EP2189741A2 - Procédé et dispositif de séchage et établissement de programmes de séchage - Google Patents

Procédé et dispositif de séchage et établissement de programmes de séchage Download PDF

Info

Publication number
EP2189741A2
EP2189741A2 EP09173190A EP09173190A EP2189741A2 EP 2189741 A2 EP2189741 A2 EP 2189741A2 EP 09173190 A EP09173190 A EP 09173190A EP 09173190 A EP09173190 A EP 09173190A EP 2189741 A2 EP2189741 A2 EP 2189741A2
Authority
EP
European Patent Office
Prior art keywords
drying
control
shrinkage
temperature
component
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP09173190A
Other languages
German (de)
English (en)
Other versions
EP2189741A3 (fr
Inventor
Joachim Lutz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Innovatherm Prof Dr Leisenberg GmbH and Co KG
Original Assignee
Innovatherm Prof Dr Leisenberg GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Innovatherm Prof Dr Leisenberg GmbH and Co KG filed Critical Innovatherm Prof Dr Leisenberg GmbH and Co KG
Publication of EP2189741A2 publication Critical patent/EP2189741A2/fr
Publication of EP2189741A3 publication Critical patent/EP2189741A3/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B21/00—Arrangements for supplying or controlling air or other gases for drying solid materials or objects
    • F26B21/30—Controlling, e.g. regulating, parameters of gas supply
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B25/00—Details of general application not covered by group F26B21/00 or F26B23/00
    • F26B25/22—Controlling the drying process in dependence on liquid content of solid materials or objects
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B2210/00—Drying processes and machines for solid objects characterised by the specific requirements of the drying goods
    • F26B2210/02—Ceramic articles or ceramic semi-finished articles

Definitions

  • the invention relates to a method for drying at least one moist and Trocknungsschwindungsbefflen semi-finished or finished component according to the teaching of claim 1.
  • the invention relates to a device for carrying out the method according to the invention according to the teaching of claim 16.
  • Drying processes known from the prior art are based on heat transfer and mass transfer between a semi-finished or prefabricated component subject to wetting and drying, a fabric component, generally water, being withdrawn through a dry medium, usually a hot air flow, to a finished or semi-finished component so that the component to be dried undergoes a volume decrease. If the volume decrease is not evenly distributed throughout the body, shrinkage tensions arise.
  • the absolute amounts of the stresses are material specific and shape dependent, whereby the component can only absorb certain amounts of stress.
  • the voltages stay close below a critical crack resistance limit, deformations can occur. When the crack resistance limit is exceeded, the component breaks.
  • the aim of an economically interesting drying process is, therefore, process parameters, in particular the parameters relative humidity and temperature, by means of actuators, which regulate the air flow and the heat generation, optimally adjust to achieve reproducible drying results.
  • the previous preparation of drying curves which can serve for repeated execution of drying processes, an iterative process, in which only with existing drying results after drying time, quality and residual moisture again a new drying process, taking into account the relative humidity and temperature, etc. can be created , see also Fig. 1 .
  • the quality of the drying processes of the prior art depends on a manual preparation and thus on the quality of the specified setpoint values for temperature, relative humidity and on the number of optimization steps.
  • the relative humidity is understood to mean the percentage ratio between the instantaneous water vapor pressure and the saturation water vapor pressure over a pure and even water surface. The relative humidity therefore indicates immediately to what degree the air is saturated with water vapor, or how much water from the air can still be absorbed.
  • the object thus arises of proposing a drying method and a device provided for this purpose, which provides a measurement-size-based and automatic determination of optimum drying parameters for any semifinished or finished components, whereby optimal parameters are already available after a few test runs and an efficient determination of drying parameters for the reproducible and qualitatively adjustable drying of a series of similar components is made possible.
  • the inventive method is used to dry at least one humid and Trocknungsschwindungsbefflen half or finished component, wherein at least a first controlled drying process is performed, in which a control of drying parameters, such as temperature, air flow rate, etc. taking into account at least one control difference between actual shrinkage of the component and a predetermined component-specific Schwindungssollverlauf is enabled.
  • a control of drying parameters such as temperature, air flow rate, etc. taking into account at least one control difference between actual shrinkage of the component and a predetermined component-specific Schwindungssollverlauf is enabled.
  • the relevant course of shrinkage is regulated online and the resulting actual values of the drying parameters such as air circulation, drying temperature, etc. can be stored and made available as future program target values for subsequent drying operations.
  • the shrinkage of a component and its comparison with a component-specific Shrinkage follow-up curve requires only a small number of drying operations until optimal drying parameters are determined.
