TECHNOLOGY FOR PINI KAY BRIQUETTES

APPLICATION

• for production of solid fuel with calorific value from 4100 kcal/kg

• for creating the eco-friendly source of energy from renewable sources

 

 

 

FINAL PRODUCTS

• bio fuel briquettes PINI KAY type (63*63 mm)

 

 

RAW MATERIAL

• wood waste: woodchips, wood shavings and sawdust of hardwood and softwood

• agricultural waste: sunflower, buckwheat and rice husks, walnut shells, peanut shells, olive pits, straw, cane, miscanthus, bagasse etc.

 

 

OPERATING CONDITIONS

• power line in the workshop: 100 kW

• production area: 250 m²

• warehouse area: 300 m²

• floor storage area for raw material: from 400 m²

 

 

 

 

TECHNOLOGY DESCRIPTION:

 

 

 

STEP №1. PREPARATION OF RAW MATERIAL  BY ITS FRACTION

 

Raw material:

• crushed to a fraction of 1 … 3 mm
• fraction less than 1 mm is sorted out

Crushing is done in 2 stages:

Stage 1.  Feedstock is crushed to a fraction of 10 … 30 mm in chips or straw cutters

Stage 2. Feedstock is crushed to a fraction of 1 … 3 mm in hammer mills

 

ATTENTION!

Grinding to a fraction of 1 … 3 mm increases the productivity of the dryer. At the same time, the grinding of wet raw materials requires about two times the high cost of electricity.

Usually the following scheme may be used:

grinding to 10 … 30 mm – drying to 6 … 8% - regrinding to 1 … 3 mm

 

 

 

 

STEP №2. PREPARATION OF RAW MATERIAL BY ITS MOISTURE

Prior the drying the feedstock is fed into the air separator. The fraction of 1 mm is deleted from the feedstock.

Raw materials are dried in drum dryers or in aerodynamic dryers.

 

 

 

 

 

At the outlet of the dryer we get the product with the moisture of 6 ... 8%.

If the raw material is over dried (the moisture is lower than 6%), the natural polymer known as lignin is being destroyed. In this case the surface layer of the briquette will not be glued together. At the exit of the press briquette will fall apart.

If the raw material is not dried enough (the moisture is more than 8%), the excess moisture will evaporate with periodical steam gathering and make the loud “explodes” when the briquettes are discharged.

In the press, the briquette is heated to 180 ... 300 °С.

From the dryer, the raw material is discharged into the operating hopper where the moisture is corrected.

In practice at the exit from the dryer, the moisture of the briquette is constantly changing in the range of 2...4%. For example, the moisture measurements every 2 ... 3 minutes can show first 8%, then 6% and so on.

In the operational bunker, within 20...30 minutes, the moisture is redistributed and averaged over the entire volume.

 

 

 

STEP №3. BRIQUETTING PROCESS IN THE MECHANICAL OIL PRESS

 

 

The raw material is fed from the operating hopper into the press.

The feeder (the rotation speed is regulated by frequency control drive) continuously pours the raw material into the vertical screw feeder inside the press. It forcefully transports the raw materials to the screw part of the oil press. A conical screw compresses the product and squeezes it into the forming console which is heated up to 180...300°C. The raw material compressed to 1.1 t/m³ moves along the console.

In the process of movement the surface layer of the briquette is melted and the lignin is sintered. Afterwards the briquette continuously is fed into the cooler.

Inside the cooler:

• the briquette is cooled
• the surface polymer layer hardens
• the density of the briquette increases

 

 

 

STEP №4. BRIQUETES CUTTING

 

 

The briquette from the cooler is continuously fed into automatic briquette cutter. The cutting length of the briquette can be varied in the range of 100 to 400 mm without stop of the process.

The briquettes are placed on the tray for their complete cooling down.

 

 

 

STEP №5. PACKAGING

 

 

Pini Kay briquettes are usually packed in 12 pcs. for one package with the general weight 10 kg.