Small Liquefier Research Articles

Development and performance test of a small trailer-mounted moveable natural gas liquefier

A portable small liquefier for natural gas or coal-bed methane liquefaction has been designed and tested. The liquefier is very compact, and the compressor is directly mounted on a trailer. The liquefier is based on a mixed-refrigerant liquefaction cycle with R22 precooling. Most of the components in the liquefier are easily available off-the-shelf refrigeration products. An oil-lubricated single-stage R22 screw compressor is used for the mixed-refrigerant compression. An aluminum plate-fin heat exchanger with four flow passages was designed as the core of the cold box. The liquefier was tested for about 4months by circulating pure methane as the natural gas resource. A maximum liquefaction capacity of 15,000Nm3 was achieved with a minimum specific power consumption of about 0.54kWh/Nm3. This liquefier can be used in various applications such as small natural gas or coalbed methane exploitations, distributed peak-shaving, and boil-off gas reliquefaction. These can also be used as a flexible distributed liquefaction center with a set of small liquefiers.

High power industrial gas bearing cryogenic expansion turbines

Helium liquefaction with cryogenic turbo expanders has been achieved since the sixties. Oil bearing turbines were used in large plants, although gas bearing turbines were used in small liquefiers. Since the beginning of their use, gas bearing turbines have been improved in many ways such as higher efficiency, higher power, industrial operation. The authors show, according to references, that gas bearing turbines are, nowadays, powerful and industrial pieces of equipment which can be used for liquefaction of helium or any other gas as air or hydrogen up to 6000 1/h.

The design and construction of simple linde hydrogen and helium liquefiers

High Vacuum and low temperature techniques are closely related but the latter are not widely used. In particular the general methods for calculating the efficiencies of heat exchangers used with small liquefiers seem to be the usual stumbling block. These have been summarised. The advantages of a low resistance path for the gas are discussed and the construction of a simple variation of the Hampson exchanger is given. By using small Linde hydrogen and helium liquefiers experiments in the corresponding temperature ranges can be carried out on a limited scale without great expense or highly skilled workshop effort. Les Techniques du vide élevé et des basses températures sont étroitement associées, mais ces dernières ne sont pas très courantes. En particulier, les méthodes générales de calcul de l'éfficacité des échangeurs de chaleur, employés dans les petits appareils à liquéfier, semblent êtere l'habituel obstacle. Celles-ci ont été résumées. Les avantages d'un passage à faible impédance pour le gaz sont discutés et la construction d'un simple appareil peu différent de l'échangeur d'Hampson est donnée. En employant les petits appareils de Linde à liquéfier d'hydrogène et l'helium, des expériences dans le domaine de température correspondante peuvent être faites sur un échelle limitée, sans grandes dépenses ou le besion de personnel qualifié.

A Small Helium Liquefier and Portable Cryostat

A small helium liquefier and portable cryostat are described. This apparatus enables a laboratory producing liquid helium in amounts of the order of 50 c.c. or less to transport the liquid to any place where it may be required. Hitherto small liquefiers have had cryostats inseparable from the main liquefying systems. An account is given of the use of a portable cryostat for the demonstration of low-temperature and liquid-helium phenomena to a large audience.

A simple type of helium cryostat

Two simple cryostats for the temperature region of liquid helium are described; they have been found to facilitate experiments in that region greatly. The apparatus were constructed with the aim of combining the advantages of a small liquefier with those of an ordinary helium cryostat.