How to choose a suitable flue gas desulfurization (FGD) pump according to the desulfurization process?

Selecting an Appropriate Flue Gas Desulfurization (FGD) Pump Based on the Desulfurization Process

When it comes to choosing a suitable desulfurization pump in accordance with the desulfurization process, the following aspects merit careful consideration:

I. Comprehending the Characteristics of Diverse Desulfurization Processes

A. Limestone - Gypsum Wet Desulfurization

1. Process Features: This is a highly mature technology renowned for its high desulfurization efficiency, making it particularly suitable for large-scale power plants.

2. Pump Requirements: Given the nature of the process, pumps with excellent wear-resistance and corrosion-resistance are essential. High-chromium alloy pumps are a common choice. These pumps must possess a robust conveying capacity to handle the large volumes of slurry involved in the process. Additionally, they need to have effective anti-clogging capabilities to ensure continuous and smooth operation.

B. Ammonia Desulfurization

1. Process Features: One of the advantages of this process is that its by-product, ammonium sulfate, can be utilized as a raw material for fertilizers, offering economic benefits. However, both ammonia and ammonium sulfate solutions are corrosive.

2. Pump Requirements: The desulfurization pump used in this process must be made of corrosion-resistant materials. Moreover, it should have an outstanding sealing performance to prevent the leakage of ammonia, which is not only harmful to the environment but also poses risks to the equipment and personnel.

C. Magnesium Desulfurization

1. Process Features: This process is characterized by a rapid reaction speed and high efficiency. Nevertheless, it incurs a relatively high cost, and the subsequent processing of magnesium sulfite and magnesium sulfate is necessary.

2. Pump Requirements: Pumps for magnesium desulfurization must be corrosion-resistant. Additionally, the selection of an appropriate pump model is crucial to guarantee the stable delivery of the slurry throughout the process.

II. Taking into Account the Performance Parameters of the Desulfurization Pump

A. Flow Rate and Head

1. Determination Based on System Requirements: In line with the design specifications of the desulfurization system, it is essential to accurately determine the required flow rate and head. The flow rate should be sufficient to meet the circulation and delivery volume demands of the slurry within the system. Meanwhile, the head must be capable of overcoming the pipeline resistance and the pressure losses in various equipment.

2. Consideration of System Variations: Given the potential for operating changes within the system, it is advisable to select a desulfurization pump that has a certain adjustable range in terms of flow rate and head. This flexibility enables the pump to adapt to different working conditions and maintain optimal performance.

B. Efficiency and Power

1. Efficiency for Cost-Savings: Opting for a high-efficiency desulfurization pump is a key strategy for reducing long-term operating costs. High-efficiency pumps consume less power while delivering the same flow rate and head, resulting in significant energy savings over time.

2. Proper Motor Power Selection: According to the power requirements of the system, the motor power of the desulfurization pump should be carefully selected. It is vital that the motor power matches the actual operating power of the pump. If the motor power is too large, it will not only increase equipment costs but also lead to higher energy consumption. Conversely, if the motor power is too small, the pump may not be able to function properly, potentially causing system failures.

III. Paying Attention to the Material and Structure of the Slurry Pump

A. Material Selection

1. Corrosion and Abrasion Resistance: Since the desulfurization slurry is both corrosive and abrasive, the choice of material for the desulfurization pump is of utmost importance. Common corrosion-resistant materials include stainless steel, duplex stainless steel, and high-alloy cast iron. In scenarios where wear is particularly severe, pumps lined with wear-resistant materials such as rubber or ceramics can be considered. In high-temperature flue gas desulfurization systems, the material's ability to withstand high temperatures must also be factored in.

B. Structural Design

1. Anti-clogging Design for Solid-Laden Slurries: For desulfurization slurries that contain solid particles, the pump's structure should be designed with good anti-clogging performance in mind. Pumps with larger flow channels and non-clogging designs, such as open-impeller pumps or spiral centrifugal pumps, are often preferred. These designs help to prevent the accumulation and blockage of solid particles, ensuring the continuous and efficient operation of the desulfurization pump.