  • the method can be used for target curve determination when introducing new components, but also serve to find out their optimal new setpoint curves after retrofitting existing equipment, as well as saving energy of the drying process for existing drying systems and a dynamic runtime adjustment to minimize the drying times with minimum energy drying curves enable.
  • a component-specific shrinkage setpoint curve which depends on the one material-dependent, on the other hand, but also on the form factor, ie the specific geometric design of the component.
  • Fig. 2 an idealized shrinkage behavior of ceramic masses by means of a Bourry diagram. It can clearly be seen that after the beginning of a drying process, the proportion of water dwindles to a so-called point of infiltration, at which the component reaches its final volume, in this case about 80% of the initial volume. As the degree of drying progresses, the water content decreases, without the volume shrinking further. As in the Fig. 3a and 3b As shown, the shrinkage setpoint curve changes depending on whether a "thin" or "thick" component is dried.
  • a shrinkage setpoint curve can be carried out quickly and easily by a person skilled in the art, even with new component geometries, and guarantees that no irregularities in the drying process and shrinkage cracks occur unless the shrinkage setpoint curve falls short of the shortest possible drying time or does not exceed the material and product-specific strength values become.
  • the inventive idea is that in the course of the drying process the shrinkage of the component is measured online and a shrinkage setpoint curve is readjusted, ensuring that the actual volume shrinkage curve never exceeds the maximum shrinkage gradients that depend on the drying progress.
  • the process parameters of the controlled drying process are logged in order to be able to generate control and / or manipulated variables for subsequently controlled or controlled drying processes.
  • a regulation means a feedback and comparison of controlled variables to reference variables for the generation of manipulated variables which influence the behavior of a controlled system.
  • a controller has no such feedback and is used to influence a device according to a predetermined plan.
  • control loop comprises a further control as a temperature control with a temperature control difference and / or a humidity control for controlling the water vapor absorption capacity of the dehumidifying dry medium based on measurement signals of relative humidity and temperature within the drying chamber.
  • the second control is based on either a temperature or a humidity, or a combination thereof.
  • further control parameters for the second control loop are conceivable, which can provide information about the drying progress of the component.
  • the value for the water vapor absorption capacity (.DELTA.g steam / kg air ) or a differential pressure, for example partial pressure of water vapor to saturation partial pressure, a good basis of a control difference formation be.
  • a humidity control is particularly suitable if in the drying chamber a supply air flap, possibly parallel to an exhaust air flap and / or antiparallel is provided as a recirculation damper for controlling the humidity and a heat generator as a burner or heater or the like. can be operated by means of a temperature control.
  • the control loop comprises a shrinkage control.
  • Fig. 2 Bourry diagram shown is achieved in the course of the drying process at the point of so-called.
  • Knick Vietnamesesfeuchte a Schwindungsendowed of the component, from which the water content decreases, but the component undergoes no change in volume and thus the degree of shrinkage can provide any information about the degree of dryness of the component .
  • the control also takes into account a temperature control, so that shrinkage and temperature are used to find optimal drying parameters.
  • a further development of the above-mentioned embodiment is that during a drying process within a first drying phase at least partially a shrinkage control and within a subsequent second drying phase at least partially carried out a temperature and / or humidity control.
  • the volume decrease is regulated until reaching the Knick Vietnamesesfeuchte means of shrinkage control, from then the drying control is continued by means of a temperature and / or humidity control until the component reaches the desired final moisture.
  • Schwindungsregelung is made and uses a temperature and / or humidity control in the second drying phase.
  • the control loop comprises at least two slave controllers, wherein the control value u 1 of a first slave controller K 1 is used as a reference variable w 2 of a second downstream slave controller K 2 .
  • the control loop by means of two slave controller K 1 , K 2 with the output of the first follower K 1 serves as a reference variable of the second controller K 2 .
  • elegantly controlled two controlled variables can be compensated for each other, for example, the component shrinkage as a first controlled variable and the temperature difference or another second variable as a second controlled variable, wherein a first controller K 1 performs a vibration control and a second controller K 2 performs a temperature and / or humidity control, or the adjustment of the second size.
  • a first slave controller K 1 performs a Schwindungsregelung, wherein the error signal e 1 of Schwindungsregelung w a Schwindungsregeldifferenz between actual Bauteilschwindung y 1 and a Schwindungssollverlauf is 1 and the output value u 1 w as a reference variable 2 is used for a temperature control or for the control of a second size of the second sequence controller K 2 , wherein the second control difference e 2 is a temperature control difference or a control difference of the second size.
  • the second controlled variable of the drying effect can be selected as desired.
