Steel Hopper Liner Silo Repair – North Carolina
Market: Education Material Stored: Coal Silo Size: 60′ diameter x 140′ tall Issue: Hopper liner peeling off. Project Background A stainless steel liner inside a silo cone. Pictured above is a stainless-steel liner inside a silo cone. The stainless-steel sheets are fixed to a supportive steel structure, then lean fill concrete is poured behind for additional support. In this instance, the stored material got behind the sheets and led to separation of the sheet from the lean fill in the silo cone. This was found during a preventive maintenance inspection. The situation could have been much costlier as additional sheets would have delaminated over time and could potentially have been pushed through the feeder system causing significant cost and downtime. Early detection helped minimize costs and downtime. A safe work deck was built to cut out the 'pealed' sheets. To repair this situation, a silo cone specific scaffold was erected from the cone bottom to the required working level. Once a safe work deck was in place, the 'pealed' sheets were cut out in alignment with the steel support structure poured in the lean fill wall. The sheets were welded to the structural steel and at the stainless-steel seams. In order to hold the sheets in place for welding and additional rigidity, anchor bolts were used to fasten the stainless steel. The head of the bolt was ground down and then puddle welded for a smooth surface. The red color at the leading edge is a three-stage epoxy that was put on all around the circumference of the silo. This was added for additional assurances that the stainless-steel sheets would not peel away from the cone in the future. A closer look at the repaired stainless liner sheets. Above is a closer look of the repaired stainless liner sheets from a different angle, with the epoxy leading edge. This repair was the direct result of regular inspections. If this situation was not detected early it could have been devastating to operations. Regularly scheduled inspections by a professional silo engineer is the best insurance for the safe, efficient operation of a bulk material handling system.
New Fly Ash Concrete Silo Construction – Michigan
Market: Power Material Stored: Fly Ash Silo Size: 45′ diameter by 118′ tall Issue: Special engineering to accommodate large door openings. Project Background A fly ash silo with finished silo walls, roof, material floor and equipment floor. In the photo above, the silo walls, roof, material floor and equipment floor are finished. This silo is unique as the drive through doors are large for the overall diameter of the silo, thus creating the need for additional reinforcement to be placed inside the silo. Two additional columns to make up for the lack of continuous walls. The columns, pictured above, were an engineering addition to the silo design to make up for the lack of continuous walls carrying the stored material weight to the foundation. This allows for full access for the use of very large mine haul trucks to drive through the center for loading and recovering the fly ash. From this picture, you can also see the very thick, squared concrete beside the door openings. These unique design elements were implemented by a professional silo engineering firm to meet the special conditions requested by the client. Continuation of the column previously shown at the foundation level. This column goes from the foundation, through the equipment floor and adds additional support to the material floor. Also pictured is the continuation of the large square structures on each side of the door openings at the foundation. These additional support structures were required by the engineer design firm for structural integrity due to the lack of vertical walls created by the over-sized truck doors in a smaller diameter silo.
Silo Roof Beam Bearing Repair – Florida
Market: Manufacturing Material Stored: Cement Silo Size: 27′ diameter by 110′ tall Issue: Potential Silo Roof Collapse Project Background Damaged silo beam pocket leaves roof at risk of collapse. Beam pockets are a critical point in silo structures as roof beams hold up the roof slab and all equipment needed to operate the bulk storage system. Found during a regular inspection of the silo structure, the above pictured silo beam pocket shows a beam resting on a bearing plate to support the roof. The beam end sits on the thick, steel bearing plate. However, the concrete under the plate is spalling leaving this beam pocket at risk for failure. Repaired silo beam pocket. After inspection, an engineered solution was proposed to reestablish the structural integrity of the beam pocket. First, the roof beam was lifted off of the beam pocket and bearing plate to allow for repairs. The pocket was thoroughly cleaned and all loose materials removed. Structural steel was placed per engineer specifications to ensure the integrity of the repaired beam pocket. Lastly, a high strength, non-shrink grout was used, and given adequate cure time, to patch the spalled area. Once completely cured, the beam was lowered back onto the bearing plate of the repaired beam pocket. Regular inspections of all equipment are imperative to eliminate potential failures in any production system, including silos. Proper silo roof design is critical. While roofs are designed to hold equipment, they are not designed for excessive amounts of material. If a loading system fails or a silo is overfilled, creating bulk material on the roof, unseen damage can result and compromise the entire structure.
Stave Silo Repair for Aggregates Storage – Florida
Market: Manufacturing Material Stored: Aggregates Silo Size: 26′ diameter by 52′ tall Issue: Bulging & Cracked Walls Project Background Left to right in the photograph: Silo 1, 4 & 5 have the engineered repair completely installed. Silo 2 has not been repaired yet and silo 3 is in process, about half way completed. Marietta Silos worked on five silos that were constructed with concrete staves and utilized steel galvanized hoops around the silo for structural integrity. Typically less than 30’ in diameter, stave silos, originally designed and utilized in agricultural markets for silage storage, are typically of simple design with a gravity fed, bottom center discharge location. With industry growth, stave silos were put into new markets as the advantages of silos for bulk storage of loose materials were quickly recognized. Side discharge chutes, vacuum or pressure loading and unloading, heavier materials and faster throughput requirements were all introduced under industrial silo use. Despite the advantages of stave silos in industry, they were not engineered for this industrial application and therefore can face problems. The silos pictured here faced continued stress on the structure which caused the wall to push or bow out from its normal form, leading to cracking. To add structural integrity to the existing silo before failure, a collar wall was added using reinforced, poured in place, concrete jump-form technology. Utilizing the existing foundation, a new steel reinforced concrete wall was implemented around the full circumference of the silo from grade to the top. This solution was completely engineered for the customer’s specific application. All penetrations and openings were placed for this application to operate as efficiently as possible, and now in a safe manner. Marietta works with the silo owners’ production schedules to repair silos with minimal or no impact on production.
