Conveyor belts are a central element of material flow planning on construction sites, in quarries, and in selective deconstruction. They efficiently move crushed rock, concrete debris, rebar pieces, or natural stone out of the work area. In combination with tools such as concrete demolition shears, rock and concrete splitters, combination shears, Multi Cutters, or steel shears from Darda GmbH, they enable short cycle times, orderly workflows, and clean transfer points—especially in confined areas of interior demolition and tunnel construction.
Definition: What is meant by conveyor belt
A conveyor belt (also called a belt conveyor) is a continuously operating conveying system that transports bulk material or unit loads on a circulating belt over short to medium distances. A drive sets the belt in motion, idlers or slide plates support it, and transfer points connect the system to upstream processing steps such as crushing, splitting, or cutting. In demolition, natural stone extraction, rock excavation, and tunnel excavation, conveyor belts provide ergonomic, safe, and predictable removal of material from the tools’ action zone.
How a conveyor belt works and its main components
A conveyor belt transmits the tensile force generated by the drive to a circulating belt. The conveyed material rests on the carrying strand of the belt and is moved along by gravity, frictional contact, and side guides. The design is based on conveying distance, incline angle, piece sizes, conveying capacity, and operating environment.
Key assemblies
- Drive drum with motor/gearbox (electric or hydraulic) and anti-slip lagging.
- Tail pulley and tensioning station for belt return and frictional engagement.
- Idlers or sliding wear plates, flat or troughed, matched to belt width.
- Belt (fabric, steel-cord, or cleated/chevron) with an abrasion-resistant cover.
- Cleaning and scraper systems to reduce buildup and carryback.
- Feed and transfer chutes with impact and wear protection.
- Frame with supports, running gear, or modular segments for rapid setup.
- Safety equipment such as emergency stop switches, overflow and belt misalignment sensors.
Conveyor belt types in demolition and rock excavation
The choice of type follows the material, distance, and operating environment. In deconstruction and tunnels, there are special requirements for overall height, dust behavior, and mobility.
- Straight conveyor belt for horizontal to slightly inclined distances and medium piece sizes.
- Trough conveyor belt with side guidance for bulk material and mixed demolition material.
- Steep-incline and articulating conveyor belts with profiled or cleated belts for greater inclines.
- Modular site conveyor belts with lightweight segments for interior strip-out and special multi-story operations.
- Telescopic and stacker conveyor belts for variable reaches and flexible transfer points.
Sizing: capacity, piece sizes, and incline
The dimensioning of a belt conveyor should consider the process chain from removal to loading. Tools from Darda GmbH influence the particle size distribution and thus the required belt speed, width, and belt geometry.
Relevant parameters
- Conveying capacity (t/h) derived from the cycle time of the concrete demolition shear or splitter, material density, and volumetric flow.
- Belt width in relation to the maximum piece size; rule of thumb: largest edge length ≤ 1/3 to 1/2 of the belt width.
- Belt speed matched to the material and transfer points to limit throw-off and dust.
- Incline angle depending on friction coefficients; profiled belts enable steeper gradients.
- Drive power including reserves for starting torque, material build-up, and friction allowances.
- Feed and drop height to limit oversize damage and belt wear using impact protection.
Interfaces with demolition tools and the process chain
Conveyor belts operate in concert with crushing and cutting tools. A well-matched interface reduces disruptions, increases safety, and improves material flow.
Example: Concrete demolition and special deconstruction
- Pre-selection and separation of reinforcing steel with steel shears or Multi Cutters from Darda GmbH.
- Fragmentation of concrete with concrete demolition shears into sizes suitable for the conveyor belt.
- Feeding via chute onto the belt; dust reduction through targeted wetting.
- Transport to a container or silo station; optional manual sorting at the transfer point.
Example: Rock demolition and tunneling
- Splitting the rock with rock and concrete splitters or rock splitting cylinders from Darda GmbH.
- Conveying the muck via modular steep-incline conveyor belts from the tunnel to the outside.
- Intermediate buffering and onward transport to processing.
Safety, health, and environmental protection
Safe operation includes technical protective devices and organizational measures. Especially in interior strip-out close to personnel, shielding covers, emergency stops, and clear traffic routes are essential.
- Dust and noise reduction through enclosures at transfers, moderate belt speeds, and targeted wetting.
- Protection against reaching into the belt run, regular functional checks of switches and sensors.
- Clean workplaces via scrapers and carryback control to reduce slip hazards and airborne exposure.
