Device for hot isostatic pressing

A device for hot isostatic pressing comprising:

• a pressure vessel having a wall;
• a heat-insulating mantle surrounding a furnace chamber and arranged internally of the wall with a first gap between the heat-insulating mantle and the wall, the heating insulating mantle being closed with a top member and provided with a lower opening and an upper opening to the first gap so as to allow pressure medium to enter a cooling loop in the first gap through the upper opening and emerge from the cooling loop through the lower opening into a first space located below the furnace chamber;
• a first guiding means adapted to guide the pressure medium and which surrounds a load space in the furnace chamber adapted to receive loads to be pressed, the first guiding means having an upper discharge opening and, a lower entry opening being arranged to define a second gap, between the first guiding means and the heat-insulating mantle such that the pressure medium flows upwardly within the load space to an upper region of the heat-insulating mantle and the pressure medium then moves downward through the second gap to a second space located below the load space and above the first space;
• a first and a second pump means, the first pump means being adapted to pump a cooled pressure medium emanating from the cooling loop upwardly from the first space to the second pump means, which is arranged in the second space to pump a mixture of the cooled pressure medium from the first pump means and a warm pressure medium emanating from the second gap upwardly through the load space;
• a third pump means arranged in the second space to pump the warm pressure medium emanating from the second gap to the second pump means;
• and
• a control unit adapted to optionally switch the first and third pump means on and off.