Many Indian recipes utilize dried, split pulses that don’t require soaking before cooking. Dal is made from different types of lentils, peas, or beans. These pulses are a staple food throughout South Asia and are used in various soups and other dishes. Dal is an important part of cuisines throughout the Indian subcontinent. Specifically, chana dal is made from a variety of chickpeas known as Bengal dram, made using a slow cooking technique with steam called dum pukht. 

Chana dal can be used in numerous ways, including through boiling, roasting, and soaking. Often added to vegetable dishes or those using lentils, it’s also used in certain areas in India for making sweet dishes. Chana dal comes from one of the two major types of chickpeas. While the Kabuli variety, also known as garbanzo beans, is used in Mediterranean and Middle Eastern cooking, the Indian variety is known as Desi chickpeas or Bengal gram. Regardless of what it’s called, chana dal is becoming increasingly popular worldwide due to its health and other benefits.

How is Chana Dal Used? 

Other names for chana dal include split yellow gram, split desi-chickpea, or kala chana. The botanical name for it is Cicer arietinum, and it’s a member of the Leguminosae family. Whereas the Kabuli chickpea features larger, rounded seeds and a creamy-colored coating, the Desi variety’s seeds are angular with a brownish coating. Around 80 percent of these Desi chickpeas are used to make chana dal, with about 80 percent of chana dal then ground into a type of flour known as besan, also known as chickpea or gram flour. Besan is often used to coat vegetable slices to make pakoras, a type of Indian fritter. Sometimes chana dal is soaked in water before cooking to reduce cooking time.

Health and Other Benefits of Chana Dal

While considered particularly tasty by a large swath of the world’s population, the rest of the world outside the Indian subcontinent has begun to realize the many health benefits of chana dal. Manufacturing processes must thus ensure that its nutritional value isn’t compromised during production. Chana dal has been shown, for example, to be a good food for diabetics, as it transforms carbohydrates into sugars slowly.

Chana dal’s health benefits include the following: 

  • Easy to digest- works well for people with celiac disease
  • Has very low glycemic index like other pulses
  • High in protein and fiber
  • Low in cholesterol, saturated fats, and sodium
  • Rich source of minerals like calcium, folates, and zinc

The Chana Dal Manufacturing Process

De-husking is the first part of the chana dal manufacturing process. It involves separating husks from the cotyledons, the embryonic leaves within the seed. These cotyledons are subsequently split, after which they’re washed, polished, and graded. De-husking additionally augments the color, consistency, digestibility, palatability, and texture of the product.

Unlike other legumes, Desi chickpeas can be milled quickly and easily. Manufacturing processes like milling also help eliminate stones and other foreign matter, with sieves being used to classify different sizes. After chickpeas are de-husked and split to produce chana dal, most are roasted and ground into besan or chickpea flour.

Machinery Used in the Chana Dal Manufacturing Process

The chana dal manufacturing process is largely determined by the particle size needed for the application. A variety of machinery can be used to process chana dal. Manufacturing processes for it largely fall under material handling, particle reduction, and quality control. Rotary airlock valves are useful tools in material handling, while rotary sieves assist with quality control of already processed material. Particle size reduction can be achieved by various types of equipment, but the milling techniques largely depend on the sizing required for the application.

Prater Industries makes a variety of equipment that works well for chana dal processing: 

Material Handling of Chana Dal

For handling and feeding chickpeas and flour, Prater’s rotary airlock valve feeders offer an efficient means to process bulk materials. Dry materials like chana dal, work well for feeding chickpeas or transporting chickpea flour during processing. They operate well for accurately loading and unloading while working proficiently as rotary airlocks.

Some of Prater’s rotary airlocks’ more advanced features include: 

  • Allows up to 50 percent more volume with each revolution, allowing the rotor to run at lower speeds to increase efficiency and lengthen the life of the equipment.
  • Bearing design and placement makes them low maintenance and easily replaceable. 
  • Castings are precisely machined out of stainless steel or heavy-duty cast iron, making them more durable and lengthening their lifespans.
  • Easy to install or replace due to its compact size.
  • Drives feature heavy duty chain with integral gearmotors.
  • Precision-machined eight-blade rotors with a robust design ensure better sealing and minimize deflection when compared to designs with fewer blades.
  • Universal and oversized flange design accommodates multiple bolt patterns for a wide array of configurations.

Additionally, standard models can operate at temperatures up to 500°F (260°C), whereas custom models can operate at up to 1000°F (520°C). Our rotary airlocks are also third-party tested to comply with NFPA-69 standards.

Particle Reduction Equipment Used in the Chana Dal Manufacturing Process

Prater has been producing particle reduction equipment for nearly a hundred years and has considerable experience with providing top-notch particle reduction equipment. Processes depend on the particle size needed. Three pieces of Prater equipment especially useful for chana dal manufacturing are Mega-Mills for coarser flours of around 35 mesh, Prater’s fine grinders for flours around 70 mesh, and Prater’s air classifying mills for flours 200 mesh or finer. 

Mega-Mills for Coarse Flour

The Prater Mega Mills design consists of swinging hammers in an equally spaced pattern throughout the grinding chamber and supported by pins at their pivot point, with precision bearings supporting the rotor, allowing close tolerance fixed screens. Size reduction occurs via repeated hammer impacts, along with particles accelerating into each other, interrupter plates, and screen surfaces.

