Dear Vahab,

Plant tissue that is freeze dried in a 1L freeze dry

system using a 120 ml flask can take less than 24 hours to finish the

lyophilization process. However, another user that is lyophilizing plant samples in

900 ml flasks on a 6L freeze dry system may need to wait over 48 hours until the

freeze dry process is complete. Similarly, freeze drying solvents can take less than

24 hours while using a 40 ml on a 2.5L freeze dry system, but over 24 hours when

using a 120 ml flask on a 12L Cascade freeze dry system.

please refer this article

https://www.laboratory-equipment.com/file_library/freezedryarticle_102312120844.pdf

Thank you very much for very nice response