Kopterflug inspects digesters, bleach towers, evaporation plants and process vessels in the paper and pulp industry – without human entry, without respiratory protection, without DGUV confined space procedures. 4K documentation, thermography and LiDAR 3D scanning in a single flight.
The ELIOS 3 with its collision-safe carbon cage – built for contaminated digesters, bleach towers and process vessels.
Digesters and bleach towers operate with aggressive caustics and chemicals – confined space entry requires respiratory protection, chemical protective clothing and elaborate DGUV safety measures. The Flyability ELIOS 3 flies into digesters, bleach towers and evaporation vessels – after flushing and gas-free clearance, without human entry, with 4K + LiDAR + thermography. Minimal downtime, maximum safety, complete documentation.
Digesters, bleach towers, evaporation plants and pulp preparation vessels – large-volume process equipment, corrosive media, narrow access. We inspect all safety-critical assets without human entry:
Our services:
Digesters, bleach towers, evaporation plants – corrosive chemicals, high temperatures, narrow access points. Conventional confined space entry is dangerous, expensive and downtime-intensive. The ELIOS 3 solves this – without human entry.
With the Flyability ELIOS 3, we inspect process plants in the paper and pulp industry without human entry – safely, precisely and with minimal downtime:
Visual inspection of linings, welds and screens. Thermography for hotspot and insulation defect detection. LiDAR survey of deposits and geometries.
Inspection of tower interior walls, linings and internals from top to bottom – without scaffolding, without climbing team. LiDAR captures geometry and deposits.
Inspection of heat exchanger surfaces, vessel walls and internals. Thermography reveals encrustations, fouling and heat loss zones.
Inspection of vat walls, base plates, agitators and internals. Sediment capture per LiDAR, corrosion capture per 4K camera.
Inspection of firebox, superheaters, tube bundles and deposits in the flue gas path. Focus on corrosion, deposit formation and structural integrity – without scaffolding and without entry.
Inspection of interior lining, burner zones and transitions. Particularly relevant for refractory lining and thermal damage.
We analyse your requirements and advise you free of charge on all technical and organisational questions – from gas-free measurement to documentation requirements per BetrSichV.
You receive a transparent quotation. Together we plan the timing, flushing protocol, access and safety concept.
Gas-free measurement, clearance, flight. We carry out the inspection with state-of-the-art drone technology – usually in a few hours after operational release.
You receive a detailed report with 4K footage, 3D models, thermography analyses and systematic findings overview – auditable for your certified inspection.
Our inspections meet the highest safety and documentation standards for process plants in the paper and pulp industry:
Christian Engelke and Dipl.-Ing. Karsten Lehrke – your direct contacts for paper and pulp inspection projects.
Since 2017, we have been carrying out drone inspections in demanding industrial plants – numerous deployments in digesters, bleach towers and process plants. We understand the special requirements: corrosive media, pressure vessel inspection obligations, gas-free measurement and minimal downtime. No human entry into hazardous areas – 4K + LiDAR documentation for your certified inspection per BetrSichV.
Christian
Founder & Drone Pilot
Karsten
Founder, Managing Director
Philipp
Founder, Operations & Logistics
Juliana
Drone Pilot
Stephan
Operations & Logistics
The inspection is carried out entirely by drone – without employees having to enter the interior. This eliminates: respiratory protection, rescue chain, DGUV confined space entry protocol and the associated safety and preparation overhead. The drone takes over.
We deploy two specialised systems: the Flyability ELIOS 3 for interior spaces – collision-protected, GPS-independent, with 4K + LiDAR + thermography, specifically for confined spaces such as digesters and bleach towers. The DJI Matrice 30T for exterior inspections of bleach tower exteriors, tank farms and pipe bridges – with 200x zoom and radiometric thermography.
Yes – with the right preparation. Digesters must be flushed, degassed and cleared before flight. We carry out gas-free measurement in advance with a calibrated multi-gas sensor. After that the ELIOS 3 flies into the digester – without human entry, with 4K camera, thermography and LiDAR.
