Comparison of ultra-low temperature electromechanical and liquid nitrogen cooling

Update:26 Jan 2019
Summary:

The use of the cascaded ultra-low temperature unit in t […]

The use of the cascaded ultra-low temperature unit in the semi-synthetic production process is mainly to reduce and control the temperature of the material system, to ensure that the temperature of the whole system is effectively maintained within the required range in different reaction stages, so that the drug synthesis process satisfies the process reaction temperature requirement. During operation, the low-temperature refrigerant is prepared by the cascade refrigeration unit, and the refrigerant does not directly contact the reaction solution, and the reaction process is affected by indirect heat exchange, so that the refrigerant can be prevented from polluting the material. In a practical production process, the high and low temperature stages of the unit are screw type compressors with R22 and R23 as refrigerants. The evaporating temperature of the unit can reach below -80 °C, and the output is -70% to -75 °C. Up to 40,000 kcal / hour.
Through the statistical analysis of the actual production process with a scale of semi-synthetic production of 1200 tons/year, the ultra-low temperature unit is compared with liquid nitrogen cooling:
2.1 In terms of product yield and consumption, the yield is increased by 1.88%, and the production solvent consumption is reduced by 36.1%:
2.2 In terms of quality, the product content is increased by 0.43%, which is better than liquid nitrogen cooling in terms of product stability and other impurities:
2.3 In terms of investment and power running costs, although the one-time investment in ultra-low temperature units and supporting cooling water devices is relatively large. Depreciation is also a factor that cannot be ignored, but the cost of purchasing liquid nitrogen is several times that of ultra-low temperature units. Compared with the two, the cost of liquid nitrogen cooling is 5.13 times that of the ultra-low temperature machine.
Through the above comparative analysis shows. In the actual production process, the ultra-low temperature unit is compared with the traditional liquid nitrogen cooling. From product yield, solvent consumption, process control and product quality, as well as investment and power costs, it has obvious advantages, which reduces product cost and improves market competitiveness. Ultra-low temperature unit refrigeration is the preferred method for building large-scale ultra-low temperature environments.
The application of ultra-low temperature units should also take into account other factors. For example, the refrigeration unit belongs to the rotating equipment, and its structure is relatively complicated. Therefore, the equipment operation and maintenance requirements are relatively high. In order to ensure the full advantage of the unit in production, the unit must be properly selected and scientifically maintained. In addition. The one-time investment in hardware such as equipment is correspondingly increased.

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