DE2617803A1 - Monitoring temp. of granular material - by static or scanning infrared sensors for display and control - Google Patents

Abstract

Temp. measurement in heat treatment of granular bulk material such as cement, relies solely on the infrared radiation existing at the measuring point to produce a signal proportional to the temperature. an i.r. radiation sensor can scan the flow cross-section for the bulk material and/or for gases continuously or intermittently (stepwise). The i.r. measurement has a very short time of response. The measurement is less affected by high dust content in the gas. The same sensors can be used for all measuring points and one sensor can cover several points if arranged in a scanning mode.

Description

Attachment to patent application. the

Klöckner-Humboldt-Deutz Aktiengesellschaft of March 18, 1976 proceedings for measuring temperatures on systems for the thermal treatment of granular and / or lumpy goods, in particular on plants for cement production and installation to carry out the procedure.

The invention relates to a method for measuring temperatures on systems for the thermal treatment of granular and / or lumpy goods, in particular on plants for cement production.

A variety of problems arise in systems of the type described above. -me in connection with temperature measurement for monitoring and control purposes of the plant. For example, in a plant for cement production are to be monitored and control of the entire system; which in principle consist of a preheating device for the material to be treated, a burning device, for example a rotary kiln and a downstream cooling device for the fired material, the temperature of the exhaust gases in the area and the preheating device the temperature of the one to be fed to the bottom Detect secondary air in the area between the rotary kiln and the cooling device. Further must be the temperature of the preheated pipe material entering the furnace, of the Finished goods exiting the cooler and the so-called sintering zone in the Rotary kiln and, depending on the type of cooling device used, also the temperatures for the fired in the cooling facility Well recorded will. In addition, when using a rotary kiln as a burning device The temperature of the furnace jacket is monitored in certain areas for damage to prevent. In view of the fact that a number of the temperatures recorded are required to regulate the entire system, it is important that the temperatures to be recorded as precisely as possible and directly usable for the regulation to generate flow signals. The fulfillment of these requirements is made more difficult that the temperature range to be detected is not with the previously known measuring methods can be detected with a measuring method Range between 200 and 4500 C, the measuring method for measuring the sintering zone temperature must cover a range from about 1800 to 25000 C. Then there is the difficulty the reliable measurement of a gas temperature, especially the dust exposure of the exhaust gases to be measured raises significant problems, as well as, for example, the problem the measurement of the sintering zone temperature, since this is measured without interference in each case must become. In this case, especially with the previously known measuring methods, erhebaul, All difficulties as well as from the dust pollution caused by the influence of the burner flanges than the content of metal and halogen vapors within the furnace atmosphere in this area.

The previously used measuring methods, for example, for measuring sintered zones with the help of partial radiation pyrometers or color pyrometers set a visible Radiation ahead, the measured values obtained by the aforementioned influences, sel'es through the This page replaces page 6 of the Offenlegungsschrift with the same number.

Burner flame, be it due to the metal vapor and / or halogen vapor content falsified in the furnace atmosphere.

The invention is based on the object of creating a method that a uniform measuring method provides for all measuring points, so that accordingly the same measuring device can be used for all measuring points and accordingly Measuring signals of the same type obtained from all measuring points using the same method are available to control the system. This object is achieved according to the invention solved in that to generate one of the respective prevailing temperature proportional Measuring signal only uses the infrared radiation present at the measuring point in question will. .aZhrend basically the existing thermal radiation in a wavelength range from 0.8 to 400 µm can be used, it is particularly advantageous if for the measurement of the wavelength range used between about 1 to 3 June is used will. This has the advantage that all product temperatures over the entire period in the system Occurring temperature range can be detected, regardless of whether the good is only preheated or glowing or partially cooled. The infrared radiation will detected here by means of an infrared radiation sensor known per se.

In an advantageous embodiment it is also provided that the temperature-wise flow cross-section to be monitored for the material to be treated and / or for gases from Infrared radiation sensor continuously or periodically, in particular step by step scanned will.

In a further advantageous embodiment of the invention it is provided that the measurement signals obtained at the respective measuring point over a predeterminable time interval stored and displayed under averaging and / or for controlling the system or is forwarded by parts of the system. This procedure has the advantage that because of the fast response time of the pure infrared measurement according to the invention a continuous temperature monitoring and display of the at any point in time measured temperature is guaranteed, but because of the s. T.

very slow temperature changes during control interventions and because of the z. T. very wide flow cross-sections to be monitored, in which "Temperaturstrahnenn can form only a mean value as a measuring signal to make the regulation more uniform is submitted for the scheme.

