A silo cell is a central building block of silo systems in cement plants, gravel plants, lime and gypsum production, agricultural logistics, or in the chemical industry. Wherever bulk materials are stored, handled, and metered, planners, operators, and specialist contractors encounter the silo cell in new construction, maintenance, modification, and deconstruction. Interventions in silo cells are technically demanding: concrete and steel structures meet confined spaces, dust and explosion protection, complex load paths, and ongoing operations. Especially here, low-vibration, low-impact methods have become established, such as controlled splitting of concrete or selective concrete removal. Depending on the task at hand, tools such as concrete pulverizer or hydraulic splitter as well as suitable hydraulics from Darda GmbH are used in connection with work in silo cells — typically in the application areas concrete demolition and special demolition, gutting works and cutting, and special deployment.
Definition: What is meant by silo cell
A silo cell is understood to be the individual chamber of a multi-cell silo system (silo battery) or the standalone, usually vertical container of a silo system. Silo cells are constructed as cylindrical, polygonal, or rectangular shaft structures made of reinforced concrete or steel. They typically consist of the shell wall (shaft), the conical or pyramidal hopper (discharge), the roof with inlet and maintenance openings, and the connections to discharge units (e.g., screws, rotary valves). They serve to store and dose bulk materials such as cement, lime, gypsum, fly ash, aggregates, ore, grain, or pellets. Design takes into account filling and emptying pressures, wall friction, temperature and humidity changes, as well as dynamic effects from operation.
Structure and design features
Silo cells combine load-bearing function and proximity to conveying. For planning, repair, or deconstruction, the structural setup is crucial because it determines the choice of methods and dictates work access.
- Concrete silo cell: Reinforced concrete walls with reinforcement, often with wear-resistant internal lining in the hopper area. Wall thicknesses vary depending on height, diameter, and load assumptions. Attachments such as fixed ladders, platforms, dust extraction lines, or knockers are common.
- Steel silo cell: Shell made of steel plate with rings, beads, or profile rings for stiffening. Hopper from conically bent plates. Often with wear linings or coatings. Attachments include conveying equipment, impact plates, and measuring sensors.
- Silo batteries: Several silo cells are combined in a common structure. Partition walls share loads, so local interventions (openings, reinforcements) must be coordinated structurally.
Typical tasks on existing silo cells
Throughout the life cycle of a silo cell, a wide range of tasks arise that must be executed precisely and in a material-appropriate manner. These include work in concrete demolition and special demolition, in gutting works and cutting, and in special deployment.
- Creating openings for inspection, conveying, dust extraction, or modifications
- Selective removal of concrete on shell walls or hoppers, e.g., for wall thickness reduction or to fit new attachments
- Removing crusts and build-ups, breaking bridges
- Deconstruction of decommissioned silo cells or partial deconstruction of hoppers and roof areas
- Repair: exposing corroded reinforcement, removing defective concrete or steel plates
- Retrofitting outlets and discharge equipment, enlarging or relocating inlets
Methods and tools for work on silo cells
The choice of method depends on material, component thickness, installations, surroundings, and safety requirements. In practice, hydraulic, low-impact methods that are controllable and usable in confined spaces have proven themselves.
Controlled splitting of concrete components
With controlled splitting, splitting cylinders are inserted into a defined drilling pattern. hydraulic splitter and stone splitting cylinders generate high, locally confined splitting forces in the borehole, causing the concrete to crack along the calculated lines of weakness. The method is precise, low-vibration, and suitable for openings in shell walls, deconstruction of hopper tips, or detaching concrete noses. Power is supplied by hydraulic power units from Darda GmbH; the arrangement allows work in areas with restricted accessibility. Typical application areas are concrete demolition and special demolition as well as gutting works and cutting.
Selective concrete removal and edge finishing
concrete pulverizer enables “nibbling” concrete with high shape accuracy, for example when exposing reinforcement, cleanly notching edges, or tying into existing installations. The device can be guided section by section, allowing opening contours or bevels to be produced precisely on silo walls. In combination with splitting technology, rough separation can be performed first and then contoured. Tools such as concrete crushers for precise removal support this method.
Cutting reinforcement and steel components
Where reinforcing steels, profile rings, impact plates, or steel hoppers must be cut, steel shear and hydraulic shear are used. They cut reinforcement and plates in a controlled manner, including in elevated areas or inside the cell. Multi Cutters are helpful when different material thicknesses and mixed construction are encountered. Working in small cutting windows and with low spark generation is an advantage in dust-sensitive areas.
