Application Of VFD in the mixer sector

The application of conventional frequency converters in the mixer sector significantly optimizes mixing process efficiency and equipment reliability, relying on their precise speed regulation, energy-saving control, and mechanical protection features. The following analysis unfolds from the dimensions of process adaptation, energy efficiency enhancement, equipment protection, and scenario compatibility, combined with the needs of the mixer industry:

I. Precise Adaptation to Mixing Process Requirements, Improving Material Mixing Quality

Multi-stage Stepless Speed Regulation for Full-process Mixing Scenarios
Mixers require differentiated speed control under different working conditions (e.g.,

Feeding stage: Low speed (10–30rpm) to prevent material splashing;

Mixing stage: Medium-high speed (50–100rpm) to enhance shearing and dispersion;

Discharging stage: Reduced speed to avoid material segregation).
Frequency converters enable stepless speed regulation from 0 to 50Hz and multi-stage speed preset functions (e.g., preset 3–5 speed programs), allowing one-key switching of speed requirements in different mixing stages. Compared with traditional fixed-frequency motors (only single-speed or dual-speed adjustment), the uniformity of material mixing is increased by 20%–30%.

High Torque Output for Viscous Material Mixing
For viscous materials such as paint, mortar, and food sauces, mixers need to overcome significant static friction during startup. Frequency converters deliver 150%–200% of rated torque at 0Hz through vector control technology (traditional motors only provide 60%–80% starting torque), preventing mixing shaft jams due to insufficient torque, especially for high-viscosity materials (e.g., slurries with viscosity >5000cP).

II. Dynamic Energy-saving Control to Reduce Operating Costs

Demand-based Speed Regulation for Real-time Load Matching Mixer loads fluctuate with material filling rate and viscosity (e.g., empty machine operation consumes only 30% of full-load power). Frequency converters can monitor loads in real time via current sensors and automatically adjust speeds:

When the material filling rate <50%, the speed is automatically reduced to 60% of the rated speed, with an energy-saving rate of 40%–60%;

Compared with the fixed-frequency motor mode of "full-speed operation + manual start/stop," annual energy consumption is reduced by 30%–50% (e.g., a 10kW mixer saves about 12,000 kWh annually).

Power Factor Optimization and Soft Start Energy Saving

Frequency converters improve the motor power factor to over 0.95 through PWM modulation technology (traditional motors only reach 0.7–0.8), reducing reactive power loss;

The soft start process (0–50Hz ramp-up time can be set to 5–15s) avoids starting current surges (fixed-frequency starting current is 4–7 times the rated value, while frequency converters control it within 1.5 times), reducing the demand for power distribution system capacity and minimizing transformer and cable losses.

III. Multiple Mechanical Protections to Extend Equipment Life

Overload and Stalls Protection to Prevent Motor Burnout
When the mixer is jammed by foreign objects or material agglomeration, the built-in overload protection function of the frequency converter (e.g., setting current threshold at 110%–150%) triggers shutdown within 0.1s, avoiding motor burnout due to stall overheating (traditional motors rely on thermal relays with a response time >1s and are prone to winding aging from frequent overloads). Statistics show that frequency converter protection reduces motor failure rates by over 60%.

Vibration and Noise Reduction to Minimize Mechanical Wear
High-speed operation of fixed-frequency motors easily causes mechanical resonance (especially at critical speed points), accelerating bearing and gearbox wear. Frequency converters reduce operating vibration amplitude by over 50% (e.g., from 0.8mm to 0.4mm) through smooth speed regulation + torque ripple suppression, while lowering noise from 85dB to below 75dB. This extends equipment maintenance cycles by 1–2 times (e.g., gearbox replacement cycles extend from 1 year to 2–3 years).