  • the reference variable w 2 and / or control variable y 2 'of the temperature control can be derived from temperature y 21 and relative humidity y 22 of the drying device (02) derivable physical difference quantity, in particular temperature difference between wet bulb temperature and dry temperature.
  • the wet bulb temperature is defined as the cooling limit temperature, ie the lowest temperature which can be achieved by evaporative cooling, in which the water delivery of a moist surface is in equilibrium with the water absorption capacity of the surrounding atmosphere, so that the surrounding gas or the air is saturated with steam ,
  • a pressure difference between the water vapor saturation partial pressure and instantaneous water vapor partial pressure (in bar), a mass difference between maximum water vapor absorption capacity in the saturation state and instantaneous water vapor content (in water / kg air ) or a similar difference variable can be determined from temperature and relative humidity. which can be used as a controlled variable for the downstream drying effect control stage of the follower controller K 2 .
  • the wet bulb temperature is difficult to determine directly by measurement. However, it is advantageous and obvious that instead of the wet bulb temperature, the relative humidity and temperature of a drying device is determined, from which the wet bulb temperature can be derived by calculation with known conversion formulas. Thus, it is advantageous to determine the temperature difference y 2 'by calculation from measured relative humidity y 22 and temperature y 21 of a drying device.
  • the drying effect control difference (13) shows a difference e 2 between a reference variable w 2 obtainable from the shrinkage control u 1 and one from relative humidity y 22 and the temperature y 21 of the drying chamber (02).
  • determinable controlled variable y 2 ' is.
  • a control value resulting from the Schwindungsregelung u 1 detectable temperature difference command value w 2 between wet-bulb temperature and a dry temperature and a relative humidity of y 22 and y 21 of the drying chamber temperature determinable Temperature difference y 2 'between wet bulb temperature and dry temperature.
  • This output control value u 1 of the first controller K 1 then serves as differential control variable w 2 of the second controller K 2 and can be regarded, for example, as a differential temperature between wet bulb temperature and dry temperature, wherein the controlled temperature y 2 'is the actual temperature difference between wet bulb temperature and dry temperature in the controller K 2 , which can be derived from the directly to be measured temperature y 21 of the drying chamber and the relative humidity y 22 , which prevails in the drying chamber.
  • pressure difference or mass difference which can be determined from relative humidity and temperature, can be used in the same way as suggested above.
  • the above-mentioned method is based on recording the actual shrinkage of the component during the drying process.
  • the first component is the fastest drying component and the second component is the slowest-drying component.
  • the pre-selection of the slowest and fastest component is based on physical relationships and the experience of the person skilled in the art.
  • the drying rate increases with increasing rate of the water-receiving medium, i.
  • the air velocity increases and as the desiccant saturates with water (air saturation)
  • the components blown directly from a hot air supply will be the fastest drying / dwindling components.
  • the most remote components are due to the increasing saturation of the dry medium by the intervening drying components and the lower flow velocity because of the greater distance the slowest drying components.
  • the user of the drying device usually knows "wet nests" which are based on circumstances that are not obvious at first sight and e.g. from uneven hot air supply through the fan or fans with different outputs. Therefore, it is easily possible to identify the location of the fastest and slowest-drying components and thus attach the Schwindungsmessauf commentary to these components according to the advantageous development.
  • the shrinkage control in a first drying phase of the shrinkage control, first the shrinkage of the first component, which shrinks fastest, is taken into account in the control and, at the end of the shrinkage phase, the shrinkage of the second component, which dries the slowest, for determining the shrinkage control difference e 1 is used.
  • the shrinkage of the fastest drying component is used for shrinkage control initially, at the end of its shrinkage process of this component, the slowest drying component continues to shrink.
  • the shrinkage control can resort to the shrinkage behavior of the slowest-shrinking member, so that it is ensured that a shrinkage control is performed until the shrinkage of all the components to be dried is completed.
  • the invention relates to a drying device for carrying out a method according to one of the aforementioned method claims.
  • the drying device according to the invention comprises a drying device for drying at least one component, at least one adjusting device for setting drying parameters such as temperature, air flow rate, air circulation or the like in the drying device, a control device for controlling the drying operation by actuating the adjusting device by means of a control value u 2 and at least a sensor for receiving a controlled variable y 1 .
  • the drying device is characterized in that the control device comprises at least one Schwindungssollkurveniser for outputting a component-specific Schwindungssollkurve least one component and at least one sensor is formed as Schwindungsmessauf scenery that can absorb the shrinkage of the component in the course of a drying process as a controlled variable y 1 , wherein the control device formed is to correct a Schwindungsregeldifferenz e 1 between actual component shrinkage y 1 and the Schwindungssollverlauf w 1 .
