Handling millions of tons of dry bulk material creates a housekeeping challenge that extends far beyond one spill point. Grain can accumulate beneath conveyors, inside underground galleries, around silo batteries, and in warehouse tunnels. In a confined environment where combustible dust may also be present, cleanup needs to remove material without simply redistributing it into the air.
At the Port of Constanța in Romania, the solution was not a larger portable vacuum. The terminal installed five centralized high-vacuum systems built around Depureco DV AIR 800 filtration units and CVS ROOTS vacuum sources. Together, the project created a fixed cleanup network with 124 suction points and approximately 1 mile of piping across warehouse, silo, and conveyor areas.
The result was a facility-wide system that lets operators connect a hose near the spill, convey grain and dust through fixed steel pipe, separate the material centrally, and discharge recovered product into big bags.
The Challenge: Grain Spillage and Dust in Underground Networks
The terminal needed to remove heavy grain spillage quickly from confirmed galleries and transport routes without raising additional dust clouds. The challenge was amplified by the scale of the site. Cleanup areas included a warehouse tunnel, multiple silo batteries, and long conveyor galleries located both above and below ground.
A portable vacuum would have required operators to repeatedly move equipment through the terminal and manage collected material locally. A fixed network instead allowed the suction equipment and separation stages to remain at ground level while operators worked from strategically placed pickup points throughout the facility.
Why a Central Vacuum Network Fit the Port Terminal
The project was divided into five installations so each section of the terminal could be engineered around its own piping length, elevation changes, number of suction points, and simultaneous-user requirements.
Across the project, the case-study summary reports five installations, 124 suction points, and approximately 1 mile of piping. Several sections placed a suction point roughly every 40 feet, giving operators a nearby connection without dragging a very long flexible hose through the facility.
This is one of the main advantages of a central vacuum layout in a large grain-handling facility: the long-distance transport happens inside engineered fixed pipe. The operator only handles the flexible hose needed to reach the local spill.
Project figures reported in the Port of Constanta case study.
How the Grain Recovery Process Works
The operator connects a hose to the nearest suction outlet. In the documented installation, outlets can include a microswitch that allows remote system start and stop from the pickup point.
Spilled grain and dust are then conveyed through the steel pipe network to the DV AIR 800 cyclone/filter pre-separator. Bulk material is separated from the air stream before it reaches the vacuum source, helping reduce the load on the filtration stage. The recovered material is automatically discharged into Big Bags for controlled handling.
The CVS ROOTS unit provides the high-vacuum source needed to move material over the long horizontal runs, branches, and vertical risers found throughout the terminal.
The operator plugs a flexible hose into a fixed suction point near the spill.
High vacuum moves spilled grain and dust through the permanent network.
The DV AIR cyclone/filter stage removes bulk solids and dust before the vacuum source.
Recovered material is automatically discharged for controlled handling.
How the Grain Recovery Process Works
Installation 1 serves the warehouse tunnel with 10 suction points along a roughly 400 foot line. The system was designed for up to two operators at once and routes recovered material directly to the pre-separator and Big Bag discharge.
Installation 2 serves a seven-silo battery. The unit is positioned centrally above the tunnel, where the pipe network splits toward both ends of the silo row. Isolation valves let the crew close the unused branch so suction is concentrated where the cleanup is taking place. This section includes 16 suction points across nearly 660 feet of piping.
Installation 3 is the largest single network in the case study. One unit serves 10 silos on two levels, with a vertical riser feeding both the silo-top gallery and the underground tunnel. Four branches provide 48 suction points across roughly 1,840 feet of pipe.
Installations 4 and 5 divide a long conveyor gallery between two systems. Together they provide 50 suction points and over 1,900 feet of piping. Because each system can support up to two operators, as many as four operators can work on different stretches of the conveyor at the same time.
10 suction points along a roughly 400 ft line. Designed for up to two operators at once, with recovered material routed to the pre-separator and Big Bag discharge.
16 suction points across nearly 660 ft of piping. The centrally positioned network splits toward both ends of the silo row, with branch isolation directing suction where cleanup is taking place.
48 suction points across roughly 1,840 ft of pipe. Four branches serve both the silo-top gallery and the underground tunnel from a single central system.
Together, the two systems provide 50 suction points across more than 1,900 ft of piping. With up to two operators per system, as many as four operators can work on different conveyor sections at the same time.
Warehouse Tunnel Cleanup Without Moving the Vacuum Unit
The silo installations demonstrate two different central-system strategies.
In the seven-silo battery, the vacuum unit sits near the center of the row and feeds two branches in opposite directions. Branch isolation allows the system to direct its available suction toward the area being cleaned.
The 10-silo installation adds a vertical dimension. A single DV AIR + CVS ROOTS system serves both the upper silo gallery and the tunnel below, using a vertical riser and four roughly 460-foot branches. This arrangement provides 48 suction points while keeping one central vacuum source responsible for both levels.
The takeaway is not that every silo network should copy these dimensions. Pipe diameter, branch length, elevation, hose length, material density, and simultaneous users all affect the required airflow and vacuum level. The project illustrates why central systems are engineered around the actual facility rather than selected from a single equipment specification.
Conveyor-Belt Housekeeping Across Long Galleries
Conveyor systems create long, repetitive spill zones. Grain and dust can collect beside rollers, bearings, structural supports, and walkways, creating both housekeeping and maintenance concerns.
