Stirred tanks are core equipment used for material mixing, reaction, and heat transfer in industries such as chemical, pharmaceutical, and food. They achieve efficient stirring through mechanical or fluid power and are widely applied in scenarios such as resin synthesis, drug preparation, and food processing. The following analyzes this key equipment from dimensions such as structural composition, working principle, and selection points.

 

I. Analysis of the Core Structure of Stirred Tanks

1. Main Vessel System

The tank body usually adopts a cylindrical design. The material is selected from stainless steel, carbon steel, or glass - lined steel according to the working conditions. The height - to - diameter ratio is mostly controlled between 1 - 3 to optimize the flow efficiency. The junction between the bottom and the side wall uses a rounded corner transition design to reduce material residue.

2. Power Stirring System

It includes a motor, a reducer, a stirring shaft, and an impeller assembly. Common types of stirrers include:

- Paddle type: Suitable for mixing medium - to - low - viscosity liquids.

- Propeller type: Generates axial flow to improve circulation efficiency.

- Anchor/Frame type: Specialized for preventing sedimentation of high - viscosity materials.

- Turbine type: Generates strong shear force and is suitable for gas - liquid dispersion.

3. Temperature Control System

There are two main heat - exchange methods: jackets and coils:

- Jackets: Cover the outer wall of the tank and are suitable for large - volume heat transfer.

- Coils: Built - in spiral tubes to improve heat - exchange efficiency.

4. Auxiliary Function Components

It is equipped with process interfaces such as sight glasses, manholes, CIP cleaning balls, pressure/temperature sensors to meet the needs of production monitoring and cleaning. There are two ways, mechanical seals and packing seals, to ensure the airtightness of the equipment.

 

II. Equipment Operation Mechanism and Functional Characteristics

1. Mixing Enhancement Mechanism

The rotation of the stirrer generates radial and axial flows, forming a forced - convection cycle. The combined use of baffles and draft tubes can eliminate the swirling phenomenon and increase the turbulence intensity.

2. Paths to Achieve Multiple Functions

- Gas - liquid dispersion: The gas distributor releases micron - sized bubbles.

- Solid - liquid suspension: Specific impeller designs prevent particle sedimentation.

- Heat - transfer optimization: Precise temperature control is achieved through jackets/coils.

3. Process Control Dimensions

It supports the regulation of multiple parameters such as rotational speed (20 - 300 rpm), temperature (- 50°C to 300°C), and pressure (from vacuum to 4 MPa), and is suitable for batch/continuous production modes.

 

III. Analysis of Industry Application Scenarios

1. Chemical Synthesis Field

In processes such as catalytic reactions and polymerization reactions, the reaction efficiency is improved by enhancing mass transfer. Typical cases include resin synthesis and dye preparation.

2. Pharmaceutical Production Link

Equipment made of 316L stainless steel that meets GMP standards is used in key processes such as vaccine cultivation and API crystallization.

3. Food Processing Application

In processes such as chocolate tempering and fruit - juice homogenization, anchor - type stirrers can effectively handle high - viscosity materials.

4. Environmental Protection Treatment Scenario

In the wastewater treatment process, rapid mixing of chemicals is achieved, and in sludge treatment, solid deposition is prevented.

 

IV. Key Indicators for Equipment Selection

1. Material Characteristic Dimension

- Viscosity range: For low - viscosity (<500 cP) materials, propeller - type stirrers are selected; for high - viscosity (>10,000 cP) materials, ribbon - type stirrers are used.

- Corrosiveness: Determine the need for special materials such as glass - lined steel or Hastelloy.

2. Matching of Process Parameters

- Volume specification: The conventional range is 0.1 - 50 m³, and customization is available for special requirements.

- Pressure grade: Conventional operation is under normal pressure, and for high - pressure conditions, the tank body design needs to be strengthened.

3. Functional Expansion Configuration

- Explosion - proof motor: Essential for flammable and explosive working conditions.

- CIP system: A must - have for cleaning verification in the pharmaceutical and food industries.

- Vacuum configuration: Suitable for distillation and defoaming processes.

 

V. Precautions for Operation and Maintenance

1. Safety Operation Specifications

- Verify the integrity of the mechanical seal before starting.

- Strictly prohibit over - temperature and over - pressure operation.

- Use inert gas to protect sensitive reactions.

2. Key Points of Maintenance Management

- Detect the radial run - out of the stirring shaft monthly (≤0.1 mm/m).

- Regularly replace the friction pairs of the mechanical seal.

- Conduct annual legal inspections of pressure vessels.

3. Cleaning and Disinfection Requirements

- Food - grade silicone seals can withstand high - temperature steam sterilization.

- The CIP cleaning flow rate needs to reach a scouring speed of 2 - 3 m/s.

 

With the development of intelligent manufacturing, modern stirred tanks have integrated intelligent modules such as online pH monitoring and torque - sensing early warning, promoting the upgrading of traditional equipment in the digital direction. When selecting equipment, it is recommended to comprehensively consider process characteristics, investment budgets, and operation and maintenance costs, and give priority to products with modular designs for later functional expansion.