  • the drying device comprises a control device with a shrinkage measuring transducer and a shrinkage setpoint curve unit, which specifies a shrinkage setpoint curve as a reference variable.
  • the sensor absorbs the actual shrinkage of the component, whereby the control device is influenced by influencing the controlled system, i. Setting device and drying device ensures that the shrinkage of the component follows the Schwindungssollverlauf during the drying process.
  • the device can work with a shrinkage sensor.
  • the device comprises at least two Schwindungsmessauf fate, wherein a first Schwindungsmessaufionat is disposed on a first fastest-drying component and a second Schwindungsmessaufionat on a second slowest-drying component.
  • the device is equipped with a temperature sensor and a sensor for detecting the relative humidity of the air within the drying device to provide from temperature and relative humidity within the drying means a second drying action controlled variable, for example, a differential temperature between wet bulb temperature and actual temperature to be able to determine a pressure difference between water vapor partial pressure and instantaneous water vapor partial pressure or a mass difference between maximum water vapor absorption capacity in the saturation state to instantaneous water vapor content.
  • a second drying action controlled variable for example, a differential temperature between wet bulb temperature and actual temperature to be able to determine a pressure difference between water vapor partial pressure and instantaneous water vapor partial pressure or a mass difference between maximum water vapor absorption capacity in the saturation state to instantaneous water vapor content.
  • control device comprises at least one first controller K 1 , which is designed as a PID controller.
  • a PID controller has the advantage, without overshooting and without remaining control difference, a uniform and rapid compensation of the control difference e .
  • the control device comprises at least two controllers K 1 , K 2 , which are concatenated as slave controller (cascade controller), wherein the first slave controller K 1 is designed to control a Schwindungsregeldifferenz e 1 and the second slave controller K 2 designed is to correct a temperature control difference, wherein the manipulated variable u 1 of the first sequence controller K 1 as a reference variable w 2 of the second sequence controller K 2 is used.
  • the second follower K 2 is advantageously possible to interpret the second follower K 2 as a PID controller.
  • control device comprises a computing unit that is designed, from the measured values y 21 , y 22 of the temperature sensor (10) and the sensor (11) of the relative humidity, a physical drying effect difference quantity (13), in particular Difference temperature between wet bulb temperature and dry temperature, pressure difference between water vapor saturation partial pressure and instantaneous water vapor partial pressure or mass difference between maximum water vapor absorption capacity in the saturation state to determine instantaneous water vapor content of the component.
  • a computing unit that is designed, from the measured values y 21 , y 22 of the temperature sensor (10) and the sensor (11) of the relative humidity, a physical drying effect difference quantity (13), in particular Difference temperature between wet bulb temperature and dry temperature, pressure difference between water vapor saturation partial pressure and instantaneous water vapor partial pressure or mass difference between maximum water vapor absorption capacity in the saturation state to determine instantaneous water vapor content of the component.
  • the drying device comprises a protocol unit which is designed to record at least the output manipulated variable u 2 and / or u 1 (optionally a plurality of output manipulated variables u 1 or u 2 ) of the control device during at least one drying operation.
  • the output manipulated variable u 2 directly influences the adjusting device, which in turn controls direct drying parameters, such as temperature of the drying air within the drying device, air circulation speed, ventilation flap opening, etc.
  • the manipulated variables u 2 output during a first or second drying process can be logged and, in a further exemplary embodiment, in which the device comprises a control device, on the basis of the protocol unit
  • the adjusting means u 2 received by the control device directly control the adjusting device of the drying device for carrying out further drying operations.
  • the initial control variables recorded by the protocol unit can be called up to carry out further, merely controlled drying operations.
  • the manipulated variable u 1 can also be recorded, so that a simple regulation according to the differential temperature can be carried out on the basis of the course of the manipulated variable u 1 given by the protocol unit.
  • a simple control by temperature and / or relative humidity is conceivable.
  • Fig. 1 shows schematically a drying method according to the prior art.
  • a dryer 02 ceramic moldings as components, in this case tiles, dried.
  • a shrinkage over the time course of the drying process whereby only the process parameters temperature and relative humidity in the drying device 02 are measured.
  • the user is evaluated for shrinkage, temperature and relative humidity and manually set temperature and relative humidity set points for subsequent drying operations.
  • These specified drying parameters are used to re-dry components in a subsequent drying operation to repeat this process several times until optimized drying parameters are found for the components.
