Generally, there is moisture in heat medium oil. And, the moisture will be evaporated during the heating process of the oil. If the water vapor is not discharged from the thermal oil heater, it will cause the fluctuation of heat medium oil pressure. However, the oil-gas separator can separate the water vapor from the heat medium oil and discharge it from the heater, which ensures the stable oil pressure.
If the final temperature of feed water doesn’t reach the saturated temperature after being heated by an economizer, (that is, the feed water has not reached the boiling state), we call the economizer as a nonsteaming economizer. Generally, the final temperature is 30-50℃ lower than the saturated temperature.
1. The storage tank is used to store the heat medium oil of the heating system;
2. The storage tank is used to receive the overrunning heat medium oil；
3. The storage tank is used to supplement heat medium oil for the heating system;
4. The storage tank should be placed at the lowest position of the system;
5. A firewall should be placed between the storage tank and the thermal oil heater;
6. The storage tank should be operated at a low liquid level.
Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at high temperature in the absence of air. This is usually a mixture of short- and long-chain hydrocarbons, aromatic hydrocarbons and some sulfur. Volatile matter also evaluate the adsorption application of an activated carbon. The volatile matter of coal is determined under rigidly controlled standards. In Australian and British laboratories this involves heating the coal sample to 900 ± 5 °C (1650 ±10 °F) for 7 min. Also as the rank of coal increases the volatile matter decreases (AMK).
Although biomass-fired boilers are environment-friendly boiler products, there are also some situations that biomass-fired boilers can’t be used. Main reasons as follows:
Fuel restrictions: The fuels that contain synthetic compounds can’t be used as the fuel of a biomass-fired boiler, such as waste wood furniture, waste paper, production and domestic waste.
Firstly, the combustion of biomass fuel is easy to control. The fuel is easy to ignite. Besides, the combustion speed is faster than that of coal.
Secondly, the biomass-fired boiler can be ignited and extinguished at any time while the coal-fired boiler cannot. The biomass-fired boiler can also be ignited automatically.
Thirdly, the biomass-fired boiler can achieve zero emission of sulfur dioxide, which belongs to environment-friendly boilers.
Advantages: the efficiency of electric dust collector can reach up to about 99%; large gas handling capacity; low flue gas flow rate, low resistance and low operation costs. Shortcomings: complex structure; large size, large area covering; high investments; complex maintenance; special requirements for dust resistance.
The economizer is a heat exchanger equipment which utilizes heat recovery of flue gases to heat feedwater. It can increase boiler efficiency, reduce the temperature of flue gas and save the fuel by absorbing recovery of flue gases. Besides, the feedwater is heated through the economizer before it is supplied into steam drum to decrease the thermal stress of the steam drum wall caused by temperature difference, which can improve the operating conditions of steam drum and prolong the service life of the steam drum.
