The core of selecting a reactor agitator isMatch material characteristics and mixing purposeThe flow fields (axial/radial circulation, shear forces) of different blade types vary greatly. Choosing the right one can improve reaction efficiency, while choosing the wrong one may lead to uneven mixing, insufficient heat transfer, and other problems. Below is an analysis of the core influencing factors, common propeller type adaptation scenarios, selection process, and misconceptions:

1、 Core selection criteria: 3 key dimensions

The selection of agitator is determined by the process requirements, and the following three dimensions need to be clarified first, which are the basis for subsequent matching of paddle types.

1. Material characteristics (most critical)

• viscosity: is the core indicator for dividing blade types, which directly determines the mixing efficiency.

• Low viscosity (<1000 CPS, such as aqueous solutions, ethanol): A paddle type with strong circulation ability is required to avoid "local dead zones".

• Medium viscosity (1000-100000 CPS, such as syrup and coatings): It is necessary to balance circulation and prevent wall deposition, and the blade should be close to the kettle wall.

• High viscosity (>100000pps, such as resin and rubber slurry): A paddle type that requires strong torque and full range stirring to prevent material "clumping".

• Solid content/particle characteristicsWhen containing solid particles (such as catalysts and sludge), wear resistance and suspension capacity need to be considered.

• Low solid content (<10%, fine particles): ordinary paddle type+sufficient circulation speed is sufficient.

• High solid content (>30%, coarse particles): Thickened blades (such as 5mm stainless steel) or wear-resistant coatings (silicon carbide) are required, and the blade shape should have strong shear force to prevent settlement.

• corrosiveThe blade material should match the kettle body, such as 316L stainless steel and Hastelloy for strong corrosion (acid/alkali), and Q235 carbon steel for non corrosion.

2. Core purpose of mixing

Different processes have different requirements for stirring, which directly determines the flow field direction (axial/radial) and shear strength of the blade type.

• Mix well：

• Homogeneous mixing (such as two liquids): A propeller with strong axial circulation is required to quickly break the concentration gradient.

• Heterogeneous mixing (such as liquid-liquid stratification, solid-liquid suspension): requires a blade type with strong radial shear force to disperse the material.

• Heat and Mass TransferTo promote the contact between the fluid and the kettle wall (jacket/inner coil) and improve the heat transfer coefficient (K value), a propeller type with strong circulation ability is usually selected.

• Dispersion/emulsificationFor paint coloring and cosmetic emulsification, high shear force paddle type is required to crush large particles into tiny droplets (particle size<10 μ m).

• Anti sedimentationFor high viscosity slurries and solid materials, the blade should be close to the kettle wall (gap<5mm), and the wall material should be scraped off to avoid local overheating or coking.

3. Structure and working conditions of the kettle body

• Shape/volume of kettle bodyVertical small capacity kettles (<500L) are suitable for small propeller types (such as push type), while large kettles (>2000L) require multiple propeller combinations (such as bottom anchor type+upper push type); Horizontal kettles should be equipped with side entry agitators to avoid sedimentation at the bottom.

• Is there any attachment?When there is a baffle (anti rotation) inside the kettle, the propulsion and turbine types have better effects; When there is a draft tube (enhanced axial circulation), it is only suitable for push type agitators.

• Speed and power limitsHigh viscosity materials require low speed (50-100rpm) and high torque motors, while low viscosity materials require high speed (200-500rpm) to avoid energy waste or material splashing caused by excessive speed.

2、 Common mixer types and adaptation scenarios

The flow field characteristics of different blade types vary significantly, and the following table provides a clear comparison of their core parameters and applicable scenarios:

Paddle type	Applicable viscosity range	Core flow field characteristics	Mixing effect	Typical application scenarios
Push forward type	<1000cps	Strong axial circulation, low shear	Rapid mixing and heat transfer	Mixing of low viscosity solutions (such as chemical dissolution), heat transfer (such as cooling water cooling)
Turbo type	<10000cps	Strong radial shear, medium cycle	Dispersion, emulsification, suspension	Liquid liquid emulsification (such as cosmetics), solid-liquid suspension (such as catalyst mixing)
anchor	1000-100000cps	Close to the kettle wall, low shear	Anti wall sedimentation, medium viscosity mixing	Medium to high viscosity slurries (such as coatings), polymerization reactions (anti coking)
Spiral belt type	>100000cps	Global axial circulation, low shear	Global mixing of high viscosity materials	Mixing of high viscosity resin, rubber slurry, and adhesive
Frame style	1000-50000cps	Stable structure, moderate circulation	Medium viscosity mixture containing a small amount of solid	Food sauce (if sauce), reaction solution containing a small amount of particles
dispersion disc	<5000cps	High radial shear	Ultra fine dispersion and emulsification