Stave Silo Wall Repair – Florida
Market: Manufacturing Material Stored: Aggregate Silo Size: 26′ diameter by 52′ tall Issue: Bulging walls Project Background Concrete stave constructed silo with steel galvanized hoops. The above silo was constructed with concrete staves with steel galvanized hoops around the silo for structural integrity. Not engineered for an industrial application, the new stressors put on the structure caused walls to push or bow from the intended form. Repair in process. To add structural integrity to the existing silo before failure, a collar wall utilizing reinforced, poured in place, concrete jump-form technology was added. Using the existing foundation, a new steel reinforced concrete wall was implemented around the full circumference of the silo from grade to the top. This solution was completely engineered for the customer’s specific application. All penetrations and openings were placed for this application to operate as efficiently, and as safely, as possible.
Wood Chip Concrete Silo Wall Repair – Louisiana
Market: Manufacturing Material Stored: Wood (dust, chipped & shredded) Silo Size: 50′ diameter by 100′ tall Issue: Grain Silo Design Used Inappropriately in an Industrial Application Project Background Silo with a wall failure. As shown in the picture above, steel galvanized hoops were installed around the silo weak zone to try to prevent failure and keep the wall intact. The inevitable failure was due mainly to the initial, light weight design of the silo. The silo lower walls were constructed half as thick as new industrial silos and only had a single layer of steel reinforcement. The lack of reinforcement around the wall openings and inappropriate design details attaching the material storage floor to the silo’s wall meant the silo was unable to handle the amount of internal pressure. The repair in process. To add structural integrity to the existing silo at the point of failure, a collar wall was added. Scaffolding was erected around the full circumference of the silo for repair construction. A specially manufactured angle steel was fabricated to act as the foundation to pour the concrete collar wall around the existing silo. All penetrations pictured had fabricated steel extensions welded to the existing steel to protrude out to the new silo wall thickness. Dowels were anchored into the existing wall and additional rebar placed prior to pouring the concrete. The completed repair creates a more structurally sound silo wall.
Grain Concrete Silo Wall Repair – Ohio
Market: Manufacturing Material Stored: Grain Silo Size: 55′ diameter by 112′ tall Issue: Grain Silo Design Inappropriately Used in an Industrial Application Project Background Former grain silo with wall failure after industrial use. This former grain silo was used for industry without prior inspection or reinforcement. As a result, horizontal and vertical cracking of significant size led to compromised structural security. Initial, light weight designs of grain silos cannot handle the pressure difference seen in industrial applications. In this situation, a collar wall was added to restore structural integrity of the existing silo wall. All penetrations pictured had fabricated steel extensions welded to the existing steel to protrude out to the new silo wall thickness. Dowels were anchored into the existing wall and additional rebar was placed prior to pouring the concrete. The new collar wall extended from grade level to 40’ up the silo. It reinforced the area of damage and enhanced structural integrity to meet requirements for the existing application and prevent future issue. Initial design in any new construction project is imperative. To ensure the longevity of your bulk storage system, it is very important to choose a company and engineering firm with experience and avoid basing decisions solely on price. Regular silo inspection is recommended to ensure structural integrity, operability and safety. The issue shown here could have been prevented prior to construction. While the cracking was severe, a thorough inspection by Marietta Silos allowed us to reverse the damage before a failure could occur.
New Fly Ash Concrete Silo Construction – Tennessee
Market: Energy Material Stored: Fly Ash Silo Size: 32′ diameter by 107′ tall, Quantity (2) Issue: Wet material storage to dry storage. Project Background Silos in the early stages of construction. The silos above show a temporary stair tower utilized by employees to access the Jump-O-Form work deck inside the silo during wall construction. These two state-of-the-art silos are comprised of hundreds of thousands of pounds of concrete and structural steel. Each is constructed with supported cones for increased safety and drive-through doors for loading semis with the fly ash material. The same silos, from a different angle, almost complete. The permanent stair tower has been erected in between the silos for access to either, equipment has been placed on the roof and the external electrical and piping systems traverse up the silo walls.
New Fly Ash Concrete Silo Construction – Colorado
Market: Power Material Stored: Fly Ash Silo Size: 50′ diameter by 148′ tall Issue: Wet ash disposal to dry ash storage. Project Background Single fly ash silo construction project nearing completion. The fly ash silo pictured above is nearly complete. The permanent stair tower has been erected with access points to different levels and the silo roof. Equipment will be placed on the roof and external electrical & piping systems will traverse up the silo walls.
New By Product Jumpform Silo Construction – Wisconsin
Market: Power Material Stored: Fly Ash Silo Size: 50′ diameter by 100′ tall, Quantity (2) Issue: Wet ash disposal to dry ash storage. Project Background Two completed fly ash silos with enclosed roofs. Two completed jumpform fly ash silos for a new coal fire power plant are pictured above. These poured in place silos are part of a vacuum system for fly ash. The permanent stair tower has been erected in between the silos for access to either and equipment has been placed on the roof and the external electrical & piping systems traverse up the silo walls. The material handling equipment on the roof is enclosed in an inexpensive, sheet metal head house. This inexpensive method of enclosure increases equipment longevity and operating efficiency by protecting it from the environment.