troubleshooting common small wood pellet mill problems. part2

This article will be a series about how to solve the pellet mill problems. First of all, let's be clear that these solutions are especially given to the small pellet mill, or you can say, wood pellet mill, and the pellet machine must be flat-die type. If you have a troubled ring-die pellet press, we may talk about it later in other series, but not here.

This series include three parts. In the first part, we will know about the inner structure of both die-turned and roller- turned small pellet mill. And I will make a brief about how does the wood pellet machine work and how are wood pellets made. In the second part, we will learn how are the crucial parts of the small pellet mill broken, and how to maintain the wearing parts. In the third part, we will talk about pellets, how to make wood pellets and why the pellet mill won't work well.

The wearing parts of small pellet mill

Generally speaking, the most vulnerable parts of the flat-die small pellet mill are the die and the roller. Because of the pressure between them, they are easy to get damaged. But this is not the only two parts wear quickly. In fact, electric parts, bearings, grease seals, belts etc. can be broken soon if they are not used properly.

In GEMCO's circumstance, the small pellet mill's characteristics are fully detailed in the brochure. Follow the directions and the parts can serve a long time. But if the parts wear, we can provide spare parts according to the model of your pellet machine. Our spare parts are all certificated with CE and ISO9000, please feel free to contact us if you need them.

Here are the charts of the wearing parts.

Main wearing part list of model ZLSP-D

Parts	Model							Qty	Installation site
	120	150	200		230	260	300
Bearing	6203RZ	6204RZ	6205RZ		6206RZ	6306RZ		4pcs	Roller
Bearing	6206	6206	6208		6209	6312	6312	1pc	Main shaft
Bearing	30207	30207	30309		32309	30312	32313	1pc	Main shaft
Bearing	6204	6204	6206		6307	6305	6207	1pc	Gear shaft
Bearing	30205	30205	30207		31309	30309	31309	1pc	Gear shaft
Bearing						30209	30209	1pc	Gear shaft
Bearing							6207RZ	6pcs	Roller
Grease seal	28*50*10	28*50*10	42*70*11		47*84*12	58*90*12	55*90*12	1pc	Gear shaft
Grease seal	Felt retainer							2pcs	Roller
Grease seal	Felt retainer							1pc	Main shaft
Washer	80	80	105	105		150	150	1pc	Coupling
Roller								1set	Upper box body
Mold								1pc	Upper box body

Main wearing part list of model ZLSP-R

Parts	Model			Qty	Installation Site
	200	300	400
Bearing	32310	32316	32318	1pc	Main shaft
Bearing	6310	6316	6318	1pc	Main shaft
Bearing	NJ207E	NJ211E	NJ213E	4pcs	Roller
Grease seal	42*62*8	60*80*8	70*90*10	1pc	Die
Grease seal	45*65*8	75*95*10	85*105*10	1pc	Dust cover for the main shaft
Dustproof	Felt retainer	60*3.55 O-shaped	70*3.55 O-shaped	2pcs	Roller
Dustproof	Felt retainer	Felt retainer	Felt retainer	1pc	Main shaft
Roller				1set	Upper box body
Die				1pc	Upper box body

How to maintain the wearing parts

Here we talk about why the parts get damaged. By know the reason, we can keep the parts from improper operations and save the cost of changing parts.

The roller

Problems	Causes	Solutions
Why the roller shaft gets deformed or fractured?	The resistance of the hard objects. The quality of the forgings.	Check the raw materials and screen the hard objects out. Choose quality pellet mills.
Why the bearings of the roller get damaged?	The bearings are  not lubricated properly. The quality of the bearings.	Make sure lubricating oil is added to gearbox and all bearings are properly lubricated. And choose quality pellet mills.
Why the roller shell wear quikly?	Improper operation. The resistance of the hard objects. Improper heat treatment.	Screen the raw materials carefully and use it follow the specification.

The die

Problems	Causes	Solutions
Why the die broke up?	There are hard objects in the material. Poor Quality.	Check the raw materials and screen the hard objects out. Choose quality pellet mills.
Why the die wears so quickly? And why there are no pellets are produced?	New die has not been ground by oily mixture or ground insufficiently. The distance between the die and the roller should be adjusted. Material contains too much moisture. Normal wear and tear.	Clean feedstock out of the pelletizing holes and grind the die with oily mixture. Adjust the distance between the die and the roller. Adjust material moisture content.

The box body

Problems	Causes	Solutions
Why the box body broke?	There are hard objects in the box body in the in the work process. Rough hit. Poor quality.	Check the raw materials and screen the hard objects out. Put the pellet mills at a safe site. Choose quality pellet mills.
The box body can't be strengthening because of the fastening thread damage.	No control bolt tightened. Rough hit to the bolt. Problematic fastening thread.	Bearizing. Change the box body.
Pinion gear damage.	The bolt or other hard objects fell in the gear box in the in the work process. Improper gear-occlude. Normal wear and tear.	Check every part before the machine started. Change the unsuitable parts.

Usually, service life of a die is 300-500 hours under normal running condition. Most of the dies can be used on both sides. As for the roller, service life is also 300-500 hours under normal running condition. It is recommended to replace roller and die at the same time. And first of all, pellet mill should be used in the proper way following the directions. No company will take responsibility for the loss or damage directly or indirectly caused by improper operations.

GEMCO provide quality pellet mills and plants. And we want to be helpful at the same time. If you're interested in our products, please leave us messages and get a quote. If you already have pellet mills, we are happy to solve your problems and also, we offer ISO spare parts. The other part of the series will be posted next week. If there is any trouble you are experiencing and I haven't talked about, leave a message, I'll give answers in the FAQ in the following days.