A method and apparatus suitable for the new vacuum spray dried to be powdered by drying a liquid material containing a substance susceptible to thermal denaturation as a pharmaceutical ingredients or food ingredients. An apparatus body having a spray nozzle with maintained under reduced pressure, and supplying superheated steam supply means for supplying liquid raw material supply means to the spray nozzle the liquid material, the method etc, the spray nozzle apparatus superheated steam a cooling means for recovering the condensed water is cooled and the volatile vapor from the liquid material and the superheated steam is discharged from the body, a pressure reducing means for maintaining under vacuum apparatus main body through the cooling means, produced in the apparatus main body and a product collecting means for collecting the powder product to have an apparatus and simultaneously sprayed in the apparatus main body from the spray nozzle and the liquid material supplied from the liquid material supply means and the superheated steam supplied from the superheated steam supply means by heat exchange with superheated steam atomized raw materials with atomizing the liquid material within the body, to produce liquid material is atomized, and pulverized by drying the liquid material.食品原料や医薬品原料等のように熱変性し易い物質を含む液体原料を乾燥させて粉末化させるのに好適な新しい減圧噴霧乾燥の方法及び装置を提供する。上記方法等は、減圧下に維持されると共に噴霧ノズルを備えた装置本体と、過熱水蒸気を噴霧ノズルに供給する過熱水蒸気供給手段と、液体原料を噴霧ノズルに供給する液体原料供給手段と、装置本体から排気される過熱水蒸気と液体原料からの揮発蒸気とを冷却し凝縮水として回収する冷却手段と、冷却手段を介して装置本体内を減圧下に維持する減圧手段と、装置本体内で生成した粉末製品を捕集する製品捕集手段とを備え、過熱水蒸気供給手段から供給される過熱水蒸気と液体原料供給手段から供給される液体原料とを噴霧ノズルから装置本体内に同時に噴霧して装置本体内で液体原料を霧化させると共に、液体原料が霧化して生成した霧状原料を過熱水蒸気と熱交換させ、液体原料を乾燥させて粉末化する。
