What to do if the granular fuel is of poor quality. How to achieve high boiler efficiency

In Europe, there are standards and requirements for the quality of pellets. In our country, this area is not standardized, you can use any fuel pellets at your discretion. But what kind of restrictions are we talking about? First of all, about limiting the ash content of the fuel material. It is the high ash content that characterizes low quality fuel. But is it so low-quality?

There are no restrictions on the use of low quality pellet fuel

Standardized granular fuel has an ash content of 0.5-0.7%. This parameter for certified pellets is within 1%. Agro granules, widely offered for purchase in Ukraine, can have an ash content of 5-7% and higher. Peat and lignin pellets - 15%.

The second important characteristic is humidity, which should not exceed 12%. It is easier with this indicator in Ukraine. The moisture content of the pellets is not higher than 8%. Ash content in this case is not a problem of the manufacturer, but of rapidly renewable agricultural raw materials. The highest caloric content is found in sunflower meal (5-7%), but its ash content does not meet EU requirements. Lignin granules have an ash content of up to 15%, while their heat transfer corresponds to the characteristics of brown coal.

However, in Ukraine there are no restrictions on the use of ash pellet fuel. Moreover, they will not appear in the near future due to the processing of agricultural waste into pellets. Poor quality fuels usually have the highest calorific value and heat transfer when burning. So you can't call it really low quality.

There are technical limitations - high efficiency of boilers can be reduced

The increased ash content of the pellet fuel implies the settling of soot on the walls of the boiler and the grates of the heat exchanger. With a layer of only 3-4 mm, the efficiency of heating equipment decreases by 20-30%. Soot is an excellent heat insulator. So, when using such fuel raw materials, you need to pay attention to the choice of pellet equipment.

Low quality fuel requires high quality boiler structural assembly

When calculating the use of high-ash pellet fuel, you need to buy a pellet boiler with an ash catcher with unloading it into a separate container. An alternative is a pellet burner with automatic or mechanical cleaning system. However, this is not enough.

If you don't have pellet boiler with an ash catcher and discharge into a separate container, when using ash fuel it is recommended to add catalytic granules. They dissolve the soot layer chemically. The catalyst is added to the pellets regardless of the presence or absence of a burner cleaning system.

Prhttp: // Technical restrictions and use pellet burner it is better to confine yourself to fireboxes with certified wood pellets. In other words, you need to give up low quality fuel. This is necessary to avoid complicated boiler cleaning and loss of efficiency for 20-30%.

Please note that the European DIN standard implies a lower combustion temperature. For this reason, the thickness of cryogenic steel, designed to use wood pellets, may not be sufficient to operate more heat-intensive fuels. As a result of the constant use of agricultural pellets in imported pellet boilers, burnout is possible.

Pellet burners FOCUS are made taking into account domestic raw materials and adapted to agro-pellets, having an effective ash catcher system in the burner. Additional cleaning measures will keep the boiler perfectly clean.

Is it possible to use high-quality and relatively high-quality pellet raw materials mixed?

Imagine a situation where you had a certified quality wood pellet in stock to heat your house, but in the new season the farmers offered a profitable agro pellet. How to proceed? When buying fuel, keep in mind that it is impossible to alter wood and agricultural granules due to different combustion modes. Agro granules begin to bake at temperatures above 560 ° C, so they simply cannot be mixed. The same applies to other types of pellet fuels.