Abstract: The frame staves (1, 1') of a heald frame have ribs (12, 13) on opposite sides of the stave extending toward the center of the frame. Movable holding elements (5, 26) on the staves include guide plates (6, 7) extending over the sides of the staves and having inbent edges (10, 11) that grip the ribs. The holding elements are drawn up against the staves by screw and spring arrangements.

Abstract: A heat exchange arrangement for use with chemically aggressive fluids has a source of direct current. Walls are provided which define a flow path for a fluid which is to undergo a temperature change, and at least a part of the walls is composed of a metallic material and connected to one of the terminals of the current source. The walls also form a chamber constituting a part of the flow path and having an opening which is closed by a cover. The cover is constituted as an electrode which is arranged in the flow path and is not in direct contact with the metallic part of the wall. This electrode is connected to the other terminal of the current source. The construction is effective for forming a protective coating on at least the metallic part of the wall when the current source is activated and fluid flows in the flow path. This protective coating prevents chemical attack of the metal by the fluid.