INDUSTRY 02

Power Plant FGD

02 / POWER

Multi-point monitoring across the wet FGD loop: limestone feed, gypsum slurry, AFT-tank density and wastewater.

2 applicable products 4 application cases

Overview

In coal-fired power plant flue-gas desulfurization (FGD), four measurement points dominate: limestone slurry feed at the absorber inlet, gypsum slurry at the absorber outlet, AFT (After-Filter Tank) gypsum density, and wastewater suspended solids. They directly determine desulfurization efficiency and equipment life. The conditions — corrosive, hot, scaling — are punishing for any density meter.

Typical challenges

  • Limestone / gypsum slurry corrodes wetted parts severely
  • Crystallization causes insertion meters to scale and require frequent service
  • Chloride-rich wastewater pits standard stainless
  • Sealed-source meters carry licensing and shielding overhead

Recommended solutions

Measurement pointPrincipleModels
Absorber inlet — limestone slurryUltrasonicPS7000
Absorber outlet — gypsum slurryUltrasonicPS7000
AFT tank — gypsum densityUltrasonic / Tuning forkPS7000 / PS7400
Wastewater dischargeUltrasonic / MicrowavePS7000 / PS7600
Slury density meter · PS7000

Online Measurement of Gypsum Slurry Density in Absorption Towers

In the wet flue-gas desulfurization process, real-time monitoring of gypsum slurry concentration is crucial for ensuring the quality of the by-product gypsum and the proper operation of equipment. However, conventional concentration meters—such as mass flow meters, tuning fork sensors, and differential pressure concentration meters—suffer from issues like radiation safety concerns, bubble interference, and scaling. Pisonics’ PS7000 employs ultrasonic technology for non-contact measurement, can penetrate bubble layers to deliver stable and reliable concentration data, and requires no maintenance, with a service life exceeding five years.

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Slury density meter · PS7000

Online Density Measurement for Limestone Slurry Preparation

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Slury density meter · PS7000

Online Measurement of Desulfurization Wastewater Density

In the flue-gas desulfurization process at power plants, online monitoring of the slurry density in the underflow from the thickener is critical. Conventional contact-type instruments are prone to scaling and corrosion, making it difficult to meet the demands of long-term, stable operation. Pisonics’ PS7000 acoustic impedance concentration meter employs a non-contact ceramic probe and a corrosion-resistant lining, effectively addressing severe corrosion and fouling while ensuring the accuracy and stability of the measurement data.

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Slury density meter · PS7000

Online Density Measurement for the AFT Tower (High-Concentration Desulfurization Slurry Processing Tower)

In the AFT tower, measuring the density of high-concentration, high-viscosity, and easily crystallizing slurries has long been a challenge. The PS7000 acoustic impedance concentration meter, employing non-contact measurement, overcomes the failures of conventional instruments caused by clogging, wear, and crystallization, enabling real-time, continuous monitoring of slurry density and automated control of the discharge process, thereby ensuring stable system operation.

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