What is an Impact Crusher?
An impact crusher is a medium-to-fine crushing machine widely used in industries such as building materials, transportation, energy, cement, mining, and chemicals. It is designed to crush various ores and rocks with compressive strength not exceeding 350MPa, particularly limestone, concrete, and other medium-hard and soft rocks. Its working principle is based on impact crushing: after material enters the crushing chamber, it is struck by high-speed rotating hammers (blow bars), gaining tremendous kinetic energy before hurtling towards impact plates where it is crushed again. Subsequently, materials collide with each other within the crushing chamber before finally being discharged from the outlet. Unlike hammer crushers, impact crushers have a larger crushing impact zone, allowing for more efficient utilization of impact energy.
Types of Impact Crusher
PF Series Impact Crusher: The most common standard model, featuring a three-chamber crushing zone design that increases the material impact area and improves crushing efficiency. It is suitable for crushing limestone, gypsum, coal gangue, and other materials below medium hardness.
Hard Rock Impact Crusher: A reinforced model designed for high-hardness rocks such as granite and basalt. It features a thicker rotor body and wear-resistant blow bars, with an optimized crushing chamber structure capable of withstanding greater impact forces.
Impact Shaping Crusher: Specifically designed for aggregate shaping. By optimizing the rotor and impact chamber design, it produces a more cubical product shape with an extremely low content of flaky particles, particularly suitable for producing high-grade road aggregates.
Track-Mounted Mobile Impact Crushing Station: An impact crusher mounted on a tracked chassis, equipped with feeding, iron removal, and dust suppression systems. It enables on-site mobile crushing and is widely used in construction waste processing and quarries.
Impact Sand Making Machine: An improved version of the impact crusher that can produce some manufactured sand by increasing rotor speed and optimizing the crushing chamber, though its sand production rate is typically lower than that of vertical shaft impact crushers.
Key Features of Impact Crusher
High Crushing Ratio: Impact crushers can achieve a crushing ratio of up to 50 or more, meaning they can reduce large blocks of material to the desired particle size in one step, simplifying the process flow and reducing equipment investment.
Excellent Product Shape: Material is subjected to multi-directional impacts within the crushing chamber, resulting in a cubical product with few flaky particles, particularly suitable for applications with high aggregate shape requirements.
Selective Crushing: Due to the nature of impact forces, materials break along natural bedding planes and joints. For ores containing minerals of different hardnesses, this enables selective crushing that preserves valuable minerals.
Adjustable Crushing Chamber: By adjusting the gap between the impact rack and the rotor, the discharge particle size can be easily controlled to meet different product requirements.
Convenient Blow Bar Replacement: Blow bars are inserted into the rotor from the side, making replacement and maintenance relatively simple and quick, reducing downtime.
Strong Adaptability: Can handle materials with relatively high moisture content (typically not exceeding 8%) without easy clogging.
Impact Crusher Customization Options
Manufacturers often offer custom configurations based on specific material characteristics and production requirements:
Blow Bar Material and Shape: Depending on material abrasiveness, options include high-chromium iron, high-manganese steel, or composite blow bars with carbide inserts, as well as different tooth designs to extend service life.
Impact Plate Structure: Impact plates can be customized with different shapes and angles, such as polyline or curved types, to optimize the crushing chamber profile and impact angle.
Rotor Structure: Options include heavy-duty integral rotors or split rotors. Heavy-duty rotors have greater inertia, suitable for hard rock crushing; split rotors are easier to maintain.
Drive Method: Options include direct motor connection, fluid coupling drive, or pulley drive to suit different operating conditions and motor configurations.
Hydraulic Auxiliary System: Equipped with a hydraulic opening device for the housing, allowing maintenance personnel to quickly open the frame for inspection or replacement of wear parts, significantly reducing labor intensity.
Wear-Resistant Liners: The interior of the crushing chamber can be fitted with wear-resistant liners based on wear patterns, protecting the housing and extending overall equipment life.
