BLOWER

Blower , a mechanical fan is an electrically powered device used to produce an air flow for the purpose of creating ventilation, exhausting out the gases from process equipment and environment.

Schematic view of Blower

Blower has a moving component ( called an impeller) that consists of a central shaft about which sets of blades are positioned.Blower suck the air at right angles to the intake of the fan, and spin air towards to the outlet (by centrifugal force)

Blower design parametersBlower capacity : CFM ( Cubic Feet for Minute)

SCRUBBER

Scrubbers are commonly used in process-air applications to eliminate potentially harmful dust ,gas and pollutants.A liquid, in general water added with active chemicals suitable to the process, is sprayed into the air flow.Scrubber systems are a diverse group of air pollution control devices that can be used to remove some particulates and / or gases from industrial exhaust streams.

Schematic view of Scrubber

The exhaust gases may contain substances considered harmful to the environment, and it is the job of scrubber to either remove those substances from the exhaust gas stream, or to neutralize those substances so that they cannot do harm to the environment/peoples as part of the exhaust stream.

Scrubber is made with Fiber reinforce plastic (FRP)Scrubber is connected with Blower.Blower will suck the pollutant gas stream from process equipment and send to scrubber. These gas are scrubbed with suitable scrubbing media ( water or water + NaOH)To scrub the pollutant stream perfectly , resident time & restricted flow is required. For this , packing rings are using in the scrubber. Once scrubbed solution reached saturation point , change the scrubbing media.

Operation of Scrubber sectionHow to start?First start the BlowerThen start the recirulation pump

How to stop?First stop the recirculation pumpThen stop the Blower

Commonly generating / escaping gasAmmonia BaseH2S Weak acidCO2 AcidicCO AcidicBF3 AcidicCl2 Acidic

Scrubbing media solution reacts with gas forming salts.Eg: HCl + NaOH NaCl +H2O H2S + 2NaOH Na2S + 2H2 O

SCRUBBER PERFORMANCE DEPEND ONSpray Nozzles cleanlinessPacking rings cleanlinessScrubbing media composition & pHManometer is used to check the performance. If pressure drop (P) across the scrubbing column is more than 150 mmwc, the packing inside the FRP column shall be removed , washed with water & fixed.

SOP related to ScrubbersOperation of BF3 scrubberOperation of Ammonia scrubberOperation of H2S scrubberOperation of HCl / Acid scrubberOperation of Cl2 scrubberOperation of PCl5 scrubber