long time, and research on heat exchanger fouling was conducted as early as 1910 and the first practical application of this research was implemented in the 1920s. The capital cost of these large heat exchangers would be considerably reduced if an inexpensive tube made of. Heat exchanger fouling and cleaning challenges and. For shell and tube heat exchanger, the common method is to use fouling factors. Influence of fouling on heat exchanger effectiveness in a. R download it once and read it on your kindle device, pc, phones or tablets. Apr 18, 2016 lets look at what heat exchanger fouling factors are and what choices the engineer has regarding them. Besides crystallization fouling, particulate fouling, due to the deposition of small suspended particles e. If the situation is reversed and steel plates are joined by copper rivets small cathode.
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