Application Of Jets In The Oxidation Treatment Of Desulfurization Slurry

In the wet limestone-gypsum flue gas desulfurization system, the desulfurization slurry is highly corrosive and abrasive, and in order to obtain qualified by-products, the oxidation rate of the desulfurization products such as calcium sulfite and ammonium sulfite is required to reach more than 99%. Therefore, there are special requirements for the structural form and material selection of the aeration device.

The jet aeration and oxidation device is powered by a slurry circulation pump, which generates negative pressure through the jet to suck air or oxygen into the mixing chamber. In the mixing chamber, gas and liquid are in close contact, and the oxidation efficiency is much higher than that of conventional oxidation devices. There is no need for an oxidation fan, any rotating parts, or any other mechanical stirring device. It comes with a secondary booster device.

Features of the Jet Aeration Oxidation Device

1. Tinier bubbles are one of the main features of jet aeration. The bubbles of micropore or mesopore bubble diffusers can only reach the millimeter level, while the bubble diameter of a jet aerator can reach about 100 microns, which provides a very large gas-liquid contact surface area.
2. Liquid-gas jet aeration has much greater mixing intensity than air jet and does not require a separate stirring device.
3. Longer residence and contact time. The air is sucked into the mixing chamber of the ejector. Under the action of the powerful jet, the bubbles are broken and the gas-liquid is mixed. The contact reaction between oxygen and slurry has already started in the ejector, and then enters the secondary efficiency device through the pipeline to entrain and mix more slurry, realizing the remixing and contact reaction of the liquid-gas mixture and the liquid in a limited space. Finally, it is released from the bottom into the oxidation tank, which greatly extends the contact time between oxygen and slurry, thereby ensuring a mass transfer efficiency much higher than that of the air injection device.
4. Jet aeration has excellent reliability. Since the jet aeration device has no moving parts, it greatly overcomes the shortcomings of air injection devices being easily clogged and damaged in complex slurries with strong corrosion and wear and high solid content. It is also more stable and reliable than mechanical stirring devices. Compared with other aeration devices, jet aeration devices can achieve long-term stable performance with less failure and maintenance.
5. Jet aeration does not require an oxidation fan or corresponding humidification and cooling measures.
6. Under normal circumstances, the circulation pump required for jet aeration does not require a high lift, and can basically use the same lift as the slurry circulation pump for flue gas spray washing. At the same time, the higher liquid-to-gas ratio required for spray washing allows the circulating slurry required for aeration without the need for a separate circulating pump.
7. When conditions permit, pure oxygen or enriched oxygen can also be used for jet aeration, which is more efficient, requires less investment, has a wide load adaptability range, stable performance, and strong reliability.

Application Experience

Judging from domestic and foreign experience, jet aeration has gradually replaced various air blast aeration methods in many aerobic wastewater treatment applications due to its efficient mass transfer, simplicity and reliability, no clogging, no faults, stable performance and no attenuation. More and more users prefer this simple installation method that does not require draining water to empty the tank during upgrades and renovation. It is foreseeable that the application of jet aeration in the oxidation treatment of desulfurization slurry will also enter a period of rapid development.

System Design and Equipment Layout

The design and equipment layout of the jet aeration system are closely related to suction capacity, residence time, stirring intensity, and energy consumption. Therefore, in order to ensure the aeration effect, our company will provide the design and construction drawings of the aeration system, including the installation positions of the liquid circulation pump, ejector, and secondary efficiency device, the determination of performance parameters of all system equipment, and the design of the system pipelines. The ejector and secondary booster device are developed, designed, and manufactured by our company.