Gas purification by metering of sulfur with LEWA ecoflow packed plunger and diaphragm metering pumps

Industrial combustion processes generate flue gas, which contains not only harmless components, but also various hazardous substances. To reduce the environmental impact, many countries have legislated limit values for the level of pollutants in flue gas.

Many processes for cleaning flue gas are carried out using electrofiltration. To increase the filtration efficiency of the electrofilter being used, sulfur trioxide can be metered in. LEWA ecoflow pumps in the piston or diaphragm design with heated pump heads are an optimum solution for this sulfur metering.


When flue gas cleaning by metering sulfur, a suitable solution is the LEWA ecoflow in the piston design or diaphragm design:

  • LEWA ecoflow in the fully heated design (piston pump or diaphragm pump)
  • Hermetic seal, reliable pump technology for hazardous substances
  • Special design of the pump heads with total heating jacket K511Z (piston) or M911Z (diaphragm)
  • Valves and plunger seals can also be heated with steam.
  • This reliably prevents the liquid sulfur from solidifying (melting point 115 °C) in each part of the pump head.
  • Intensive heating and production using high-quality materials ensure that the pumps have high process reliability.
Flue gas cleaning with LEWA ecoflow pumps


Purification of flue gas

Flue gas is produced during various combustion processes and can contain different dust particles, oil vapors and acid vapors, carbon monoxide as well as other toxic substances. In order to reduce the environmental impact, arising flue gas has to be purified.

One possibility for flue gas purification is electric filtration. In this process, ash and dust particles are ionized in an electric field. The electrically charged particles migrate to the collecting electrode, where they are discharged. Then they stick to the electrode in form of a dust layer because of adhesive forces. The electrode needs to be cleaned regularly.

To improve the efficiency of the electrostatic precipitator, sulfur trioxide (SO3) can be added to the flue gas. For this purpose, sulfur is first melted and fed in liquid form into a sulfur burner, where a sulfur-trioxide-air mixture is produced. This mixture is added to the flue gas. The SO3 reacts with the fly ash, and thereby changes the electrical resistance of the flue gas.

The conditioning of the flue gas increases the collection efficiency of the electrostatic precipitator substantially and has approximately the same effect as doubling the filter volume.

By using LEWA pumps, legal emission limits are met and the environmental pollution is reduced. Our progressive and elaborate technology provides an efficient solution in such applications.

Contact Person

  • Sales Office Czech Rep.
  • LEWA NIKKISO Austria GmbH (odštěpný závod)
  • +420 5 432360-52

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