Ertan AYDEMİR
Sales Engineer
Set Teknik A.Ş
Issued under the scope of Industrial Air Pollution Control Regulation (SKHKKY), the Notice of Continuous Emission Monitoring Systems (SEÖS) made it obligatory to install continuous measuring system according to the features of the sectors’ plants set forth in this Notice. Being one of the leading industries among these sectors, Cement Industry has been subjected to a great variety of parameter measurements due to different fuel products it uses.
Using petroleum coke and lignite as fuel in general, Cement sector has had recourse to alternative fuels along with them for the purpose of decreasing energy costs. However, the use of these fuels has caused cement factories to be subject to the waste incineration regulation.
In addition to the continuous measurement of exhaust gases (CO, SO2, NO, O2) as well as that of dust and flow, the continuous measurement of HF (hydrogen fluoride), HCl (hydrogen chloride) and TOC (total organic carbon) parameters has been also included in the Cement sector due to the variety of the fuel products.
After determining the parameters to be measured, the appropriate equipment should be selected following the determination of flue and flue gas conditions. While FTIR (fourier transform infrared spectroscopy) is used as the measuring method for the gases in plants where waste is incinerated as alternative fuel, what is commonly used for dust measurement is light scattering method and for flow measurement, they are ultrasonic transmitter and differential pressure transmitter methods.
Selected according to the flue conditions (such as temperature, pressure, gas concentration, dust concentration, moisture and dew point temperature), the system with QAL1 (Quality Assurance Level) certificate, will be made ready for the data transmission to the Ministry as it will be subjected by the authorized environmental laboratory to the QAL2 test. The QAL3 tests that will be performed monthly after this phase lead to certain difficulties in FTIR gas analysis systems with regard to processing. In accordance with the article “The QAL3 procedure shall be performed by transmitting gas through probe in all gas analysis systems in compliance with EN14181 standard. (CO, NO, SO2, O2, HCI, HF, TOC)” set forth in the relevant standard, the QAL3 tests are a procedure that needs to be performed by transmitting span gas through probe. This process is realized via span gas probes determined according to the emission limit value of the measured gas parameters.
Although providing, storing and processing span gas do not pose any problem for exhaust gases, they do for HCl and HF gases. HCl and HF gases are the gas derivatives which contain toxicity and whose shelf life is short for storage. Taking these reasons into consideration, different methods have been developed by the producers for the QAL3 procedure regarding HCl and HF parameters (By means of transmitting proxy gas or test filter).
Gasmet FTIR Gas Analysis System, of which our company SET TEKNİK is the sole representative in Turkey, can conduct the QAL3 procedure for methane (CH4) designated as proxy gas as well as HCl and HF parameters. This part regarding the QAL3 is found in the QAL1 Certificate of Gasmet FTIR analyzer.
This procedure has advantages as follows.
• Moreover, the QAL3 procedure can easily be performed for HCl and HF parameters as well as a cheap gas like
Methane that will be used for FID analyzer measuring Total Organic Carbon (There is no need for a different equipment and gas for HCl and HF).
• There is also no need for the provision and operation of an extra high-cost equipment with a period of change necessary for test filter.
• In accordance with the article “The QAL3 procedure must be performed by means of transmitting the span gas through probe”, the QAL3 procedure is conducted in accordance with the EN14181 Standard.
• Thanks to the fact that the span gases can be transmitted to the analyzer dry, there is no need for extra high-cost devices which moisten the gases before transmitting them to the analyzer.
WThe second step after selecting the gas analysis system is the selection of a suitable, continuous dust and flow measurement device. These devices must be selected in conformity with the flue gas content and conditions. Even though dust concentration is seen as the first factor affecting this selection, gas concentration in flue, dew point temperature and flue gas velocity play the leading role as well. Cement factories in our country mostly have bag filtration systems. This helps dust concentration remain at low levels. Flue gas temperature is over the dew point in general. Taking this fact into consideration, the devices functioning through back light scattering method which is able to easily measure the small or medium amount of dust can be the best option. Since these devices have no special part within the flue, they are not directly affected by the flue gas.
As for flow measurement, the option can be the devices with differential pressure or ultrasonic measuring principle. Both principles are used in all industrial areas including Cement.
After making the appropriate installation and putting it to use, the systems are required to measure without any problem and ensure data transmission. In order to ensure continuity in measurement and data transmission, the maintenance of the system must be carried out in determined periods and regularly followed. What is also needed is responding problems fast, solving them and putting the system into use again. Giving crucial importance to this whole service, our company SET TEKNİK offers a fast and competent service throughout Turkey thanks to a regional network of 25 technical specialists.
