Procedure for forming cocks closable by freezing, belonging to a liquid batch handling unit, and handling unit set up according to the procedure

Procedure for providng valves for a liquid batch handling unit with the use of two blocks having surfaces which define the valves at predetermined valve areas as the surfaces are brought against each other, the procedure comprising the steps of

• providing two blocks having valve areas at their surfaces, a first block and a second block, said first block with flow passages leading to valve areas at the surface of said first block;
• connecting the second block to a permanently operable refrigerator and providing electric heating elements to register with valve areas of its surface;
• providing cavities in at least one of said two blocks in the vicinity of the valve areas of its surface and filling the cavities as formed with thermal lagging material;
• providing depressions to the surface of at least one of said two blocks at its valve areas;
• providing the surfaces of the two blocks which define the valves with a layer of a chemically inert material so that the electric heating elements and the thermal lagging material are covered by said inert material, at least the block which is connected to the refrigerator and is provided with the heating elements having the inert material layer at its valve areas so thin as to have a thermal conductivity in the range of 0.2-100 mV/.degree.C. mm.sup.2 ;
• placing the block surfaces against each other so that the respective valve areas at the opposite surfaces will mate with each other;
• and
• conducting a liquid between the surfaces;
• so that any gaps between the different valves as providing are filled with said liquid and closed permanently by freezing the liquid by means of the refrigerator, the valves being then constituted by said depressions providing valve chambers between the opposite surfaces, the valves being connected to said flow passages and defined by the inert material layers covering said surfaces and the permanently frozen liquid as present between said surfaces, and the valves being controllable by means of the electric heating elements which, when in operation, keep the respective valves open for a flow conducted through said flow passages and, when out of operation, let the refrigerator close the valves by freezing the liquid as conducted to or present in the valve chamber.