Impact Crusher OEM Process
Original Equipment Manufacturing (OEM) for impact crushers focuses on the dynamic balancing performance of the rotor assembly and the metallurgical quality of wear-resistant materials.
Design & Analysis: Finite Element Analysis (FEA) is used for strength and modal analysis of the rotor, main shaft, and frame, optimizing the structure to avoid resonance and ensure reliability under high impact loads. Material trajectories are also simulated to optimize the crushing chamber geometry.
Material Selection: The main shaft is forged from high-strength alloy steel. The rotor body is welded or cast from high-quality carbon structural steel. Wear parts such as blow bars and impact plates are made from high-chromium iron, high-manganese steel, or alloy wear-resistant steel based on operating conditions.
Precision Casting: Wear parts like blow bars and impact plates are manufactured using lost foam casting or precision casting processes to ensure dimensional accuracy and internal quality, enhancing wear resistance.
Machining: Critical areas such as the main shaft, rotor body end faces, and bearing seats are precision-machined to ensure the accuracy and balance of the rotor assembly.
Dynamic Balancing Test: The assembled rotor must be precisely corrected on a dynamic balancing machine to ensure vibration values meet standards during high-speed rotation, preventing premature bearing failure and equipment vibration.
Final Assembly & Test Run: Assembly is carried out strictly according to procedures, followed by no-load and load test runs to check performance indicators such as current, vibration, temperature, and noise.
Impact Crusher Price
The price of an impact crusher varies based on its model, specifications, configuration, and brand. Small impact crusher prices may range from $30,000 to $80,000. Medium-sized PF series impact crushers, with processing capacities ranging from tens to two hundred tons per hour, typically fall between $80,000 and $100,000. Large hard rock impact crushers or those with high-end configurations (such as hydraulic assistance and intelligent controls) may range from $100,000 to $150,000. Key price drivers include rotor specifications and motor power, processing capacity and crushing ratio requirements, the material of blow bars and liners, automation level, and whether it is a mobile configuration.
Impact Crusher Supplier
PASCAL is a professional impact crusher supplier, with its factory established in 2017, based in Luoyang, China. The company serves as a global supplier of heavy industrial machinery, specializing in crushers and various mechanical equipment used in the mining and construction sectors. They provide efficient PF series crushers, hard rock impact crushers, and mobile impact crushing stations to meet the demands of aggregate crushing and construction waste resource utilization.
Impact Crusher FAQ
What is the difference between an impact crusher and a hammer crusher?
Both use impact crushing, but the main differences are: impact crushers have impact racks and a larger crushing chamber, offering a greater crushing ratio and better product shape; hammer crushers primarily control discharge through grate bars, are suitable for softer materials, but produce more fines in the product. Impact crushers are better suited for producing high-quality aggregates.
When do blow bars need replacement?
Replacement is needed when the working face of the blow bar is worn thin at the edges, affecting crushing efficiency; when blow bars develop cracks or fractures; and when blow bar wear causes rotor imbalance, leading to severe equipment vibration. Typically, blow bars can be flipped once to use the opposite side.
How do I adjust the discharge particle size?
Mainly by adjusting the gap between the impact rack and the rotor blow bars. Increasing the gap produces coarser material; decreasing the gap produces finer material. For hydraulically assisted impact crushers, adjustment can be done remotely via the operation interface.
What should I do if the equipment vibrates excessively?
Common causes include: uneven wear or detachment of blow bars on the rotor causing imbalance; bearing damage; unstable foundation or loose anchor bolts; feed particle size exceeding the design range; or entry of uncrushable objects. Targeted inspection and correction are needed.
What causes bearing overheating?
Possible causes include: too much, too little, or contaminated/deteriorated grease; improper bearing installation with insufficient clearance; excessive vibration due to rotor imbalance affecting bearings; or seal damage allowing dust to enter the bearings.
What should I do if the crushed product contains too many flaky particles?
Try adjusting the impact rack gap to change the crushing angle; check blow bar wear and replace if necessary; appropriately reduce rotor speed to increase material residence time in the crushing chamber; or check for blockages in the crushing chamber that affect material flow.