We inspect all typical process plants: digesters (batch and continuous), bleach towers (all stages), evaporation plants and evaporators, black liquor vessels, vats and pulp preparation vessels, recovery boilers, lime kilns, chip silos, large-diameter pipes (≥ DN 1200), flue gas ducts and more. Exterior structures (cooling towers, storage tanks, pipe bridges) with the DJI M30T.
The ELIOS 3 is not ATEX-certified. Before every deployment, we carry out a gas-free measurement (O², LEL, H²S, CO). The drone only flies after confirmed gas-free status. This applies to all deployments in digesters, bleach towers and evaporation vessels. The gas-free measurement is part of our service.
Relevant are the BetrSichV (Betriebssicherheitsverordnung) for pressure vessels, TRBS 1201 for inspection requirements and DGUV Rule 113-004 for confined spaces. Our documentation is structured to serve as the basis for the next certified inspection by TÜV, DEKRA or equivalent.
The plant must be flushed and released before flight – then no chemical contamination is active. The drone can be decontaminated after deployment. For deployments in areas with residual contamination, we discuss appropriate measures with your HSE team in advance.
Yes. The 4K camera clearly shows cracks, delamination and damage to GRP, rubber and enamel linings. Thermography can detect voids behind linings and moisture ingress before visible damage develops. LiDAR documents lining geometry and local protrusions.
LiDAR creates complete 3D models of the vessel interior – regardless of lighting conditions. This enables: precise capture of encrustation volumes for cleaning planning, geometry comparison for deformation analysis and repeatable follow-up inspections at the exact same positions.
The components to be inspected must be taken out of service, flushed and cooled. Integration into planned annual shutdowns or turnarounds is recommended to minimise downtime. Exterior structures (pipe bridges, chimney exteriors, cooling towers) can also be inspected during normal operation.
Drone inspection is generally significantly cheaper: no chemical protection team, no scaffolding, no respiratory protection equipment, no rescue team. The biggest saving factor is often the shortened downtime – entry preparation can take days or even weeks, the drone inspection is completed in hours.
The most important limitations: the ELIOS 3 requires a minimum cross-section of approx. 50 cm for safe flight. It is not ATEX-certified – gas-free status is a prerequisite. At temperatures above 50°C the drone cannot be deployed – the plant must be fully cooled. Very narrow or complex geometries can limit flight coverage.
Yes – this is a core strength of LiDAR-supported inspection. The LiDAR of the ELIOS 3 captures deposit volumes, layer thicknesses and distribution patterns quantitatively. Calcium carbonate encrustations, lignin build-up and similar deposits are not only visible but also measurable – for cleaning planning and comparison inspections.
Drone inspection is an instrument for information gathering, not a replacement for certified inspection. Our data (4K video, LiDAR 3D model, thermography) forms a strong basis for certified inspectors from TÜV, DEKRA or equivalent. The formal inspection responsibility remains with the appointed inspector – we deliver the data foundation.
Generally no – the vessels to be inspected (digesters, bleach towers, evaporators) must be out of service, flushed, degassed and cleared. Exterior structures such as pipe bridges, chimney exteriors and cooling towers can also be inspected during operation.
The actual flight time is 1–4 hours per vessel depending on size. Add on-site setup (gas-free measurement, safety check, coordination with your HSE team). Total time on site is typically one working day per vessel – significantly less than conventional confined space entry with its days-long preparation.
Yes. Chimneys and flue gas routes from pulp and paper mills (recovery boilers, lime kilns, auxiliary boilers) can be inspected from the inside with the ELIOS 3 and from the outside with the DJI Matrice 30T. Typical findings: masonry damage, liner cracks, flue gas duct corrosion, sooting.
There are situations where conventional methods are more appropriate: For wall thickness measurement by ultrasound (UT), direct sensor contact is needed – we can localise the spots, the measurement itself requires specialist UT technicians. For very complex 3D geometries with very narrow clearances below 50 cm, the ELIOS 3 reaches its limits. We advise honestly about what the drone delivers – and where other methods are better.
Questions about drone inspection for paper and pulp plants, or need a quote? Fill out the form and we will get back to you within 24 hours.