Silo cleaning using the professional method of sandblasting technology is part of our specialists’ daily business. The rope access technique for entering the inside of a silo system has proven its worth. The freely swinging rope replaces a complex scaffolding structure when working in the silo and enables precise access to the desired work areas. In special cases, additional work steps are required in addition to silo cleaning.
What was our mission?
Our customer operates a bulk material storage system for sand and gravel. Enormous forces act here when the bulk material exits through the relatively narrow discharge hopper on a daily basis. The entire material from the silo system leaves the storage facility through a relatively narrow point, which is therefore subject to extreme abrasion. In addition to the scheduled cleaning of the silo, our job was to apply a high-quality wear protection application to several discharge hoppers. This measure serves to extend the service life of the silo system.
How was the order carried out by our employees?
The first part of the work was the complete and thorough cleaning of the silo system using sandblasting technology. Ferrite-free garnet sand is used to avoid damaging the surface of the silo walls. As the system is exposed to different loads from the escaping material when filling and emptying a silo, our experts check the wall thickness of the silo in a second step. This determines deviations between the target and actual values of the silo walls.
Once the cleaning work had been completed, the additional task during our assignment was to apply a high-quality wear protection to several discharge hoppers of the silo system. As particularly abrasive material leaves the silo here, these areas are permanently exposed to high levels of wear. The spray application of wear protection is a particular challenge for the employee hanging from the rope. This is due to the fact that no residue must remain on the sandblasted and cleaned surface before the wear protection is applied. The work of the rope access technician is made even more difficult by the fact that the product to be applied must be heated using microwaves before application.
What special features are there to report in connection with the wear protection application?
In the past, we have already tested several metal solutions in practical applications on test objects. We were not satisfied with the results achieved there. As we place the highest demands on the quality of our work, this also applies to the materials and substances used. For this reason, the PUR spray solution from Pucest is the ultimate solution for our applications. With the kind permission of the manufacturer of the application, Pucest, here are some details about the product we use.
The material:
The wear protection consists of a solvent-free 2-component elastomer that is applied by spraying. Polymerization begins just 1 minute after application. This allows layer thicknesses of 2 to 50 millimetres to be achieved on vertical surfaces without material flowing off.
With steel, brass, aluminum, bronze and concrete, almost any coating can be sprayed in a silo system. The surface treated by us is dry to the touch after approx. 5 minutes and ready for use after 24 hours (at 20 °C). The wear protection solidifies without tension and develops a mechanical adhesion effect in addition to the chemical adhesion. Multiple applications are no problem.
Details of the application process:
Our employees must wear protective equipment when carrying out this type of work. The spray material is supplied in cartridges and applied through a spray nozzle during use. To achieve the desired effect, the spray material must be heated using microwaves directly before application. Hanging from a rope, this process requires extreme concentration and manual skill from our specialists in the silo.
How was our mission overall?
After assessing the situation in the silo facility, the team management planned the assignment. The focus is always on an exemplary safety concept. All possible scenarios that could occur during the operation are recorded, evaluated, taken into account and discussed with the employees. Work can only begin once the concept has been documented by the team leader.
Thanks to the cooperation of all team members, the work was completed faster than expected. Our well-trained experts completed both the silo cleaning and the application of the wear protection to the customer’s complete satisfaction while hanging from a rope. We handed over a silo system to the plant operator that is expected to have a significantly longer remaining service life thanks to the application of the wear protection.
