Healthy Nutrition (Millet/Ragi Malt) Vending Machine
Nutrition (Millet/Ragi Malt) Vending Machine is a vending machine designed to mix and dispense upto 3 types of Millet drinks (malt) with options of Milk/Jaggery which is also highly configurable and self-cleaning.

Background

This idea for millet drink machine was sparked at a local high school in Mysore (Excel Public School) as an Atal Tinkering Lab Project to commemorate "The Year of the Millets" in 2023. The students had made a basic working prototype.

However, the school and the Atal tinkering lab wanted the machine to be made reliable and ruggedly so it can be used in the school. For this, Ideas Unlimited, ಮೈಸೂರು built this rugged, commercially usable Healthy Millet Drink Machine.

Nutrition (Millet/Ragi Malt) Vending machine front view.

Dispensing Area for the Drink

Jaggery Packet Dispensing area

Inside view of the Nutrition vending machine

The Design of a daily usable millet drink (Ragi malt etc) vending machine had its share of challenges. Millet powder doesnt completely dissolve in hot water or hot milk completely and tends to give out a residue. So a mixer had to introduced into the system before final dispensing. Flow of millet powder from dispenser to the mixer was another challenge to be addressed. Also millet powder if mixed directly with hot water, coagulates and forms large granules in the final drink.

All the lines where the food material passes through are made with FOOD GRADE chambers, food grade transfer pipes etc.
Detailed explanation of how the Millet Vending Machine works.
The drink vending machine enforces access control by using RFID tokens too! Several parts of the machine are kept simple and with easy access so routine maintenance can be done on the machine.

All of the above problems were addressed and this final usable prototype of the Nutrition vending machine was created at our lab Ideas Unlimited, Mysuru.

The shell of the machine was kept intentionally transparent so the students can see the working of the entire machine inside!

High Level Features

User Features

  1. This millet vending machine prepares 3 types of millet drink
    • User can select any one of the 3 drinks
    • User can select whether he wants milk or not
    • User can select whether he wants Jaggery or not
  2. After inserting a valid token within 1 minute the drink will be prepared and dispensed
  3. Machine can sense valid/invalid tokens
  4. Jaggery is dispensed separately from a sachet dispenser mechanism if user selects jaggery is required. (Jaggery hydrates if kept in canisters)
  5. After dispensing the drink, the machine cleans the mixer areas
  6. Appealing LCD display with graphics indicating whats going on inside the machine
    • Displays hot water temperature in key screens
    • Displays current state of machine

Special features

  1. Method of preparation: Mixes millet powder first with cold water and then starts preparing the drink to prevent powder from forming lumps.
  2. Cleaning focus: Machine cleans mixer and other important areas after each drink is dispensed
  3. Initial Power on Clean Cycle: When machine is switched on, machine cleans itself once.
  4. On Demand Clean cycles: On Demand cleaning, draining of mixer also available.
  5. Maintains water Temperature: Preheats water at regular intervals to ensure fast dispensing of drink.
  6. Clear transparent enclosure so students can observe how machine prepares their drink!
  7. Machine continuously monitors and executes
    • Water Temperature
    • Water Level
    • Cleaning cycles necessary

Specifications

  1. Machine inputs:
    • 20 litres of Water can, can be fed into the machine and Water level sensor which stops operation and alerts when low on water
    • 3 Canisters to hold different millet drink powder – Can hold upto 1 Kg powder
    • 1 Canister to hold Milk Powder – Can hold upto 1 kg powder
  2. Two Cold water pumps
    • one goes to supply cold water to mixer
    • Another is connected to feed heating kettle
  3. Water can has an external level sensor
  4. Heating kettle has temperature sensor, and pre-heating temperature is set to 85° Celsius
  5. Solenoid to dispense prepared drink
  6. Separate Drain solenoid to evacuate water after cleaning cycle
  7. After dispensing every drink the mixer is cleaned thoroughly

Diagnostic Features

  1. Individual motors, pumps and solenoids testing
  2. Clean mixer cycle
  3. Drain water from mixer
  4. Fill minimum water to kettle
  5. Sensors check (Temperature, level)
  6. Powder dispense check for calibration
  7. RFID Token Sensing/Reading
  8. Jaggery Packet Dispense test

Maintenance Features

  1. UI Button combination for
    • Cleans mixer by putting cold water and running the mixer, and finally draining
    • Opens Solenoid to evacuate anything in the mixer
    • Fills kettle with minimum level of water
  2. Machine cleans mixer and other important areas after each drink is dispensed
  3. When machine is switched on, machine cleans itself once.
  4. On Demand cleaning, draining of mixer also available
  5. Preheats water at regular intervals to ensure fast dispensing of drink

    6. Product Maintenance Videos:


    Mixer Maintenance Video.

    Refilling Canisters with Millet power and Milk powder.

    Kettle Removal and Inserting back.

    Reloading Sachets to Jaggery Dispenser.

    Drain tray maintenance.