3Y series high efficiency flue gas desulfurization circulating pump is a new type desulfurization pump which is well designed by the company basically on the experience of successfully manufacturing LC-T slurry pump and the research of the national industrial FGD pump. The pump is developed from similar pumps manufactured in other countries, high efficiency, safe, easy maintenance and long life.
It is used for pumping corrosive and abrasive liquid in mine, coal or metallurgy, also used for wastewater treatment and river dredge.
Operation parameter：PH：2.5～13；chloride ion concentration =60000ppm；weight concentration: =60% ；media temperature：=100℃
Capacity Range: 500m³/h ~ 19000m³/h
Head Range: 10m ~ 70m
（1）FGD circulation pump is single stage, single suction centrifugal pump, which is suitable for pumping corrosive and abrasive slurry in FGD absorber tower.
（2）The impeller and wear plate are not sealed with ring, since the ring may be worn out fast and make the efficiency down.
（3）It has axial direction controlling device which can expediently regulate the clearance among impeller, front casing cover and wear plate to insure the maxium efficiency of the pump. That is the best effective way to insure the pump operating in high efficiency all the time.
（4）The pump use back- pull out structure. While the impeller, mechanical seal and shaft are being disassembled, the discharge-suction pipelines don’t need to take down.
（5）The bearing is lubricated with oil and fixed in the dismountable auxiliary seal bearing housing with grommet to prevent dirt and water.
（6）The pump shaft in the form of full diameter and short spindle nose can diminish the flexivity during running, prolonging the operating life of the seal.
（7）Back-pulled out design, the whole rotor parts can be pulled from motor end for easy maintenance. The casing can be kept on the pipeline without taking down the motor.
（8）Front-pulled out design, wear plate, impeller and mechanical seal can be disassembled from suction end.
（9）Bearing support can be adjusted to enhance the abrasive resisting.
（10）The bearings are lubricated with oil to improve the performance;
（11）Casing: the dimension of the pump casing is sufficient for pressure bearing and abrasive resisting.Use the material 2605N which canbe welded. Cochlea tongue has been specially treated in abrasive-resisting. The casing has flow passage tangent outlet and is supported by bracket.
The 2605N is extra-low-carbon duplex stainless steel, and its metallurgical structure is austenitic phase, ferrite phase and precipitated phase. Such structure makes it has both high tenacity like austenitic stainless steel, high rigidity and chloride corrosion resistant performance like ferrite stainless steel. PRE ( PRE=Cr%+3.3Mo%+16N% ) is more than 40 and has much better chloride corrosion and inter-granular corrosion resistant performance than common austenitic stainless steel.
（12）Wear plate: it is fixed between casing and inlet. The wear plate is made of the material Cr30A which is of excellent wear-resisting and errosion- resistance integrative property, so it prolongs the operating life of the casing and impeller.
（13）Impeller: it is made of the material Cr30A which is not weldable. It will be more economical in long running because the shaft support can be adjusted; the impeller can be remachined to prolong the operating life when it is wearable.
Cr30A is duplex white cast iron and its metallurgical structure is austenitic, ferrite, grainy eutectic carbides and secondary carbides. Cr30A contains large quantity of Chromium, Molybdenum and Cuprum with easy passivation and excellent pitting corrosion resistant performance. Cr30A’s corrosion rate is 0.5mm/a in the vitriol condition with 100000ppm chlorides, PH=4 at the temperature of 70℃. Carbides make Cr30A have excellent abrasion resistant performance. Impact resistance is 10.79J/cm2 and tensile strength is 554.2MPa.
（14）Mechanical seal: for disassembling easily, the mechanical seal is designed as single face packaging frame. These are two kinds of design schemes for flushing: one is to set up the flushing pipeline to fix the flushing water .the other is to flush segmentally without fixed on the flushing pipeline. Within the work area of mechanical seal, if the medium contains gas, the mechanical seal will get dry run. In that case, the impeller is designed with gas vents to avoid contacting mechanical seal by dirty large grain. It is tend to discharge emptily while the pump is discharging water. The cubage of the seal cavity is big, lubricated and cooled enough.