Freezing and cooling

In the fight against bacteria, one of the most effective weapons is chilling and freezing. Cryogenic freezing also maintains the natural quality of food. Freezing a product leads to the formation of ice crystals. The smaller and more evenly distributed these are, the better the quality and taste of the defrosted product. Quick-freezing at cryogenic temperatures is the only way to ensure that small crystals are created uniformly, both inside and outside the product’s cells. Cryogenic liquid gases also provide an effective, flexible and low-noise way of maintaining the precise temperature of chilled or frozen foodstuffs during transit.

Cryogenic condensation with liquid nitrogen (LIN) is a flexible, cost-effective process which can be used in a wide range of applications.

We are focused on the following features:
• Treatment of highly concentrated exhaust gas flows,
• Recovery of valuable components,
• Realization of low residual concentrations,
• Reuse of vaporized liquid nitrogen as inert gas for inerting and blanketing.
We offer a range of standardized products for you to choose from (CIRRUS M50, M150, M500). If the range of standard units do not fit your needs we can also provide customized units that are tailor made to your requirements, all of which we offer installation, start up and liquid nitrogen supply.

Once skimmed, thermiting of dross should be prevented as rapidly as possible to preserve its metallic aluminum content which can range from 18% to 80% but cooled safely without polluting the environment. The argon based dross cooling solution Inert Gas Dross Cooler (IGDC) from the STAS company is able to cool all types of dross at any temperature without the use of mechanical moving parts and cooling water, whilst simultaneously snuffing out the thermitting reaction and stopping the generation of fumes and dust.

Advantages:
• Completely safe, because no water is used in either the cooling of the dross or with the equipment.
• Environmentally sound, therefore no emission of dust or fume.
• Provides for easy working conditions, therefore is operator friendly.
• No moving parts, thus minimizing maintenance costs as well as emitting no noise.
• Retains as much of the aluminium alloy present in the dross immediately after skimming (can range from 18-80%) as possible.
• Treats all kinds of dross (black and white dross).
• Easy to operate, efficiency is independent of the filling level.

Under certain conditions, ground freezing with liquid nitrogen is the best solution compared to conventional soil treatment methods.
• The set-up of a LIN-freezing plant can be done quickly as large quantities of specialist hardware is available in stock.
• The investments for a LIN freezing plant is only a fraction of the amount to install a brine freezing unit.
• The temperature of the frozen soil is substantially lower compared to the use of a brine freezing plant, which increases stability.
• The low temperature of LIN (-196°C) allows freezing in about 4 to 7 days which is substantial faster than the brine freezing process which easily can take a month.
• Environmental friendly process, no hazardous substances, no vibrations and no ground water pollution or extraction.
• Automatically working process. Flexible in design of frozen soil. Combination of sealing and static support.
• High tolerance to soil humidity (5 – 100%). Frozen soil is 100% watertight, there is no leakage.
• The hardness of frozen soil is comparable to concrete.
• The solidification of the soil is only temporary.
• After shutting down the LIN-supply the frozen soil will melt in a few weeks.

Thermal spraying is the collective expression for several different spraying methods, one of which is flame spraying. When spraying equipment, the additive material, which can be in the form of powder, wire or sticks, is heated to smelting point or a practically smelted condition. The heated material is finely powdered and sprayed by means of a gas flow towards the surface of the piece (the substrate) where it fastens and stiffens. The surface cover can be used as is or worked to the correct dimensions.

Flame spraying with the correct additive material can improve the surface’s resistance to corrosion, wear and high temperatures. You can achieve surfaces with high or low friction or alter the surface’s conductivity. Damaged surfaces can be repaired and faulty parts can be corrected to the right dimensions.

Rapid cooling is sometimes required during industrial production processes. Liquid nitrogen (LIN) and carbon dioxide (CO2) are popular cooling agents due to the low boiling point of LIN (-196°C) and the low sublimation point of CO2 (-78,5°C). This enables large-scale heat transfer in a short time period.

Advantages of rapid cooling agents:
• Unlimited cooling capacity.
• Flexibility to reach temperatures as low as -196°C.
• Excellent peak-shaving qualities.

In the production of tires for passenger cars some finalizing work has to be done in order to make the tire perfect and attractive. This means rubber flashes need to be removed. Flashes can be found on the surface of a tire on the friction area as well as on the shoulders. Deflashing can be done easily by dipping a rotating tire into liquid nitrogen for cooling the flashes making them brittle enough for scrapers to wipe them off. We offer: Various types of cryogenic deflashing machines including shot blasters and tumblers for a wide range of moulded rubber parts.
Development of special devices based on your demands. Deflashing tests on your specific products and provide you with the most suitable machine with consideration paid to all economical and technical aspects. Support with equipment installation and assistance during start-up.

Shrink fitting is a method used in making mechanical joints when axles, bushings and similar are to be fitted inside a part with a hole. The hole is made slightly too small for fitting at even temperature, which means that the outer part needs to be heated or the inner part needs to be cooled. Heating the outer part may take a long time, and in some cases metallurgical reasons may prevent heating altogether. However, cooling the inner part will not affect the property of the metal, and can be achieved much faster.
When using liquid nitrogen as a coolant, a temperature difference of up to 200 °C can be achieved. In order to cool the inner part it should be kept in liquid nitrogen (temp. -196 °C), which will make it shrink enough to fit in. The joint becomes durable when the temperatures of the parts are even.

The solidification of concrete is an exothermic process. As large quantities of heat are released inside the concrete structure, it is important that temperature changes are monitored and influenced, in particular:

• In cases with high quality requirements for concrete such as bridges, tunnels and storage tanks.
• In cases requiring large volumes of concrete such as dams, large foundations.
• In hot climates.

Solution cooling with liquid nitrogen has proved to be an effective and cheap method. One particular advantage is that coolant costs are generated only if cooling is really needed. Nitrogen cooling can be applied to cool the aggregates, mixing water or mobile mixer. Using cryogenic cooling and freezing power to enhance safety, productivity and environmental performance across a wide range of applications.