Energy briquettes are a sustainable fuel made by biomass briquettes presses from biomass materials such as saw dusts, wood shavings, straws, rice husks, wasted border, abandoned furniture, etc. Biomass briquettes have different sizes and shapes which are decided by the requirements of the combustion chamber and the biomass briquettes presses. Briquettes are used to replace fossil fuels by households and industries for they are green , environment friendly and sustainable and easy to be handled. The burning effect of briquettes are the concerns of briquettes consumers.
As a biomass fuel, there are factors that influence the briquettes burning, such as, briquette calorific value, briquette density, briquette resistance to humidity and air flow, ash removal, positioning of briquettes in burning equipment, etc.
Briquettes quality is one of the most significant factors influence the burning of briquettes. Briquette calorific value density and resistance to humidity are the influencing briquetting burning directly.
Calorific value of briquettes are one of the most influential factors to briquette burning. Higher the calorific value is, the easier and better they will be burned. For your reference, the calorific value of some of biomass are presented in the following forms:
Briquette density influences the briquetting burning. High density briquettes tends to have a longer burning time and release more heat. Briquette density is significantly affected by raw material particle size and moisture content. The smaller the particle size is, the higher the density of the briquettes is. Moisture content also influences the density. Water in feedstock will obstacle the briquette compression and water evaporator formed because of the high temperature will voids and decrease apparent density.
Resistance to humidity
Briquettes are going to be damaged when subjected to humidity because lignin and majority of binders added are water soluble. Water vapor, released from inherent moisture of briquettes during combustion creates a saturated climate at high temperatures, which is more fundamental to a briquette’s humidity resistance. During combustion if the briquettes crumble too quickly, the loose particles will elutriate unburned through the boiler or will block the airflow.
Factors influence briquettes quality
Briquettes quality influences the burning of briquettes significantly. Do you know what influence briquettes quality during briquettes productions? The quality of the briquettes is directly affected by physical parameters in briquetting process, such as pressing temperatures, compacting pressure, and moisture content.
Pressing temperature influences briquette quality and strength significantly. Pressing temperature impact the soften and excretion of lignin which will function as natural binders to join the fibers of the feed stocks to form solid high density briquettes. The interaction between pressing temperature and briquettes strength are shown in the following table.
The optimal pressing temperature is at the curve peak where maximum strength is achieved by briquettes. When the temperature is lower, briquettes are unstable, have less strength and are likely to crumble during burning, having shorter burning time and producing less heat eventually. When the temperature is higher, the volatile compounds may be burned out and cause burning during pressing.
Briquettes strength is increased with the increasing compacting pressure within the compacting limit of the feed stock. When the pressure is increased, the atmospheric humidity in the feed stock is decreased and briquettes durability is increased.
Moisture content is mainly affected by the feed stock species and its properties. The optimal moisture content is around 10 – 18 %. When the moisture content is lower than 10% or higher than 18 %, particles of feed stock are not consistent and briquette is tended to fall into pieces.
In order to provide you a better understanding, the following video present you how the briquettes are made by commercial briquette making machine, hoping it is useful for you. Click here to watch the video here.
All in all briquettes quality is one of the most significant factors influence the burning of briquettes. Briquette calorific value density and resistance to humidity are the influencing briquetting burning directly. In order to produce high quality briquettes, the processing variables, such as pressing temperatures, compacting pressure, and moisture content should be focused.
External factors influence briquettes burning
Besides the factors mentioned above, there are other factors that affect the burning of briquettes. They’re air flow, ash removal and positioning of the briquettes in the stove.
Airflow is one of the most important factors. Good airflow means good oxygen supply which is a must condition for burning. Only when the adequate supplying of airflow is grantees, the burning of the briquettes can be kept in a higher combustion rate, which means the optimal fire is possible and also prevents the happening of the smoky fire which is caused by insufficient airflow.
The positioning of briquettes may influences the air flow and eventually influences the burning characteristics. Generally, the main purpose of positioning briquettes is to put them in a position enjoying good air flow. When position the briquettes, it’s better to intentionally leave a path for the air flow which make the oxygen available for the briquettes. Take the doughnut shaped briquettes for example. The briquettes should be put in an upright position, which makes the air easily go through the inner hole, enlarges the contact surface of the air and briquettes, and improves the burning efficiency.