Horizontal Mixer

Equipment Introduction

The horizontal ribbon mixer, also known as a horizontal agitator, is a mainstream intermittent homogenizing mixing equipment in the powder engineering field. Standardized and mass-produced by equipment manufacturers such as Zhengzhou Huaqiang Heavy Industry, its core technology relies on a double-layer counter-rotating spiral ribbon to achieve material convection and circulation mixing. It boasts five core advantages: high mixing uniformity, low material residue, wide material compatibility, gentle low-speed mixing that does not damage particles, and simple maintenance.

Key Performance Features:

1. High Mixing Uniformity: Batch mixing coefficient of variation (CV) ≤ 5%, uniformity up to 97%~99%, capable of handling multi-component materials with density differences ≤ 10 times;
2. Low Residue Optimization: The gap between the screw ribbon and the cylinder wall can be adjusted to near zero, with a large bottom unloading door, resulting in a residue of < 0.5%;
3. Gentle Agitation: Main shaft speed is generally below 45 r/min, resulting in low shear force and a breakage rate of < 5% for fragile particles;
4. Strong Functional Expandability: Can be equipped with jackets (heating/cooling), top spray system, vacuum feeding, pneumatic dust removal, and frequency conversion speed regulation;
5. Low Installation Threshold: Minimal operating vibration, no need for heavy concrete foundation, carbon steel/304/316L stainless steel materials can be customized as needed.

Structural Components of the Equipment

The horizontal ribbon mixer mainly consists of the following five systems:

1. Mixing Container (Cylinder)

Typically a U-shaped elongated structure with a smooth inner wall to reduce material movement resistance. Some models have a jacket on the outer wall of the cylinder for introducing heating or cooling media to achieve temperature control. The cylinder cover can be designed as arched (pressure-bearing) or fully open (easy to clean). Considering the characteristics of organic fertilizer raw materials, the inner wall of the cylinder is often lined with 304 stainless steel or high-molecular-weight polyethylene plate for corrosion resistance and to prevent sticking.

2. Mixing Components (Core Working Parts)

Constitutes double or triple-layer spiral blades (ribbons) mounted on a horizontal main shaft. The spiral directions of the inner and outer layers of the ribbon are opposite:

Outer spiral ribbon: gathers material from both sides of the cylinder towards the center.

Inner spiral ribbon: conveys material from the center to both sides.

The edges of the ribbon blades are usually overlaid with wear-resistant alloy to resist sand and gravel erosion.

3. Transmission System

Composed of a motor, reducer, pulleys, V-belts, and couplings. The system employs a belt-driven cycloidal reducer, whose elastic connection offers the advantage of protecting transmission components under overload conditions. The motor and mixing shaft are directly connected via a cycloidal pinwheel reducer, resulting in a simple structure, high operational reliability, and convenient maintenance.

4. Discharge Device: A pneumatic or manual large-opening arc-shaped discharge port with a discharge angle greater than 70 degrees is installed at the bottom. Powder materials utilize a pneumatic large-opening structure, offering advantages such as fast discharge and no residue; high-fineness materials or semi-fluid materials use a manual or pneumatic butterfly valve.
5. Auxiliary Systems: Includes a shaft end packing seal device, a liquid injection device (for injecting liquid during solid-liquid mixing), and a flying knife device (for special materials).

Applications of the Equipment

Equipment Working Principle

After the equipment is started, the rotor drives the inner and outer double-layer helical ribbons to rotate.

1. The inner helical ribbon pushes the material from the center to both sides.
2. The outer helical ribbon gathers the material from both sides towards the center.

Under the action of the double-layer helical ribbons, the material forms bidirectional convection and is continuously sheared, penetrated, and diffused during rotation, thus achieving a highly uniform mixing effect in a very short time (usually 3-10 minutes).

Raw Materials for the Equipment

This equipment can process the following types of raw materials:

Raw Material Requirements:

1. Material Moisture Content: It can adapt to higher moisture content, but materials with excessive viscosity are difficult to clean;
2. Avoid mixing in large stones, iron blocks, and other hard objects to prevent damage to the mixing blades;
3. For materials with high fiber content and significant density differences, applicability needs to be assessed.

Equipment Operation and Maintenance Methods

1. Installation and Commissioning

1) Construct the foundation according to the foundation drawing, reserving foundation holes (no particularly strong concrete foundation is required);

2) After installation, check whether the bolts in all parts are loose and whether the main unit’s door is secure;

3) Install the power supply and control switch according to the equipment’s power configuration;

4) After inspection, conduct a no-load test run. Production can only begin after normal operation.

2. Operating Procedures

1) Start-up: Must be started under no-load conditions. Starting with material is strictly prohibited to avoid overloading and damaging the motor;

2) Inspection: Before starting, check all bolts, bearing seats, reducer oil level, and rotation direction;

3) Feeding: Large stones, iron blocks, and other hard objects must not be mixed into the material;

4) Shutdown: Before stopping, stop feeding first, and stop the machine only after the material in the mixing chamber has been emptied. Stopping the machine with material is strictly prohibited.

3. Daily Maintenance

1) Check the tightness of bolts and the wear of vulnerable parts every shift;

2) Regularly clean residual material in the mixing chamber to prevent clumping;

3) Check the tension of the V-belt and adjust or replace it in time;

4) Stop the machine immediately for inspection if the bearing oil temperature rises.

Equipment Application in Production Lines

In organic fertilizer or dry powder production lines, the horizontal ribbon mixer is typically located after the automatic batching scale and before the granulator or packaging machine. It plays a crucial role in connecting these processes, ensuring that the raw material components entering subsequent stages are completely consistent, which is a key factor in guaranteeing product quality stability.

Equipment Application in Production Lines

1. Core Position in Organic Fertilizer and Compound Fertilizer Production Lines

The horizontal ribbon mixer is the key link between the crushing and granulation processes in organic fertilizer and compound fertilizer production lines. In the entire fertilizer production line, the horizontal mixer is usually located after crushing and screening and before the granulator.

Core Function: It precisely homogenizes the crushed organic powder, nitrogen, phosphorus, and potassium fertilizer powder, trace elements, and microbial agents, providing stable and nutrient-uniform raw materials for the granulation process, directly determining the pelleting rate and granule strength.

2. Automated Production Line Configuration

The equipment boasts a high degree of automation and can be integrated with batching machines, conveyors, and granulators to form a fully automated production line. This achieves continuous feeding, intelligent mixing, and quantitative discharge, supporting 24/7 uninterrupted production and fully adapting to the needs of large-scale fertilizer processing.

3. Key Process Indicators

Mixing Uniformity: The coefficient of variation (CV) can be stably controlled within 5%, far exceeding the 10%–15% of vertical models.

Residual Rate: Utilizing the reverse thrust of the screw conveyor, materials can be completely discharged within 3–5 seconds, with a residual rate of less than 0.5%, effectively preventing cross-contamination between different batches of formulations.

Single Batch Mixing Time: 3–8 minutes

4. Multi-Process Integration Capability

The equipment can simultaneously complete multiple processes such as material dispersal, microbial inoculation, and moisture adjustment. It is capable of handling both dry powder proportioning and semi-wet material mixing.

Common Equipment Problems and Solutions