My work: A common day in laboratory of development and research

Hello Again.

One of part of my work is the research and development process for a new products, for example, the freeze drying, also known as lyophilisation, is a low temperature dehydration process which involves freezing the product, lowering pressure, then removing the ice by sublimation. 

FREEZE DRYING PROCESS 

At  9:00 am turn on the freeze dryer machine, from 9:00 am to 13:00 pm the chamber low the temperature until to desired -30°C. 24 hours before  I prepared the fruits or vegetables than I'm going to freeze. The product freeze at -50°C in Ultrafreezer machine. 

How do we achieve low pressures?  With the vacuum pump connected to chamber

What is the minimum pressure for freeze drying process? 300 mmTorr  equal to 40 pascales

So, open the chamber and put the fruits on trays and  turn on the vacuum pump. when the pressure is 300 begin the process. The proccess has two steps:

First drying. On this step the temperature is between -20 °C to 40°C

Final drying. On this step the temperature is constant to 45° or 50 °C (depending the product)

 24 hours aprox. end the process and check our products. The moisture is 1.5 to 5 %RH.