1热杀菌工艺设计(中英文).ppt

* * * * * * * * * * * * * Heat Penetration Thermocouple Placement: Thermocouple installed in a can. To data acquisition Slowest heating Spot 热穿透 传递加热时电偶的位置: 容器的几何中心(GC). 传递 Heat Penetration Position of thermocouple for Conduction Heating: Container geometric center (GC). Conduction 热穿透 对流加热时电偶的位置: 容器底部上方1英寸 对流 Heat Penetration Position of thermocouple for Convection Heating: About one inch above the bottom (1” AB) of the container. Convection 热穿透 传递加热与对流加热的标准曲线 (300 x 407 can): 15 30 45 300 200 100 0 Time (min) Temperature (oF) 对流 传递 Heat Penetration Standard Plot of Conduction and Convection Heating (300 x 407 can): 15 30 45 300 200 100 0 Time (min) Temperature (oF) Convection Conduction 热过程计算 计算方法 一般方法 Plot F/t vs. t, or lethality per unit time vs. time F/t = 10[(121-T)/Z] Calculate area under curve = Lethality F0 (minutes) Thermal Process Calculation Calculation methods General Method Plot F/t vs. t, or lethality per unit time vs. time F/t = 10[(121-T)/Z] Calculate area under curve = Lethality F0 (minutes) 热过程计算 计算方法 Ball 公式法 热致死力的作用 加热曲线的斜率 加热结束后终产品温度与介质温度的差异 更灵活 – 参考热渗透数据可以: 改变初始温度 改变杀菌锅温度 改变致死力 计算新的加工过程 Thermal Process Calculation Calculation methods Ball Formula Method Lethality of heating is a function of the slope of heating curve difference between final product temperature and heating medium temperature at end of heating More flexible – with heat penetration data can: Change IT (initial temperature) Change retort temperature Change lethality And calculate a new process 热过程计算 计算方法 每一种方法都需要大量的时间去了解 电脑软件可用于计算加工过程 每种方法都需要修正 由热力杀菌权威指导热加工过程的计算 Thermal Process Calculation Calculation methods Each method requires a significant amount of time to learn Computer programs are available to calculate processes with either method Modifications to the methods are also available Thermal process calculations should be made or direc