Wood fired boilers come in the form of stationary boilers, manual fuel supply, and are engineered for the best fuel economy.Wood-burning boilers can use a variety of fuels such as: Firewood, coal, cashew shells, rice husks, …
In Vietnam, firewood is an ancient and most popular fuel, not only in Vietnam but also around the world. Firewood plays an important role in production and processing. But in the industrial scale firewood is difficult to use, transport as well as store, because firewood has heterogeneity in physical and chemical properties, different sources and types.
In particular, Vietnam is a country with a distinct and diverse geographical climate, with many types of trees that can be harvested for firewood. Vietnam does not have large-scale firewood plantations but only small-scale ones, so it creates many difficulties for industrial parks if they want to buy.
A. Wood fired boiler overview
Fixed wood-fired boiler with external combustion chamber includes 3 burning passes and these 3 passes can be used at the same time, the fuel that a wood-burning boiler can use is as diverse as firewood, coal, rice husk, etc. ..
1. Structure of wood-fired boiler
The structural design of a wood-burning boiler includes the following main components:
- Furnace: It is made of cast iron with high temperature resistance, and is designed according to customers’ wishes if customers want to use coal, firewood, rice husk, …
- Buildable: The part needs to operate stably for a long time to be able to improve efficiency while burning all the fuel.
- Radiant Heat Collector: Built on cast steel tubes specially manufactured for the boiler, responsible for capturing the direct radiant heat generated when the furnace is fired.
- Disposal of ash and slag: In order to optimize the user’s energy, the wood-burning boiler is integrated with 2 ash and slag discharge screws.
- Pass 1 2 3: with 1 being the furnace tube, 2 – 3 being the fire tube beam.
- Technological pipes: Main steam valve, safety steam valve, air release valve, blowdown, water supply line, control signal assembly,…
- Deduster: For environmental protection and pollution-free all boilers are equipped with a deduster
- Dust suppression tank: After passing the dust collector, they will go to the centrifugal dust suppression tank along with water spray in the opposite direction, settling and striking the dust with the water surface.
In addition, the wood-fired boiler also has a drying oven, chimney, absorption tower, centrifugal fan, flotation tank, chemical tank, …
2. Working principle of wood-burning boiler
Wood-fired boilers work similarly with other fuel-fired boilers. Steam boilers generate heat by themselves when the fuel is burned and then converted into heat energy of steam. The amount of steam generated is applied in industrial production and processing industries.
Wood fired boilers operate with the requirement that the water supplied to the boiler must be distilled water without metal impurities. The amount of heat that a wood-burning boiler can provide is from 1300 – 1900 degrees.
The smoke part of the boiler will be passed through 3 passes, the temperature will gradually decrease when exiting the boiler, the steam will be separated into steam and recirculated back to the operation process.
B. Technology of wood-burning boiler
On the market, we can see many technologies of wood-burning boilers such as: Static recording, chain burning, internal combustion, … But the most popular and popular, there are only two types of technology:
- Push burning technology: This technology is popular in wood-burning boilers because it has the characteristics that meet the properties of firewood fuel that it can use many different types of firewood in terms of shape, size, moisture content, … This technology also shows its superiority when it can use firewood with low calorific value and high humidity.
- Fluidized bed technology integrated with smoke circulation system: The principle of smoke circulation makes it easy to adjust the combustion chamber temperature according to user needs. Helping the operator control the glue in the combustion chamber, the wood-burning boiler still operates normally and stably despite the fuel changes.
C. Advantages and disadvantages of wood-burning boilers
Wood fired boilers have the following advantages that you should choose:
- The obtained heat efficiency is high.
- Easy to use and operate the boiler.
- Wood-burning boilers during operation have low emissions, avoiding environmental pollution.
- The boiler has a variety of fuels to burn at the same time such as: sawdust, shavings, cashew residue, firewood, rice husk, … Combined combustion helps save fuel effectively.
- The output steam is stable, the quality and especially the wood-fired boiler has a large supply temperature and pressure stability.
Besides the advantages, wood-burning boilers also have the following disadvantages:
- Firewood fuel emits CO, CO2, SO2,…
- Self-sufficient fuel requires workers to observe additional fuel at the right time.
- The characteristic of firewood is that it leaves a lot of soot when burning because it costs more to clean the furnace.
- Unpopular in large industrial zones due to unsuitability.
D. Attention when using a wood-burning boiler
Extremely high pressure boilers are very dangerous in the event of an accident, so we need to pay attention to the following issues:
- Inspect the wood-burning boiler before operation to ensure that there are no broken or leaking parts.
- To make the fire burn faster, arrange the smaller firewood on the bottom and the larger firewood on the top.
- Make sure someone is on duty to ensure that the fuel is continuously added and completely burned out.
- Do not allow water shortage in the boiler, always observe and check before, after and during the operation of the wood fired boiler.
- The water supplied must be treated with distilled water free of parametallic contamination.
- Water and steam should be introduced slowly and should be done with the oven turned off.
- Clean the oven periodically to avoid dirt that causes a decrease in the operating efficiency of the oven.
- Wood-burning boilers need periodic maintenance and if damaged, contact reputable boiler service companies.
In addition to wood-burning boilers, you can learn about other boilers such as fluidized bed boilers, static grate boilers, etc. To make the right decision and best fit your industry.
KS Boiler is a reputable boiler installation, repair and maintenance service provider in Vietnam.