APPLICATIONS

FLUE GAS ANALYSIS

1 - Combustion in a Boiler/Furnace

PROCESS:

• A mixture of fuel and air are burned inside the chamber.

• An excess or extra air is admitted along with the fuel to ensure that every fuel molecule finds sufficient oxygen to combine with, and form carbon dioxide , i.e. to burn completely.

• Whatever excess air was given in the beginning, comes out through the stack, along with the other flue gases. The oxygen concentration in this air is measured, and it tells us whether the combustion is complete and has been efficient.

• Less than adequate oxygen, measured in the stack, tells us that the fuel doesn’t get sufficient oxygen, and so some of the fuel is left unburnt, and maybe CO is also produced.

• More than adequate oxygen tells us that whatever heat is produced in the chamber, is taken away by the extra air that is given along with the fuel. This heat loss also means inefficient combustion in a way.

MEASUREMENT:

For this application , it is always O2, CO, and CO2 that are monitored. O2 tells us the type of combustion, either complete or incomplete. The CO levels tell us how much fine tuning is required for the air to fuel ratio.

SOLUTION:

For this application, for all small boilers, 327 and 330-LL can be offered. And for large power plants, and bigger boilers and furnaces, 340, and 350 are the right solutions. Offcourse with O2 and CO sensors, CO2 is always calculated.

2 - Emission Monitoring in Boilers/Furnaces

PROCESS:

• All liquid, solid, and gas fuels are basically hydrocarbons, and the process of burning them results into production of various air pollutants. Especially uncontrolled combustion produces a high concentration of pollutants. These pollutants damage the environment and are harmful to the population as well as the vegetation.

• Pollution Control Board has certain norms, and industries have to adhere to such norms and regulate the hazardous emissions, released from their exhausts.

• It is very important that pollutants like CO, NO, NO2, SO2, HC, H2S, and to some extent, CO2, need to be monitored, so that they can be controlled later.

MEASUREMENT:

In the combustion exhaust, gases like CO, NO, NO2, SO2, HC are to be measured in the stack, of all burning processes in boilers, furnaces, incinerators, and heaters.

SOLUTION:

testo 340 and testo 350 with 4 and 6 sensors can be used in this application, depending on the no. of gases to be measured, and the other process conditions.

3 - Diesel Engine Exhaust Analysis

PROCESS:

• Fuel(diesel) and air are mixed and burnt inside a diesel engine. The resulting energy, is then converted into mechanical energy.

• Adequate air will ensure complete combustion of the diesel, and this will provide optimum amount of heat energy.

• Providing less than adequate air would mean, starving the fuel of proper air(oxygen) thus resulting into incomplete burning of diesel, and also production of CO, or carbon monoxide.

• A diesel engine also has a working point. Working point of an engine, is the point at which the engine is most stable, and works at optimum efficiency. At this point, the NOx emissions are minimum. In an engine, as the wear and tear increases, the NOx emission levels also increase. Monitoring the NOx emissions gives an indication of wear and tear on the engine.

MEASUREMENT:

• Measuring O2 & CO, to know whether combustion is efficient, and

•Measuring NO & NO2, to know the wear and tear on the engine.

SOLUTION:

The most ideal solution for this measurement is the testo 340, with 4 sensors, O2, CO, NO, and NO2, and a 335 mm engine probe, with sintered filter, and an operating temperature of max 1000 deg C.

4 - NOx Monitoring in Gas Turbines

PROCESS:

• A gas turbine is basically an engine.

First, the compressor compresses air and converts it to high pressure air.

Then, combustion takes place, and high pressure hot gas is produced.

In the last stage, energy is extracted from high pressure hot gases, and for instance a rotor is driven at high speeds.

• Control of combustion temperature plays an important role in running a gas turbine efficiently. If the combustion temperature increases, the NOx levels also increase, while the CO goes down. Reverse happens when the combustion temperature is brought down. A turbine therefore, has to be run at optimum temperature, to keep a control over NOx and CO levels.

• A wear and tear of turbine parts is also indicated by an increase in NOx levels. Hence, it is very important to monitor exhaust gases coming out of a turbine.

MEASUREMENT: O2, CO, and NOx are measured at the Gas Turbine exhaust.

SOLUTION: The testo 340 with sensors for CO, NO, NO2 is the perfect solution.

5 - Flue Gas Analysis in a Cement Plant

PROCESS:

1)A cement kiln is a cylindrical furnace. From one side of the kiln, pieces of lime stone enter this furnace, and a hot flame is at the other end. The inside temperature is around 1200 deg C. At this high temperature, the limestone is heated, and it breaks into calcium oxide, and carbon dioxide.

CaCO3 ------ > CaO + CO2.

This process is known as calcination. From the CO2 content, the efficiency of calcination is known to the operator. Also they can judge on the final cement quality. Hence it is very important to measure the CO2 at the Cement Kiln.

2) In the pre-heater, the ball mill, and the raw mill, air ingress from outside, will increase the false air, and thus reducing the heat available. This air enters inside because of negative pressure, and because there are cracks or openings in the stack. Inside the stack, the heat produced cant be effectively used in the process, because of false air. So it is very important to measure this false air in all above locations.

3) In a ball mill and raw mill, O2 & CO is also checked for effective or complete combustion. Improper combustion will increase CO content.

MEASUREMENT:

1)In a Cement Kiln – measuring CO2 directly using an IR (infra red) sensor.

2)At the pre-heater, ball mill and raw mill – O2 content is checked to monitor the change in false air, due to air ingress.

3)Combustion in ball mill and raw mill – O2, CO, CO2 measured to check effective and complete combustion.

SOLUTION:

The testo solution for the above cement applications is a testo 350 with O2, CO, and a CO2 IR sensor. It is recommended to use a Peltier Chiller, and a fresh air valve. This will help long term measurements, and also take care of moisture that may be present in stack gas.

6 - Emission Monitoring in Incinerators

PROCESS:

• An Incinerator is a furnace. “To incinerate”, means to destroy by burning.

• Here, all kinds of bio-waste, organic waste and that produced from hospitals, diagnostic labs, blood banks, etc are destroyed. It is very important that such waste should be burnt and not disposed off in a waste bin. There is a likelihood of formation of dangerous bacteria spread, if weather assists.

• Most large hospitals, municipal corporations, pharma companies, paint manufacturing, dye manufacturing units have an incinerator.

•Incinerator manufacturers also can be useful potential clients.MEASUREMENT:

Since its a furnace, O2 content is important to ensure efficient use of fuel. In addition, CO, SOx, NOx also are monitored.

SOLUTION:

Depending on what gases are measured, we can either suggest testo 340 or testo 350.

Bio Medical Waste Incinerator

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