Abstract: Improvements in textile material dyeing apparatuses in which the liquid used for dyeing the material is circulated or contained in a vessel, and the material is penetrated by the liquid. It is necessary to heat or cool the liquid and the heating or the cooling is effected indirectly by a heating or cooling medium which is fed into a chamber in heat exchanging contact with the liquid in the vessel. The chamber is open at the top end thereof and communicates at said end with the vessel. Thus, the pressure between the chamber and the vessel will be equalized and there is no need to use expander or similar means between the chamber and the vessel. The problem pertaining to stresses in mechanical connection will be reduced greatly and the construction of the apparatus simplified. By forming the chamber as disclosed in the drawings in which several embodiments have been shown, the effective heat exchange area between the chamber and the vessel will be large for giving a maximum of efficiency.