Lean Phase Conveying and Grinding System

Challenges

To convey sugar at required capacity without contamination.
To grind sugar at given rate maintaining the grinding temperature & conveying air in controlled conditions to avoid melting of sugar which leads to deterioration and affects its grade & size.
To avoid lump formation & chocking issues of sugar while storing in hopper.
Maintaining controlled working parameters to avoid chocking issues in conveying system.
To remove any unwanted impurities from the products.
Avoids entry of foreign particles into the product and keep the plant hygienic.

Solution

Rieco has offered lean phase positive conveying of sugar to Air Classifying Mill & further to movable bins.

Sugar bags are placed on Automatic Bag tilting table which tilts the torn sugar bags into the bag dump station & bin mounted bag filter is used to capture the sugar fines generated while dumping and vent out fresh air with the help of centrifugal fan.

The material is then conveyed through inclined screw conveyor to the metal separator using variable frequency drive to control the feeding rate.

The mechanically conveyed sugar is then passed through the metal separator to avoid entry of foreign particle while unloading the bags.

The material is then conveyed into the conveying line with the help of LPR type rotary air lock valve specially designed for food applications.

The material is conveyed by the pressure generated using the roots blower through the conveying pipes & bends into bag filter where the generated sugar fines are again extracted by the dust extraction unit in bag filter.

The conveyed Sugar into bag filter hopper is fed to Air Classifying Mill through specially designed Rotary Air lock valve in a controlled manner.

In Air Classifying Mill, sugar is grinded to the required size. The grounded sugar is then transferred to bag filter by vacuum conveying system using negative pressure generated by roots blower.

In air classifying mill, while grinding, the temperature of grinding chamber is increased. High temperature of air while grinding results in degradation of sugar quality & melting of sugar which then creates chocking issue in conveying line & bending by gradual saturation of melted sugar.

To avoid these issues, the air which is released from roots blower is recirculated to the Air Classifying mill through vacuum.

To control the temperature of grinding chamber of Air classifying Mill the temperature of recirculated air is dropped with the help of heat exchanger. Followed by heat exchanger, demister is provided to avoid the entry of moisture through the recirculated air.

Explosion isolation valve & rapture discs are provided to avoid the explosion while conveying the grounded sugar.

The sugar fines are separated by air using filter bags. To prevent the entry of fine particles into the roots blower, a secondary filter is provided. For safety purpose vacuum bypass arrangement is provided.

Bin activator is provided at bag filter hopper to avoid suage lump formation inside the hopper.

The grounded sugar is then discharged by gravity into the movable bin which is placed on weighing scale. The arrangement is provided is such a way that the exact quantity of sugar is dumped into the movable bin with the help of rotary valve.

The whole system is controlled using PLC cum MCC.

Why Pneumatic Conveying System?

Low maintenance system as compared to the mechanical conveying system.
As food industry demands complete hygienic system so pneumatic conveying system is the best solution.
It also provides a clean and dust free operation ensuring zero contact of human on the product.
Dust-free operation, less spillage resulting in good yield recovery.
Flexibility in routing – can be transported vertically and horizontally by the addition of a bend in the pipeline.
Automized powder handing ensuring better process controls, less manpower, safety in plants.

Value addition by RIECO

RIECO has provided a reliable system.
Less footprint area.
Manpower and labour cost is optimised.
Low maintenance cost.
Quality of the product is maintained as per international norms.
Optimum power consumption.