Showing posts with label shell and tube heat exchanger. Show all posts
Showing posts with label shell and tube heat exchanger. Show all posts

Tuesday, June 20, 2017

Shell and Tube Heat Exchangers

large shell and tube heat exchangers at oil refinery
These shell and tube heat exchangers are at an oil refinery, but
their application crosses all industry boundaries.
Cars are something which exist as part of the backbone of modern society, for both personal and professional use. Automobiles, while being everyday objects, also contain systems which need to be constantly maintained and in-sequence to ensure the safety of both the machine and the driver. One of the most essential elements of car ownership is the understanding of how heat and temperature can impact a car’s operation. Likewise, regulating temperature in industrial operations, which is akin to controlling heat, is a key process control variable relating to both product excellence and operator safety. Since temperature is a fundamental aspect of both industrial and consumer life, heat management must be accurate, consistent, and predictable.

A common design of heat exchangers used in the oil refining and chemical processing industries is the shell and tube heat exchanger. A pressure vessel, the shell, contains a bundle of tubes. One fluid flows within the tubes while another floods the shell and contacts the outer tube surface. Heat energy conducts through the tube wall from the warmer to the cooler substance, completing the transfer of heat between the two distinct substances. These fluids can either be liquids or gases. If a large heat transfer area is utilized, consisting of greater tube surface area, many tubes or circuits of tubes can be used concurrently in order to maximize the transfer of heat. There are many considerations to take into account in regards to the design of shell and tube heat exchangers, such as tube diameter, circuiting of the tubes, tube wall thickness, shell and tube operating pressure requirements, and more. In parallel fashion to a process control system, every decision made in reference to designing and practically applying the correct heat exchanger depends on the factors present in both the materials being regulated and the industrial purpose for which the exchanger is going to be used.

The industrial and commercial applications of shell and tube heat exchangers are vast, ranging from small to very large capacities. They can serve as condensers, evaporators, heaters, or coolers. You will find them throughout almost every industry, and as a part of many large HVAC systems. Shell and tube heat exchangers, specifically, find applicability in many sub-industries related to food and beverage: brewery processes, juice, sauce, soup, syrup, oils, sugar, and others. Pure steam for WFI production is an application where special materials, like stainless steel, are employed for shell and tube units that transfer heat while maintaining isolation and purity of a highly controlled process fluid.

Shell and tube heat exchangers are rugged, efficient, and require little attention other than periodic inspection. Proper unit specification, selection, and installation contribute to longevity and solid performance. Share your project challenges with application experts, combining your own process and facilities knowledge with their product application expertise to develop effective solutions.

Thursday, November 17, 2016

Shell and Tube Heat Exchanger Refurbishment

shell and tube heat exchangers tube bundle removed for refurbish
Two shell and tube heat exchangers getting refurbished
at industrial site. Tube bundles have been removed.
Shell and tube heat exchangers are regularly employed throughout industrial and commercial sites as a means of producing heated or cooled fluids. They consist of a pressure vessel and an internal tube bundle. The flow paths of the pressure vessel and the tube bundle are isolated from one another, giving a shell and tube heat exchanger four nominal connections.

  • Vessel inlet
  • Vessel outlet
  • Tube bundle inlet
  • Tube bundle outlet
Most often, the subject process fluid to be heated or cooled will flow through the pressure vessel, contacting the surface of the tube bundle contained within. If the heat transfer fluid flowing through the tubes is warmer than the process fluid in the vessel, heat will conduct through the tube wall into the process fluid, increasing its temperature. If the fluid in the tube bundle is cooler than the process fluid in the vessel, the process operates in the reverse fashion. Construction details of shell and tube heat exchangers can vary, but the basic operating scheme remains constant.

The lack of moving parts and ruggedly constructed nature of shell and tube heat exchangers tends to grant them a good measure of longevity for most applications. Regardless of any exceptions to that statement, there will eventually come a time when refurbishment or replacement is needed. If the pressure vessel is serviceable, or can be made so with a reasonable amount of cost, replacing the tube bundle may be the main element of an operation aimed at returning the heat exchanger to like new service.

Tube bundles are just that, bundles of tubes. With the right set of dimensional information and specifications, an identical fabrication can be purchased and put in place. It is not always necessary to revisit the original manufacturer. If drawings are still on file for the unit, sufficient information can be gleaned from them to produce a replacement tube bundle that will provide rated performance.

Ordering up a replacement tube bundle is not complicated, but the operation can be smoothed out through contact with involvement of an experienced engineer that can make sure all the necessary information is on hand and step you through the process. 

Monday, May 16, 2016

Shell and Tube Heat Exchanger Fundamentals

shell and tube heat exchanger diagram and cutaway view
Shell and Tube Heat Exchanger
Shell and tube heat exchanges are found throughout fluid based industrial process control operations where heat must be transferred between two closed fluid systems. There are numerous design variants intended to provide levels of performance tailored to specific process requirements.

Provided below is a white paper that illustrates and explains the fundamentals of heat exchanger performance for shell and tube units. Covered are the three modes of heat transfer: conduction, convection, and radiation. Three sample application cases are covered, showing how the formulas are applied, and illustrations provide for even better understanding of basic operating principals. The article is sure to refresh or enhance your heat exchanger knowledge.

MSEC brings many years of heat exchanger application experience to bear on your application requirements. Share your new or drop-in replacement heat exchanger challenges with MSEC and work toward the best installed solution.

Wednesday, September 17, 2014

Shell and Tube Heat Exchangers for Industrial and Commercial Application

tubing bundle
Tube Bundle
A shell and tube heat exchanger is a type of heat exchanger consisting of a shell (a pressure vessel) with a tubing bundle (or core) inside. Two fluids are used, one inside the tubing and one outside the tubing, to change temperature of the fluid contained in the shell. The amount of surface area provided by the tubes determines the efficiency of the heat transfer, and is sometimes augmented by additional lengths of tubing, or with fins.

The function of a shell and tube heat exchanger is very basic. Two different fluids, physically isolated from each other, and at different temperatures, are allowed to transfer thermal energy from one to the other through thermal conductivity.