English EN
中国 CN
French FR
German DE
Portuguese PT
Spanish ES
Russian RU
Japanese JA
Korean KO
Arabic AR
Italian IT
Hindi HI
Short answer: Most plate heat exchangers use a herringbone/chevron embossing on each plate. The chevron angle (β) is the rib inclination relative to the main flow. Higher β generally creates more turbulence (higher heat-transfer coefficient) but also higher pressure drop; lower β relaxes pressure drop but delivers less turbulence. Designers often combine “H” (high-theta) and “L” (low-theta) plates to meet both the temperature approach and the allowable ΔP.
What “Chevron Corrugation” Means
Chevron corrugation is the V-shaped (herringbone) rib pattern pressed into each stainless plate. When adjacent plates are stacked with opposing patterns, the channels force the fluid into a disturbed, swirling path. This geometry increases surface renewal, raises the convective heat-transfer coefficient, and helps avoid stagnant zones within the channel.
The pattern also strengthens the plate mechanically. Distributed contact points formed by the corrugation support differential pressure while keeping the metal thickness low and the exchanger compact.
What the “Chevron Angle (β)” Is
The chevron angle (β) is the angle of the herringbone ribs relative to the mean flow direction. Industry literature and OEM catalogues commonly group plates into:
Low-theta (L) plates: smaller β; hydraulically “more open,” typically lower pressure drop and lower heat transfer.
High-theta (H) plates: larger β; induces more turbulence; typically higher heat transfer with higher pressure drop.
Some series also reference mixed or “M” channels. Naming varies by manufacturer; always check the actual β values and channel definitions in the relevant plate catalogue.
How β Influences Performance
Increasing β generally increases turbulence intensity in the channel. The upside is a higher overall heat-transfer coefficient; the downside is a higher friction factor and thus greater pumping power. Conversely, reducing β lowers resistance to flow but also reduces turbulence and the heat-transfer coefficient.
In practice, designers choose the plate/channel combination that satisfies two constraints at once:
Thermal: required heat duty and target approach temperature.
Hydraulic: maximum allowable pressure drop on each side (and available pump head).
Because the two constraints often pull in opposite directions, plate packs are frequently built from a mix of H and L plates (or a defined “channel type”) rather than one β across the entire exchanger.
Why Chevron Corrugation Helps with Fouling
The chevron pattern promotes turbulence and surface shear, which reduces the tendency for dead zones where deposits accumulate. This is why herringbone plates are preferred for compact exchangers designed for close temperature approaches. Note that this does not eliminate the need for proper filtration and CIP; it simply makes the channels less prone to localized stagnation.
Notes You Will See on Datasheets
Common terms include H-plate / high-theta, L-plate / low-theta, and mixed (M) channels. You may also see references to the distribution area at the plate inlet, which is embossed to spread flow evenly across the plate; good distribution is essential for any β to achieve its expected performance.
Selection Guidance (Non-proprietary)
Start from the duty, inlet/outlet temperatures, fluids, and the allowable pressure drop. If approach is tight and ΔP is generous, lean toward channels with higher turbulence (often H or mixed). If ΔP is limited, use lower-theta channels on the constrained side, then compensate with area or passes as needed. Always validate the choice with the OEM’s selection software and curve data for the specific plate geometry.
Caveats
β is vendor-specific. Exact angles, rib geometry, contact point density, and even the L/H naming vary by model series. Do not infer performance across brands solely from the L/H label. Confirm with the manufacturer’s data for the exact plate code and channel definition.
Simple Figure
Plate A (chevrons \ / \ / ) Plate B (chevrons / \ / \ ) Flow → forced into swirling paths between opposing ribs β (beta) = inclination of the ribs vs. main flow Smaller β → less rib obliquity → lower ΔP, lower turbulence (L-plate) Larger β → more obliquity → higher ΔP, higher turbulence (H-plate)
