Types of agitators

(1) Propeller agitator
It consists of 2-3 propeller blades with high working speed. The circumferential velocity of the outer edge of the blade is generally 5-15 m/s. Rotary agitator mainly causes shaft
It is suitable for stirring low viscosity (< 2Pa. s) liquids.
Suspensions containing less than 10% body, emulsion and solid particles. Rotary Shaft of Agitator
It can also be inserted into the groove horizontally or obliquely. At this time, the circulation loop of the liquid flow is asymmetrical and can increase.
Turbulence is added to prevent liquid level depression.
(2) Turbine agitator
Installation of 2-4 straight or curved blades on a horizontal disc
Composition. The ratio of outer diameter, width and height of blade is generally 20:5:4.
The circumferential velocity is generally 3-8 m/s. Turbines cause high turbulence when they rotate.
Radial flow, suitable for dispersion and liquid-liquid reaction of gases and immiscible solvents
Process. The viscosities of stirred liquids generally do not exceed 25 Pa. s.
(3) Paddle agitator
There are two types: flat and inclined. The flat impeller agitator is composed of two flat blades. The ratio of blade diameter to height is 4-10, and the circumferential velocity is 1.5-3 m/s. The flow velocity is small. The two blades of an inclined impeller agitator (Fig. 4) are reversed 45 or 60 degrees in opposite direction, resulting in an axial fluid flow. The impeller agitator has simple structure and is often used for mixing low viscosity liquids.
Dissolution and suspension of solid particles.
4. Anchor agitator
The shape of the outer edge of the impeller blade should be the same as that of the inner wall of the stirred tank (Fig. 5). There is only a small gap between the outer edge of the impeller blade and the inner wall of the stirred tank, which can remove the viscous reaction products attached to the tank wall or accumulate at the bottom of the tank.
It can keep good heat transfer effect for solid substance. The circumferential velocity of the outer edge of the blade is
0.5-1.5 m/s can be used to mix Newtonian and pseudoplastic fluids with viscosity up to 200 Pa.s (see viscous fluid flow). Only when stirring high viscosity liquids,
There is a large stagnation zone in the liquid layer.
Screw-belt agitator
The outer diameter of the screw belt is equal to the pitch of the screw belt. It is specially used for mixing high viscosity liquids (200-500 Pa. s) and pseudoplastic fluids. It is usually operated in laminar flow.