Influencing factors of slagging on heating surface of boiler
(1) Ash characteristics of pulverized coal
Generally, the softening temperature ST of ash is used as the main indicator of slag formation. Coal with low ash melting point (ST<1200℃) is easy to slag. In addition, the slagging index also includes: silicon ratio, alkali-acid ratio, slagging index, limit viscosity and so on.
（2）Aerodynamic characteristics in the furnace
Improper air flow organization leads to flame center deviation, and the pulverized coal air flow flame adheres to the wall, causing local slagging of the water-cooled wall;
Improper air flow organization, forming flue gas retention vortex area and forming a reducing atmosphere (with CO), reducing the ash melting point and increasing the possibility of slagging.
Excess air coefficient: When the excess air in the furnace is too small, a reducing atmosphere may be generated, and the tendency of slagging will increase accordingly.
（3）Influence of boiler heat lo
Industrial boilers will produce wastes that needs to be treated during the use process, which is what we mentioned of boiler blowdown. What are the methods for boiler blowdown?
1. Regular blowdown
1) The time interval and quantity of discharge depend on the test results of boiler water. It usually do not exceed 5% of the water supply.
2) When the regular blowdown is being made under high load of the boiler, the blowdown of the water-cooled wall header is generally not required to avoid affecting the normal water circulation of the water-cooled wall and forming a tube explosion incident.
2. Continuous blowdown
The amount of blowdown shall be determined according to the test results of the boiler water, and shall be completed by adjusting the needle-shaped angle of the blowdown tube.
The temperature of flue gas generated by a biomass-fired boiler is relatively high. But it is not corrosive. So, it is suitable to use heat resisting glass fiber needled felt bag which has a good use effect. Moreover, this kind of cloth bag is not very expensive.
One of the most important accessories you can have for your steam boiler is a water softener, which serves several purposes and plays a crucial role in helping your boiler avoid malfunctions and run more efficiently. Let's go back to the basics and walk through how water softeners are used in steam boilers.
The choice between a steam system or a thermal fluid system is governed by the process requirements. The range or process temperature is a deciding factor. If the system’s required temperature is above the freezing point of water (0°C) and below approximately 160°C, the choice is usually steam. However, if the required temperature is above 160°C, thermal fluid may be a better solution. Thermal oil heater systems can be designed with maximum operating temperatures to 325°C.
Yes, it is recommended to turn your boiler off whilst the tank is being filled and to leave it off for a short period afterwards of up to 30 minutes. This will ensure that any sediment that has settled on the base of your tank is not stirred up and drawn into your fuel line.
The main sectors in which industrial steam boilers are used are:
Food, in industrial bakeries or baby food (as an example)
Textile, in rotary dryers
Chemical, for reactors or storage
Pharmaceutical, for the manufacture of medicines
Cosmetics, for the production of perfumes and creams
Stationery and printing, in drying tunnels
The cement industry, for the manufacture of cement parts
Oil, for the storage and distribution of heavy oils
Wood, involved in the process of melanin production
Hospitals and hotels, especially in the laundry and kitchen areas
Automotive and surface treatment, for the final metal finishing.
In a water tube steam boiler, unlike a fire tube, water circulates inside the tubes. The heat that is generated and the combustion gases that surround the tubes heat the water that circulates inside them. Many water-tube boilers operate according to the principle of natural water circulation.
The capacity of this type of boiler can be enhanced by increasing the number of tubes in the boiler.
