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  • The customized propeller stirrer paddle
  • The customized propeller stirrer paddle
  • The customized propeller stirrer paddle
  • The customized propeller stirrer paddle
  • The customized propeller stirrer paddle
  • The customized propeller stirrer paddle

The customized propeller stirrer paddle

No.00370
The propeller stirrer is a commonly used component in stirred reactors. It has a large circulation capacity, low energy consumption and is suitable for stirring low viscosity fluids.
Description

I Definition

The propeller stirrer  is also called as a marine propeller or propulsive stirrer.
When it is running, the paddles will propel the material forward, creat a strong flow of water and shear forces.

II Fluid form produced by propeller stirring paddle

picture of Fluid form produced by propeller stirring paddle  This type of stirrer can make the material circulate in the reaction kettle when stirring, and the function is mainly volumetric circulation, with small shearing effect and good up-and-down tumbling effect. 
 When a larger flow rate is required, the reactor can be equipped with a deflector cylinder.

III Structure and general specification

Standard propeller stirrer has three blades, whose pitch is equal to the paddle diameter d. 

·Diameter

About 1/4~1/3 of the inner diameter Di of the reactor. 

·Speed 

The speed of the blade end is generally 7~10m/s, Max. up to 15m/s.
The rotational speed is 300~600RPM

·Material

Cast iron, cast steel, stainless steel, non-metal, or nonferrous metal alloy with high corrosion resistance.

IV Features

4.1 Advantages

Axial flow agitator.
Large circulation volume and low stirring power.
Commonly used for mixing of low viscosity fluids such as aqueous solutions, emulsions, etc.
Low turbulence of the fluid during mixing.
Simple structure, easy to manufacture.

4.2 Disadvantages

Due to the large shear force generated, it is easy to cause material shear damage and gas-liquid mixing.
It is not suitable for process not allow the material shear damage.

V Application

Low viscosity, large flow rate, with a smaller mixing power, can get a better mixing effect.
Mainly used for liquid-liquid system mixing, make the temperature uniform, in the low concentration of solid-liquid system to prevent silt settlement.

VI Improvement

The vortex could be avoided if the vessel is equipped with baffle plate, the stirring shaft is installed eccentrically, or the stirrer is tilted installed.

VII Commonly used parameters of propeller agitators

 Common size  Common operating conditions  Common medium viscosity range  Flow condition  Remarks
 d/D=0.2~0.5(mostly 0.33) p/d=1,2 Bn=2,3,4(mostly 3)
p - pitch
 n=100~500r/m
 in
 v=3~15m/s
 Less than 2Pa·s   Axial flow type, high circulation rate, small shear force. The application of baffle or deflector can produce stronger axial circulation.  Maximum speed up to 1750r/min.
 The highest blade end line speed up to 25m/s.
  Speed below 500r/min, the viscosity of the applicable medium up to 50Pa.s

VIII Standards

HG/T 3796.1-2005 Agitator type and basic parameters
Chapter
HG/T 3796.8-2005 Propeller stirrers
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