stak pellet mills general operating handbook 1

STAK Pellet Mills

General Operating Handbook

ã STAK Properties, LLC

For the best alternative energy products available, visit us online atwww.stakproperties.com

This handbook is designed to serve as a general guideline

for all STAK pellet mills. Your particular model may have

more or less features then are described in the following

text. The intention of this book is to provide a basic

understanding of all STAK pellet mills. If you have a

question concerning your pellet mill that is not covered in

this manual please send a descriptive email to

[email protected]

Save harmless agreement

Because the use of the materials, instructions, and information being sold is beyond our control, the purchaser or user agrees, without reservation to save the seller, its agents, distributors, resellers, consultants, promoters, advertisers or employees harmless from any and all claims, demands, actions, debts, liabilities, judgments, costs and attorney’s fees arising out of, claimed on account of, or in any manner predicted upon loss of or damage to property, and injuries to or the death of any and all persons whatsoever, occurring in connection with or in any incidental to or arising out of the purchase, sale, viewing, transfer of information and/or use of any and all property or information.



Contents:

1. Introduction

2. Safety and operation

3. Application range and performance features

4. The factors which influence pellet quality

1. Raw materials;

2. Operating and experience;

3. Installation and spare parts;

5. Electric control circuit

6. Maintenance

7. Troubleshooting

8. Warranty

9. Sample drawing



1. Introduction:

1. What is pelletizing?

Pelletizing is the process of making waste materials into solid fuel. The pellets are typically used for burning purposes. However, pellets can be used in several processes from making animal feed to electricity production.

2. What materials can be used for making pellets?

Pellets can be made from any type of Agro-Forestry waste. Including but not limited to wood, leafs, grass, cornstalks, cardboard, switch grass, pinecones, hay, nut-shells, corn cobs, tobacco waste, straw, animal waste, and so on.Biomass is fed to a press where it is squeezed through a die that contains several holes. The high pressure of the press causes the temperature of the biomass to increase greatly. As the biomass is heated, the lignin (organic polymer found in the cell walls of plants) plastifies forming a “natural glue” that holds the pellet together as it cools.

3. Machine function

All STAK pellet mills are simple to operate, have excellent stability, low noise, and great performance. STAK pellet mills operate by “direct drive” power transmission. The electric powered mills have no belts, which means no slipping. This is one of the reasons why STAK pellet mills provide better power transmission than our competitor’s machines. Diesel engine powered mills are also available.

The entire drive assembly is contained inside an oil filled gearbox. The gearbox housing is constructed of cast iron.

The template and press rollers last 3-4 times longer than the typical templates and rollers found on other pellet mills. When properly maintained, STAK pellet mills can last for several years!

2. Safety and Operation:ã STAK Properties, LLC


Before operating, the operator must familiarize himself to the structure and function of the machine.

Warning! The machine has moving parts! To avoid injury or damage to the machine, never use your hands or other hard tools to clean the die or rollers. A wood stick can be used to help feeding the materials.

The operator should never leave the machine unattended. When operating, listen for any abnormal noise. Stop the machine immediately when a problem occurs. Perform troubleshooting then start it again.

If the machine be driven by a diesel engine, the engine should be declutched before starting. Slowly engage the clutch after the engine is started.

Operation

1. First make sure the ground wire is connected well. It is dangerous to start the machine without connecting the ground wire!

2. When connecting the power supply and running the machine, don’t touch any electrical parts in the electrical control cabinet and operation platform. Doing so can cause an electric shock.

3. To avoid getting an electric shock, do not operate the pellet mill with wet hands.

4. Do not check and change the electrical parts while the power is connected. Doing so can cause electric shock, burns, and possibly death.

5. To avoid accidents, only qualified individuals with a strong mechanical aptitude and knowledge of electricity should perform maintenance on the machine. 6. When maintaining the machine, the machine should be locked out and tagged out (LOTO). If LOTO is not possible to repair the machine, the power supply must be within arms reach.

7. To avoid severe injury, never use your hands to touch the moving parts of the machine.

8. The workshop must have good ventilation and good lighting/visibility. The workshop must be kept clean; smoking should be strictly prohibited to avoid the



explosion of dust.

9. Check the fire-protection and fire-proofing devices of your shop as well.

10. To prevent severe injury, never allow children to come close to a running machine.

11. Add lubricating oil into the bearings of the roller when the machine runs for 12 hours.

12. When the operator turns the roller, the machine should be locked out and tagged out (LOTO).

13. Individuals who do not understand the performance of the machine should not operate and maintain the machine. New operators should review this manual thoroughly before operating. If possible, new operators should have close supervision when learning to operate a pellet mill.

14. The distance between roller and template should not be less than 0.1mm. When the distance is less 0.1mm, it will heavily damage the roller and template.

3. Application range and performance features:

1. Application range

STAK Pellet mills can produce pellets from many forms of biomass (sawdust, straw, grass, chopped leafs, exec.), the raw materials may contain coarse fiber up to 70%.

2. Performance characteristics:

Pellet mills mainly consist of a gear-box, flat die, roller, and lubrication system.