Another advantageous embodiment provides that the Measurement signals in the form of a temperature profile are received at the respective measuring point of the monitored flow cross-section and / or to control the system or is forwarded by parts of the system. This procedure has the advantage that "temperature streaks" determined with regard to their position in the flow cross-section can be and that then a targeted, only on this "temperate strand" aligned Control intervention can be made. This procedure is for example before Especially interesting for the monitoring of grate coolers on production plants from @ement, as this procedure streaks in the good layer on the moving grate let see whose temperature is above the permissible product temperature.

In another advantageous embodiment it is provided that the measuring zone detected by infrared radiation sensor by means of a signal converter as Image is displayed. This makes it possible to use the same device with the For example, the temperature of the sintering zone is detected, including the condition the sintering zones can be monitored optically, in particular with regard to the formation and growth of a ring in a rotary kiln is important is.

In an advantageous embodiment of the invention, it is also provided that for the measurement of gas temperatures from a radiant body located in the gas flow Infrared radiation emanating with high thermal conductivity and / or low mass is used. With the help of this procedure, it is me, with practically no adulteration measure the gas temperature directly. This is especially the case with dusty gases of great importance, since the infrared radiation emanating from the radiator is practical always reflects the respective gas temperature, regardless of whether in the course the time due to the dust load of the gas flow to be measured on the jet body a layer of dust is deposited, since it is always the one emanating from the surface of the jet body Infrared radiation is taken as the basis for temperature measurement. By having a body with high Warmth and / or low mass is used, it is guaranteed that the radiant body can measure the temperature of the gases flowing around it within a very short time accepts.

The invention also relates to a device for performing the method according to the invention and is characterized by the use of an known infrared radiation sensor.

While previously thermocouples were used to measure the gas temperature, for measuring the sintering zone temperature radiation pyroineter, for optical monitoring TV cameras had to be used in the sintering zones, which had a direct effect has on the quality and comparability of the measurement signals obtained the temperature measurement with only one device type for all measuring points directly with each other comparable measurement signals and thus a significant simplification of the regulation. Another advantage is that the response time of such sensors is in the range of 1/10 seconds, so that for example with such a device also the Shell temperature of the rotating furnace and the like can be monitored. So-called "red 'vellen't on the furnace shell, which occur when the lining is damaged, can be detected immediately due to the short response time.

In an advantageous embodiment it is also provided that the infrared radiation sensor swivel for measurement detection and / or is slidably mounted. This has the advantage that with only one sensor, either several measuring points one after the other can be traveled, for example when monitoring the jacket of a rotary tube, or but a temperature profile of a cross-section through which the gas or material flows or a corresponding medium value can be generated.

In a further advantageous embodiment of the invention it is provided that for the measurement of gas temperatures from a radiant body located in the gas flow Infrared radiation emanating with preferably high thermal conductivity and / or low mass is used. Such a radiation body can be at the most favorable point in Flow cross-section can be arranged, with the appropriate size at the same time a shielding of the optics of the sensor against the radiation effects of those behind it .fundungsteile offers. When using materials with high thermal conductivity and / or with a low mass of the radiation body results in a fast, the change in the temperature of the gas corresponding to the change in the gas temperature Radiant body and thus sufficient for the regulation of such a system short period of time until the radiation body reaches the temperature of the gas flow surrounding it accepts.

Here, in a further embodiment, it is advantageous if the radiating body is attached to holding means with low thermal conductivity, so that practical no falsification of the measurement result over the niss through the holding center 'flowing off Amount of heat enters.

In the case of dust-laden gas flows, it is ultimately advantageous to that the surface of the reinforcing body is partly roughly the same Color, like the expected dust build-up. This leads to the infrared radiation sensor must be calibrated at the start of operation, as this will change over the course of the operating time forming dust deposits due to the given color of the body surface The infrared radiation emanating from the radiating body practically becomes dust deposits hardly changes.

