Stack Monitoring Kit : Explained

Stack Monitoring Kit is designed to serve the most crucial purpose of measuring the total volumetric discharge of particulate matter and gaseous pollutants from the Boiler, DG stacks, Process outlets, Scrubber Outlets.

It is very important to measure harmful pollutants emitted from industries in order to take decisions based on collected data to minimize the pollution. Stack monitoring kit plays major role in collecting samples from chimneys / Stacks in Stack monitoring Procedure.

All the Gaseous stream effluents in accordance with the Air Act 1981 (Prevention &Control of Pollution) by which all industrial establishments have to measure and monitor emissions from their plants and keep them under controlled limits. To ensure this, each & every company (chemical, Pharmaceutical, manufacturing) should monitor their gaseous pollutants discharged into the environment at regular interval.

Stack Monitoring Kit / Equipment consists of:

1. Pitot tube: “S-type” fabricated from SS304 or equivalent grade. Coefficient of Pitot tube should be above 0.95 in stack monitoring system.

Stack velocity Range: we can find the velocity of gaseous pollutants through stack with the help of inclined manometer.

Temperature of gaseous effluents: we can use digital temperature indicator with thermocouple to find the temp of gaseous effluents. Range is from (0-6000C). Velocity & temperature is different at different location inside the stack diameter. To achieve a desired sample, samples are taken at various traverse points inside the stack diameter in stack monitoring procedure.

Thimble holder: It is designed to capture particulate matter form gaseous effluents. It is incorporate with the thimble to capture PM size greater than 0.3 micron.

Nozzles: Nozzles shall be fabricated with SS 304 or equivalent material with internal diameters suitable to cover the full range of stack velocities. The leading edge of the nozzle should be sharp and tapered. The minimum internal diameter of the nozzle shall not be less than 8 mm to achieve iso-kinetic sampling. (Iso-kinetic condition can be achieved by adjusting suction velocity at nozzle through pump equal to velocity of stack gases i.e. both needs to be same. If any of those increases might changes in higher or lower side results)

Rotameter: 0 to 60 LPM for particulate monitoring and 0 to 3 LPM for gaseous monitoring

Vacuum pump: Vacuum pump shall be of rotary design, with a capacity of to 0 to 120 LPM gas flow with single phase motor, 220 V. The pump shall also have a moisture trap and air inlet valve. It shall be mounted inside pump housing and shall be portable.

Dry Gas meter: The sampling train shall have a dry gas meter with the facility for measuring temperature and static pressure. The capacity of the meter should be adequate to record upto 60 lpm of airflow and a minimum readout of 0.001 cubic meters.

By taking proper/ representative sample from stack Monitoring kit, we can calculate

• Stack Velocity
• Volumetric flowrate per hour
• PM (Particulate matter)
• Moisture Content
• Gaseous Contents

Stack Monitoring kits are very lightweight and can be easily carried to site. Also it has inbuilt battery which can be charged, so no need of power supply while monitoring stack. We can also adjust flow control as per our requirement.

What are uses of Stack Monitoring Kit?

The Stack Monitoring kit is used to measure total volume, velocity, Flowrate and Moisture content of discharged gaseous pollutants which includes particulate matter, SO2, NO2, etc. The gases which needs to be measured are pre-defined by government agencies such as CPCB and EPA.

How is stack monitoring performed?

Stack monitoring is performed to monitor emissions thrown out of the stack, chimneys DG Sets, Boilers etc. in the air. It is also referred to as air quality monitoring. In this process, the operator climbs the stack to a specific height and then he/she inserts a pitot tube from the stack monitoring kit to the available port from Stack and keep it for a certain period to collect the sample.

What is stack monitoring?

Stack monitoring is the process that enables EHS managers, inspectors and directors to measure the level of pollutants are released into the atmosphere from the Stack.

Why is stack monitoring done?

Stack monitoring is performed to monitor emissions thrown out of the stack, chimneys DG Sets, Boilers etc. in the air. It is also referred to as air quality monitoring. The Major pollutants are checked from stack monitoring are Particulate matter (PM2.5, PM10), SO2 and NOX. It is performed on regular basis as per instructions from Pollution control boards.

What is the stack emission?

Stack emissions are pollutants thrown out of the stack. Those pollutants can be Particulate Matter (PM2.5 and PM10), Carbon Dioxide (CO2), Carbon Monoxide (CO), Sulphur Dioxide (SO2), Oxides of Nitrogen (NOx), Methane (CH4) and Hydrocarbon Compounds.