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Importance Of Freeze - Drying Technology For Freeze Dryer
- Jul 03, 2017 -

The Freeze Dryer is composed of refrigeration system, vacuum system, heating system and electrical instrument control system. The main components for the oven, condenser, refrigeration unit, vacuum pump heating / cooling devices.

In a certain vacuum conditions under the ice crystal sublimation, products are completely frozen. So as to achieve the purpose of low temperature dehydration This process is known as freeze-drying.

Freeze the dryer and keep the volume of the original freeze, freeze-dried solid material due to the sublimation of tiny ice crystals and showing porous structure. After the addition of water easily dissolve and recovery, the product in the sublimation process to maintain the temperature in the lower temperature state (generally lower than -250C and therefore for those who are not heat-resistant substances such as enzymes, hormones, nucleic acids, blood and immune products such as drying Especially for the drying of the results can be discharged more than 95 to 99% of the water, is conducive to the temporary custody of the product drying process is carried out under vacuum conditions are not easy to oxidize the local biochemical drugs for the chemical, physical, biological instability And freeze-drying has been proved to be a very effective means.With the rapid development of biochemical drugs and biological agents, freeze-drying technology will increasingly show its importance and superiority.

Freeze dryer long-term work will bring parts and other wear and dust and other impurities affect the work, let's take a look at the Freeze Dryer for a long time do not clean the harm: freeze dryer indoor unit evaporator and outdoor unit condenser filled Dust, it will affect the cooling air and heat dissipation, resulting in Freeze Dryer cooling or heating effect is weakened, the cost of electricity; when the freeze dryer is turned on, Freeze Dryer bacteria will be directly blown to the indoor air In the human body caused direct damage. Many families in the past after the freeze dryer to stop using, will ignore the freeze dryer cleaning, so freeze dryer vacuum adsorption of a large number of dust, mites, pollen, lice and mold began to multiply. By the second year when the freeze dryer is used again, these bacteria, viruses, molds and dust are blown out by the freeze dryer, often causing large-scale respiratory infections and allergic dermatitis.

Cleaning method: Therefore, the freeze dryer is generally used before or during the summer after the use of a cleaning and maintenance. To completely kill the bacteria in the freeze dryer, it is best to ask the professional technicians to use a special cleaning solution for the freeze dryer.

The application procedure of the freeze dryer is mainly used for the corresponding calculation of the PID. It works under the action of the normally closed relay SM0.0 of the PLC. It includes setting the loop input and output options, setting the loop parameters, setting the cycle Alarm option, to specify the specified memory area, specify the initialization subroutine and interrupt procedures. From the above three characteristics of the analysis can be seen, on its regulation function, to equal percentage of the characteristics of the best, its regulation unchanged, good regulation. The parabolic characteristics and better than the linear characteristics of the regulation effect is good, depending on the application of the request is different, screw-type nitrogen machine to choose any one of the flow characteristics.

Freeze dryer pressure interrupt subroutine using PLC and inverter to change the motor power frequency, to adjust the air compressor speed to change the air compressor outlet pressure, than by regulating the valve to control the air compressor outlet pressure, the freeze dryer has reduced Pipeline resistance greatly reduces the effectiveness of cutoff losses. As the variable machine work in the frequency conversion conditions, in its outlet flow is less than the rated flow, the motor speed decreases, oxygen machine, reducing the bearing wear and heat, to extend the air compressor and motor mechanical life. Fluency Cv is one of the important parameters of the selection of nitrogen generator valve, nitrogen generator control valve is defined as the fluency: When the nitrogen generator valve is fully open, the valve at both ends of the pressure difference of 0.1MPa, fluid density 1g / cm3, the flow rate per hour of nitrogen flow control valve flow, called fluency, also known as flow coefficient, expressed in Cv, the unit is t / h, liquid Cv value according to the following formula. According to the size of fluency Cv value table, you can determine the nominal diameter of the nitrogen generator valve DN. The flow characteristics of the nitrogen generator control valve (nitrogen generator) are the relationship between the relative flow rate of the medium flowing through the nitrogen generator regulating valve and its opening condition under the condition that the pressure difference between the two ends of the valve is constant. Nitrogen flow control valve flow characteristics of linear characteristics, such as percentage characteristics and parabolic characteristics of three.