condensated distillate in the arrangement in accordance with this embodiment the distillate vapor is condensated by contact with the porous separating wall 2 and after this it is diffused through the pores of the porous separating wall 12 in other aspects the action of the fluid in the chamber 4 is the same as for the chamber 4 in the arrangement shown in fig1 in dependence upon the running mode the gas supply to the chamber 13 can be allowed to pass only through the pores of the porous separating wall 2 or its part can also pass through the pores of the porous separating wall 12 the arrangement in accordance with the abovedescribed embodiments are suitable particularly for liquid mixture or solutions wetting the porous separating wall 2 with which also the condensated distillate wets the porous separating wall 2 the arrangement for separating a liquid mixture or a solution in accordance with the embodiments shown in fig3 corresponds in principle to the embodiment of fig2 here the porous separating wall 2 and the porous separating wall 12 are formed by pipes the pipes which form both porous separating walls 2 and 12 are arranged concentrically relative to one another all other parts of this arrangement correspond to the respective parts of the arrangement of fig1 and 2 moreover the arrangement shown in fig3 has a double jacket 14 which is used for heating or cooling of the chamber 13 the chamber 13 can be.