Client: A leading spice manufacturer company
Location: Guntur, Andhra Pradesh
Farm produced chillies from cold storages that are directly shifted to the chilli processing plants for processing into pizza cut or fine powders contain impurities in many forms such as stones, mud balls, fine dust, nails ,human hair etc which deteriorates the quality of the final product in terms of color, value, and taste.
The aim was to provide a highly efficient chilli cleaning system which can remove all types of impurities.
- Difficulty in handling due to the delicate nature and irregular shape of chillies.
- Low bulk density and clogging issue due to steam.
To overcome this challenge, M/s RIECO designed a highly efficient (97 to 98%) four – stage chilli cleaning system which can remove all types of impurities such as stones, mud balls, human hair etc without deteriorating the quality of the final product by dividing impurities into 4 classes as per their nature.
Parameters to be considered
Types of impurities:
- Heavy impurities like stones, mud balls, nut bolts.
- Lighter Impurities like dust and feathers
- Impurities like hair on which static charge is being generated
- Ferrous impurities like nails, nut bolts, metallic wires
- Material to be ground – Chilli
- Feed size – Whole with stem
- Operating Temperature – 40 0C
- Capacity (Designed) – 500 – 2500 kgs/hr
- Bulk density (feed) – Chilli: 150-200 kg/m3
- Feed Moisture -10- 16 %
Stage 1- To remove heavy impurities like mud balls, stones and an additional plate magnet to arrest the ferrous particles
Chillies are fed through a feed hopper along with a doffer arrangement which sprays the chilli uniformly on a conveyor belt that operates through a variable frequency drive to control the feed capacity.
A plate magnet is provided at the inlet of the Zig Zag component to arrest the ferrous particles.
The belt conveyor feeds the whole chilly to the Zig Zag Classifier which is designed to remove heavy impurities. Then the chillies are conveyed because of the negative air suction.
Due to difference in bulk densities, stones and mud balls are separated from the chillies by the Zig Zag classifier after which these impurities are collected in a collection bin which is placed below.
Zig Zag Classifier
Impurity collected at Zig Zag (Stones and Mud Balls)
Stage 2- To remove the lighter dust particles
Pneumatically conveyed chilli from the Zig Zag classifier now enter the tangential separator. This tangential separator with a static classifier is equipped with a Rotary airlock valve; the complete unit will work to remove the finer dust particles and collect them in the bag filter. The dust-free chilli is then discharged to the next cleaning cycle.
Impurity collected by Bag Filter through Tangential Separator (Fine Dust)
Stage 3- To remove the coarser dust
The chillies discharged from the tangential separator through RAL are then fed directly to the grader by gravity. This Grader has a screen of size 1 or 1.5 mm with an anti-vibration arrangement. The chilli passes through the screen by vibration and the coarser dust is collected below the screen into the collection bin. Furthermore, an aspiration channel is provided after the screening section to arrest the finer dust which is generated through screening and collected into the bag filter.
Impurity collected at grader (Coarser Dust)
Stage 4 – To remove human hair and feathers
The Chillies from the Grader are then fed to the Static Roller. This specially designed Static Roller works on the principle of static charge. It is fixed on a flat belt conveyor that generates the static charge which helps in arresting human hair and feathers that then get collected in the collection bin through a small conveyor. The cleaned chilli is further collected separately for packing or feeding to the Grinding Section.
- Cleaned Chillies help increase the color value of the final products.
- Reduce wear and tear of machine grinding part.
- High quality final products due to absence of impurities.
- Increased product shelf-life.