CONRAD® 冷冻干燥机

CONRAD® 冷冻干燥机专为大批量连续加工咖啡和茶、水果和蔬菜、肉类、海鲜和熟食等产品精心设计。CONRAD® 冷冻干燥机是大多数冻干速溶咖啡工厂的核心，这些工厂不仅以提供优质产品远近驰名，而且还以其稳健的运行闻名遐迩。

干燥工艺

CONRAD® 过程已全自动化，只需最少的工作人员即可实现连续操作。所有动作和过程参数都得到了精细的控制、监视和记录。

产品经过准备、冷冻并装载到 CONRAD® 托盘上以流经冷冻干燥机。所有的材料都经过称重以确保每个托盘上的体积正确，从而实现完美的冷冻干燥。托盘通过高效的气闸系统装载到干燥机中，到达 CONRAD® 腔室内的入口升降机。当升降机的产品托盘堆栈装满时，整个堆栈将被推入第一个干燥区。更多的堆栈将依次被推入干燥机的各个后续干燥区 - 每个都经过调整以提供所需的干燥特性。当托盘到达干燥机出口升降机时，它们将再次通过气闸卸载，产品将从托盘中倒空。

来自冷冻干燥工艺的蒸气将被收集在特殊的冷凝器中。为了确保连续加工，所有 CONRAD® 冷冻干燥机都配备了连续除冰 (CDI) 系统，可在不损失任何运行真空的情况下对冷凝器进行自动除冰。

CONRAD® 冷冻干燥机配备带有 GEA 独有的内置除冰系统的内部蒸气冷凝器。与外置冷凝器系统相比，它不仅节省空间，更可靠，不会造成产品损失，而且使用较少的能源，从而确保最佳的整体设备效率。

设计细节

加热板：采用阳极氧化铝制成并置于排柜内，以便为冷冻干燥过程提供能量。热水在系统中循环，确保热量有效传递到产品。此过程通过辐射进行。可以在冷冻干燥过程中调节水温，实现最佳蒸发环节并避免产品过度加热。正确装入排柜后，产品托盘将置于加热板之间，以实现最佳的热传递。由于热量会损坏产品，因此必须避免产品捕集器和加热板之间的直接接触。

蒸气冷凝器：安装在排柜中以冷凝升华的水蒸气从而进行连续除冰 (CDI)。当其中一个蒸气冷凝器需要除冰时（通常在一小时后），该部分将被密封，另一个蒸气冷凝器将接管冷凝功能。为了熔化积聚的冰块，会将 25 ̊ C 的水蒸气（真空蒸汽）引入腔室内。

水蒸气现在将凝结在冷凝器的冰冷表面上，从而将冰熔化。为了将除冰的冷凝器恢复到运行状态，必须通过冷却冷凝器腔室中的任何剩余蒸气，直至达到适当的运行温度和真空条件来将它冷凝。在需要下一个除冰周期时，现在可以采用直接切换的方式，而不会损失任何操作真空。

冷库：通过外置组合式升降机和输送系统将空的托盘送回以重新填充冷冻产品。

冷冻干燥是保存不同食物类型营养价值的好方法，同时还可以延长室温下的保质期，并减少浪费。

Benefits of processing freeze-dried coffee on the GEA CONRAD®:

Maximized uptime enabled by continuous, 24/7 processing - 8000 hours per year
Preservation of key aromas
Even heat transfer to the product
Uniform final product quality
Minimal product loss – less than 0.1% - during drying
Low comparative energy consumption
Compact design thanks to internal condenser system
High efficiency
GEA CONRAD® ECO models offer even greater energy efficiency

So how does freeze drying of coffee work?

Freeze drying typically creates higher quality instant coffee than spray drying, because freeze drying is carried out at very low temperatures (-50°C in a vacuum), which preserves much more – up to 90% - of the volatile coffee aromas. In contrast, spray drying uses high heat, which can degrade aromatic compounds and sensitive coffee oils.

The freeze drying process is carried out in stages. Precisely weighed, preprepared frozen coffee extract granules are loaded onto trays, which are introduced into the freeze drying chamber via an airlock. The pressure in the chamber is constantly kept low and heat applied to the trays via heating plates, which causes the ice to turn directly into vapour, a process called sublimation. This water vapor is collected in a condenser and removed. In a secondary drying phase the temperature is further increased to remove remaining water in the frozen coffee extract. The drying conditions, including temperature, pressure, and residence time, are precisely adjusted in each zone of the CONRAD® to create a final premium quality product with exactly the right residual moisture content.

Technology of choice for high capacity coffee freeze drying

The CONRAD® technology enables continuous processing at high capacity.
Continuously, trays filled with frozen coffee granulates are stacked and pushed through sequential drying zones for primary and secondary drying. Trays arriving at the dryer exit are then unloaded through an airlock, and the product is emptied from the trays, which are returned to the start. GEA CONRAD® freeze dryers are equipped with an internal vapor condenser system that features our unique, continuous de-icing technology, enabling automated condenser de-icing without loss of operating vacuum. It’s this technology that lets the CONRAD® carry out continuous, rather than batch-process freeze drying. Compared with external condenser systems our space-saving technology is also more reliable, minimizes product loss to 0.1%, and uses less energy, for more efficient, productive manufacturing.

At our test center, working with your product we can measure extraction yield, identify optimal drying conditions, and simulate the full evaporation and freeze drying process as part of a complete line evaluation, from roasted beans to final product.