OLI VBS · bin aerators

Bin aerators for silos, hoppers and pipes

A disc in the silo wall that directs compressed air towards the outlet instead of up into the material.

Dry, fine powders consolidate in the cone and stop flowing. A VBS is a small disc-shaped aerator with a silicone membrane, mounted in the wall, that fluidises the material exactly where it is stuck. The range covers nine variants from Ø55 to Ø104 mm, in food-grade, high-temperature and metal-detectable versions.

VBS9 variants0.8–6 bar−40 to 235 °CFDA 177.2600

Tell us about your plant See the specifications

Download the datasheet Dimensions, specifications and all variants PDF · 4 pages · 108 kB

Two VBS bin aerators with a white disc-shaped head and a threaded stem.

The problem

Two faults, one cause

A bridge and a rathole look different, but they share a cause: the particles have been allowed to consolidate, and the material now carries its own weight. Pressurised air breaks that cohesion, and the material starts to flow again.

Bridge over the outlet

The material forms an arch across the opening and carries its own weight. The silo is full, but nothing comes out. The technical term is bridging.

Rathole through the middle

A narrow channel runs down through the centre while the rest stands still along the wall. Only a fraction of the capacity comes out, and the remainder ages in the silo.

Loadout too slow

The material does come out, but more slowly than the plant needs. This is what the VBS is built for: the air flow is aimed at the outlet instead of spreading in all directions.

Walkthrough

Four steps through the product

Click through: from the powder that will not move to the number of units and where they go on your own cone.

01 The problem

Drag the line from side to side

Without air the material carries its own weight: the bridge stands and the silo does not empty. With air the powder loses its internal cohesion and behaves once more like something that can flow. It is the same silo on both sides of the line.

02 The technology

The disc has a Venturi-shaped cavity on its underside. That gives the air a preferred direction, down towards the outlet, instead of spreading it evenly in all directions. The outer face is smooth, so material does not settle on the disc.

White silicone · −40 to 170 °C
VBS · VBSI · VBSM · VBSMI · VBSME
Red silicone · −40 to 235 °C
VBSIHT · VBSMIHT
Blue silicone · −40 to 170 °C
VBSIMD · VBSMIMD

03 The installation

An aerator is never alone. From the compressed air supply the air passes through a filter and a flow control valve to one solenoid valve per ring, and the controller opens the rings in sequence from the bottom up, so the material always has a free outlet to fall towards.

Compressed air supply The VBS runs on non-lubricated compressed air of class 5.4.1, or on dry inert gases. The recommended working pressure is 4 bar. The full range is 0.8 to 6 bar, and 0.8 to 2 bar for the Micro versions.
Filter and flow valve The circuit requires a filter and a flow control valve. This is where the air volume per aerator is set, before the air is distributed to the rings on the cone.
Control and solenoid valves One solenoid valve per ring, and a controller that opens them in sequence from the bottom up. That way the material always has a free outlet to fall towards. An electronic control board is available for the sequence, activating up to fifteen units, with a timer and multi-voltage coils from 24 V DC and AC up to 230 V, also in an ATEX version. The controller can run on a timer or be started by a signal from the rotary valve, so the aerators only work during loadout. We set the number of valves and the pulse time together with you, once the plant is known.
The aerators in the cone The discs sit in the lower part of the cone, where the material is most consolidated. The disc is Ø104 mm in the standard version and Ø55 mm in the Micro version, with a 1/2 inch and 1/4 inch BSPP connection respectively.
Outlet and rotary valve Because the air flow is directed towards the outlet rather than up into the material, the aerators work where the material needs to leave. The rotary valve meters it on into the plant.

04 The placement

Number of rings

4 rings · 16 aerators in total

The aerators sit in concentric rings around the cone, offset by half a step from ring to ring. Drag the slider to see how the rings build up from the bottom, and what that means for the count.

The drawing is an example, not a sizing rule. We work out the number and the placement for your silo together with you, from the cone angle, the material and the pressure you have available.

The technology

Tramontana®: air in one direction

An ordinary fluidising nozzle blows air evenly in every direction. That loosens the material, but a large share of the air goes upward, where it is not needed.

The Tramontana® disc is shaped differently. Its underside is a Venturi cavity, which gives the air a preferred direction, down towards the outlet. The material is loosened where it needs to leave, not up in the silo. The outer face of the disc is smooth, so no layer builds up on it.

The aerator runs on ordinary non-lubricated compressed air. The circuit needs a filter and a flow control valve, and the recommended working pressure is 4 bar. The full range is 0.8 to 6 bar, and 0.8 to 2 bar for the Micro versions.

Data

Technical specifications

Application	Silos, hoppers and pipes. Also dry bulk tank trailers and dry bulk rail tankers
Material in the vessel	Dry, fine, granular powder
Problem solving	Bridge and rat-holing
Duty cycle	Continuous or discontinuous
Working pressure	0.8 to 6 bar (12 to 87 psi). Recommended 4 bar (58 psi)
Working pressure, Micro	0.8 to 2 bar (12 to 29 psi)
Pneumatic circuit	Filter and flow control valve
Air supply quality	Non-lubricated compressed air, class 5.4.1, or dry inert gases
Technology	Vibro-aerator
Membrane	Silicone, food grade, FDA 177.2600. Red membrane for high temperature, blue membrane metal detectable
Stem	Aluminium or AISI 316 stainless steel, food and pharmaceutical grade
VBSE, external version	Polyamide body with steel ring and Supralen filter
Options	External mounting kit, rectangular or circular, stainless steel. Electronic control board for up to fifteen units, with a timer and coils from 24 V to 230 V, also in an ATEX version

Models

All nine variants

Air consumption is given in Nl/min, normal litres per minute at the stated pressure. The dashes at 4 and 6 bar for the Micro versions are not missing data: the Micro works at a maximum of 2 bar. Dimension A is the disc diameter, B the overall length.

