CONRAD™ 凍結乾燥機

加熱板: 陽極酸化アルミ製であり、凍結乾燥プロセスにエネルギーを与えるためにキャビネット内に配置されています。製品に対する熱伝導効率を上げるため、システム内を温水が循環しています。これは、熱放射により実施しています。水温は、最適な蒸発周期を達成し、製品の過熱を防止するため、凍結乾燥プロセス内で調整することができます。キャビネットに正確に積み込むと、製品トレイが加熱板の間に配置され、熱伝導が最適化されます。熱によって製品が破損する可能性があるため、製品トレイと加熱板を直接接触させてはいけません。

蒸気凝縮器: 昇華した水蒸気を連続除氷 (CDI) を目的として凝縮させるため、キャビネット内に設置されます。蒸気凝縮器の一方に除氷 (通常は 1 時間後) が必要な場合は、他方が凝縮機能を継承している間、該当セクションを密封します。蓄積した氷を融かすため、25 °C の水蒸気 (真空蒸気) が該当ルームに導入されます。

水蒸気が凝縮器の冷たい氷の表面上で凝縮するため、氷が融けます。除氷された凝縮器を稼動状態に復旧するには、凝縮器チャンバ内に残っている蒸気をすべて、適切な稼動温度まで冷却することにより、真空状態になるまで凝縮する必要があります。次の除氷サイクルが必要になったら、運転真空圧の損失なしに、切り替えを直接実行することができます。

冷蔵倉庫: 空になったトレイは、凍結済み製品を補充するため、外部結合されたエレベータおよび搬送システムを通って返送されます。

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.