Challenge/Solution Case Study: Reducing Costs and Improving Reliability for Dense Phase Limestone Transport System

Nestor Rentas Challenge/Solution Case Studies


Eliminated $1,000,000 in trucking expenses and increased overall system reliability by designing and supporting the implementation of a continuous dense phase system.

The project was completed on time and the trucking contract was cancelled two months after start-up. The solution met savings and reliability improvement goals.


The client’s original dense phase limestone transport system (traveling between a grinding mill and a shingle manufacturing plant) could not meet production requirements. As a result, 25% of the limestone requirement was being trucked to the plant at a cost of over $1,000,000 per year.

EFI Group was engaged to increase transport system capacity in order to reduce trucking expenses.


EFI Group investigated the options for increasing the transport rate and eliminating the trucking option.

A continuous dense phase system was selected and designed to eliminate the need for trucking and offer increased reliability. EFI Group completed the detailed design of the entire system, including structural platforms, and coordinated the installation, PLC programming and equipment start-up.


  • Detailed mechanical and structural drawings.
  • Equipment specifications for the transport system and support equipment.
  • Operating and start-up plans.
  • PLC control description.

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