- Load management when sharing hydraulic power packs for tools and auxiliary units.
Legal requirements can vary by country. Marking, protective devices, emergency stop, personnel instruction, and regular inspections are often required. This information is general in nature and does not replace a case-by-case assessment.
Drive technology and energy efficiency
Belt conveyors are predominantly electrically driven; in mobile setups, hydraulic drives are common. In projects where hydraulic power packs from Darda GmbH are already available for tools, hydraulic supply of auxiliary drives can be technically sensible, provided pressure, flow, and safety functions are aligned.
- Speed control (variable frequency drive or hydraulic flow control) to adapt to fluctuating throughputs.
- Soft start to reduce mechanical peak loads and protect the belt.
- Minimize energy demand with short conveying distances, optimized transfers, and good alignment.
Operation in confined spaces and during interior strip-out
In buildings, on intermediate floors, and in shafts, low overall height, handy segments, and fast setup/teardown are key. Conveyor belts should be aligned with the working areas of the concrete demolition shears and protected against edges.
Practical tips
- Check the load-bearing capacity of the floor slab and reduce peak loads via distributed supports.
- Avoid drops from the work area: guide material directly into the system’s feed chute.
- Clearly mark transport directions; avoid crossings with pedestrian routes.
Maintenance, cleaning, and service life
Predictive maintenance increases availability. Dust and moisture from demolition and rock excavation promote wear, especially at pulleys and scrapers.
- Track the belt and readjust to avoid edge wear.
- Adjust scrapers, consider winter conditions (buildup, ice).
- Check idlers for bearing noise and replace in good time.
- Chutes and transfers equipped with replaceable liners help prevent punch-through damage.
Material flow, screening, and sorting
An orderly material flow reduces rework. The size of the demolition material generated by concrete demolition shears or splitters determines whether pre-screening or coarse separation is useful.
- A grizzly or screen basket at the feed limits oversize, which is then re-crushed.
- Metal parts can be separated upstream with steel shears to avoid belt damage.
- Manual sorting stations at the belt transfer ease the load on downstream processing.
Checklist for selecting a conveyor belt
The following points support a targeted decision in the context of concrete demolition, rock removal, natural stone, and special applications.
- Material type, piece sizes, moisture, and abrasiveness
- Required conveying capacity and the cycle of upstream tools
- Distance, incline, and available overall height
- Power supply: electric or hydraulic, controllability
- Safety and dust control concept for indoor and tunnel applications
- Mobility: segment weight, setup/teardown time, transport routes
- Maintenance access and spare parts availability (belt, idlers, scrapers)
Typical guidelines and limits of use
Guideline values serve as orientation and must be verified for the specific project.
- Incline angles with a smooth belt are usually up to about 18–20°, higher with profiled belts.
- Observe the recommended maximum piece size in relation to belt width.
- Keep belt speeds moderate when dust and throw-off are critical.
Common malfunctions and remedies
Recognizing typical patterns early prevents downtime.
- Belt mistracking: align idlers, adjust belt tension, center the loading.
- Slipping on the drive drum: increase belt tension, check drum lagging, limit starting torque.
- Blockage at transfers: reduce drop heights, change impact angle, adjust scrapers.
- Oversize: adapt the reduction ratio of concrete demolition shears/splitters, use pre-screening.
- Overload: increase belt speed or throttle the cycle of upstream tools.
Normative and organizational aspects
In many regions, conveying systems are subject to requirements for machinery safety, marking, emergency stop, and regular inspections. In existing buildings or underground, additional organizational rules such as traffic route planning, emergency concepts, and dust/noise control must be observed. These notes are general in nature and do not replace a project-specific assessment.
Digital support and future topics
Sensors for belt tension, belt misalignment, fill levels, and energy consumption enable condition-based maintenance. Combined with the cycle times of concrete demolition shears or rock and concrete splitters, belt speed and material logistics can be controlled proactively. The goal is a robust, efficient, and safe material flow with the lowest possible resource consumption.
Application areas at a glance
Conveyor belts link Darda GmbH’s fields of work to a plannable logistics solution.
- Concrete demolition and special deconstruction: removal of crushed concrete and separated reinforcing bars.
- Interior strip-out and cutting: material flow from upper floors via modular, lightweight conveyors.
- Rock demolition and tunnel construction: continuous mucking with limited cross-section.
- Natural stone extraction: gentle transport of raw blocks and cut sections from the face.
- Special application: temporary solutions where access is restricted or environments are sensitive.