We are using standard equipment and systems while constructing cold storage for long term working ability. Cold Storage Air Cooling System is being selected on basis of the material has to be store in the cold room and the temperature range to be maintain inside. First take a site survey than on basis of outer temperature they decide the best cooling system according to material has to be store. We believe only in customer satisfaction and that’s why we always complete the whole project on computer with all details taken by customer and site survey before start the construction work.
We frequently use ammonia refrigeration systems for very large cooling applications, such as Industrial Refrigeration. Chillers using ammonia are becoming commonplace in green buildings and may be a viable option for District Cooling systems. As refrigerant legislation continues to get tighter, encouraging the use of alternative environmentally-friendly refrigerants, ammonia becomes a more attractive alternative. Ammonia’s global warming potential and ozone depletion potential are both zero.
Ammonia, a naturally-occurring gas composed of hydrogen and nitrogen, belongs to a class of refrigerants considered natural refrigerants; which also includes hydrocarbons, water, air, and carbon dioxide. As their name implies, these are naturally-occurring substances capable of refrigeration; they are all environmentally friendly with negligible global warming potential and ozone depletion potential, with ammonia being harmless for the environment. This is especially true when compared to the synthetic refrigerants that have been popular for the last century.
Freon is a man-made refrigerant that was developed as an alternative to both sulfur dioxide and ammonia. While Freon is less efficient than ammonia on a BTU per pound basis, Freon refrigerants are not nearly as inefficient as assumed. For example, consider a 200-ton freezer application at a -20°F (-29°C) suction temperature and a 95°F (35°C) condensing temperature with a two-stage intercooled system using open-drive screw compressors. The overall brake horsepower (BHP) per ton (a generally regarded level of a refrigeration system’s efficiency) on an ammonia system with these characteristics is approximately 1.86, while the equivalent R-22-based system has a BHP per ton of 1.96. At a -40°F (-40°C) suction, the two systems are virtually identical at 2.41 BHP per ton for the R-22 system and 2.44 BHP per ton for the ammonia system (figure 1). The anomaly exists because R-22 is still at a positive pressure at the lower temperatures, while the ammonia system is in a vacuum below -28°F (-33°C).
The main difference in the perception of Freon vs. ammonia systems has as much to do with the systems as the refrigerants themselves. Ammonia systems traditionally have been applied with open-drive compressors and evaporative condensers, which operate near the wet bulb temperature. Although some Freon systems use open-drive compressors and evaporative condensers, most Freon systems use hermetic or semihermetic compressors and air-cooled condensing. The open-drive system motor rejects the motor heat to the atmosphere, while the hermetic or semihermetic compressor rejects the majority of the motor heat to the refrigeration system. The evaporative condenser operating near the wet bulb will have a condensing pressure lower than an air-cooled unit that relies on the dry bulb temperature. When these inefficiencies are added to the system, the BHP per ton difference is much larger than just the difference in refrigerant properties.
Originally the blast chillers for trays, GN containers and trolley’s were created to meet the regulatory obligations imposed by french decrees on the 9 May 1995 and the 29 September 1997 for the commercial and social food services.
These regulations aim to control microbiological dangers during the cooling down food temperatures after cooking. Most of the pathogenic bacteria are killed at a temperature of + 63 ° C and they are blocked at a temperature lower than + 10 ° C. The critical range is between + 10 ° C and + 63 ° C when bacterial multiplication and environmental contamination, including from equipment and staff is present. Therefore it is important that this temperature range passes through quickly to minimize microbial growth.
In Today’s world, food preservation is more important than ever before, Historically there were many Methods of food preservation, like drying, smoking, pickling, salting etc.. These rather primitive methods are still widely used today, not only in backward societies, where no other means are available, but also in modern societies where they serve to supplement the more modern methods of food preservation like refrigeration.
In the Individual Quick Freezing (IQF) process, unlike other freezing processes, the products are frozen as individual pieces. This offers greater convenience to the consumers and hence adds more value to the product. The Individual Quick Freezers (IQF) process is far superior to the conventional processes.
In Quick freezing, small ice crystals forms within the product thus its own fresh quality is maintained even after extended shelf life. Most foods can be preserved for a long time if they are frozen quickly and kept at a low temperature until ready for use. Slow, natural freezing destroys food because the low temperatures draw all the water from the tiny cells of the food, affecting color and flavour.
Quick freezing method prevents breakage of the cell walls as the freezing process is so quick. Thus, in quick-frozen food most of the flavour, colour and firmness are retained.
Application of Individual Quick freezing (IQF):
- Fruit & vegetables processing
- Meat & fish Processing
- Ready to eat products
- Other Cooked Food items
Like all chiller systems, screw chillers are composed of an evaporator, expansion valve, refrigerant, internal piping and controls. Their compressors are the main point of difference for screw chillers, using two helical rotors that propel and compress the refrigerant gas. This type of chiller has nearly constant flow performance, and is powered by an electric motor, steam or gas turbines. Their capacity range is anywhere from 25 to 800 tons, and they are effective when used with liquid that has higher evaporating temperatures.
The screw, or helical compressor in screw chillers consists of two mating helical grooved rotors-the male lobes and the female gullies. They are housed in a stationary casing and move simultaneously. As they rotate, the refrigerant gas is compressed by direct volume reduction between the two rotors, and transformed into vapor
These compressors are equipped with a slide vane that adjusts the length of the compression path. The suction, compression and discharge all occur in one linear direction. An oil lubricant on the rotors acts additionally as a sealant. The motor cooling happens when refrigerant flows through holes in the screw, and the screw operates as a liquid separator. It is important for screw chillers to be appropriately sized.
When they are too big, they have long anti-recycle times and will shut down if there is no demand for cooling. This will also happen if the motors are running at high, unnecessary speeds or they are open drive. When configured properly, however, screw chillers can be reliable and efficient liquid chillers for a whole host of industrial and air conditioning applications.