A distillation column is constituted by a cylindrical shell which contains mass and heat transfer elements and which is closed at one end by a cap and at the other end by a domed bottom and a cylindrical skirt that has the same diameter as the cylindrical shell, is aligned coaxially with the cylindrical shell and is fixed to one end of the cylindrical shell so as to surround the domed bottom, forming a space between the bottom, the walls of the skirt and a base, the skirt comprising at least one opening to allow the passage of a flushing gas.

A stackable modular element comprises a parallelepipedal caisson, the caisson comprising at least one layer of thermal insulation of thickness less than one-third of the width of the caisson, the layer of insulation covering at least the lateral and frontal faces of the caisson and surrounding at least one chamber having a parallelepipedal volume within the caisson, the chamber containing at least one body of material that permits the exchange of mass and/or of heat, the body being parallelepipedal in shape and filling at least part of the chamber, the chamber having an opening on the upper face and/or an opening on the lower face to allow fluid to be transferred to the body from outside the element and/or from the body to outside the element.

Disclosed are a helium gas liquefier and a method for liquefying a helium gas. The disclosed helium gas liquefier includes: a first cooling part including a first cooling column; a first cold head installed on the first cooling column, and a first cylinder in which the first cooling column and the first cold head are built; a second cooling part including a second cooling column, a second cold head installed on the second cooling column, and a second cylinder in which the second cooling column and the second cold head are built; and a liquid helium storage disposed under the second cooling part.

Insulated enclosure having at least one surface that is planar, containing at least one piece of equipment intended to operate at a temperature below 0 C., the interior space of the enclosure being intended to be at a pressure below atmospheric pressure and being filled with thermal insulation, and the thermal insulation being made up of a multitude of spherical beads made of thermally insulating material.

A process for establishing vacuum insulation under cryogenic condition and an apparatus compatible with such process are described. When an insulation enclosure filled with high purity CO.sub.2 is evacuated to around 100 absolute Pa at ambient temperature, hard vacuum of below 1 absolute Pa may be automatically obtained within the insulation enclosure when temperature drops to around or below 170 C. This process can be employed to provide vacuum insulation for cold box housing air separation units operated under cryogenic condition.

A cryogenic technology for the cost-efficient capture of each known component of emissions, such as carbon dioxide, sulfur oxides, nitrogen oxides, carbon monoxide, any other acid vapor, mercury, steam, in a liquefied or frozen/solidified form, and unreacted nitrogen (gas) from industrial plants, such that each of the components is captured separately with minimum use of energy and is industrially useful.

A conduit seal assembly includes an outer conduit having a first end with a first opening and a second end, opposite the first end, with a second opening. A first seal is positioned in the first opening for resisting a first temperature, and a second seal is positioned in the second opening for resisting a second temperature less than the first temperature. The first and second seals define a cavity and provide an air-tight seal of the cavity, and the assembly includes a monitoring assembly configured to sense a characteristic in the cavity.

A conduit seal assembly includes an outer conduit having a first end with a first opening and a second end, opposite the first end, with a second opening. A first seal is positioned in the first opening for resisting a first temperature, and a second seal is positioned in the second opening for resisting a second temperature less than the first temperature. The first and second seals define a cavity and provide an air-tight seal of the cavity, and the assembly includes a monitoring assembly configured to sense a characteristic in the cavity.

An enclosure for a column for low-temperature distillation comprises a distillation column, which has a circular cross section and is to be thermally insulated, the column containing liquid during use, at least one pipe attached to the column for transporting a liquid, a parallelepipedal casing enclosing the column in a sealed manner, pulverulent thermal insulation filling the space between the column or columns and the casing, a liquid-retaining tank, which has a flat bottom and four side walls, defining a liquid-retaining space, the tank being arranged inside the casing below the column in order to collect liquid that has leaked from the column, the tank being made from stainless steel or from aluminium and the casing being made from carbon steel, the column resting on the bottom of the tank through a skirt, the skirt being a cylinder made from stainless steel and having the same diameter as the column, the liquid-retaining space containing pulverulent thermal insulation.

Disclosed are a helium gas liquefier and a method for liquefying a helium gas. The disclosed helium gas liquefier includes: a first cooling part including a first cooling column; a first cold head installed on the first cooling column, and a first cylinder in which the first cooling column and the first cold head are built; a second cooling part including a second cooling column, a second cold head installed on the second cooling column, and a second cylinder in which the second cooling column and the second cold head are built; and a liquid helium storage disposed under the second cooling part.