3. Feeding style:

Full feeding under gravity.

3.3. Flat Die

1). Raw material:

Flat dies are available in two different high strength alloys. The available alloys are a medium carbon alloy steel and a stainless steel.



The medium carbon alloy steel has 20CrMnTi, 40Cr, 35Crmo, and exec. The stiffness and toughness are good. The Rockwell hardness after heat treating is HRC 55-66. This alloy provides good abrasion resistance and a long lifespan.

The stainless steel alloy contains 4Cr13, 3Cr13, 2Cr13, and exec. The Rockwell hardness after heat treating is HRC 55-62.

2). Compression ratio:

The flat die’s hole compression ratio depends on the raw material and the quality of raw material. The general rate scope is 1:4-8.

3.4. Lubrication

The oil level of the reducer should be checked frequently. 55#65# hyperbola gear oil is recommended. After operating 500hours, the oil should be changed.

4. The factors which influence pellet quality:

1. Raw materials: 　　　1.1 The quantity and cubage of raw material:

Generally speaking, the quantity of pellets produced depends on the cubage of raw material fed into the machine. However, soft materials compress more than hard materials. One cubic foot of grass will produce fewer pellets than one cubic foot of sawdust. Additionally, pellet mills will have less output of pellets when using hard materials as feed-stocks when compared to using soft materials.

1.2 Moisture content:

If the moisture content is high, it can influence the quantity and quality of the pellets produced. Feeding materials with a high moisture content into a pellet mill can be difficult and can cause “bridging” or blockage. Generally the moisture content should be between 13-16% for best results.

2. Operating and experience

2.1 After mixing water and materials, slowly begin feeding the mixture into the hopper.



　2.2 The distance between roller and die has a big influence on pellet quality. The distance should be between 0.05 and 0.3mm. When the distance is more than 0.3mm, the material will not have uniform distribution across the flat die. This will decrease the quantity of pellets produced.

When it is less than 0.05mm, machine damage can occur. When the distance between the roller and die is less than 0.05mm, the components can grind and cause huge abrasions.

Generally speaking, the easiest way to estimate the distance between roller and die is to monitor the temperature and sounds of the roller and die during machine operation. You should listen carefully for the sound of metal components grinding together. If these sounds are present, more than likely the distance between the die and roller is too close. If smoke is present, the die and roller may be too hot. If the die and roller becomes too hot, it may be due to the distance as well.

2.3 The surface finish quality of die holes:

The die should be kept oiled to prevent rust. If rust is present, friction will increase. If this occurs, the quality and quantity of pellets will be reduced. To remove rust, the die should be abrasive blasted with 100 grit or finer media.

If abrasive blasting equipment is not available, an alternative way of polishing treatment is as follows:

1). Using a steel nail with a diameter less than the die holes, remove the materials that are jammed inside the die holes.

2). Apply grease on the feeding surface of the die and adjust the distance between the roller and die.

3). Mix together 10% fine sand (100 grit or finer) and 80% biomass, then add 10% grease. Mix these materials together to make the polishing material.

Start the machine and feed in the polishing material. The polishing material should be continually fed into the machine for at least 40 minutes. When the surface finish quality has improved, the pellets will become loose and will not plug inside the die. The die should have more than 95% of the holes available to produce pellets.

2.4. When starting the machine for the first time, your materials should have 10% grease added. After feeding the grease material mixture for 5 – 10 minutes, you may begin feeding the main material. Put aside the grease material mixture for future use.



2.5. You should check the ring die and use a steel nail to clean the holes every week. This will help to guarantee stable operation.

2.6. Never overload the hopper. Materials should be added continuously as they are consumed. Material inside the hopper should be kept to a minimum. Overloading the hopper can increase the force required to make pellets. This can lead to machine or motor damage.

2.7. Die holes may jam due to bad material, improper polishing, or when pelletizing without feeding the grease mixture through a new die. If a die hole is jammed, you should use a steel nail to open it.

2.8. When the friction modulus is too small or too big, the material will not force through the die, reducing the pellet quality and quantity. If this problem occurs, you must adjust the distance between the die and roller.

2.9. The operator should know the moisture content of feeding material. If it is too high or too low, it can cause the die to clog. If the die clogs, production should be stopped immediately.

Operating with a clogged die can be dangerous. When the die is clogged, the temperature of the die will increase and can cause the material to burn. If a machine runs more than 5minutes with clogged conditions, the die and protective cover will be very hot! Do not open the flat die protective cover to remove the clog until it is cool enough to touch!

3. Machinery installation and spare part’s selection

3.1. Feeding board position:If the feeding board position is incorrect, the quality of pellets will be reduced. Additionally, the motor could be damaged. The proper installation distance is between 10-30mm (0.4” - 1.1”) between the feeding board margin and flat die.



3.2. Cutter:

If the cutter is too close to the flat die, it will influence the pellet size and capacity. It

should be adjusted properly.　3.3. Roller:

After installation, you should fill the lubricate oiler with a grease gun.

