Pasta Dryer Four-Stage Drying Technology and Process Control
Pasta dryers (面食干燥机) are critical equipment in pasta production, responsible for removing moisture from noodles after cooking or steaming. Proper drying technology ensures product quality, prevents mold growth, and extends shelf life. This guide covers the four-stage drying process and key control parameters.
Stage 1: Cold Air Shaping Stage (冷风定条阶段)
This stage is primarily for shaping the noodles. The cold air shaping stage mainly involves controlling the temperature, time, and humidity.
- Time: 20–30 minutes
- Temperature: 20–25°C
- Humidity: 55–65% RH
During this stage, the室温 (room temperature) is controlled at 20–30°C with 30 minutes of strong ventilation. The moisture content drops from 32–35% to 27–28%. This stage allows the noodle structure to set and prevents deformation during subsequent drying stages.
Stage 2: Moisture Retention and Perspiration Stage (保潮发汗阶段)
This stage is mainly for diffusing the moisture within the drying room. It is important not to rush this stage.
- Time: 30–40 minutes
- Temperature: 30–35°C
- Humidity: 75–85% RH
As room temperature increases, the noodles continuously absorb heat, accelerating moisture evaporation. Simultaneously, the noodle temperature rises rapidly, allowing internal moisture to diffuse toward the surface more effectively. The dewatering capacity and drying speed during this stage are nearly twice that of the pre-drying stage.
Stage 3: Heating and Humidity Reduction Stage (升温降湿阶段)
This stage takes a bit longer and is critical for removing the majority of moisture from the noodles.
- Time: 80–90 minutes
- Temperature: 35–45°C
- Humidity: 65–75% RH
After the first three stages, 95% of the moisture in the noodles has been removed. The temperature difference between the drying medium and the noodles drives efficient moisture transfer from the interior to the surface and then into the air.
Stage 4: Cooling and Heat Dissipation Stage (降温散热阶段)
After the previous three stages, the moisture has basically been completely removed, so this stage is a slow baking period.
- Time: Around 90 minutes
- Temperature: 26–28°C
- Humidity: 50–60% RH
Benefits of Using Heat Pump Drying
- Prevents the phenomenon of broken hanging noodles (noodle breakage during drying).
- Reduces the operating costs of drying.
- Shortens drying time compared to natural drying methods.
- Quality is greatly improved — color and appearance are excellent.
- Saves expenses compared to traditional drying methods.
- Eliminates problems such as noodle mold, poor appearance, and inferior finished products.
Comparison: Old vs. New Drying Methods
- Old method (natural drying): Weather-dependent; low temperatures over long periods cause mold and foul odors; uneven heating from sun exposure causes poor color and quality.
- New method (mechanical/heat pump drying): Weather-independent; consistent temperature and humidity control; superior product quality and appearance; significantly improved production efficiency.
