The circuit comprises a series of cooling and heating exchangers in series through which a heat exchange medium is circulated by a pump. The components are interconnected by 304 stainless steel pipe work. The medium is circulated through the shelves to effect heat transfer to/from the product.
The heat exchange medium is a low viscosity 5cSt silicone oil ensuring optimum shelf temperature uniformity at the ultimate shelf temperature.
The cooling exchangers are a brazed stainless steel plate construction, which minimises the volume of heat transfer fluid and heat exchanger mass to maximise heat transfer efficiency, leakage risks are also minimised. Each one is cooled by direct expansion of refrigerant from a dedicated compressor. The cooling exchangers are insulated externally with a polymer foam.
电加热器由一个带有多根加热组件的圆柱形AISI304 不锈钢容器组成，加热组件是不锈钢管式加热器。提供2 个温度调节安全装置，以避免硅油过热。一个外附在加热器的外部和一个在加热器的内部。加热器采用聚合发泡材料保温。
The electrically heated heat exchanger comprises a cylindrical stainless steel vessel fitted with multiple heating elements with stainless steel external protection. Two thermostatic safety switches are provided to minimise the risk of over heating the silicone oil, one attached to the external surface of the heater and one embedded within the heater elements. The heat exchanger is insulated externally with a polymer material.
The silicone oil is circulated by means of a centrifugal pumping system. A single motor canned pump is used for the Lyomax 1, a twin impeller/motor pump is used for machines from Lyomax 3 to and a single impeller/motor pump for or larger. The pump body is externally insulated with a polymer foam. The pump provides a high rate of flow through the system to ensure a high degree of shelf temperature uniformity. A differential pressure switch provides feedback, to the PLC, that the pump is operating and is also electrically interlocked with the heater to prevent fluid over temperature. Dual pressure gauges are installed on the inlet and outlet of the pump to monitor the pump and system performance.
The heat exchange circuit is equipped with an expansion tank to accommodate volume changes between the various stages of the freeze drying process. The expansion tank is fitted with a silica gel moisture trap to prevent water being absorbed by the heat exchange medium. A fluid level indicator (sight glass) is provided.
加热和冷却系统可以将导热流体的温度控制在-55°C 到+80°C 之间。在稳定状态下，空载，板层温度在-40°C 到+40°C 之间时，板层温度均匀性为板层之间的温差为2°C；板层降温速率为从+20°C 到-40°C 在 60 分钟之内；加热速率为从-40°C 到20°C 在60 分钟之内。搁板Z低温度可达到-55°C。
The heating and cooling systems are automatically controlled to enable the heat exchange fluid to be controlled between -55°C and +80°C. Under steady state, unloaded, conditions the uniformity of temperature across and between shelves is 2°C within the shelf temperature range of -40°C to +40°C. Unloaded, the shelves may be cooled from +20°C to -40°C within 60 minutes for LYOMAX 40 equipped with 2 screw compressors. The ultimate minimum shelf temperature is -55°C
欣谕冻干机问卷调查1.冻干机将用于:产品的研究与开发冷冻干燥的放大试验液体物料冻干固体物料冻干2.如果需要散装冷冻干燥:物料数量:L Kg （冻干机理论装量10kg/㎡）产品厚度:10 mm15 mm20 mm托盘种类:不锈钢铝其他:3.所需求的冻干板层面… [了解更多]