The invention is explained in more detail with reference to Schentai drawings. E3 show: FIG. 1 a plant for the production of cement by the dry process FIG. 2 shows a section along the line II-II in FIG. 1 in FIG. 1 schematically The plant shown for the production of cement by the dry process has a Rotary kiln 1, which is connected to a preheating device 2 on the material feed side is through which, with the aid of a supply line 3, the hot ones emerging from the furnace Gases in countercurrent to the granular material introduced at its upper end for preheating be guided.

The preheated material passes through a material supply line 4 Inlet chamber 5 in the rotary kiln. The exiting from the preheater 2 Depending on the system, gases are, for example via a gas conditioning tower 6 and ine filter anisge 7 discharged.

A furnace head 8 is provided at the product outlet end of the rotary kiln 1, to which a cooling device, for example a Bostkühler with a moving grate, is connected is. The cooling device 9 is a removal device 10 for the cooled ones Downstream out. About a held in the furnace head 8 burner lance 11 is for the preheating and thermal treatment of the goods required thermal energy introduced into the rotary kiln.

For the operation of such a system both from the point of view the lowest possible energy consumption as well as a trouble-free process flow is now a monitoring of the temperature of all the different points of this system necessary, because of the large number of influencing variables and possible controlled variables a temperature determination that is as exact as possible is required. With your present Measurement method is advantageously used to generate the monitoring, control and control of the system necessary partial temperature proportional measurement signals only the infrared radiation present at the relevant measuring point is used it is via the infrared radiation of the product, be it when measuring the gas temperature via the infrared radiation of one located in the gas flow at the relevant measuring point Radiating body. In the following the essential measuring points for a such system explained in more detail.

To measure the material temperature in the sintering zone, there is a on the furnace head Arranged infrared radiation sensor 13, desser. Optics on the area of the sintering zone is aligned. The optics are aligned and shielded so that the radiation emanating from the flame 14 is not also measured. On this sensor 13 is a display device 15 on the one hand and a screen 16 for optical purposes on the other Monitoring of the sintering zone 12 by means of the converted by a signal converter Measurement signals from sensor 13.

The measuring signal fed to the display device 15 is at the same time a not shown in more detail supplied control device via which both the speed of the furnace and the fuel supply as well as the furnace train are not shown in detail Fan is regulated.

In addition to monitoring the sintering zone temperature, there is also the Monitoring and regulation of the secondary air flowing into the furnace from the cooling device 9 significant. For this purpose, a cooling device 9 is provided in the area of the inlet opening Arranged sensor 17, which from a befirdlichen in the secondary air flow radiation body 19 picks up outgoing infrared radiation, displays it and forwards it for control purposes. The secondary air is here essentially through the with the cooling device connected cooling fan.

The cooling device 9 is also provided with at least one sensor 20, by which the product temperature in the first cooling chamber both in terms of the temperature as well as the temperature p ofile is monitored. To that end is the sensor 20 is expediently arranged to be pivotable, so that it covers the entire outer flow section of the grate in the first cooling chamber can be painted over, so that any occurring Strands of good material with increased or too high material temperature, also with regard to their position can be detected and appropriate remedial action can be taken.

Another sensor 21 is arranged in the area of the cooler outlet, which monitors the cooler end temperature. This monitoring is primarily for protection the downstream conveyors 10 is important.

In the area of the goods inlet side, the Temperature of the entering the furnace via the material supply line 4, preheated Good monitors. In addition, the outlet temperature of the hot furnace exhaust gases are monitored again with the aid of a radiator 19 '. Further Sensor radiation body arrangements 24, 25, 26 are used to monitor the exhaust gas temperatures both behind the preheating device 2 of the conditioning device 6 and behind the E-filter 4, with the recorded values so fully for the control of the entire system, in particular the regulation of the rotary kiln as well as the regulation of system parts, for example, the water supply in the conditioning tower can be used. The rule system - '; em as such, it is not shown in more detail in the schematic drawing. The easier one Each sensor is represented by a display device tied together. This also applies to the rest, the temperature of the material and / or the gas flow measuring sensors of this system, with measured values that are not directly used for regulation used, but when using a process computer for the process computer carried out balancing can also be used.

In Fig. 2, the arrangement of a leak point for measurement is schematically of gas temperatures using the example of measuring the secondary temperature. In the illustrated horizontal section through the inlet to the cooler 9, there are several Radiant body 19 is provided, which flows from the cooler into the rotary kiln Secondary air flow lie. The radiating body 19 are arranged here so that they can be scanned one after the other by the pivotably mounted sensor 17. The scanning takes place here, for example, with a stepper motor, the in Measured values obtained for each measuring period via a corresponding arithmetic unit Mean value can be summarized.

