REPLACEMENT OF SILO WALLS FOR TWO CULLET STORAGE SILOS
Through continued innovation and excellence, Zenith remains at the forefront of the specialist access industry having all of the in-house competencies to safely and successfully complete major mechanical installation and refurbishment projects.
Our world class engineering team are industry leaders in providing bespoke temporary works access and lifting solutions and we are continually looking to innovate our designs by utilising industry first techniques.
We aim to complete our designs with the minimum disruption at site level and interface closely with the clients operations teams to fully understand the design brief from the outset. As full members of LEEA, we design and detail bespoke fabrications and solutions.
Having all the necessary skills in-house, our highly skilled onsite teams work in demanding environments adhering to the latest B31.1, BS EN and ASME standards. We provide extensive welding repairs, replacement and installations oftentimes carried out during tight shutdown periods at both low and high levels.
Zenith has built a first class long term relationship with our much valued client Encirc 360 having previously safely and successfully completed several demanding projects at their Elton site in Cheshire.
Encirc 360 required the replacement of the silo walls to 2no. cullet storage silos (nos. 21 & 23) which were located inside a portal frame building. The silos were fabricated in two flanged sections with a combined overall height of 23m and a diameter of 4m each.
Zenith provided all of the engineering involving temporary works design and lifting design, all necessary health & safety competence and onsite contract management including specialist access, lifting and mechanical services.
James Engineering Constructions Limited of Alfreton (James Engineering), Derbyshire were selected for the fabrication of the silos.
James Engineering scope of works consisted of the following:
All Steel Sections: material grade S355 J0
All Steel Hollow Sections: material grade S235/S355 J2H
All Plates/Fittings, Flat Bar & RSA sections: material grade S275 JR
All Materials: Class A
All welds: 100% visually inspected, frequency of all other testing as specified in BS EN 1090-2:2018 Execution Class 2. Only working to table 24 of NDT requirements. All NDT: in accordance with Table 24 – All Butt welds: tested to MPI 17638
All fabrication and erection tolerances: in accordance with annex B of BS EN 1090-2:2018 class one
All Surface preparation: P1 U.O.S. All material painted externally
Including an internal band for the spigot joint to the top of the upper sections
Design
Method 3 of declaration in BS EN 1090-1:2009:+A1:2011 or BS EN 13084-7
Quality Assurance
BS EN 1090-2:2018 execution class 2 and in strict accordance with relevant industry accepted standards. Default designs BS-EN 1993-1-1 Steel Structures
Weight
Silo Upper Sections: 7497 Kg
Silo Lower Section: 11230 Kg
Site Works
Once Encirc 360 had emptied both silos, cleaned the cullet dust, disconnected all electrical and mechanical (M&E) connections and equipment, Zenith proceeded with the site works commencing with silo 21.
Using a 450t crane, a suitable section of the existing roof covering and support purlins (including M&E) were removed to suit the extraction of the silo sections and were set aside at grade for re-use. In addition, the chequer plate flooring around the silo headhouses and sections of the existing adjacent access platforms and gantries were set aside for reinstallation
Using Rope Access Techniques and in accordance with Zenith’s design, the existing welded connection joints at the hopper and headhouse levels on both silos were prepared ready for silo wall cutting and removal. The silo walls were cut through to form additional lifting points.
To afford protection from inclement weather, a temporary lightweight scaffold and clad structure to suit the temporary building roof opening was designed and installed.
The upper and lower sections of the silos were cut into manageable sections and using the 450t crane were lowered to grade. It was determined by Zenith’s engineers to effectively reduce the size of the cut sections of the silo walls due to the imposed wind loadings as a result of seasonal weather conditions and the buildings height. The headhouse for each silo were lowered to grade where repairs and alterations were carried out.
The new lower sections of the silos were lifted into position through the building temporary roof to sit on the retained in-situ silo hopper. At this level, a temporary working platform was installed and the lower section was tack-welded as a temporarily fix to the hopper.
The new upper silo sections were lowered through the building temporary roof opening to sit on the previously installed lower silo section. Using rope access techniques, 25% of the flange bolts were secured to the upper and lower wall mating flanges.
A temporary working platform was installed at the mating flange level. The adapted headhouse was lifted through the temporary roof opening and lowered onto the new upper silo sections.
Additional temporary working platforms at the flange levels were installed and gaining access from the platforms the remaining mating flange bolts were installed and torqued as required together with carrying out any required external welded connection works.
Site weld testing was performed by Zenith and any disturbed external painted finishes were made good.
The entire project was safely and successfully completed to an extremely high standard and demonstrates Zenith’s ability to plan, manage and execute a demanding project from start to finish.
As Zenith has all of the core competencies for a project of this nature in-house, it gives our valued clients the assurance that we can exceed expectations including having the flexibility to respond quickly and efficiently to any unexpected developments.