Blast cleaning – intelligent blasting technology is considered indispensable and very efficient for large-volume silo systems
When reporting on blasting work, thoughts immediately go in the direction of collapsing industrial plants or residential buildings that collapse after a few seconds. Few consider the solution of a material blockade in a closed storage silo to be a suitable measure in connection with intelligent blasting technology. However, it is precisely this method with electric ignition that proves to be very successful without causing any damage to the inside of the silo. But how is it possible to work so precisely in a silo system?
The experts at NTService GmbH have the know-how and the technical capabilities to remove a material blockage in a silo with targeted blast cleaning. The operation is safe and efficient and causes no damage to the silo system or the environment.
What was our job?
Massive material compaction and blockages in a storage silo were reported to us by a company in the filter dust disposal sector (Fig. 1 shows the full closure on the silo outlet hopper and the location where our detonator was placed for the blasting). Our job was to loosen the blockage and remove the silo compaction by means of a loosening blast. The heavily clumped material had to be broken up so that it could be sucked out after the blast cleaning. (Fig. 6 shows the silo blockage of the discharge hopper in an image taken through a side opening) Safety aspects and the complete preservation of the silo system are central components of the order processing.
What was special about the use of blasting technology on site?
In a conventional operation, the plant operator would have the silo emptied manually by industrial climbers, which would be extensive and laborious. With our efficient blasting technology, the job is completed safely and cost-effectively in the shortest possible time and to the complete satisfaction of the plant operator.
How did our experts prepare for the mission?
In the event of an operation involving explosives, the first step is the risk assessment at the operation site by the NT Service team leader. (Fig. 2 shows the extensive marking of the safety area with appropriate signs)
The safety concept is drawn up and then documented by the team leader. The following steps were defined for the operation:
- Safe access to the silo system using proven rope access technology
- Safe maneuvering of the access technicians within the silo system
- Professional and precise positioning of the drill holes for the explosive charges
- Orderly withdrawal of the technicians and safe exit from the silo facility
- Determining the safety and rescue measures for all conceivable scenarios during the entire operation
Preparation, discussion with all parties involved and documentation of the safety concept is a prerequisite for the start of the actual work.
What special features need to be taken into account when inspecting silos before blast cleaning?
The German Social Accident Insurance (DGUV) provides guidance for authorized blasters and companies on the implementation of blasting work in the form of the application instructions Spreng TR 310. The top priority is to avoid accidents at work and health hazards that could arise during blasting operations. In addition, application and practical examples are explained in detail. Furthermore, the application notes serve to ensure that the technical regulations of the law on explosives are properly complied with.
Here you will find detailed information and instructions on the DGUV’s Spreng TR 310, including a version for download: https://publikationen.dguv.de/regelwerk/dguv-informationen/3796/sprengarbeiten-anwendungshinweise-zur-sprengtr-310
How were the silo inspection and preparation for blast cleaning carried out according to plan?
Thanks to the current slightly cooler outside temperatures, our well-trained team members in full protective gear were able to access the inside of the silo without any problems using the tried and tested rope access technique. (Fig. 3 shows the team leader during the access inspection in the silo; Fig. 4 shows team members inspecting the completely closed discharge hopper).
These factors are critical prior to blast cleaning:
- Drilling system with perfectly pre-calculated position of the individual holes for the explosive and its compaction
- Selection of the appropriate explosive and ignition type
- Earth fault and resistance measurement of the electric detonators as charge variables (see also Fig. 1)
All activities were carried out strictly in accordance with the specifications of the exemplary safety concept. The technicians then left the interior of the silo.
Execution of blast cleaning by the team leader
All team members have left the inside of the silo and are at a safe distance (Fig. 5 shows the blasting technician giving the blasting signal via the horn). The blasting technician then carried out the combination blasting with 18 detonated charges at intervals of 20 milliseconds. This measure succeeded in breaking up the silo blockage and shredding the material safely and efficiently.
The silo wall was not exposed to increased pressure during the blasting work. The vibration measurements carried out on the inner walls of the silo system during the blasting serve as proof of the “material-friendly blast cleaning”. The job was completed successfully. Both our customer and the NT Service team were delighted with the results achieved.
CONCLUSIONS:
“Intelligent blasting technology” is a gentle and cost-effective concept for removing material blockages, clumping or blockages at the discharge hopper in silo systems. In addition to technical know-how, a comprehensive risk assessment and a consistent, exemplary safety concept are required. Both can only be implemented by professionals with specialist knowledge and decades of experience.
NT Service GmbH has been a successful and trusted partner to the silo cleaning and blasting technology industry for many years. Well-known companies from a wide range of industries rely on our expertise (https://tnt-reinigung.de/de/referenzen). Our team stands for professional competence, quality and reliability. We offer you tailor-made solutions for every challenge and support you in optimizing your operational processes.
Get in touch with us today. Our experts will advise you without obligation and free of charge and answer all your questions. We will be happy to discuss your individual requirements with you and visit you directly on site.
