LC High-Efficiency Flue Gas Desulfurization (FGD) Circulation Pump

Advantages of LC Series Desulfurization Pumps
The pump adopts an all-metal structure. The pump body is made of ultra-low carbon nitrogen-containing duplex stainless steel CD4MCuN, and the impeller and wear plate are made of high-chromium wear-resistant alloy Cr30A, featuring excellent corrosion and erosion resistance and long service life.
It is a single volute, single-stage, single-suction centrifugal pump with a back pull-out design. The impeller, mechanical seal, shaft and other components can be removed without disconnecting the inlet and outlet pipelines, making maintenance convenient.
A single-end cartridge mechanical seal is generally used for easy installation and disassembly. The impeller is equipped with balance holes to prevent large particles from contacting the mechanical seal.
The axially adjustable structure allows convenient adjustment of the impeller to maintain clearances between the impeller, front cover and wear plate, thus preserving high pump efficiency.
The pump shaft features a large diameter and short shaft overhang, which reduces shaft deflection during operation and extends seal life.
The impeller is connected to the shaft with double keys and dual locking devices, solving the problem of impeller reversal and loosening during shutdown and backwashing.
The bearings are lubricated with thin oil, equipped with an oil level gauge and constant-level oil cup to ensure reliable lubrication. A safe and reliable labyrinth dust cover effectively prevents dirt and impurities from entering and stops lubricating oil leakage.

Structural Features of LC Desulfurization Circulation Pump
1.1 Structural Features
(1) The pump is a single-stage, single-suction centrifugal pump, which has been proven in practice to be particularly suitable for conveying abrasive and corrosive slurries as absorption tower circulation pumps in FGD systems.
(2) No wear ring sealing is used for the impeller and wear plate, since wear rings are rapidly eroded by slurry, causing a sharp drop in pump efficiency.
(3) An axial adjustment structure is provided, allowing convenient axial adjustment of the impeller to maintain clearances between the impeller, front cover plate and wear plate, thus sustaining high pump efficiency. This is a simple and effective way to maintain consistently high operating efficiency.
(4) The pump adopts a back pull-out design, enabling removal of the impeller, mechanical seal and shaft assembly without disconnecting the inlet and outlet pipelines.
(5) Bearings are lubricated with thin oil and installed in a removable bearing housing with auxiliary rubber sealing rings to prevent ingress of dirt and water.
(6) The pump shaft features a large diameter and short overhang, reducing shaft deflection during operation and extending the service life of the seal.
1.2 Design Advantages of Absorption Tower Circulation Pumps
Summary
Back pull-out design: The entire rotor assembly can be pulled out from the motor end for easy maintenance. The pump body remains installed in the pipeline, with no need to remove the motor.
Front pull-out design: The wear plate, impeller and mechanical seal can be disassembled from the suction side.
Adjustable bearing bracket: Improves wear resistance.
Oil-immersed lubrication for bearings.

Pump Body
The pump body is sized for sufficient pressure resistance and wear resistance, manufactured from 2605N material with weldability. The volute tongue features special wear-resistant treatment, and the flow path adopts a tangential discharge design. The pump body is supported by foot mounts.
Wear Plate
This component is installed between the pump body and the suction inlet, made of Cr30A. This material delivers excellent combined resistance to abrasion, erosion and cavitation, thereby extending the service life of both the pump body and the impeller.
Impeller
Constructed from Cr30A, non-weldable. This material choice ensures greater economy over long-term operation. Thanks to the adjustable bearing bracket, the impeller can be re-machined to restore service life when worn.The front vane design prevents large particles from entering the clearance between the impeller and the wear plate. A larger clearance between front vanes and the wear plate reduces fluid velocity in this gap, minimizing abrasive wear. Vanes are engineered with special wear-resistant treatment.Back vanes are incorporated to reduce axial thrust and block large particles. Bearings are designed for high pressure ratings (hydraulic model simulates axial thrust without back vanes).Vented holes on the impeller allow gas entrained in the medium to be expelled, preventing dry running of the mechanical seal.
Rear Pump Cover
Fabricated from 2605N with weldability. Wear typically occurs in the back vane region. Mounted on the bearing support frame to relieve stress, accommodate increased wear and extend service life.The rear pump cover is bolted to the bearing bracket for easy assembly and disassembly, avoiding contact with the pump body and potential damage to the mechanical seal during maintenance.
Bearing Housing
The bearing assembly consists of two parts: a support frame and a bearing cartridge. The bearing cartridge can be horizontally adjusted within the frame via bolts and adjusting screws.This design offers the advantage that the bearing cartridge shifts within the frame (to compensate for re-machined impeller dimensions) without relative movement between the bearing inner and outer rings, ensuring proper functioning of the oil seals.During disassembly, the lower section remains fixed on the baseplate for convenient removal and precise positioning, eliminating component interference during installation.
Mechanical Seal
The mechanical seal features a single-end cartridge design for easy installation and removal.Two flushing schemes are available:
Fixed flushing water via dedicated piping;
Intermittent flushing without permanent flushing lines.
Dry running may occur if gas is present in the medium at the seal interface; the vented impeller prevents this and keeps large, abrasive particles away from the seal faces.
The pump facilitates complete drainage during operation. The large seal chamber volume ensures sufficient lubrication and cooling.