How to increase impact crusher output

Increasing the output (measured in tons per hour, or TPH) of an impact crusher involves a holistic approach that combines operational adjustments, strategic maintenance, and optimizing the entire crushing circuit.Increasing the output of an impact crusher involves optimizing several key factors, from the material feed to the crusher's internal settings and regular maintenance. 

How to increase impact crusher output

1. Optimize Material Feed:

Consistent and Uniform Feed: This is paramount. An erratic or inconsistent feed rate can lead to underloading or overloading, both of which reduce efficiency.

Underfeeding: The crusher is not working at its full potential, leading to wasted energy and reduced throughput.

Overfeeding: Can cause clogging, increased wear on components, higher power consumption, and poor product shape.

Solution: Use a vibrating feeder or grizzly feeder to ensure a steady, even flow of material across the full width of the rotor. Adjust the feeder speed to match the crusher's capacity.

Optimal Feed Size:

Larger Feed Size: Can slow down processing and increase wear. Ensure the maximum feed size is within the crusher's recommended limits (typically 80% of the feed opening depth).

Solution: Pre-screening is crucial. Use screens to remove oversized material before it enters the crusher, which can overload the machine and increase wear.

Material Cleanliness (Pre-Screening Fines):

Fines Content: Excessive fines (material already smaller than your desired output) in the feed can reduce efficiency, increase wear on blow bars and liners (as they're cushioning the impact rather than breaking rock), and lead to packing in the crushing chamber.

Solution: Implement pre-screening to bypass fines directly to the product conveyor or a secondary screen. This ensures only material that needs to be crushed enters the impactor, optimizing its performance.

Moisture Content:

High Moisture: Wet or sticky material (especially with clay or soil) can clog the crusher, reduce efficiency, and cause build-up on internal components.

Solution: If possible, consider pre-drying very wet material or adjust your process to handle it. Ensure proper dust suppression systems are not introducing excessive moisture into the feed if not necessary.

2. Adjust Crusher Settings:

Rotor Speed:

Higher Speed: Generally results in finer product and a higher reduction ratio, thus potentially increasing throughput for finer products. It also increases the impact force.

Lower Speed: Produces a coarser product.

Finding the balance: Too high a speed can increase wear significantly and power consumption. Too low a speed reduces crushing efficiency. Consult your manufacturer's recommendations and conduct trials to find the optimal rotor speed for your material and desired product.

Apron Gap Settings (Discharge Opening):

Closer Gaps (Tighter Setting): Increases the reduction ratio and produces finer product. However, it can also lead to increased recirculation, higher wear, and potentially reduce overall throughput if the material is held in the chamber too long.

Wider Gaps (Looser Setting): Produces coarser product and allows for higher throughput.

Finding the balance: The goal is to achieve the desired product size with the most efficient throughput. Adjust both primary and secondary aprons (if applicable) in tandem. A common rule of thumb is to set the secondary apron to the desired output size, and the primary apron to three times that amount to allow for gradual reduction.

Blow Bar Condition and Rotation:

Worn Blow Bars: As blow bars wear, the gap between them and the aprons increases, reducing crushing efficiency and product quality.

Solution: Regularly inspect blow bars. Many designs allow them to be flipped (rotated) to utilize unworn faces, effectively extending their life. Replace them promptly when both sides are worn to maintain consistent crushing action and prevent damage to the rotor.

Breaker Plate Liner and Side Wear Plate Condition:

Worn Liners: Reduce the effectiveness of impact and increase wear on the main crusher body.

Solution: Monitor and replace these wear parts as needed to maintain optimal crushing geometry and protect the crusher's frame.

3. Equipment Maintenance and Optimization:

Regular Maintenance: A well-maintained crusher is an efficient crusher.

Lubrication: Ensure all bearings and moving parts are properly lubricated according to the manufacturer's schedule.

Belt Tension: Check and adjust drive belt tension regularly. Loose belts can cause slipping, reducing rotor speed and crushing efficiency.

Component Inspection: Regularly inspect for loose bolts, cracks, or damage to any components.

Cleanliness: Keep the crusher free of material buildup, especially in the crushing chamber and discharge area.

Wear Part Quality: Invest in high-quality wear parts (blow bars, liners) made from appropriate materials for your specific application (e.g., high-chromium iron for abrasive materials). Better wear parts last longer and maintain crushing efficiency.

Vibration Monitoring: Excessive vibration can indicate an imbalance in the rotor (often due to uneven blow bar wear) or other mechanical issues. Addressing these promptly prevents damage and maintains performance.

Proper Discharge Conveyor: Ensure the discharge conveyor belt is wide enough and running at an appropriate speed to prevent material buildup under the crusher, which can impede output.

Closed-Circuit Crushing: If your process allows, implement a closed-circuit system with a screening unit after the impact crusher.
Benefit: Oversized material is returned to the crusher for further reduction, ensuring that all product meets the desired specifications and maximizing the crusher's overall reduction capabilities. This reduces the number of passes needed for material that hasn't met the size, increasing overall efficiency.

4. Process Optimization:

Multi-Stage Crushing: For large-scale operations or when a high reduction ratio is required, using multiple stages of crushing (e.g., jaw crusher for primary, impact crusher for secondary/tertiary) can optimize overall plant throughput. Each crusher can then be optimized for its specific role.

Operator Training: Well-trained and experienced operators can significantly impact output. They understand how to adjust settings for different materials, identify potential issues early, and perform routine maintenance effectively.

Monitor Power Consumption: Monitoring the crusher's amperage draw can indicate if it's being overfed or underfed. Keep the amperage consistent to ensure optimal loading.

By systematically addressing these factors, you can significantly increase the output and overall efficiency of your impact crusher, leading to higher production rates and profitability.