How to use Industrial Shell and Tube Heat Exchanger Sizing Calculator
- Enter Hot Side Fluid Properties and adjust the options as needed.
- Run the tool and inspect its results, evidence and limitations.
- Copy or download the result, then verify it against the actual website, source data or business records.
Try a concrete example
In a petrochemical heat recovery train cooling 25.0 t/h treated process water from 90.0°C down to 50.0°C (ΔT = 40.0°C) using plant utility cooling water warming from 20.0°C to 40.0°C (ΔT = 20.0°C) via a horizontal TEMA E 1-2 exchanger with Ø25.0×2.5mm tubes of 3.0 m length: thermal duty equals 1,162.8 kW, requiring 49.9 t/h cold water flow. Counterflow LMTD is 39.1°C, with segmental baffle crossflow yielding F = 0.94 for an effective delta-T of 36.8°C. At an overall heat transfer coefficient U = 1,300 W/(m²·°C) including fouling allowance, required surface area is 24.3 m². Configured in a 31.75mm 30° triangular pitch, 108 seamless tubes provide 25.4 m² (105% design margin) housed in a Ø380 mm shell with 1.5 m/s tube velocity.
How to interpret results
Shell and tube heat exchangers represent the workhorse thermal transfer equipment across refineries, petrochemical plants, power station boilers, and district energy networks. Primary components include a cylindrical pressure vessel shell, tube bundles, channel heads, stationary/floating tubesheets, and segmental baffles. One process stream flows through the tube interior (Tube Side) while the secondary stream circulates around outer tube walls (Shell Side), exchanging continuous steady-state heat. Sizing follows the fundamental equation Q = U · A · F · LMTD. Multi-pass configurations (1-2 or 1-4) incorporate co-current and crossflow segments that require LMTD correction factors (F-Factor < 1.0). Tube pitch layouts (triangular vs square) govern heat transfer rates, shellside pressure drops, and mechanical cleaning access.
Frequently asked questions
How are tube-side and shell-side fluid paths allocated in thermal design?
Allocating fluid routing between tube and shell side follows core thermal-mechanical engineering criteria: First, high-pressure fluids are routed through the tube side, since small-diameter tubes handle extreme pressures efficiently, allowing substantial shell wall thickness reductions and major cost savings. Second, fouling, scaling, or dirty slurries go tube side, where straight tube channels facilitate hydro-blasting and mechanical brushing. Third, corrosive fluids belong in the tubes, restricting noble alloys (titanium, duplex steel) to tubes and channel bonnets while retaining carbon steel shells. Fourth, viscous, low-flow, or clean streams run on the shell side, where segmental baffles generate turbulence and boost convection.
What is the physical meaning of F-Factor and why must it never drop below 0.75?
Pure countercurrent flow produces the highest thermal driving force (F = 1.0). In practice, structural constraints favor 1-2 multi-pass units. Because tube fluid flows counter-current on one pass and co-current on the return pass, effective temperature difference drops below pure counterflow, requiring a geometric correction factor F (F ≤ 1.0). F quantifies heat transfer effectiveness: when F < 0.80 (and especially below 0.75), severe temperature cross occurs inside the exchanger, degrading performance and forcing massive surface area overexpansion. In such cases, designers must transition to two shells in series (TEMA F two-pass shell) to restore thermal temperature driving margins.
What are the trade-offs between 30° triangular pitch and 90° square pitch tube layouts?
Triangular pitch (30° or 60°) offers superior compactness and heat transfer coefficients. It packs roughly 15% more surface area into the same shell diameter compared to square pitch, and staggered tubes generate intense turbulence and higher convective U-values. However, curved cleaning lanes prevent mechanical lancing or scraping of external tube walls, restricting its use to clean, non-fouling shell fluids. Square pitch (90° inline) creates unobstructed continuous straight physical lanes between tube rows, enabling mechanical hydro-cleaning and chemical scraping, making it the preferred choice for heavy oils, sludges, and severe shellside fouling duties.
How does tube-side velocity affect exchanger operations, and what are the hazards of extremes?
Tube velocity is typically held within 1.0 to 2.5 m/s (1.2 to 1.8 m/s standard for water). Sub-optimal velocity (<0.8 m/s) drops Reynolds numbers toward the laminar regime, forming thick thermal boundary layers that collapse convective heat transfer coefficients while encouraging silt deposition and rapid scale fouling. Conversely, excessive velocity (>2.5 to 3.0 m/s) escalates pumping power exponentially with V² and, more dangerously, induces severe tube-inlet erosion-corrosion. It can also trigger vortex shedding resonance and fluid-elastic instability, vibrating tubes until they fatigue and shear against baffle hole edges, causing catastrophic leaks.