Explosion protection of pneumatic transport systems

icon-0Aligning with MS GOST, ATEX, NFPA standards
icon-1Reducing risks and preventing losses from dust explosion
icon-2Approval of the explosion protection project with supervisory authorities

What endanger your pneumatic transport system?

Pneumatic transport is a convenient and efficient system for fast transportation of free-flowing materials through pipelines to different heights and along routes of any complexity. The tightness of the system provides protection of the transported products from losses and environmental influences, and the personnel from harmful dust.

The main resource of the pneumatic transport line is air. It is supplied under pressure with the help of an electric fan (injection or vacuum) and, mixed with free-flowing products, is able to move tons of material per day – from coffee beans or wheat grains to wood flour or cement.

Inadvertent ingredient

With the maximum load of the pneumatic transport system, intensive friction of the equipment components is inevitable, as well as grinding of the transported material. These factors are the main causes of combustible dust formation.

Dust, which eventually fills the entire air system of the pipeline, reaches a critical concentration at a certain moment. This moment is almost impossible to capture.

Imagine that just at this moment, one small spark enters the system.

According to EN 1127-1, sources of sparks can be:

  • hot surfaces of the air blower motor,
  • collision of free-flowing material with metal surfaces,
  • electrical equipment,
  • static electricity,
  • lightning
  • self-ignition at high temperature,
  • electromagnetic waves.

Why does the explosion happen?

An explosion in a pneumatic transport system occurs as a result of a combination of such components under certain parameters:

  • Oxygen;
  • Combustible dust;
  • Confined space inside equipment;
  • Ignition source;
  • Explosive concentration of dust-air mixture

In a matter of seconds explosive combustion in a chain reaction mode fills the entire pipeline in search of an exit. If the line is connected to containers for storing or drying free-flowing material, the flames can spread to neighbouring production components, machinery, and vehicles at the unloading / discharging area or maintenance personnel.Because of one small spark in an explosive mixture, people, production and commodities can be affected.

How to avoid destruction of the pneumatic transport system?

The system protection solution is based on international standards for explosion protection, as well as a number of indicators that you need to know to develop the comprehensive explosion protection:

  • LEL – lowest concentration of dust (g/m3) at which an explosion can occur.
  • UEL – highest concentration of dust (g/m3) at which an explosion cannot occur;
  • P max – maximum overpressure (bar) in the vessel as a result of the explosion;
  • P red – residual pressure (bar) inside the equipment after explosion venting or explosion suppression;
  • P stat – pressure (bar), at which the explosion venting device opens;
  • K st – rate of explosion pressure rise within 1 m3 of space in 1 second (bar/m/s);
  • Pressure of pressurized air in the system (bar).
  • Volume of the closed line (m3);
  • Pipeline cross section (m2), pipe diameter (mm).
  • Type of free-flowing materials.

Explosion protection standards for pneumatic transport

  • Explosion isolation systems EN 15089:2017
  • Explosion isolation systems EN 16447:2017
  • Explosion suppression systems EN 14373:2017
  • Flameless explosion venting EN 16009:2017
Stop the flame!

The main task of explosion protection is to detect and stop the explosion by shutting off the pipeline. The task of explosion isolation is successfully handled by two reliable comprehensive solutions from the Czech manufacturer RSBP spol. s.r.o. and its official representative – ATEX.CENTER.

№1 HRD BARRIER
Certified according to standard EN 15089 and ТР ТС 012.

How does this work

Special pressure sensors DetEx and optical sensors LumEx 1 or LumEx 4 monitor the working situation in the protected section of pneumatic transport. When an explosion is detected, the sensors instantly transmit a signal to the control unit, which processes the signal and activates the HRD containers with explosion suppressive agent. The substance of the containers is dispersed inside the vessel, suppressing the flame.

Special features
  • a few milliseconds HRD barrier response from explosion detection to its isolation;
  • continuous monitoring and data archiving from sensors;
  • variability in dislocation of sensors and HRD containers;
  • safe use in closed and open spaces;
  • easy replacement of spent HRD containers;
  • full compliance with sanitary standards in the food and pharmaceutical industry.
Where is it installed

The HRD barrier can be used as a stand-alone solution or in combination with the HRD system, VMP panels and FLEX flameless explosion venting. HRD containers are widely used between:

  • storage tanks for free-flowing;
  • filters;
  • separators;
  • silos;
  • cyclone separators;

№2 QUICK-ACTING SLIDE VALVE GATEX

Certified according to standard ТР ТС 012/2011, ТР ТС 020/2011 and EN 15089
How does this work

Special pressure sensors DetEx and optical sensors LumEx 1 or LumEx 4 monitor the working situation in the protected section of pneumatic transport. When an explosion is detected, the sensors instantly transmit a signal to the control unit, which processes the signal and activates pneumatic drive closing the quick-acting slide valve, located in the pneumatic transport system.

The advantage of the GatEX quick-acting slide valve is that it can be used in limited space, as well as for equipment designed for the maximum system pressure P max. In the event of power failure or air pressure drop in the system, the valve closes using the Fail-safe function.

Special features
  • installation in limited space;
  • a few milliseconds response;
  • possibility of installation on pipes from DN 50;
  • installation in a pipeline with pressure up to 21 bars.
Where is it installed

Quick-acting slide valve GatEx can be used as a stand-alone solution or in combination with the HRD system, VMP panels and FLEX flameless explosion venting. GatEx is widely used between:

  • storage tanks for free-flowing;
  • filters;
  • separators;
  • silos;
  • cyclone separators.

Why is it worth to install a pneumatic transport explosion protection system at ATEX.CENTER?

  • You will be confident on the explosion safety of your production. All the components used in solution have been tested by experienced specialists from RSBP spol. s.r.o. and ATEX.CENTER engineers.
  • The explosion protection system for pneumatic transport from ATEX.CENTER fully complies with the requirements of international labour protection legislation and explosion protection standards for enterprises. Certified specialists of the Company will assess the explosion hazard of a production and select an effective solution for its explosion protection in strict accordance with the standards.
  • All service documentation for explosion protection of pneumatic transport is adapted for local markets. ATEX.CENTER provides full service support according to the manufacturer’s standards.
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