The Port of Constanța conveyor was too long for a single system, so the cleaning route was divided between two central vacuum installations. One section contains 22 suction points across roughly 840 feet of piping. The second contains 28 points across roughly 1,070 feet of piping, including the longest single branch in the project at approximately 650 feet.
With fixed outlets distributed along the conveyor, operators can clean local spills without relocating the vacuum source. The case study also notes that removing grain and dust before it builds up helps keep material away from rollers, bearings, and surrounding surfaces.
Installations 4 and 5 together provide 50 suction points across approximately 1,920 feet of conveyor-area piping.
Inside the DV AIR 800 + CVS ROOTS System
The system separates the jobs of material handling, filtration, vacuum generation, and discharge.
The DV AIR 800 acts as the filtration and pre-separation stage. In the documented project, it uses four large M-Class cylindrical cartridges, SP automatic filter cleaning, a tangential inlet, and HEPA H14 secondary filtration. A pneumatic double-flap valve supports automatic and continuous discharge of collected material.
The CVS ROOTS unit supplies the high-vacuum source through a rotary-lobe pump. The case study also documents a soundproof cabinet, inlet silencer, and safety relief valve.
Because the Romanian project was engineered for an ATEX-classified environment, it also includes ATEX-certified isolation valves and flameless venting as part of the explosion-protection strategy.
System architecture
CVS ROOTS rotary-lobe vacuum unit for demanding long-distance conveying.
Four large M-Class cartridges with SP automatic filter cleaning.
Helps pre-separate bulk material and reduce the load reaching the filter stage.
Double-flap discharge supports repeated material unloading into Big Bags.
The project specification includes a HEPA H14 second filtration stage.
The Romanian installation uses ATEX components including flameless venting and isolation valves.
Documented Results From the Port Installation
The case study reports a 90% reduction in cleaning time, 35% maintenance savings, and 90% material reclamation/recovery. Those figures belong to this specific installation and should not be treated as guaranteed results for another facility.
More broadly, the project shows how a central vacuum system can turn a large cleaning route into a network of local access points. Operators work close to the spill while the pipework, separation equipment, vacuum source, and discharge system perform the long-distance material handling.
Case-study results
Reduction in cleaning time reported by the case study.
Maintenance savings reported for the installation.
Material reclamation/recovery reported in the project summary.
These are customer/project results from this specific installation and should not be treated as guaranteed results for other facilities.
What U.S. Grain Facilities Should Evaluate
The Port of Constanța installation is a European ATEX project. A U.S. grain terminal, elevator, or processing facility should not copy the ATEX specification and assume that it automatically satisfies local requirements.
Start with the actual dust hazard and facility classification. The system design should account for the dust hazard analysis, classified or ordinary locations, required explosion isolation or venting, bonding and grounding, filtration, discharge method, and the combustible properties of the material being recovered.
The central vacuum itself also has to be sized around the physical network: the longest pickup distance, vertical lift, pipe diameter, hose length, material density, expected spill volume, and the number of operators who need to work simultaneously.
For a facility this large, the right question is not simply which vacuum has the highest horsepower. It is how the complete suction unit, filtration stage, pipe network, pickup points, safety systems, and discharge method work together as one engineered system.
Grain Silo Central Vacuum FAQs
Why use a central vacuum system in a grain silo or port terminal?
A fixed central system places suction outlets close to recurring spill areas and uses one engineered pipe network to move material to a centralized separator and discharge point. This can simplify housekeeping across long tunnels, silo batteries and conveyor galleries where carrying portable equipment between locations would be inefficient.
How far apart should central vacuum suction points be?
There is no universal spacing. In this Port of Constanta project, several sections used an outlet roughly every 12 meters. Actual spacing should be engineered around hose reach, facility geometry, pressure loss, material characteristics and the number of simultaneous operators.
Can more than one operator use the system at the same time?
Yes, if the system is sized for simultaneous demand. The individual installations in this case study were designed for up to two operators at once. The two conveyor-belt systems together could support up to four operators working on the same conveyor.
What happens to the grain and dust after it is vacuumed?
In this project, grain and dust are conveyed to a DV AIR cyclone/filter pre-separator. The recovered material is then discharged automatically into Big Bags, reducing repeated manual emptying during large-volume cleanup.
Does an ATEX grain-silo vacuum system automatically meet U.S. requirements?
No. ATEX applies to the European installation described in this case study. A U.S. grain-handling facility should select and engineer its vacuum system around the actual dust hazard analysis, area classification and applicable U.S. codes and standards. The equipment configuration must match the local hazard and installation requirements.
What equipment was used in this centralized grain-handling system?
Each installation was built around a Depureco DV AIR 800 filtration and pre-separation unit paired with a CVS ROOTS high-vacuum source. The documented configuration includes M-Class cartridge filtration, SP automatic filter cleaning, HEPA H14 secondary filtration, automatic double-flap discharge and explosion-protection components for the ATEX installation.
Grain Silo Central Vacuum FAQs
Tell Depureco USA what material you handle, the facility layout, required pickup points, number of simultaneous operators, longest conveying distance, and any combustible-dust or classified-location requirements.
Our central systems team can help engineer the suction source, filtration, pipe network, collection method, and discharge strategy around the actual facility.
What to send our central systems team
Grain type, dust characteristics, bulk density and expected spill volume.
Silo, warehouse, conveyor and tunnel dimensions plus elevation changes.
Required outlet locations and how many operators must work at the same time.
Dust hazard analysis, area classification and applicable explosion-protection requirements.
Depureco USA can help engineer the vacuum source, filtration, pipe network and discharge strategy around your facility.
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