Steam Boiler is a machine used for generating steam by applying thermal energy into water. Steam generated by steam boiler is the medium for transferring the heat energy to production system. This steam will be utilized in the production system.
Steam boiler capacity depends on how much steam is required. This ranging from 50 Kg/hour until 20 TON/hour or even more. If steam boiler has capacity of 500 kg/hour, meaning steam boiler produces 500 kg of steam every hour.
There are a lot of advantages of using steam boiler, however let’s learn how this steam boiler works.
How does Steam Boiler work?
Because how complicated steam boiler operate, the explanation is simplified by dividing into three sections. These are three crucial system for steam boiler can operate properly:
1. Feed Water System
Feed water system provides water into the boiler. This water soon will be evaporated into steam after reaching its saturation (Boiling) point. This system connection is started from source then with feedwater pump, feedwater transferred into boiler through various treatment process.
There are 2 sources of feedwater. First source is from external sources. External source feedwater can collect from either rain, nearby lake, pump water, etc. To be processed in the steam boiler, the feedwater required to be demineralized and purified (water treatment*) with mechanical (deaerator) and chemical process (water softener) This is a necessary for the lifespan of boiler.
Second source comes from steam condensation. After thermal energy in steam utilized in the system, this thermal energy is transferred from steam into the system. When steam lose thermal energy, the temperature is decreasing. When temperature decrease lower than its saturation point, steam will be condensed and transform into water. However, this water still contains some thermal energy leftover. It will be a waste to neglect this leftover energy. So, this water can be recirculated into steam boiler as second source. The steam can be condensate using equipment called deaerator.
Also, to be noted, water store in steam boiler can occur sludge on the bottom of steam boiler. So, blowdown is required to clean bottom of steam boiler. Ever
*The importance of water treatment (and how crucial it is)
Many industrial underestimates the importance of water treatment. Steam boilers have an exceptionally high value because of their long-life usage. However, this long-life of steam boiler cannot be achieved without excess blowdown, scale deposits, and condensate loss. Water treatment is a crucial in feed water system. Water treatment will protect steam boilers from all of the harmful effects that decreased efficiency or even boiler shutdown. That is why water treatment is a necessary to have a long-life steam boiler system.
2. Steam System
Steam system include from how water evaporate into steam until steam transferred into production system.
Generally, waters are stored in steam boiler. Then combustion caused by burner (Fuel: Gas/Solar) or furnace (Fuel: Coal/Biomass) produces the thermal energy. Thermal energy applied into water, heating the water until reaching its saturation point and water evaporate transform into steam. This process is controlled by complicated sensor and wiring for controlling the output steam flow rate, temperature, and pressure.
Steam produced is directed to the production system through pipe and valve specifically for steam. Steam pressure also monitored regularly using steam pressure gauge and regulated using valves.
3. Fuel System
Fuel connection also require to transmit fuel into burner or furnace. There are several types of fuel used for this system with each of them have their own mechanism. There are four most fuel utilized for boiler:
1. Diesel
2. Gas
3. Dual (Diesel & Gas)
4. Coal / Biomass
Then the flue gas from the combustion of those fuel will be discarded through some purification process. This purification is required so the flue gas won’t pollute the ecosystem around it.
An importance of fuel system not stop there, the flue gas still contains little heat energy. These waste energies can be utilized to be implement as a preheat for feedwater. To achieve that require another equipment called Economizer.
WHY STEAM BOILER?
1. First of all, Steam contains more energy per mass unit than other fluid medium. Water and
steam can be compared trough illustration below.
Water at 100 degree Celsius & pressure on 1 bar has an energy around 294 kJ/kg
Oil at 150 degree Celsius has an energy around 276 kJ/kg
And steam contain 2550.4 KJ/kg at 100 degree Celsius and on 1 bar
2. Steam boiler use pressure so there no necessary for pump to carry the energy. With pressure differential steam can be transported through the system
3. Have a faster time to reach high temperature because heating process is help with pressure.
4. Because using pure water the steam is not dangerous when for food producing industry.
5. Can produced steam in a high temperature in a relative faster because the heating process is help by pressure.
6. Water itself is a useful and cheap medium for transferring heat energy into the system. However, water require a water treatment before transferred into steam boiler.
THINGS TO BE CONSIDERED:
Poor maintenance can cause a huge damage, considering pressure in steam boiler.
Require more Operating cost than others. This operating cost include water treatment, maintenance, worker, and others
Require certificate to operate Steam Boiler because Steam boiler use pressure for heating up the water so can be quite dangerous.
Without proper maintenance and water treatment, could cause corrosion inside steam boiler.
APPLICATIONS
1. Hospitals/Pharmaceuticals
Sterilization
Autoclaves
Humidification
2. Food Processing
Bakeries
Jacketed vessels
Dairies
Breweries
3. Laundry & Dry cleaning
4. Jacketed kettles
5. Steam Tunnels
6. Bottling
7. Building heat
8. Power Plant (Turbine)