Cutting tanks and steel silos
For metallic silo cells or tank-like vessels, segmental deconstruction can be carried out with a cutting torch. Before such work, clearance measurements, inerting, and suitable extraction are usually prepared. These tasks often fall under special deployment when special geometries or media are present.
Planning, structural analysis, and safety
Interventions in silo cells affect load-bearing capacity, operational safety, and explosion protection. Careful planning is essential and should assess the individual case with expert knowledge. The following points provide general guidance but do not replace project-specific planning or approvals:
- Check existing documentation: structural analysis, reinforcement drawings, material specifications, linings, attachments
- Clarify filling state and residual material, exclude bridging; if necessary, empty in a controlled manner
- Risk assessment incl. dust explosion protection, clearance measurements, and ventilation; define personal protective equipment
- Access and rescue: work in confined spaces only with a coordinated rescue plan and communication means
- Plan temporary shoring and load relief, especially for openings in load-bearing areas or hopper modifications
- Emission reduction: dust suppression (e.g., mist), dust extraction, enclosures
- Organize work permits, briefings, and cordoned-off areas
Workflow: From concept to a clean opening
- Survey and define the intervention goal (opening, deconstruction, repair)
- Isolate, clean, and if applicable inert; document measurements and releases
- Access and logistics concept (suspension, platforms, lifting gear, material removal)
- Method selection: splitting, pulverizer work, shears or cutting technology; selection of suitable hydraulic power pack
- Trial split or trial cut in a non-critical area to verify parameters
- Execution in sections with ongoing monitoring of component behavior and emissions
- Finishing: refine edges, treat reinforcement, add protective layers; acceptance and documentation
In practice, hydraulic splitter are often used for structured separation, e.g., Rock splitters, and then contours are finished with concrete pulverizer. Metallic components are cut with steel shear, hydraulic shear, or Multi Cutters.
Specifics for cement, lime, and grain silos
Cement and lime silos
Build-ups and crusts are typical. Mechanical loosening requires a controlled approach to avoid abrupt changes in wall pressures. For structural adjustments, openings can be created with splitting technology; edge areas are defined with concrete pulverizer. Dust binding and grounding of conductive components contribute to explosion protection.
Grain and feed silos
Often built as steel silos, with special requirements for explosion protection and hygiene. For cutting plates and stiffeners, methods with low sparks and ignition sources are advantageous. steel shear and, where appropriate, cutting torch enable segmental dismantling.
Ore, gravel, and aggregate silos
High abrasion can lead to worn hopper tips or local damage. For replacement, damaged areas are often removed via a drilling pattern and hydraulic splitter to protect the adjacent structure. Edge finishing is then performed with concrete pulverizer.
Emission and environmental aspects
Work on silo cells requires an emissions concept. Hydraulic splitting and pulverizer work are generally low-vibration and support a controlled emissions level. Dust is reduced by extraction and wetting, noise is minimized by enclosed work areas and adjusted working hours. Arising materials are separated by fractions (concrete, reinforcing steel, plates, linings) and properly disposed of or routed to recycling.
Practice-oriented application scenarios
- Opening in a concrete silo cell for a new discharge: drilling pattern, splitting with hydraulic splitter, exposing the reinforcement, contoured finishing with concrete pulverizer.
- Segmental deconstruction of a decommissioned steel silo: removing attachments, cutting shell plates with steel shear, trimming larger sections with cutting torch and controlled lowering.
- Refurbishment of a hopper with replacement of the tip: local exposure using splitting technology, removing corroded reinforcement with Multi Cutters, fitting new components.
Checklist for preparing work on silo cells
- Define objectives and delineate the work area
- Documentation status: drawings, structural analysis, material data, linings
- Risk assessment incl. dust and explosion protection; measurement and release concept
- Clear, empty, clean; waste management chain for residual materials
- Access, fall protection, rescue, and communication
- Method and tool selection (e.g., concrete pulverizer, hydraulic splitter, steel shear, hydraulic shear)
- Plan hydraulic supply (hydraulic power pack, hose routes, leak protection)
- Emission and noise control measures
- Sectional planning, trial areas, documentation
- Quality control and final inspection
Terminology distinction
Silo cells are containers designed for bulk materials with specific flow properties. They are to be distinguished from bunkers (usually open and with short drop heights) as well as liquid containers and tanks. For tank-like steel vessels, interventions resemble those on steel silos; steel shear and cutting torch are frequently used here. For massive concrete structures with bulk material contact, hydraulic splitter and concrete pulverizer have proven effective — typically in the application areas concrete demolition and special demolition as well as gutting works and cutting.