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Plant: Flue Gas Treatment, Filtration, Acid neutralization

Application: Chemicals, Waste Management, Foundry

Location: Latvia

Gas treatment: dedusting, SOx treatment

Garanteed emissions of dust - below 1 mg/Nm3



The flue gas treatment plant described in this case study is realized for a new Latvian company, specialized in lead recovery from exhausted lead-acid batteries.  TVT Termoventiltecnica was engaged by the customer during the construction of the factory. Therefore TVT has studied the process and, together with the client, developed a system for flue gas treatment for all production phases, including the melting zone for lead material laden with sulfuric acid in a rotary furnace, the refinery zone for refining and skimming the molten metal, and the slag warehouse area for handling the slag.


The requirements of the customer of regarding the flue gas treatment plant :

  • Efficient suction from emission sources to prevent dust dispersion in the workplace environment.

  • Dust emission below 1 mg/Nm3.

  • SOx neutralization up to legal limits.

The peculiarities and challenges of the process included:

  • Suction from various process points with significantly different temperatures and flue gas characteristics.

  • Regulation of flow rate and temperature.

  • High toxicity of lead dust.

  • Client's request for dust emissions reduction below 1 mg/Nm3.

  • Presence of high loads of sulfur oxides in the gas requires the regulation of the correct gas temperature to prevent condensation and consequent corrosion.


To meet the customer requirements, TVT realized and supplied a turnkey flue gas treatment plant, which includes following phases: adeguate suction, gas mixing and temperature regulation, basic reagent dosing and injection (lime) for first-stage SOx neutralization, bag filter for final dust collection, and basic scrubber for final SOx neutralization.

The gas sucked from 14 points is conveyed into a calm chamber for the purpose of temperature regulation and coarse dust collection. In the subsequent pipe segments the gas undergoes two type of treatment:

  • Temperature regulation;

  • Addition of the reagent (powder lime) aimed at preliminary SOx neutralization.

Afterwards the fumes are conveyed to the bag filter for dust separation, being then evacuated from hoppers through discharge valves and a chain conveyor (reddler) to convey the dust to a single discharge point.


The gases are then directed to the second stage for final SOx treatment in counter-current washing tower with a static bed, equipped automatic NaOH dosing system for washing liquid pH adjustment.

The plant is equipped with a continuous dust emission control system.


Garanteed dust emissions below 1 mg/Nm3

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