Deprecated: Function eregi() is deprecated in /home/h101150-2/siemens71.ru/docs/new/cat.php on line 184
The FLK gas sampling system consists of the following components:
Liquid-cooled sampling probe
The probe is available with an immersion depth of between 1 500 and 3 500 mm. It is manufactured from stainless steel mat. no. 1.4571 and its oval shape gives it a high vertical flexion strength. The sampling point is at the tip of the probe on the side pointing away from the flow in order to suck in as little dust as possible from the gas.
The probe is suitable for process gas temperatures of up to 1 400 °C.
Liquid-cooled sampling probe
Electrically heated dust filter
The dust filter is used to purify the gas/dust mixture extracted from the process area, and is suitable for dust loads of up to 2 000 g/m3.
Electrical heating up to a temperature of approx. 200 °C prevents crustation or caking of the filter pipe.
Cleaning is carried out automatically at regular intervals, using compressed air at a pressure of approx. 8 bar. To avoid blockage of the filter pores, the compressed air must be free of oil and water residues. Oil residue in particular can lead to caking in the filter pores, which then cannot be removed using compressed air cleaning.
Depending on the dust load, the dust filter can be fitted with filter pipes with different pore sizes.
Electrically heated dust filter
Compressed air valve manifold
Together with the PLC, the valve manifold carries out the regular cleaning programs for purging the gas sampling system.
The purging frequency and duration can be adapted to the conditions of the respective plant using the operator panel of the control unit.
Purging can be initiated manually at any time using the integrated pushbutton. An integrated pressure switch detects imminent blockages in the gas paths as early as possible, and initiates immediate purging of the gas sampling system by sending a signal to the control unit.
A condensation trap is fitted on the valve manifold for preliminary separation of condensation and dust from the process gas.
The sample gas is cut off from the downstream gas preparation by means of a four-way solenoid valve with metal-free gas paths.
For purging purposes, compressed air that is free from dust, water and oil and has a pressure of approximately 8 000 hPa must be provided.
Compressed air valve manifold
Retraction unit with electrical and pneumatic drive
In the event of an incident, the retraction unit automatically removes the probe from the rotary kiln in order to protect it against thermal overload. Depending on the probe length, approx. 90 seconds are required up to complete retraction. An electrical geared motor is used as the drive.
Faults that result in immediate retraction of the probe are:
- Excessively high temperature in cooling circuit
- Coolant level below minimum
- Flow fault
Should the power supply fail, emergency retraction of the probe is carried out by a pneumatic motor provided the supply with compressed air is guaranteed. For maintenance purposes, the probe can be manually retracted at any time using a pushbutton.
The heavy-duty industrial design of the retraction unit guarantees reliable and practically maintenance-free operation.
Retraction unit with electrical and pneumatic drive
Heat exchange unit
The gas sampling probe is cooled by means of a depressurized air/liquid heat exchanger. Use of a synthetic heat transfer liquid with a boiling point above 300 °C permits temperatures of up to 200 °C in the cooling circuit, and therefore equivalent gas sampling temperatures.
To prevent condensation of the flue gas in the gas sampling equipment, gas sampling is only enabled if the temperature in the cooling circuit is at least 130 °C.
The temperature in the cooling circuit is kept as constant as possible by controlling the flow by means of a speed-controlled circulation pump. Depending on the temperature, the flow can be between 1 000 and 3 500 m3/h.
Heat exchange unit
Control and monitoring unit
The core of the FLK gas sampling equipment is the compact control and monitoring unit with Siemens SIMATIC S7-300 programmable logic controller. The equipment is optionally available with an Allen Bradley SLC500 controller.
In addition to the monitoring functions for safe operation of the probe, the control unit is also responsible for regular cleaning of the gas paths.
The operator can use an integrated operator panel to adjust all the parameters, such as the frequency and duration of probe purging, to suit the requirements of the respective plant. No programming knowledge is required to do this.
Control and monitoring unit