Heat Exchangers : Design , Operation & Maintenance

Explore heat exchangers through heat transfer theory, mechanical design, and process control. Access downloadable files, complete technical quizzes, and learn from practical examples grounded in operation and maintenance expertise.

Explore floating tube sheet heat exchangers where one sheet moves to accommodate differential thermal expansion, with maintenance features and types like outside packed stuffing box and internal floating head exchangers.

Examine how a spiral plate heat exchanger uses two plate strips wound around a split center to form concentric spiral passages. Fluids flow through adjacent passages and exchange heat.

Bayonet heat exchangers use concentric tubes with a bayonet inside a sealed scabbard, attached to tubesheets; fluids enter, flow through the tubes, and exit, allowing independent expansion for temperature differences.

Explore shell and tube heat exchangers, focusing on operation, maintenance, and component functions, using 3d models, cross sectional views, and real world videos for assembling and troubleshooting.

Explore AEB exchangers, outside backed floating head designs used as inter coolers or after coolers in reciprocating compressor systems, examine stationary head, floating head skirt, packing, tube-side flow, vents.

Explore AEP Tema type exchangers operation, focusing on the outside packed floating head that accommodates thermal expansion and contraction, protecting the tube bundle while illustrating shell and tube flow paths.

Learn the 2D dismantling of an AKT TEMA type exchanger by unbolting channel covers and floating head cover, removing tube bundle as a single piece for maintenance inspection and cleaning.

Explore tube side header designs in heat exchangers, including type A removable channel cover, type B bonnet, and type D forged components for high pressure, emphasizing inspection of tube ends.

Analyze tube layout options for heat exchangers to maximize heat transfer area while ensuring cleanability inside and outside. Compare triangular, square, and diagonal pitches, including center-to-center spacing and flow directions.

Understand tube sheets in heat exchangers, including fixed and floating types, and single, double, or triple arrangements where tubes are inserted into holes, expanded into grooves, or welded.

The kettle-type reboiler shell uses shell-side vaporization with dome space for vapor-liquid separation and surge capacity, and requires two outlets: overhead vapor and bottom liquid draw-off; tube bundle floods.

Protect the tube bundle from high-velocity, condensing, or two-phase shell-side fluid at the inlet with impingement baffles, typically rectangular plates (circular plates are more desirable) mounted on two spacers.

Longitudinal baffles in fixed tubesheet heat exchangers create multi-pass shells by welding to the shell, eliminating bypass and boosting heat transfer, with solid or perforated options.

Minimize fouling and facilitate cleaning to preserve thermal performance and manage pressure drop in heat exchangers, favoring tube-side access and hydro blasting over shell-side chemical cleaning.

Corrosive fluids drive material choices, placing them in the tubes to avoid shell-side corrosion resistance, and enable easy replacement for maintenance, with cooling water on the tube side.

Prefer the shell side for phase-change services, as it provides a larger cross section for vapor flow and lowers pressure drops when vapors condense or liquids vaporize.

Learn practical design of shell and tube heat exchangers, calculating the effective temperature difference and heat transfer coefficients with simple equations for daily plant use.

Bypass on the shell side distorts temperature profile and lowers LMTD. Weld baffles or seal gaps to prevent bypass; otherwise, use baffle spacing of 20% of the shell inner diameter.

Determine the cmt ds for each load zone in a multi-zone heat exchanger, then compute the wmtd to accurately represent heat transfer and prevent condenser oversizing compared with standard mtd.

Examine multi-pass tube side flow: higher velocity and heat transfer coefficient, reduced effective temperature difference, and greater pressure loss, with lmtd corrected for mixed countercurrent and cocurrent passes.

Examine how the shell side heat transfer coefficient varies with baffle spacing and cross-stream flow, considering leakage and bypass streams that limit heat transfer due to pressure losses.

Calculate shell side pressure losses in a heat exchanger from bypass factor and baffle windows, shell flow, and nozzle losses, using Reynolds number based friction models to determine total losses.

Design a shell and tube heat exchanger using practical design tables drawn from standards, selecting a fit from estimated area and flow rates VR and VM at 1 m/s.

Compute W, the shell side longitudinal stream cross area, as baffle window area minus tubes' cross area, using C and n_w; apply NF and use d_h to minimize edge-strip effects.

Practice session 11 demonstrates calculating shell side flow velocities—cross, longitudinal, and average—using tube pitch and baffle spacing. Apply these velocities to assess pressure drop, heat transfer, fouling, and maintenance.