A measuring period can in this case one or more overflows of the sensor 1 7 include. The averaging avoids that if there are any Strands of different temperatures within the Strönune cross-section, pure local temperature deviations, which are insignificant in the overall balance, have a direct impact on the regulation.

When measuring the temperatures on the exhaust gas side, it is usually sufficient the arrangement of a radiator in the flow cross-section as a permanently installed sensor.

The radiating bodies are flat, expediently as Discs formed and with corresponding holding means on the wall of the respective Flow channel attached.

A very important monitoring function, but not immediately related to the regulation of the system, the sensor 27 has to take over, through that the temperature of the furnace shell in the area of the sintering zone is monitored. For this this sensor can be moved over a specified distance in the longitudinal direction of the furnace stored so that the endangered shell parts with security with regard to any occurring "red spots" are monitored.

The above-described measuring method is not limited to that which has been schematically described above Limited training of a plant for the production of cement. Instead of a moving grate cooler A rotary kiln with a planetary cooler can also be used, with a corresponding Sensor the jacket temperatures of the individual planet-shaped at the outlet end of the furnace is monitored with this permanently connected cooling tubes. Likewise, can take the place The grate cooler shown also includes a fluidized bed cooler.

The above-described measuring method can be modified accordingly for a multitude of processes for the thermal treatment of granular or lumpy products Good, for example with alumina decalcination, the direct reduction used by iron ore and similar processes.

Expectations L e r s e i t e

Claims (13)

Claims: Method for measuring temperatures in systems for thermal Treatment of granular and / or lumpy goods, in particular on plants for cement production, thereby g e k e n n -z e i c h n e t that to generate one of the respective ruling Temperature proportional measuring signal only the existing at the relevant measuring point Infrared radiation is used. 2. The method according to claim 1, characterized in that g e k e n n z e i c h -n e t, that the infrared radiation by means of a known Infralqo-t - radiation sensor is detected. 3. The method according to claim 1 or 2, characterized in that g e k e n n -z e i c h n e t that the flow cross-section to be monitored in terms of temperature for the material to be treated and / or for gases from the infrared radiation sensor continuously or periodically, in particular is scanned gradually. 4. The method according to any one of claims 1 to 3, characterized g e -k e n n z e i c h n e t that the measurement signals obtained at the respective measuring point over a predefinable time interval is saved and displayed under averaging and / or is forwarded to regulate the system or parts of the system. 5. The method according to any one of claims 1 to 4, characterized in that g e -k e n n z e i C h n e t that the measuring signals obtained at the respective measuring point in The form of a temperature profile of the flow cross-section to be monitored is displayed and / or is forwarded to regulate the system or parts of the system. 6. Consumption according to one of claims 1 to 5> thereby g e -k e n n z e i c h n e t that the measuring zone detected by the infrared radiation sensor by means of a3 converter is displayed as an image. 7. The method rach one of claims 1 to 6, characterized g e -k e n n z ei c h n e t that for the measurement of gas temperatures those of an in gas flow located radiating body with preferably high thermal conductivity and / or low mass emitted infrared radiation is used. 8. Device for performing de method according to one of the claims 1 to 7, indicated by the use of a per se known Infrared radiation sensor. 9. Device according to claim 8, characterized in that g e k e n n z e i c hn e t, that the infrared radiation sensor can be swiveled and / or displaced to record measured values is joked. 10. Device according to claim 8 or 9, characterized in that g e k e n n -z e i c h n e t that for measuring gas temperatures in the respective flow channel at the Measuring point at least one preferably flat radiating body (19) is arranged with high thermal conductivity and / or low mass. 11. The device according to claim 10, characterized in that g e k e n n z e i c hn e t that at least one surface of the radiation body is planar and that this area is preferably at 90 ° to the measuring direction of the infrared radiation sensor is aligned. 12. Device according to claim 10 or 11, characterized in that g e k e nnz e j c h n e t that the radiating body (19) on holding means with low thermal conductivity is attached. 13. Device according to one of claims 10 to 12, characterized g e k It is noted that the surface of the radiating body (19) is at least partially free approximately the same color as the expected dust build-up.