A wood-based rectangular batch fryer with an inbuilt heat exchanger is an industrial food processing machine designed for frying snacks like potato chips, namkeen, and fryums.¹ Unlike traditional "Inbuilt direct-fired" systems where the flame hits the pan directly, this system uses a Heat Exchanger (HE) to heat the oil indirectly, ensuring better oil quality and fuel efficiency.²

1. Technical Specifications

Most industrial models (like those from Gungunwala, Fry-Tech, or Blaze) follow these general parameters:

2. How the Inbuilt Heat Exchanger Works

The core of this system is indirect heating. Instead of heating the frying pan directly with a wood fire, the oil follows a specific path:

1. Combustion Chamber: Wood is burned in a separate furnace box (usually located at the bottom or side).
2. Tube Network: The cooking oil is pumped through a series of SS seamless tubes (coils) located inside the heat exchanger.
3. Heat Transfer: The heat from the wood fire warms the tubes, which in turn heats the oil flowing inside them.
4. Circulation: An oil pump continuously moves the hot oil from the heat exchanger into the frying pan and back again through a filtration system.

3. Key Features & Benefits

• Oil Longevity: Because the flame never touches the oil pan directly, the oil doesn't "crack" or burn as easily. This significantly extends the life of the edible oil.
• Temperature Control: These fryers often include a digital temperature controller. Even with wood fuel, the system can regulate the flow of oil to maintain a consistent frying temperature ( to ).
• Fuel Efficiency: The "three-pass" or "two-pass" design of the heat exchanger ensures maximum heat absorption from the wood, reducing fuel consumption by up to 20–30% compared to traditional bhattis.
• Tilting System: Most rectangular models feature a manual or automatic tilting mechanism, allowing the operator to unload an entire batch of snacks in one stroke, ensuring uniform frying time.
• Filtration: Usually equipped with a bucket-type continuous filtration system that removes food particles (fines) to keep the oil clean.

4. Typical Applications

• Potato & Banana Chips: High-quality finish without burnt spots.
• Namkeen & Dals: Ideal for Moong Dal, Chana Dal, and Sev.
• Pellets/Fryums: High-capacity frying with quick recovery of oil temperature.