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.
Condensing boilers can achieve up to 98% thermal efficiency, compared to 70%-80% with conventional designs (based on the higher heating value of fuels). Typical models offer efficiencies over 90% when the return water temperature is at 110 ºF or less; the lower the return water temperature, the higher the efficiency gain.
In a boiler, energy from the fuel is transferred to liquid water in order to create steam. Once the water is heated to boiling point, it is vaporized and turned into saturated steam. When saturated steam is heated above boiling point, dry steam is created and all traces of moisture are erased. This is called superheated steam.
All boilers, whether hot water or steam, depend on fuel to run. The heating process is initiated when the burner heats or evaporates the water inside it, which is ultimately transported via pipe systems. Hot water boilers rely on pumps to move the heat through the system, while steam boilers are transported with the pressure generated in the heating process. Eventually, cooled water or condensed steam is returned back through the pipes to the boiler system so that it can be heated once again. While the boiler is generating energy in the form of heat, flue gases, a byproduct of this process, are removed through a chimney system - which is why regulating the emissions of industrial boilers is taken very seriously.
There are a number of considerations to factor when determining the best boiler for your steam generation needs like operating pressure, steam pounds/hour output, demand fluctuation, general application requirments and total cost of ownership, etc.
Two primary boiler types, the firetube boiler and the watertube boiler, are essentially opposite in design. The firetube boiler passes combustion gas inside a series of tubes surrounded by water in a vessel to produce steam, while a watertube instead sends water through a series of tubes surrounded by combustion gas used to transfer heat energy and produce steam.
Reliability is absolutely essential to optimal boiler performance. In order to achieve the highest degree of dependability in a boiler it is important to identify and address the primary causes of boiler problems. One of the most common issues that can compromise a boiler is poor water quality.
The effect of water quality on boiler performance is a huge concern for plant owners and operators. Premature boiler failure often occurs as a result of poor or inconsistent feed water quality. Hard water elements in feed water are responsible for a number of issues:
Safety is always a top priority when working with industrial boilers, at least it should be. Fortunately, safety has become less of an issue with more modern water tube boilers. Compared to traditional fire tube boilers, water tube boilers are far safer, almost to the point where you don’t have to worry about a catastrophic explosion taking place.
Boilers with low water volumes require a minimum flow requirement to prevent localized boiling and subsequent heat exchanger damage in a low to zero water flow situation. Minimum flow requirement varies by boiler design. Regardless if a boiler itself has a minimum flow requirement, every hydronic heating system needs to be designed to carry the energy being created away from the boiler to avoid high temperature shut down.
