COOLING OF CONCRETE WHILE KNEADED WITH CONCRETE MIXER

PURPOSE:To enable the title method to prevent scattering of liquefied gas or gasification of the same before it is brought into contact with concrete, by a method wherein simultaneously with performance of separation of a two-phase flow to be supplied through a conduit pipe from a liquefied gas storage tank into gas and a liquid by making use of a filter of a porous substance or a cyclone the liquefied gas is supplied within a concrete mixer under a state close to gravity-drop. CONSTITUTION:An opening part 4 is provided on an upper lid 2 of a concrete mixer 1, into which a filter 5 of a porous substance or a cyclone 6 is inserted and low-temperature liquefied gas is supplied within the concrete mixer under a state close to gravity-drop. Although the liquefied gas is gasified partly, in case of the filter 5, the same is discharged upward of the upper lid 2, kinetic energy possessed by the liquid is decreased while passing through the porous substance, in the liquid and supplied downward under a state of the gravity-drop. In case of the cyclone 6, the same is discharged outside through an exhaust duct 10. Then the liquid is supplied into the concrete mixer 1 through a lower liquid taking-out port 6c.