NOZZLE
SPRAY NOZZLES FOR THE POWER GENERATION INDUSTRY
SYNERGY Systems has a rich history of providing spray nozzles to the power generation industry, with our nozzles being widely used in fossil fuel power plants for desulphurization and other gas scrubbing applications. Our silicon carbide twist nozzles are becoming an industry standard in vent gas desulphurization applications worldwide. The ceramic material used in the construction of these nozzles offers superior nozzle lifetime, while the twisting design significantly improves overall scrubbing efficiency, making it easier to achieve emission targets.
Nozzles for Flue Gas Desulphurization in Power Generation
Removing pollutants from exhaust gases is a common application in any fossil fuel power station. The primary principle involves spraying a liquid into the gas flow that will react with the gas to form a compound that will fall under gravity, thereby eliminating the pollutant. One example is the removal of sulfur dioxide by spraying a basic lime slurry into the pipe, which reacts with SO2 to form Calcium Sulfate (gypsum) and water. Gypsum is solid at the temperatures involved and falls to the ground, where it can be collected and used for various building materials.
Typically, the nozzles used in such applications must produce a relatively fine spray over a large area but also need to create a spray that will not be quickly swept away by fast pipe gases. We recommend using twisting nozzles for such applications.
Nozzles for Fire Protection in the Power Generation Industry
Due to the nature of the industry, any fossil fuel power station has numerous fire hazards near expensive assets. Fire protection systems differ from fire suppression systems in that they are not intended to extinguish a fire but to protect assets from damage once a fire has started. Examples include keeping volatile materials cool, providing a water curtain to allow people to escape, keeping flammable material wet, and protecting equipment from fire damage.
Nozzles for Pipe Gas Desulphurization
While this application is an example of gas scrubbing, the success that Synergy has had over the years in improving emissions from power stations worldwide means that FGD warrants its own section on our website. The primary principles of FGD involve spraying lime slurry into the pipe gas emissions from fossil fuel combustion. The lime spray reacts with the sulphur dioxide in the gas, forming gypsum, which falls under gravity, thus eliminating the acid rain-causing pollutant.
Guidelines
Concerns about the environmental impact of fossil fuel burning have resulted in increasingly strict regulations and emissions targets for power stations. Heavy fines for non-compliance mean that meeting these targets is a business imperative.
Improving Performance
Synergy's twisting nozzle designs often offer superior levels of performance for gas cleaning applications. They typically produce a smaller drop profile than other similar flow rate nozzles, resulting in a larger surface area of slurry present in the gas flow at any one time. This leads to greater reactivity and, therefore, a more efficient scrubber.
Materials of Construction
The environment for FGD is highly abrasive, making metal nozzles unsuitable in most cases. Synergy manufactures nozzles for applications like pipe gas desulphurization in tough ceramics like silicon carbide.
Large Spray Regions – Key Spray Challenge
Scouring of emission gases in force stations is a vast undertaking that requires the use of spray nozzles in extremely large peaks. Achieving a sufficiently fine spray across the entire region is a significant engineering challenge. To achieve this, different variations of nozzles, including a lot of line work, will be required. However, selecting the right nozzle can significantly reduce the required piping.
The key to selecting the right nozzle is finding the right balance between having small drop sizes (which is desirable for maximum reaction) and the span of the spray. A nozzle that can deliver fine drops over large areas is ideal. The TF range of twisting nozzles has precisely this combination of spray qualities and is, therefore, used in about 80% of pipe gas desulphurization installations.
In situations where protection of resources from fire over large areas is needed, a twisting nozzle is an excellent choice.
Spraying in Threatening Conditions – Spray Challenge
In spray applications at power stations, the general environment is often warm and harsh. This requires the use of special material nozzles. Ceramics are often a good choice. Although they may be more fragile than their metal composite counterparts, the superior heat and abrasion resistance of ceramics make them the obvious choice. If fragility is a concern, abrasion and heat-resistant metal alloys can be used instead.
Abrasion Resistance – Spray Challenge
The spraying of slurries for gas cleaning can be particularly wearing on nozzles. Slurries are, by their very nature, uneven and abrasive. The fact that spraying is continuous and needs to be at relatively high volumes only adds to the speed of wearing. Additionally, spraying liquid into a fast gas stream will mean that particles swept along in the gas flow may cause wear on the nozzle.
