Spot Extraction in Tunnel Construction

Dust Control. Tunnel Construction.

Grydale Mobile Dust Collectors.  Spot Extraction Solutions. 

Having a holistic approach to ventilation through staged ventilation plans and dig sequencing is cost effective, however, what happens when you have out of sequence work? Out of sequence work can result from equipment shortages, labour shortages and geological challenges and creates issues with managing airborne contaminants. When the main tunnel ventilation has not been scoped to accommodate out of sequence work, Spot Extraction is critical.

Spot Extraction is a term used for extracting dust at its source.

Spot Extraction can take pressure off the main ventilation system, resolving out of sequence issues using fast and direct extraction methods.

Spot extraction reduces the dust loading in the air and therefore the load on the main ventilation system and can stop dust from travelling down the length of the tunnel and impacting workers in-between the main ventilation system and the source of dust. Without spot extraction every worker within that environment would be negatively impacted.

Internationally Patented.  Track-Mounted Dust Collectors.

In tunnel projects worldwide, contractors have been able to use Grydale track mounted dust collectors to work alongside excavation equipment to extract dust at its source.

By controlling dust at the source it allows more efficient equipment to operate underground, generating operational efficiencies and advance tunnel construction rates.

For example:

• Previously the efficiency of surface miners for excavation have not been able to be used within tunnel environments due to the volume of dust created. However, by pairing a surface miner with a mobile dust collector trailing behind, allows dust to be managed and production efficiencies to be gained. Previous approaches to cutting service trenches is firstly with a saw and then rock hammering.
• Track mounted trenching systems have been used underground for the installation of service lines. Using previous methodology, they would be cutting less than 100m in a day, while track mounted trenchers were able to do 300m in one shift.

These operational efficiencies were only possible because the dust was being extracted at the source by Grydale’s patented track mounted dust collectors trailing behind the excavation equipment.

Track mounted dust collectors are small enough to work within restricted construction sites and stop dust from travelling down the length of the tunnel, which impacts on workers in between the main ventilation system and the source of dust.

By taking a complete approach to dust control and using a combination of main ventilation and spot extraction, you can reduce airborne dust, increase productivity and reduce construction timescales.

The following videos show how our internationally patented track mounted dust collectors can provide dust extraction at the source of creation. This reduces the impact of dust generating activities on the main ventilation system and prevents dust from travelling along the length of the tunnel, exposing works and equipment to hazardous respirable dust.

Spot Extraction.  Video Gallery.

Dust Control with Roadheader

Dust Control with Surface Miner

Mobile Dust Collectors have been used alongside surface miners to enable cost-effective excavation of benches.

Dust Control with Large Track Trencher

Dust Control with a Twin Header / Pineapple Head

Dust Control with Profiler

Mobile Dust Collectors have been used alongside terrain levellers and profilers to drop the floors or on final cuts.

Dust Control with Rockhammer

Mobile dust collectors have been used, alongside rock hammers – commonly used to drop the floors after road headers have done a first pass. Commonly dropping the floor around 1.5m.

Grydale JMS M-Series.  Track-Mounted Dust Collector Range.