3.4. The adjustment between roller and flat die:

As shown in the picture below, the adjustment is clockwise. Adjust the spaces between the roller and flat die and adjust the nut. Rotate with balanced pressure using a wrench. 3.5. Adjustment of distance between the roller and bearing:

A large distance between the roller and bearing will cause damage to the bearing, roller oil seal, and roller axle. To prevent damage, the distance between the roller and bearing should be checked frequently. The distance between roller and bearing should rotate easily with the smallest gap possible If the distance is too small, the roller will overheat and damage the bearing.



Notice:

The distance between the roller and flat die can not be less than 0.1mm. If the distance is too small, the roller will contact the flat die directly and can cause damage.

When you rotate the roller by hand, you must disconnect the power.

You should add grease to the roller and bearing at least every 12 hours of operation.

3.6. Installation Method of Roller Bearings:

5. Electric control circuit:

1. General STAK pellet mill electric circuit drawing



2. Operator Interface

2.1. Electrical Control Board: 1. Urgent Stop; 2. Voltage Meter; 3. Current Meter, 4. Temperature of Pellet Press C1; 5. Temperature of Motor C2; 6. Power On/Off Key; 7. Starting Button; 8. Stop Button; 9. Power Indicator; 10. Running Indicator; 11. Alarm,



6. Maintenance:

Preventative maintenance should be done routinely. The machine operator should check for, and tighten any loose bolts before starting the machine. This step can help prevent machine damage and is necessary for safe operation.

After 200 hours of use, dissemble and check the axle to see if there is sufficient pyro-lubricant. If not, clean the axle and add lubricant immediately. This will prevent the axle from drying and wearing due to friction.

Mills powered by diesel engines should have the gearbox checked every six months to ensure that it is well lubricated. Lubricant must be added as needed and replaced annually.

General Maintenance

1. The oil level of the reducer should be checked frequently. 55#65# hyperbola gear oil is recommended. After operating 500hours, the oil should be changed.

2. The oil surface of gear reducer box should be checked periodically.



3. Check the foundation bolts and connection bolts once per shift. If the bolts are flexible or loose they should be repaired.

4. Always clean machinery after use.

5. You should often check the indicator lights and on/off. Replace if needed.

7. Troubleshooting:

Problem Potential cause

It is difficult to start the motor

1. Low voltage2. Blown fuse3. Low oil in gear case4. Overheated or bad relay

The motor is too hot 1. Wrong size material fed into machine2. Plugged holes in die3. 3 phase motor is only running with 2

phase (not applicable to single phase or diesel engine powered mills)



Pellets are not forming properly or machine can not make pellets

1. Clogged die2. High moisture content3. Dry material4. Insufficient binder (Some materials may

require a binder. Try adding some water and a binding agent like corn starch, vegetable oil, flour, wax, gluten, distiller’s grain, corn meal, corn, soybeans, sunflowers or experiment with other available materials.)

The bearing is too hot 1. Too much or too little grease2. Bad quality grease3. Bent axis or imbalanced rotor4. Hopper is being overfilled when operating5. Dry material6. Clogged die

The axis leaks oil 1. The oil level is too high2. Improper oil type3. Bad oil seal

Short bearing lifespan 1. Using improper or low quality bearings2. Using improper grease3. The feed material has low moisture

content4. Too high RPM on diesel engine

Pellets smolder in pellet stove and do not burn

1. The moisture content is too high. Allow pellets to dry longer before using

Pellets come out short and in little pieces

1. Dry material2. Insufficient binder3. Improperly polished holes in die

Spare Parts (STAK-SD400 as example):

Name Model Q’ty Installation Location



Bearing 32228 1 Under the main shaft

6316 1 Top of the main

shaft

30213 4 Roller

Oil Seal 80*110*12 2 Pellet Press

O Ring 75*3 2 Roller

Template 400 Pellet Press

Shell of Roller 2 Pellet Press

Main Shaft STAK-SD400 1 Pellet Press

Roller Bracket STAK-SD400 1 Pellet Press

Oil Seal on Roller STAK-SD400 4 Pellet Press



8. Limited warranty:

Our pellet mills are warrantied against industrial defects for 90 days upon delivery. The warranty includes repair labor cost. The warranty does not include “consumable” wear items such as rollers and dies. Users are responsible for paying for the replaced parts and relative charges. The warranty does not include costs associated with the repair of damaged units determined to be caused by improper operation. If any components are damaged during shipping, please contact us immediately.

9. Sample Drawing:



This operation manual contains technical parameters of pellet

machines; we reserve the right to revise all concerning information.

Save harmless agreement

Because the use of the materials, instructions, and information being sold is beyond our control, the purchaser or user agrees, without reservation to save the seller, its agents, distributors, resellers, consultants, promoters, advertisers or employees harmless from any and all claims, demands, actions, debts, liabilities, judgments, costs and attorney’s fees arising out of, claimed on account of, or in any manner predicted upon loss of or damage to property, and injuries to or the death of any and all persons whatsoever, occurring in connection with or in any incidental to or arising out of the purchase, sale, viewing, transfer of information and/or use of any and all property or information.



stak pellet mills general operating handbook 1

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