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Pellet Mill New Type Rolls Out: Capacity up to 800 kg/h for Wood Pellets

By Jack Huang    Jun 05, 2014

GEMCO Pellet mill with the screw feeder: model 550B

550 B Pellet Mill with Screw Feeder

New GEMCO Pellet Mill Introduction

This new pellet mill, model ZLSP-R 550B is for sale now! It is designed to produce wood fuel pellets and feed pellets from raw materials of sawdust, straw, rice husk and tree bark, etc. Unlike other ring die pellet mills or briquetting machine, this 550B pellet mill is so small that it enables you to make your own homemade wood pellets. Watch this pellet mill operation video below:


Application of the pellet mill

Biomass pellet is a kind of high efficient clean renewable energy with the advantages of saving energy, reducing carbon emissions, easy to be stored and transported. This 550B pellet mill is widely used for making pellets for in house-warming and power generation. It is an alternative fuel for non-renewable energy resources of coal, oil, gas, etc. Also you can make feed pellets from this machine.

Structure of the pellet mill

The struction is simple and compact. GEMCO ZLSP 550B pellet mill is consisted of the foundation frame, motor, decelerator, power transmission system and electrical control system, etc. The crushed biomass raw materials is compressed into densified fuel pellets under the pressures caused by the interaction between the die and the rollers of the pellet mill, shown in the following diagram.


GEMCO pellet mill plan
GMC-ZLSP550B Pellet Mill Structure Diagram

1.Upper box body  2.Fixing nut  3.Roller  4.Die  5.Middle box body
6.Main shaft  7.discharging hopper  8.Bearing 9.Bearing seat
10.Decelerator 11. Motor 12.Shaft coupling 13.Foundation frame
14.Electrical cabinet.

Parameters of the pellet mill

Model Power(kW) Capacity(kg/h)* Weight(kg) Dimension(mm)
ZLSP-R 550B 55 wood pellets feed pellets 1770 2300*750*1850
500-800 800-1100

*NOTE: The estimated capacities used here are for reference purposes and are based on a generic biomass material that has been properly prepared for pelleting. We have done testing with many different types of biomass and have found a large variance in capacity based on the type and preparation of material. Please contact GEMCO Engineering for estimated capacities using your specific product.

Screw Feeder

Even though the GMC-ZLSP550B Pellet Mill is efficient, the pellet line can be more efficient with the associated equipment, the screw feeder!

The screw feeder is one of the associated equipment, which is not included in the pellet mill and can be purchased according to the requirement of the customer. The function of the screw feeder is to improve the feeding efficient of pellet mill. The screw feeder can feed the pellet mill evenly with adjustable speed and at the same time protect the motor of pellet mill from the damage of the current shock.

screw feeder for pellet mill
Screw feeder

Parameters of the screw feeder

  • Volumetric weight of the raw material: 500-600kg/m³
  • Capacity:                                                   1500kg/h.
  • Motor power:                                            1.5 kw converter motor with the controller.
  • Diameter of the outlet:                            φ114mm,the vertical distance from the outlet to the ground: 1750 mm, the distance between the outlet and the edge of the foundation frame: 410mm.
  • Volume of the feeder:                              around 0.06 m³
  • The screw feeder is movable with locking devices on the wheels.

What to do before starting your new pellet mill machines?

1. Before running, check and tighten the bolts of the roller ends in order to avoid the breaking of the roller caused by the nuts, which are falling down into the material. Inspect other parts to avoid looseness or missing parts.

2. A new die must be properly ground. Please grind in before the first operation. The oily mixture is made up of 10 kg fine sand, 32 kg biomass material (sawdust) and 8 kg of used engine oil.

sawdust and fine sands and wasted oil  for wood pellet mill  oily mixture production

Grinding-in procedures

a. Place a bucket under the discharge outlet. The collected material can be used to preheat the pellet mill successively.

b. Start-up.

c. Put the proper amount of oily mixture into the mill.

d. Continue to pour the oily mixture in and let it run through the pelletizing holes.

e. Use again the oily mixture in a recycling manner for 40-60 minutes.

oily materials for wood pellet mill

Oily materials and the pellets made of it

How to operate the ZLSP-R 550B Pellet Mill?

1. Adjust the clearance between the die and the rollers, shown in the following picture. Release the locking bolt before introducing material to the pellet mill. Screw the fixing nut in a clockwise direction until it cannot be tightened and then screw with the wrench in counter-clockwise by 15°-30°. Later, tighten the locking bolt at last.

How to operate the Gemco 550B pellet mill?

2. Before running the machine, adjust the clearance between the feed scraper and the flat die to be around 10 mm, the optimal distance. The feed stock should be fed on the lighting of the running button which may take a relatively longer time because of the large power motor to ensure the good performance of the pellet mill.

3. Preheat the pellet mill before pelletizing.

Preheating method: Insert the oily mixture into the pellet mill in order to preheat the die above 50 degrees Celsius.

Oily mixture proportion: Take 5-10 kg biomass materials and mix it evenly with 10 % of used engine oil.

Preheating procedures:

a. Place a bucket under the discharge outlet so that the material can be collected and put back into the pellet mill several times to preheat the pellet mill.

b. Starting up the pellet mill.

c. The amount of oily mixture in the pellet mill must never exceed the full load of the hopper.

d. When the vapor shows above the feeding hopper, it means the temperature in the pelletizing chamber is rising. When the discharged pellets are well-formed with certain hardness, it means the die had been enough heated to produce pellets continuously.

4. Before stop the pellet mill, the oily mixture should be fed into the pellet mill to fill the die holes of the pellet mills for the sake of future running of the pellet mill.

How to prolong the life-span of the Pellet Mill by lubricating?

1. Add lubricating oil to the gearbox and other parts before the first operation. Make sure each part is fully lubricated before running.

Lubrication requirements

No. Part Lubrication grease category Period for lubricating Period for changing grease 1 Roller Lithium base grease Twice each shift 2 Main shaft Lithium base grease Twice each shift 3 Gearbox Hyperbola gear oil Add (for the first time) to the specified position (referring to the oil dipstick scale). Per 6 months

No. Part Lubrication grease category Period for lubricating Period for changing grease
1 Roller Lithium base grease Twice each shift  
2 Main shaft Lithium base grease Twice each shift  
3 Gearbox Hyperbola gear oil Add (for the first time) to the specified position (referring to the oil dipstick scale). Per 6 months

2. The die must be visually inspected prior to the start-up. Make sure there are no foreign materials in the bearings and each part is tightened. You can use both sides of the die.

The dual usage of the die can prolong the lifespan of the pellet mill.

pellet die needs to be lubricated according to the requirements

The pellet die needs to be lubricated according to the requirements.

3. The roller must be visually inspected prior to each start-up. Make sure there are no foreign materials and check the running of the roller is normal. The service life of the roller is around 800 hours under normal running condition. It is recommended to replace the roller and the die at the same time.

Rollers of  550B pellet mill

The pellet mill rollers need to be lubricated to prolong the life-span of the pellet mill.

After talking about the pellets mills, it would be better for you to have a more vivid understanding. Now please check the following video about how to operate and maintain the pellet mill. It would be useful for you if you have already had a homemade pellet mill or you have a pellet mill plan. Please enjoy!

Wood pellet mill operation and lubrication video