Mining Contract: Maintenance Free Impingement Screen In-Mine Testing

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Contract # 75D30122P14890
Start Date 9/1/2022
End Date 8/31/2023
Research Concept

The cutting head on continuous miners is a major source of dust in underground room-and-pillar coal mining. Flooded-bed scrubbers installed on continuous miners are responsible for dust removal from the active mining face. A multi-layered fibrous screen installed in these scrubbers captures dust, but the screen is subject to clogging and requires regular cleaning during the shift. Clogged screens greatly decrease the airflow through the scrubber and therefore more dust becomes available in the underground environment. To address this issue, a need exists for non-clogging efficient impingement screens that both clean the air efficiently and allow airflows through the scrubber that match the design of the existing screens but perform consistently throughout the shift without maintenance.

Under a previous NIOSH Mining contract, “Maintenance Free Filters for Continuous Miner Scrubber Systems,” researchers developed computer models and physical screens consisting of multi-staged perforated plates that fit the machine as a direct replacement. The development took a three-pronged strategy: computer design and simulation, laboratory physical testing, and in-mine conditions testing. The contract represented the major design work necessary to get this new screen technology adopted. The computer models can now be used to guide small but important changes in the screen design based on the previous research results. The current contract focuses entirely on using the screens in real-world conditions.

Contract Status & Impact

This contract is complete. To receive a copy of the final report, send a request to

This contract research is designed to address the last known barrier to the implementation of the multi-layered fibrous screen described in the Research Concept section. According to Technical Support Services at the Mine Safety and Health Administration (MSHA), mine ventilation plans do not always specify the filter that must be installed in the scrubber. The most important factor in ventilation plans is the quantity of air flowing through the scrubber. After experiments with different screen designs allowing for different airflows and different levels of resistance, a small revision to the screen design is currently being tested to achieve the full airflow performance of the existing screen.

The objective of this research is to test the maintenance-free flooded-bed scrubber screen for acceptable use in underground coal mining applications. These filters have been shown to be comparable to the existing fibrous filters, but more field work is necessary to prove that these are safe to use in existing flooded bed scrubbers without major modification to the machine.

Under this contract, the University of Kentucky (UKY) will work with mine partners to fabricate screens to test and use in existing continuous miners. The associated tasks will include filter fabrication and shakedown testing, test design and regulatory approvals, and in-mine short- and medium-term testing.

The contract research and process are specifically aimed at product commercialization for a screen tailored for use in existing continuous miner machines. The ultimate goal of this technology is to implement the most highly efficient and effective filter in current and future revisions of the flooded-bed scrubbers.

Page last reviewed: January 11, 2024
Page last updated: June 15, 2023