How to choose the right freeze dryer?

How to choose the right freeze dryer?
How to choose the right freeze dryer, today Songyuan Huaxing's small series will be sorted out, choose the freeze dryer, first from the freeze-drying area, cold trap temperature, cooling rate, ultimate vacuum, vacuum time and lamellar temperature Considering the uniformity and flatness, let's take a look at it one by one:
1, freeze-dried area
The number in the lyophilizer model represents the lyophilization area of ​​the lyophilizer of this model. For example, the lyophilization area of ​​the lyophilizer is 0.18 m2. The user should calculate the lyophilizer to be used according to his own needs. For example, for each batch of products that require lyophilization of 1.8 kg (liter) of liquid, and load the material with a material tray, each loaded with 10 mm thick, the load area of ​​the lyophilized layer can be calculated:
A (area, m2) = V (volume, m3) / H (height, m) = 0.0018 m3 / 0.01 m = 0.18 m2
A lyophilizer with a laminar load area of ​​0.18 m2 is required.
2, cold trap temperature
The cold trap is a device for capturing moisture in the freeze-drying process. Theoretically, the lower the temperature of the cold trap, the stronger the water trapping ability of the cold trap, but the lower the temperature of the cold trap, the higher the cooling requirement, the higher the machine cost and the running cost. The cold trap temperature of the experimental series  freeze dryer mainly has several grades of -50 °C, -60 °C, -80 °C. Freeze-drying at -50 °C is suitable for some products that are easy to freeze-dry. The freeze-drying machine with a cold trap temperature of -60 °C is suitable for lyophilization of most products, and the freeze-drying temperature is -80 °C. Suitable for lyophilization of some special products. The effect of cold trap temperature on water-trapping capacity shows that the temperature of the cold trap drops from -35 °C to -55 °C, and the water-trapping capacity is obviously improved. The cold trap temperature is lower than -55 °C, and the water trap capacity of the cold trap is not significantly improved. Therefore, in the absence of special needs, the choice of cold trap temperature -60 ° C is the ideal choice. The cold trap temperature of  freeze dryer in Shanghai Zhixin freeze dryer is ≤-50°C, and the cold trap temperature of  series and  series freeze dryer is ≤-60°C,-80 °C. And the mixed refrigerant refrigeration technology, in the case of the same refrigeration unit, the refrigeration temperature is low, the refrigeration capacity is large, the work stability is high, and the failure rate is low. The Shanghai Zhixin freeze dryer has a  freeze dryer with a cold trap temperature ≤ -50 °C, which is suitable for lyophilization of some freeze-dried products. The  freeze dryer has a cold trap temperature of ≤ -80 ° C and is especially suitable for lyophilization of pharmaceuticals and special products.
3, cooling rate
The cooling rate reflects the cooling capacity of the refrigeration system. Under no-load conditions, the temperature of the cold trap should reach the minimum temperature specified in the index within one hour. For example, a lyophilizer with a cold trap temperature ≤ -60 ° C, the machine starts from the time of opening the refrigeration, and the temperature of the cold trap reaches -60 ° C should be no more than 1 hour.
4, the ultimate vacuum
The ultimate vacuum reflects the leakage of the freeze dryer and the pumping efficiency of the vacuum pump. The degree of vacuum of the freeze-drying box, the past view that the higher the degree of vacuum, the better, the current view that the degree of vacuum should be within a reasonable range. The degree of vacuum is too high, which is not conducive to heat transfer, but the drying speed is reduced, but the vacuum limit of the freeze-drying box should be less than 15Pa.
5, vacuum time
The emptying speed of the freeze-drying box should be pumped from atmospheric pressure to 15Pa within half an hour.
6, the layer temperature uniformity and flatness:
The uniformity and flatness of the lamellar temperature have a great influence on the uniformity of product quality. The better the temperature uniformity and the flatness, the better the uniformity of the quality of the freeze-dried product. The lyophilizer shelf temperature control has a heater type and an intermediate fluid type, and the freeze-drying machine shelf with the intermediate fluid control plate layer has uniform temperature uniformity and flatness, and the lyophilizer layer is a hollow sandwich structure, the slab layer The cooling and heating are achieved by circulating the intermediate fluid in the fluid channel inside the ply, so the ply temperature is uniform. The freeze dryer in the beijing songyuan freeze dryer uses the technology of the intermediate fluid in the shelf. The shelf temperature control of the bell-type lyophilizer is basically a heater, and the temperature uniformity of the layer is slightly poor. However, in general, the temperature difference of the lyophilizer for medical use should be controlled at ±1.5 °C, the temperature difference within the plate is ±1 °C, and the food freeze dryer can be appropriately relaxed.