Air consumption in Nl/min
Model	Membrane	Stem	0.8 bar	2 bar	4 bar	6 bar	Temperature	A	B	Connection
VBS	White	Aluminium	600	800	950	1150	-40 to 170 °C	Ø104 mm	79 mm	1/2" BSPP
VBSI	White	Stainless steel	600	800	950	1150	-40 to 170 °C	Ø104 mm	79 mm	1/2" BSPP
VBSIHT	Red	Stainless steel	600	800	950	1150	-40 to 235 °C	Ø104 mm	79 mm	1/2" BSPP
VBSIMD	Blue	Stainless steel	600	800	950	1150	-40 to 170 °C	Ø104 mm	79 mm	1/2" BSPP
VBSM	White	Aluminium	150	200	—	—	-40 to 170 °C	Ø55 mm	54 mm	1/4" BSPP
VBSMI	White	Stainless steel	150	200	—	—	-40 to 170 °C	Ø55 mm	54 mm	1/4" BSPP
VBSMIHT	Red	Stainless steel	150	200	—	—	-40 to 235 °C	Ø55 mm	54 mm	1/4" BSPP
VBSMIMD	Blue	Stainless steel	150	200	—	—	-40 to 170 °C	Ø55 mm	54 mm	1/4" BSPP
VBSME	White	Nylon	130	150	—	—	-40 to 80 °C	Ø66 mm	62 mm	3/8" BSPP

How to read the model name: VBS is the OLI aerator, VBSM the Micro version, I means a stainless steel stem, HT high temperature, MD metal detectable and E external mounting.

The membrane

White, red or blue — and when to choose which

The colour is not cosmetic. It tells you which silicone the membrane is made from, and therefore what the aerator can take and what it may touch.

White silicone

−40 to 170 °C

The standard version. Food-grade silicone to FDA 177.2600. This is the one most plants need.

VBS · VBSI · VBSM · VBSMI · VBSME

Red silicone

−40 to 235 °C

The high-temperature version, 65 degrees above the rest. Chosen where the material or the silo is hot, typically downstream of a dryer or a kiln.

VBSIHT · VBSMIHT

Blue silicone

−40 to 170 °C

Metal detectable. If a piece of the membrane comes loose, the metal detector in the line will catch it. A requirement in many food and pharmaceutical plants.

VBSIMD · VBSMIMD

The VBSME is the only one with a nylon body and is therefore limited to 80 °C. The other eight have an aluminium or AISI 316 stainless steel stem.

Mounting

How a disc gets inside a closed silo

The aerator is normally fitted from the inside: you enter the vessel, push the stem out through a hole in the wall and tighten the nut from outside. But many silos cannot be entered, and then the disc has to go in through the wall from outside. That is what the two mounting kits solve, each in its own way.

Circular mounting kit: a white round flange with three bolt holes and a grey gasket with a hole in the middle.

Circular mounting kit CPKIT

For round silos and hoppers. Here the hole in the wall is larger than the disc, so the aerator passes straight through.

Hole in the wall	Ø 110 mm
The disc	Ø 104 mm — passes straight through
Material	AISI 304 stainless steel plate with an S235JR steel flange, NBR gasket
Working temperature	−40 to +80 °C

A round hole of Ø 110 mm is cut in the silo wall.
The aerator is pushed through the hole from outside so that the disc ends up inside the silo and the stem points outwards.
The flange with its gasket is placed over the hole and fixed with the three bolts. The gasket seals against the wall.
The nut is tightened on the stem from outside and the air line is connected. All the work is done outside the silo.

Rectangular mounting kit: a black oblong plate with a bracket across it and a nut in the middle.

Rectangular mounting kit RPKIT

For rectangular silos and hoppers. Here the hole is a narrow, long slot, and the disc is turned into place behind the wall.

Hole in the wall	67 × 162.5 mm
The disc	Ø 104 mm — enters edgewise through the slot
Material	AISI 304 stainless steel plate, EPDM gasket
Working temperature	−20 to +95 °C

A slot of 67 × 162.5 mm is cut in the wall, oriented along the slope of the cone.
The slot is longer than the diameter of the disc. The aerator is therefore fed in edgewise through the slot, with the disc at an angle.
Behind the wall the disc is turned a quarter turn so that it lies flat against the wall and covers the whole slot from inside.
The cover plate with its EPDM gasket goes on the outside and is tightened with the nut. The plate closes the slot, and the stem is ready for the air line.

The aerator is not included in the mounting kit. The VBSME is a ready-made Micro version for external mounting with its own nylon body.

Application

Where it sits and what it works in

Vessels	Silos, hoppers and pipes
Transport	Dry bulk tank trailers and dry bulk rail tankers
Materials	Cement, lime, pigments, plastics, starch, flour, sugar and coffee
Suitability	Compatible with foods and chemicals. Available in two sizes, Micro and standard, and with external mounting

FlexCore

Getting the air to every aerator

An aerator is nothing without compressed air at the stud. The hoses come from our own range.

ARIAFORM/15TPE air hose for industry and workshop. Handles water, air and oil-laden compressed air, and is light enough to move around.

Yellow EPDM compressed air hose, coiled.

ARIACORD/YELLOWRugged EPDM hose for compressed air and water, 25 bar. Weather and UV resistant, so it can live outdoors beside the silo.

ARIAFORM/TPULight polyurethane hose for tools and reel systems. The softest of the three, where the hose has to follow the work.

See the full hose range →

Further

Shall we work it out?

Tell us what is in the silo, how large the cone is and what your compressed air can deliver. We come back with a number, a placement and a price — not with a catalogue.

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