Drum blanchers, also known as rotary drum blanchers, are widely used in the potato processing industry for their ability to provide continuous, uniform, and efficient blanching. They are ideal for large-scale operations and can handle a variety of products, including potato slices, strips, and dices, as well as other vegetables and fruits.

Working Principle

• Product Infeed: Potatoes are introduced into one end of a rotating cylindrical drum, which is partially submerged in a tank filled with hot water or exposed to steam.

• Rotation and Conveyance: As the drum rotates, internal flights or a helical auger gently move the potatoes forward through the blanching zone.

• Heat Transfer: The potatoes are immersed in the heated water or exposed to steam, which rapidly raises their temperature. This inactivates enzymes, preserves color, and partially cooks the product, preparing it for further processing.

• Discharge: At the outlet end, the blanched potatoes are discharged, often via a dewatering device or conveyor for the next processing step.

Components of a Drum Blancher

• Perforated Drum: An elongated, cylindrical drum with perforations allows water or steam to circulate freely around the potatoes, ensuring even heat distribution.

• Flights or Helical Auger: These internal components move the product along the length of the drum, ensuring all pieces receive uniform heat treatment.

• Water Tank: The drum is partially submerged in a heated water tank, which can be heated by direct steam injection or a heat exchanger.

• Steam Injection System: For steam blanching, steam is injected directly into the drum or water tank, providing rapid and efficient heating.

• Circulation Pumps: These maintain even temperature and flow of water or steam throughout the blancher, preventing hot or cold spots.

• Temperature and Time Controls: Integrated sensors and control units allow operators to set and monitor blanching temperature and retention time for precise processing.

• Quick-Release and Access Features: Easy-opening lids, inspection hatches, and CIP (clean-in-place) systems facilitate cleaning, maintenance, and hygiene.

• Discharge System: Blanched potatoes are removed at the outlet, often via a vibratory or water flume conveyor for efficient transfer.

Process and Operation

• Loading: Potatoes are fed into the drum blancher, either manually or via an automated conveyor.

• Blanching: The drum rotates at a controlled speed, moving the potatoes through the hot water or steam. The immersion time and temperature are carefully controlled to achieve the desired level of enzyme inactivation and partial cooking.

• Uniform Treatment: The combination of rotation, immersion, and internal flights ensures that every potato piece is evenly blanched, preserving texture, color, and nutritional value.

• Discharge and Dewatering: The blanched product exits the drum, is dewatered, and transferred for further processing such as cooling, frying, or freezing.

Key Features and Benefits

• Continuous and High-Capacity: Drum blanchers are designed for uninterrupted, high-volume processing, supporting industrial-scale potato operations.

• Uniform Blanching: The rotating action and internal design ensure all product pieces are evenly exposed to heat, resulting in consistent quality.

• Energy and Water Efficiency: Modern drum blanchers feature innovations to minimize steam and energy consumption while maintaining high product quality.

• Versatility: Suitable for potatoes as well as other vegetables, fruits, pasta, and rice.

• Hygienic Design: Easy access for cleaning and maintenance, with options for CIP systems and hygienic pipework.

• Automation: Integrated control units monitor and adjust temperature, drum speed, and water flow for precise, repeatable results.

"Drum blanchers play a vital role in potato processing, offering continuous, uniform, and efficient blanching through a rotating, perforated drum immersed in hot water or exposed to steam. Their robust design, high capacity, and precise control systems make them indispensable for large-scale potato processing, ensuring consistent product quality and operational efficiency.."