Suction and filtration

We design, manufacture and install suction systems for air and fumes, equipped with suitable filtration systems.
Our scientific approach to the problem of the suction of dusty gaseous streams of gases,
takes into account the physical and chemical features of pollutants inside the sucked stream.
The suction of air with wood dust is completely different from the suction of air or fumes containing inert or fertilizing dust.

For each installation, we consider the real density of the powder to be transported in the stream,
the relative humidity of the gas, the configuration of pipelines, the filtration system and the vacuum generator.
In the design of bag filters, cyclones, multicyclones, settling chambers and pipe lines,
we take care to choose the materials for the various components, the metallic parts and filter medias,
with particular attention to the real features of the dust.
Regarding the aspiration network pipelines, we take into account the abrasiveness of dust and how sticky the dust
is so as to avoid or to reduce problems in the operating phase.
We choose a fan only after carefully calculating how much the pressure will drop as a result of the different components of the pipe network:
captation hoods, length of pipes, joints, curves, chimneys etc.

Bag filter

The bag filters are certainly the heart of the suction and filtration system, and thus the choice of each component, from the filter media, to the equipment for counter-current washing, from the dust evacuation system to the filter shape, is fundamental for the entire system to function effectively.

Based on our experience, we choose and calculate each filter detail taking the following into account:
• The gaseous fluid (specific weight, temperature etc.) to be treated.
• The pollutant that needs to be filtered (actual specific weight, dust granulometry, dust concentration etc.).
• The chemical and physical compatibilities between the media filter and gaseous fluid to be depolluted.
• How abrasive or gluey the dust is.
• The operating temperature.
• The relative humidity of the gaseous fluid.

With the operating parameters in mind, we choose:
• Media filter type and how it is coated.
• Bag cage filter: number of wires and how it is attached to the tubesheet.
• How the gaseous fluid is admitted into the filtration chamber.
• The filter cleaning system (valves, nozzles and Venturi)
• The dust evacuation equipment ( screw, rotary valve or clapper valve)
• The preheating system for the hopper and the filtration chamber.

Cyclone

The cyclone is positioned in the dedusting line before the bag filter seeing that,
although with a higher pressure drop, it ensures that the bag lasts longer and functions better.
Due to the centrifugal effect, all particles, that are smaller than a few dozen microns, dragged along by the gaseous stream,
are separated before they enter the filtration chamber.
Depending on how abrasive the pollutants are, we design and manufacture cyclones of different materials:
Carbon steel, Wear-proof steel, Steel clad with hard carbides

Settling chamber

It is often worthwhile installing a settling chamber in the network pipeline in order to separate the bulky pieces.
Despite its name, our experience confirms that the fundamental function of a settling chamber is to constitute a prefixed and stable pressure point,
to which all the branches of the network pipelines can be linked.
With finite element software, we can calculate the aerodynamic functioning of the settling chamber,
that often has to be positioned in a specific area of the plant, and its shape can be rather irregular.

SCHEMA DISTRIBUZIONE DELLE VELOCITÀ ALL'INTERNO DELLA CAMERA DI CALMA

Multicyclone

When it is not possible to treat the dusty gaseous stream directly with a bag filter, a multi-cyclone can be used,
a device consisting of many small cyclones working parallely.
The entire gaseous stream to be treated is distributed over dozens of small cyclones, which,
thanks to their very small size, can break down, at a percentage rate of more than 90%,
powders with dimensions greater than or equal to 30 ÷ 40 microns.
A very significant application of the multi-cyclone, that we have successfully adopted several times,
is on the fumes coming from biomass boilers. The mutlicyclone, positioned before the bag filter,
not only separates the dust but also prevents any incandescent sparks coming from the furnace
from reaching the filter bags and piercing or worse, burning them.

Heat recovery at low temperature

In biomass boilers it is not possible to lower the smoke exit temperature below a certain limit,
because it is possible that condensation is formed inside the bag filter.
The condensation, that occurs at temperatures below dew point, compromises not only how the filter works,
but also how the entire system functions.
We have developed a system that allows for the recovery of energy after the bag filter,
the zone in which condensation does not create other substantial problems.

Recuperatore di calore a bassa temperatura

Fan and chimney

Among the suction and filtering equipment, the choice of fan is fundamental for the entire system to work well,
and for that reason we utilize the software that the fan suppliers provide in order to choose the most suitable fan.
Despite its apparent triviality, the design of the chimney also requires careful study and accurate calculations.
It is enough to think of the complexity inherent in the assessment of structural resistance
in correspondence with the stream admission holes in the vertical tube, and the maximum permissible deformation at the upper end.
Another key aspect is the respect of emission controls standards.
These require the appropriate shape and size of the hole and of the flange for measuring instruments,
and the suitable positioning of access systems (stairs and walkway).

Containment cabins and smoke suction

When it is necessary to perform machining operations that produce intense amounts of smoke and dust (e.g. gouging of large components of steel),
we need to have containment cabins with a roof that opens, in order to allow overhead cranes to handle the pieces to be treated.

We design, build and install containment cabins with sliding roofs, and soundproofed walls.

Vacuum cleaner for mixtures of large size inerts and dusts

In many factories the collection and transport of large size solids, (stones, cullet etc.)
dispersed in piles of dust is particularly difficult because of the very different consistency between the solid bodies and the fine powders.
We have studied, designed and manufactured a special machine which sucks up mixtures of powder and solids,
separates the dusts from the solids and then filters the dusty gaseous stream.
The system consists in a vacuum pump, two bag filters, a vibrating screen and a cyclone.
All the equipment is arranged on a transportable skid.