IV. Flexible Adaptation to Multi-industry Scenario Requirements

Food/Pharmaceutical Industry: Precise Speed Control for Process Safety

In scenarios like chocolate mixing and ointment blending, frequency converters achieve speed accuracy of ±0.5% with encoders (traditional motors have ±5% error), preventing material overheating and degradation due to speed fluctuations (e.g., chocolate separates if temperature exceeds 35℃);

Frequency converters with FDA-certified stainless steel housings meet food-grade hygiene requirements, protecting electronic components from oil corrosion.

Chemical/Construction Materials Industry: Harsh Environment Resistance and Explosion-proof Design

 

For dusty and humid environments (e.g., concrete mixing plants), frequency converters can be configured with IP54 or higher protection levels, and built-in dust filters reduce dust accumulation;

In flammable and explosive scenarios (e.g., paint mixing workshops), explosion-proof frequency converters (e.g., certified to Ex d IIB T4) can be selected, combined with soft starts to avoid spark generation, complying with ATEX explosion-proof standards.

Laboratories/Small Equipment: Modularity and Convenient Debugging
Small mixers can use compact frequency converters (e.g., 0.75–2.2kW power), supporting direct speed setting via knobs/touch screens without additional PLC control, reducing debugging time from 2 hours for traditional systems to 30 minutes.

V. Intelligent Control and System Integration

Linkage Control and Remote Monitoring

Frequency converters can be connected to DCS/PLC systems via Modbus protocol, linking with weighing sensors and temperature sensors: automatically starting mixing when material weight reaches the set value, and reducing speed when temperature exceeds the threshold;

Support mobile APP remote monitoring of operating status (e.g., speed, current, fault codes), suitable for centralized management of large production lines (e.g., multi-unit collaborative control in concrete mixing plants).

Process Parameter Storage and Replication
For batch production scenarios, frequency converters can store 10+ groups of process parameters (e.g., mixing speeds and times for different formulas), enabling one-key calling via shortcut keys to avoid manual setting errors and improve batch product consistency (e.g., sauce mixing yield increases from 85% to 95%).

VI. Reducing Lifecycle Costs

Lower Initial Equipment Investment

The frequency converter + ordinary motor solution costs 30%–50% less than servo systems and eliminates the need for additional gearboxes (frequency converters directly control low-speed high-torque operation);

Require lower grid capacity, eliminating the need for large transformers (e.g., a 15kW frequency converter has a starting current ≤30A, while a fixed-frequency motor of the same power has a starting current >100A).

Long Life and Low Maintenance Costs
Frequency converters have a service life of 8–10 years (based on 8 hours of daily operation) and no mechanical contact wear. Combined with their fault early warning functions (e.g., advance alerts for capacitor aging and fan failures), planned maintenance reduces unplanned downtime losses by 50% compared to traditional systems.

Conclusion

The core value of conventional frequency converters in the mixer sector lies in solving the efficiency and reliability pain points of traditional mixing systems through "precise speed regulation + intelligent control," with remarkable advantages in multi-process adaptation, high-energy-consumption scenarios, and complex working conditions. From food processing to heavy construction material mixing, frequency converters are further expanding their application boundaries through technological iterations (e.g., integrated IoT functions, explosion-proof designs), becoming key components in the automation upgrade of industrial mixing.

This equipment is composed of a frequency converter, a water pump motor, a PID controller and a pressure sensor. The built-in PID regulation function can adjust the frequency in real time to maintain a constant pressure in the pipeline network. Its energy-saving principle is based on the cube proportional relationship between the shaft power of the water pump and its rotational speed. By reducing the power supply frequency, it significantly reduces energy consumption, and the measured power-saving rate reaches 20% to 60%. It is equipped with a soft start-stop function to eliminate the water hammer effect and extend the service life of the equipment. At the same time, it supports time-segmented pressure timing control and unattended operation mode, and integrates automated management and multiple safety protection mechanisms.

 Excellent energy-saving effect: 

  

Under VFD drive, as the motor power factor improves, the operating current decreases, thereby reducing equipment power consumption and saving operating costs.