Specific design features of the Mega Hammer Mill include:

  • Cantilever design of rotor and ample-sized, hinged doors allow for easy cleaning and maintenance, along with easy removal of screens and rotors
  • Allows for multiple hammer shapes and styles to permit efficient processing of a wide array of materials
  • A dust tight design well suited for use in pneumatic convey systems
  • Interrupter plates located to amplify grinding while allowing for easy removal of screens
  • Robust design enables longer lifespan.
  • Well-balanced rotor assembly with precision-built allows for better performance and longer life

Additionally, particle-size requirements and throughput can be regulated through changing the number and size of screen holes, hammer tip speed, thickness, and number of hammers and clearances between screens and hammers.

Fine Grinders for Medium Flour

Prater’s M Series fine grinders produce uniformity with narrow particle size distributions. After being fed into the fine grinder,

raw materials undergo high-speed impacts from the rotor blades within the mill, which then accelerate material outward to create more impact and shear against stationary screens and jaws. This results in particle deceleration, which maximizes the difference in impact speed when material moves back into the pathway of the rotor blade. Once properly sized, particles are pulled through the screen before moving on to the next production stage.

Prater’s fine grinders have features that include:

  • Allows high throughputs due to the ratio between horsepower and screen size
  • Designed for maximum bearing life and to limit internal electrostatic discharges
  • Easily replaceable jaws, grinding blades, and screens
  • Grinding jaw and rotor blade have precise tolerances to enable more uniform size reduction
  • Interchangeable screen & jaw combinations for more versatility
  • Most free-flowing dry material requires only a single grinding stage
  • Streamlined interior and larger access door allow easy access for maintenance and cleaning

Made from welded carbon or stainless steel, Prater’s fine grinders come with optional features: bearing monitoring packages to assist with predictive maintenance, pressure-resistant construction, and features that support sanitation. It’s also versatile, with interchangeable configurations for jaws and screens.

Air Classifying Mills for Fine Flours

For the finest grinding, Prater’s air classifying mills combine grinding and milling within a closed circuit, utilizing an interstage air classifier to continuously recirculate larger particles back to the grinding zone. The design works particularly well for products requiring narrow particle distribution or difficult-to-grind materials. Made from carbon or stainless steel; its design produces ultra-fine particles down to a mean size between 5 to 7 microns.  

Allowing the processing of difficult-to-grind materials in three steps, the Prater air classifying mill first conveys air along with metered product, where high-speed impact with the grinding blades fling particles outwards to cause additional collisions against screens and jaws. Particles that are still too big to pass through the screen’s openings remain in the grinding chamber. Particles that pass the screen are fluidized and cooled by additional pneumatic air while being classified by the independently controlled classifier wheel. Larger particles are rejected into a second, more aggressive grinding stage, then re-combined with the first stage particles to pass back thru the screen. On-size particles are passed through the classifier wheel and pneumatically conveyed to dust collector.

Prater’s air classifying mills feature: 

  • Allows greater throughput through ratio between horsepower and screen.
  • Better access due to large doors and uncomplicated interior for easier maintenance and cleaning
  • Designed for maximum bearing life and to mitigate electrostatic discharges internally
  • Easily replaceable grinding blades, jaws, and screens
  • Screens and jaws can be reconfigured to allow greater versatility
  • Uniform size reduction supported by design with precision tolerances between grinding jaw or screen and rotor blades

Prater’s air classifying mills also feature optional monitoring packages for the bearings to enhance existing preventive maintenance strategies, along with sanitary and pressure-resistant construction.

Quality Control Equipment for Chana Dal Processing

Prater’s version of the rotary sifter, or rotary sieve, is the Rota-Sieve®, which scalps and sizes chickpea flour to ensurel quality. Rotary sifters work to remove insects, stones, and other contaminants during chana dal manufacturing. Processing is made easier due to the simple design of the Rota-Sieve®, which utilizes lightweight components to make standard inspections easy.

A specially fitted inlet with a auger moves product into a screening chamber where paddles apply centrifugal force to accelerate fluidized particles across the screen’s surface. Finer particles pass through the screen to be discharged into a hopper. Coarser material is forced to the end of the chamber by  the rotor paddles, where it empties into a separate discharge hopper. Near-size and over-size particles hit the screening surface as it’s operating, which causes the screen to vibrate, enhancing its self cleaning properties.

Prater’s Rota-Sieve® has distinctive features that include: 

  • 3 Bearing design minimizes wear on shaft seals while improving rotor support
  • Easy-to-remove rotor and accessible internals allow for quick cleaning or maintenance
  • Enables greater throughput relative to its screen are
  • Has a smaller footprint than competitors’ sifters
  • Operates with little dust, noise, or vibration 
  • Adjustable rotor for custom screening capabilities
  • Screens can easily be inspected in place or separately
  • Body and hoppers come standard in stainless steel

Prater’s Rota-Sieve® has an adjustable screen frame that can be used with various screen fabrics to improve performance. An optional patented Rota-Trap® is also available to screen out larger contaminants during chana mal manufacturing. Processing options also allow sanitary finishes for applications that comply with USDA, FDA, 3-A, BISSC, and other regulatory bodies in the US and EU.

To learn more about how Prater Industries can assist with chana dal manufacturing processes, contact us today