Heat transfer plate plate pack and plate heat exchanger

A plate pack comprising a plurality of heat transfer plates (1) which each comprise an inlet portion (A), an outlet portion (B) and a heat transfer portion (C) which is located between the inlet portion (A) and the outlet portion (B) and which presents a number of ridges (210) and troughs (220) pressed into the plate and extending between a geometric top plane (P2) and a geometric bottom plane (P3) of the plate (1), said planes being essentially parallel to the geometric central plane (P1) of the plate (1), a fluid being intended to flow in a number of the flow areas (110e) that are formed by the interspaces between the heat transfer plates (1) constituting the plate pack along a main flow direction (F) which extends between the inlet portion (A) and the outlet portion (B), characterised in

• that the heat transfer portion (C) has a plurality of juxtaposed rows (200) of said ridges (210) and troughs (220), said rows (200) extending in the main flow direction (F),
• that the rows (200) of ridges (210) and troughs (220) are separated from each other in a transverse direction (G), which is essentially perpendicular to the main flow direction (F) and extends along the central plane (P1) of the plate (1), by essentially plane channel portions (240) of the heat transfer portion (C), which extend essentially parallel to the central plane (P1) of the plate,
• that each row (200) presents alternating elongated ridges (210) and elongated troughs (220) which extend in said main flow direction (F),
• that the ridges (210) of two juxtaposed heat transfer plates (1) bear against each other,
• that the transition between each ridge (210) and an adjacent trough (220) in the same row (200) is formed by a continuous, essentially straight transition portion (230) of the plate (1), which is inclined relative to said central plane (P1) of the plate (1) and of which a first part forms an end wall of said ridge (210) and a second part forms an end wall of the adjacent trough (220),
• that a main part of the fluid stream flows in the main flow direction (F) in main flow channels which extend along the main flow direction (F) and which are formed by the essentially plane channel portions (240) of two juxtaposed heat transfer plates (1), and
• that a small part of the fluid stream flows in the transverse direction (G) in the portions where the troughs (220) of two juxtaposed heat transfer plates (1) form open transverse connections between the main flow channels.