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Dr Fodisch

Dr. Födisch is a leading manufacturer of CEMS monitoring air pollutants, dust and flow. Their measuring devices “made in Germany” have been used in operation worldwide for more than 30 years now. The clientele comprises of power plants, cement plants, incinerators for waste, biomass and sewage sludge as well as plants for chemical and metallurgical industry. A wide service and maintenance network and on-call duties guarantees short and quick routes to customers nationwide and abroad.

Dust measurement

There is dust everywhere in our environment. Industrial processes are the reason for dust and because of the general population growth dust particles continue to increase. The permanent control of dust emissions is becoming more and more important. Especially considered worldwide the potential and the necessity are high. Country-specific, legal conditions specify the compliance with limit values for certain plants.

For emissions and pollution monitoring Dr Fodisch provide dust measurement technique for legally required and process-related measuring tasks.

Tracing particulate matter Filter monitoring Dust concentration Mobile dust measurement

Tracing particulate matter

The air is the elixir of life. However, the air contains impurities, whose composition and concentration vary depending on the location. Various researches have shown that the fine dust particles in the air are damaging to the heart, lungs and brain. For measurement is often used complex and expensive measurement technology. Thanks to the compact fine dust sensors of Dr. Födisch this is now history. These are a low cost measuring devices for industrial applications.

Whether the application is for outdoor, indoor, stationary or mobile – the device handling is easy, the measurements are precise and independent from the weather conditions. By means of preconditioned air the particulate matter content of the air is measured every two seconds. By WLAN, the the devices can be linked to other air quality / climate sensors to achieve an efficient, meaningful environmental monitoring. There are many benefiting advantages, for example the analysis of ambient air for particulate matters at workplaces.

Filter monitoring

A qualitative dust measurement, for example by triboelectric filter monitoring, includes both the monitoring of the clean gas dust content after dust collectors as well as the evaluation of the status of the exhaust gas cleaning systems.

The signal generation is based on the triboelectric measuring principle. In other words the charge exchange between the probe and the streaming as well as the bouncing dust particles is carried out.

According to the triboelectric measuring principle the filter monitoring device will be installed as in-situ measuring device in the clean gas pipes after the dust collectors. Devices are suitable for monitoring baghouse-, envelope- and cartridge filters and centrifugal separators (cyclones).

There are more than 10,000 pcs of Dr. Födisch filter monitor devices operating worldwide i.a. in the food processing or cement industries, in the metal- and woodworking and chemical industries.

Dust concentration

Devices used for the continuous dust measurement register in the wider sense the physical changes caused by the particles in the measuring system converting them into electrical signals. For that the measured object can be analysed directly in exhaust gas channel (in-situ measurement) or a partial volume flow is collected and fed into a measuring device (extractive sampling).

As result of the in-situ techniques, the measurement signals derive from the direct interaction of light or a triboelectric probe with the dust particles in the exhaust gas channel. For evaluation the scattered light or the absorbance of a transmitted light beam respectively triboelectricity can be used.

The in-situ measuring devices are only suitable for the measurement of dust in dry gases.

In case of wet or saturated with water vapour gases, the existing water droplets and aerosols create also light scattering effects, which distort the measurements results. Therefore in these cases the extractive measurement technique should be selected. The basis of the extractive methods constructs a preferably isokinetic partial flow extraction from the main gas flow. As measuring principles the scattered light measurement or the triboelectric measurement can be carried out.

The process-related restrictions have substantial influence over the choice of the measurement method.

Periodic dust concentration measurements are usually used as a standard reference method (gravimetric) for calibration of continuous dust concentration measuring devices.

Mobile dust measurement

The measuring of dust emissions can be carried out discontinuously or continuously depending on the requirements.

Periodic measurements are applicable only to a limited sampling for the determination of emissions behaviour on site. However, it has to allow conclusions about the continuous behaviour of the system and take into account possible seasonal variations of the measured air pollution.

The reasons for this may be diverse:

acceptance tests (warranty certificate)
measurements made to verify compliance with the emission limits
control measurements for the determination of the system status or when complaints are made
measurements to initiate an approval process (for example extensions, remodifying etc.)
measurements in the context of self-monitoring, in case of malfunctions, in the context of safety inspections
measurements of the emission declaration
measurements for functional testing or calibration of continuous emissions measurement systems
measurements to analyse the cause of a particular emission behaviour
measurements to forecast the emission behaviour in certain operating states

Gas analytics

In the area of analysis technology, we offer you measuring devices and systems for versatile applications. Regardless whether it is for hot or cold gas analysis as well as for stationary or mobile measurement - you will find the right measuring instrument. There can be up to twelve measuring components such as CO, NO, SO₂, HCl, NH₃ and H₂O precisely determined. Special applications complete the product range portfolio.

