The fundamental justification behind buying solid-fuel boilers is that the fuel used is a cheaper alternative to oil and gas, which can lead to faster returns. Several years ago, all boilers were solid; However, the ease of oil and gas pipelines along with falling fuel prices, rising labor costs, and strict EPA regulations have raised questions about which boiler type will save more money.
Technology has brought a solid fuel boiler in the last few years. The system can be built to run automatically with an electromechanical fuel feed system, variable frequency control, and even an automatic de-ash engine.
Nevertheless, although with modern engineering, saving of solid-fuel boilers must be obtained. When operated properly, this boiler can run continuously, stopping only for the scheduled shutdown procedure.
In order to take advantage of the advantages of solid fuel boilers, some principles of fuel flow and combustion should be understood. Here are three tips for optimizing the operation of a solid fuel boiler.
Solid fuel boilers can also be mounted for easy portability. This flexibility proves to be convenient for users with hot water applications and / or seasonal heat heating.
Continuous and Uniform Fuel Feed is Key
The boiler system is on and off (so to speak) with the fuel flow into the furnace. A boiler that has many problems is a problem that does not have very good control over how uniform and consistent these currents are. This principle is even more important in applications with frequent load fluctuations. The system should utilize fuel input controls because although a slight supply disruption can cause disruption to the load. The fuel metering into the boiler must be in accordance with the load requirements or the process will not be in equilibrium. It can help to see fuel as a material that, along with fire under fire and over-fire fire (discussed later), generates energy.
With solid fuel, there is almost always a row of particle sizes. Due to this fuel size difference, fuel metering should keep current in constant turbulence so that different sizes will not break away. If there is a tendency of separation, the furnace bed will not be uniform and the combustion will be biased against a certain area. Uniform fuel consistency will make the burning surface area larger and prevent hot spots and dead air zones inside the furnace.
Using fuel transfers and metering systems that apply augers to fuel transfers is an effective way to control the feed rate appropriately as well as to maintain a consistent fuel mixture.
Screw conveyors prove to be far more effective than chain conveyors or belts. Flight mode and auger casing enable bait level projections to be more accurate. Other types of conveyors are notorious for causing “bridging” fuels that cause an uneven fuel layer on the furnace floor, leading to inefficient combustion. The measurement system that applies the screw conveyor also makes a plug between the furnace and the outside environment. The chain metering system does not create such a seal, thereby allowing unmeasured amounts of excess air into the combustion zone.
Under & amp; Dash; Fire Air: Less is More
More often than not, solid fuel systems use too much air under fire and, consequently, do not have sufficient fuel stacks in the furnace. When the air / fuel ratio is unbalanced, combustion occurs prematurely which not only reduces the efficiency potential, but also can cause damage to the furnace.
As solid fuel burns, it develops. First, the moisture in the fuel evaporates. Once dry, the fuel will start releasing volatile gases. As more air is introduced, the gases ignite and release energy. This process will continue until the carbon remains. Finally, the ashes are released and remain discarded.
This scheme shows the process by which fuel enters the furnace and passes through various stages of combustion.
When looking at the pile of fuel in the furnace, there should be no visible fireplace. Actually, it should not look like a heap of burning. When sufficient amount of air is used, the fuel pile will appear “smoking”, but the truth is that heat and air react with fuel and release volatile fuel gas. If underfoot is used too much, volatile gas will detach and burn simultaneously, releasing heat on the furnace floor and not at the top of the furnace where heat transfer will begin. This premature burning can quickly reduce the storage period and also interfere with heat transfer and even absorb dust / dust particles in the flue gas.
This is a good photo showing the volatile gas flow released from the fuel and up to the top of the room where the combustion process will be finished.
Be careful not to reduce the air under fire so low that the boiler loses burning. This can be dangerous because the system may react by reducing the fan level which will cause more fuel to evaporate and fill the furnace. If these gases are suddenly triggered, there could be a dangerous backlash and cause damage to the boiler equipment and anyone nearby. The best way to ensure proper amount of air is to have a control system that drains the air input along with the fuel input. For certain types of fuel, different ratios need to be used. Keep note of which scenario stores the best fuel stack in grates and enough air to evaporate the fuel at a certain level to fit the production.
Dial In on the Over & amp; Dash; Fire Air
After heated fuel reacts with air under fire and volatile gases are released, too much fire is used to confuse it with gas and cause it to burn, releasing heat to be transferred through the boiler heating surface and inside. Water inside the vessel. The goal is to achieve stoichiometric combustion; That is, where every available fuel molecule is released is matched by the oxygen molecules of the fan that produce a flue gas analysis that does not reveal carbon monoxide and no oxygen. This perfect mixing is possible only in the laboratory environment; However, there are ways to achieve highly efficient combustion in a boiler environment.
This is another great photo on the inside of the furnace. As volatiles are released from the fuel, they meet the high-pressure airflow from over-fire jets. This volatile air and volatile gas mill completes the combustion process, releasing heat to be transferred into the boiler.
If there is not too much air to burn, large amounts of carbon monoxide and other fuels will run through the system and out of the pile. This waste of fuel generates heat loss and reduces efficiency. Excessive excessive combustion air produces heat loss absorbed by excess air, also lowering efficiency. The goal here is to find a “sweet spot” for over-fire water. In the same way as air under fire must be modulated at the rate of fuel feed, the amount of air above the fire must depend entirely on the amount of oxygen in the pile. Lower amounts of oxygen indicate more efficient combustion. Take a heap reading to see the correlation between carbon monoxide and oxygen levels to determine the best oxygen settings for each boiler system.
Understand how solid fuel boilers work to understand fuel and combustion processes and equipment that control how fuel is burned. Improper operation can lead to unwanted maintenance and frustration time for boiler owners. On the other hand, when operated properly, solid-fuel boilers can be very reliable, consistent, and cost-effective.