Cedar Rapids 1313 Impact Crusher in Closed Circuit Applications

[MikePhua]

Historical Background and Machine Profile
The Cedar Rapids 1313 impact crusher was developed by the Iowa Manufacturing Company, a firm that played a pivotal role in shaping the American aggregate and road-building equipment industry. Founded in 1923, Iowa Manufacturing became synonymous with rugged crushers and screens under the Cedarapids brand. The 1313 model, part of their horizontal shaft impactor (HSI) series, was designed for high-volume secondary crushing in quarry and recycling operations.
This machine features a rotor diameter of 50 inches and a feed opening of approximately 52 by 34 inches, allowing it to process large material with consistent reduction ratios. The 1313 is typically powered by a 400–500 hp electric motor and configured with adjustable aprons to control product size. Its robust frame and replaceable wear liners make it suitable for hard rock, concrete, and asphalt recycling.
Closed Circuit Operation and System Integration
In a closed circuit setup, the 1313 impact crusher is paired with a screen and return conveyor to create a looped system. Material is fed into the crusher, reduced, screened, and oversized particles are returned for further crushing. This configuration improves efficiency and ensures uniform product gradation.
Advantages of closed circuit operation:

• Tighter control over final product size
  
• Reduced oversize material in stockpiles
  
• Improved fuel and energy efficiency
  
• Lower wear rates due to consistent feed
  

Operators often use a triple-deck screen to separate fines, mid-size, and oversize fractions. The oversize is routed back to the crusher via a return conveyor, while the mid-size is stockpiled or sent to tertiary crushers.
Rotor Dynamics and Wear Management
The heart of the 1313 is its high-inertia rotor, typically equipped with four blow bars. These bars strike incoming material against stationary breaker plates, fracturing it through impact and shear. Rotor speed is critical—too slow and the material bounces; too fast and wear accelerates.
Best practices for rotor management:

• Maintain rotor speed between 500–650 rpm depending on material
  
• Use high-chrome or martensitic steel blow bars for hard rock
  
• Rotate blow bars regularly to balance wear
  
• Inspect rotor bearings every 500 hours for heat and vibration
  

One operator in Arizona reported that switching to ceramic-reinforced blow bars extended service life by 40% when crushing granite. However, these bars are more brittle and require careful handling during installation.
Apron Adjustment and Product Control
The 1313 features two adjustable aprons—primary and secondary—that control the size of the crushed material. The gap between the rotor and aprons determines the reduction ratio and affects throughput.
Adjustment tips:

• Set primary apron at 4–6 inches for coarse reduction
  
• Set secondary apron at 1.5–3 inches for fine control
  
• Use hydraulic actuators for quick changes during production
  
• Monitor product gradation with belt scales and sampling
  

In recycling applications, tighter apron settings help produce consistent base material for roadbeds. In quarry operations, wider settings allow higher throughput with less fines.
Maintenance and Downtime Reduction
Impact crushers require regular maintenance to ensure uptime and safety. The 1313’s modular design allows access to wear parts and internal components without major disassembly.
Routine maintenance checklist:

• Check blow bar wear weekly
  
• Inspect apron liners for cracking or spalling
  
• Grease rotor bearings daily
  
• Clean dust suppression nozzles and water lines
  
• Monitor vibration and temperature sensors for anomalies
  

A contractor in British Columbia implemented a predictive maintenance program using wireless sensors on the rotor and motor. This reduced unplanned downtime by 25% over a six-month period.
Modernization and Retrofit Potential
Though the 1313 is no longer in production, many units remain in service across North America. Retrofit options include:

• Upgrading motors to variable frequency drives (VFDs)
  
• Installing automated apron control systems
  
• Adding remote monitoring for bearing and rotor health
  
• Replacing analog controls with PLC-based panels
  

These upgrades improve safety, reduce energy consumption, and extend machine life. Some operators have integrated the 1313 into fully automated plants with real-time performance dashboards.
Conclusion
The Cedar Rapids 1313 impact crusher remains a workhorse in closed circuit crushing systems, offering reliable performance and adaptable configuration. Its legacy reflects the engineering strength of Iowa Manufacturing and the enduring value of well-built equipment. Whether processing hard rock or recycled concrete, the 1313 delivers consistent results when paired with proper screening and return systems. With thoughtful maintenance and modernization, this classic crusher continues to shape the ground beneath our roads and foundations.