Emission measurement Process measurement Hot-wet gas analysis Cold-dry gas analysis Oxygen measurement Odour measurement Mobile gas analyser Immission measurement

Emission measurement

Industrial plants requiring approval are subject to strict requirements for compliance of emissions limit values. For monitoring it is only allowed to use measuring devices approved by the Federal Environment Agency. The approval requirements are defined in EN 15267. The number of measured components depends on the plant type, but also on the used fuel.

The determination of the gaseous components takes place after the extractive method of measurement. Therefore a partial gas stream is withdrawn from the exhaust gas stack and led via gas sampling probe to the analyser cabinet.

Process measurement

All Dr. Födisch emission measuring devices or systems can in principle also be used for various process applications. Furthermore devices for special requirements and applications are designed by Dr. Födisch technical-team.

Typical applications are:

Delta CO (carbon monoxide) measurements for monitoring smouldering fire, e. g. in coal mills, coal silos or baghouse filters
Delta NO (nitric oxide) measurements for denitrification plants control
NH₃ (ammonia) latency measurements at SCR / SNCR systems
HCl (hydrogen chloride)- and SO₂ (sulphur dioxide) measurements in the raw gas for the flue gas cleaning systems / desulphurisation plants control
O₂ (oxygen) measurement for monitoring inerting systems in chemical and pharmaceutical industries

Extractive solutions are in particular suitable and used. Thereby sensitive measurement technology is not directly exposed to the often harsh exhaust conditions. By modifying the sample extraction even the most difficult applications (high temperatures, very high dust content, corrosion) can be solved.

Hot-wet gas analysis

The method of hot-wet gas analysis is widely used – in power plants, in waste incinerations, in paper, glass and cement industries and many more. A partial flow of gaseous components is withdrawn by a sampling probe and sampling pipe and led to the analyser cabinet. The sample gas is tempered at 185 °C for the whole gas path and monitored for flow and temperature. This high temperature level is necessary in order to prevent condensing of water-soluble components.

The multi-component analyser is the heart of the hot-wet measuring system analysing simultaneously up to 12 components. That includes e.g. HCl, NH₃, H₂O, CO, NO, NO₂, CH₄, SO₂ and CO₂. Oxygen is measured by an integrated zirconium dioxide sensor.

Dr Fodisch gas analysers are qualified for almost all applications. The types MCA 04 and MCA 10 passed the suitability test and got certification according to EN 15267-3 (QAL1). Mobile measuring equipment offers high flexibility for special situations. Test it!

Cold-dry gas analysis

Cold-dry measurement is – same like hot-wet measurement – based on the extractive working principle. A partial flow of gaseous components is withdrawn by a sampling probe and sampling pipe and led to the analysis cabinet. A gas conditioning inside the cabinet cools the sample gas to 5 °C. Then up to five components are measured in parallel – a real added value for you.

For the detection of smells i.e. metal oxide sensors are applied.

For different customer requirements we use the most efficient method each. Of course, we are able to offer certified equipment as well. In any case we have a solution for your application. Test it!

Oxygen measurement

Quick and exact oxygen measuring values by direct in-situ measurements are necessary for optimization of combustion control and emission monitoring. The oxygen analyser of the Dr. Födisch is used for the oxygen concentration measurement in flue and process gases.

The oxygen is measured by a zirconium dioxide cell, whereby the concentration of free oxygen is analysed. Based on the proven proportionality of signal and concentration a constant accuracy in all oxygen concentration ranges is ensured.

Odour measurement

Smells are only perceptible in subjective way and can be hardly quantified. Especially in locations with high building density these smells are regarded as annoyance. Upon making food or other productions smells can arise from various processes. In order to measure smells complex gas sampling equipment and elaborate evaluation software are required.

The smell analyser of the Dr. Födisch can be used for continuous monitoring of odour emissions in order to identify early potentially bad smells for the neighbourhood and thereby to ensure an environmentally-friendly plant operation. The measuring system detects the composition respectively the pattern of smells.

Mobile gas analyser

Immission measurement

Dr Fodisch's portfolio includes devices for monitoring the air quality at outdoor areas, in buildings and at workshops.

The measuring devices have been developed for year-round use indoors as well as outdoors. They are factory-calibrated under the highest quality requirements.

The suitability for monitoring nitrogen dioxide in the outside air and at the workplace has been proven with comparative measurements in the field at a certified air quality measuring station by third parties (Karlsruhe Institute of Technology).

Flow measurement

The continuous velocity and temperature measurement is very important when operating a system with gas flows (for example indoor exhaust air, exhaust gases).

At emission measurements the current concentrations are determined. For conversion into absolute emitted masses one needs the volume, which is calculated on the gas velocity. This also plays an important role in emissions allowance trading.

Flow measuring device FMD 09 Flow measuring device FMD 02

Flow measuring device FMD 09

continuous measurement of exhaust gas velocity, exhaust gas flow, pressure and temperature
compact unit with differential pressure probe
can be used in flue gases with high dust contents
suitability tested and certified according to EN 15267-3 (QAL1)
approved for all plants covered by IED

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Flow measuring device FMD 02