Fact Sheet: Most asked question about explosive cleaning/deslagging.

How safe are explosives and the deslagging process?
Explosives are very safe. The likelyhood that the explosives will detonate prematurely is next to impossible due to our adherence to strict safety protocol.

What type of experience do our 1st Call blasters have?
Each supervisor has between 8 and 22 years of experience working in various explosive fields. All of our supervisors have extensive work experience in the boiler industry.

Do you stay inside the boiler to blast?
No, we see no reason to ever blast from inside the boiler.

How do the explosives remove the ash?
The percussion, blast wave, and tube vibration work together to break loose the material between and on the tubes.

Who does your vacuuming and hydro blasting service?
We sub-contract to H2O Underpressure, Inc. for our vacuum and hydro services. We don’t own any vacuum trucks or hydro equipment.

How long does it take to clean a boiler?
If the boiler is small, the job may take as few as 4 hours with a 4-man crew. A larger boiler may take as long as a week with a 6 to 8-man crew working 2-10 hour shifts. It all depends on the job scope, boiler size, type/hardness of material, and plant scheduling. If you use explosives every year, the time line will shorten with each subsequent cleaning.

What areas of the boiler can explosives be used in?
We can use explosives in the firebox, pendent, slope area, generating banks, and back passes. We can also clear clinker grinders, unplug ash and lime silos.

How does explosively cleaning/deslagging compare to hydro blasting?
Explosives are safer and quicker than hydro blasting. Explosives clean and break up all of the ash regardless of how hard or soft it is, it’s location or amount. Some areas cannot be cleaned with hydro blasting. Explosive deslagging reaches all the “webbing” between the tube bundles. With hydro blasting, only gas pass lanes are cleared/cleaned. Hydro blasting is time consuming and only removes a fraction of the material. Finally, with explosive there is no water in your boiler to clean up.

How does explosive cleaning compare to cleaning by hand?
Hand cleaning is time consuming and only removes about 30-40% of the material (ash). What may take 5-6 weeks, 8 hr days, with 4 men by hand to complete, would only take 10-12 hours with explosive at a comparable cost.

What type of shifts do we work?
We work an 8 to 10 hour shift rather than a 12 hour shift. After about 9 hours you start to get tired, your production drops tremendously, and safety becomes a major factor. For safety reasons, we will not work more than 12 hours regardless of the situation. If we see that we can’t finish in 10 hours we will call in another crew to finish or stop the operation and get 8-10 hours of sleep and return to finish the job.

Do you need fan on to blast?
It sure does help! If you don’t have fans it will take longer and cost more. This is due to the time it takes for the natural draft to evacuate harmful gases from the confined space to a safe level for entry.