  • the creation of optimal drying parameters is an iterative process, which is characterized by high costs and a large amount of energy and time and a high degree of rejects of the components to be dried.
  • Fig. 2 schematically shows a Bourry diagram representing the shrinkage process of a clay component.
  • the volume is 100%, wherein in the example about 28% of the component volume consists of water.
  • the water content decreases, whereby a shrinkage of the component size in the example to about 80 to 85% occurs.
  • Knick-point moisture ie the temperature at which the decrease in water content leads to no further significant shrinkage, air pores are formed, so that the body volume remains constant.
  • a Schwindungssollkurvenver foundation is shown, where in Fig. 3a a Schwindungssollverlauf a "thin” and a "thick" component is shown.
  • An example of a thin component may be a beaver tile, a thick component may be a solid brick brick.
  • a thin molding can in principle due to the shorter diffusion paths and a larger surface / volume ratio faster than a thick, solid molding dry. With a standardized drying time, it can also be seen that the thin molded article requires a shorter phase of moisture from the point of contact to the same residual moisture.
  • the easy-to-classify curves are highly similar, with the most significant difference being the molding or component geometry, ie, the surface or sphere model of the thin or thick molding.
  • the shrinkage setpoints for the shrinkage are mainly determined by the component size and geometry, the reference distance on the component, the planned drying time, the mixture of raw materials and the water content.
  • angles ( ⁇ 1 , ⁇ 2 and ⁇ 3 represent the start angle of the shrinkage process ⁇ 1 , the angle of the moisture point of curvature ⁇ 2 and the shrinkage curve end angle at the end of the drying time ⁇ 3.
  • the type of cracks can be very high
  • the shrinkage gradient is adapted to the starting value of the gradient of the shrinkage setpoint curve, wherein a tangential setting of the shrinkage setpoint course to the respective drying case is achieved If the actual value of the shrinkage is too great from the outset despite the supply air being closed, the circulation capacity can be reduced, as far as the dryer equipment permits, and the drying speed can be slowed down so as to ensure that the actual flow rate is maintained tion the shrinkage setpoint course, as it is, for example, in Fig. 3b is shown, can be tracked.
  • the shrinkage is no longer suitable as a measure of the drying process and thus to regulate the drying process to the desired residual moisture content.
  • Fig. 4a shows schematically a known from the prior art control loop.
  • the input variable is the reference variable w , which is also referred to as the nominal value.
  • the controlled variable y which is also referred to as the actual value and which is output at the end of the controlled system G , subtracted, so that a control difference e results.
  • Controller K attempts to adjust the manipulated variable u in such a way that the control difference e disappears.
  • the manipulated variable u is entered into the controlled system G , wherein the controlled system G generates a controlled variable / actual value y after the manipulated variable u .
  • This control variable y is also subject to a disturbance d , which must be compensated by the control loop.
  • Fig. 4b schematically shows an embodiment of a control loop by means of a sequence control of the two controllers K 1 and K 2 according to an embodiment of the invention.
  • the reference variable w 1 serves as a desired shrinkage setpoint course, from which the actual shrinkage profile y 1 is subtracted, so that a shrinkage rule difference e 1 09 results.
  • the controller K 1 12 outputs a manipulated variable u 1 , which is entered as a reference variable w 2 in the downstream controller K 2 .
  • the drying effect controlled variable e 2 13 which is calculated as the difference of the reference variable w 2 and an actual quantity y 2 ', which results from conversion by means of the arithmetic unit from the actual size y 2 .
  • the controller K 2 outputs a manipulated variable u 2 , which flows into the controlled system G , in this case in the drying device 02 by influencing the adjusting device 03.
  • the output quantities y 1 are then supplied as manipulated variables of the shrinkage control and y 2 as control variables of the temperature control.
  • Fig. 5 shows an embodiment of the drying method according to the invention by means of in Fig. 4 schematically illustrated control circuit components.
  • roof tiles are dried by means of a dryer and hot oven exhaust air and a circulating air circulation (not shown), wherein the output variables y metrologically be determined by means of sensors 05.
  • a Schwindungssollverlauf the components flows into the scheme and serves as Sollschwindung w 1 .
  • the actual shrinkage y 1 is recorded by means of shrinkage sensors, for example strain gauges, potentiometers or optical systems, and transformed into a control value u 1 by means of the PID controller K 1 12.
  • This control value u 1 serves as a reference variable w 2 of the downstream PID controller K 2 14 and is considered as the difference temperature between the current temperature and the cooling limit temperature of the drying device 02.
  • the actual temperature and the relative humidity of the air within the drying device 02, y 21 and y 22 are recorded. From these, an arithmetic unit 15 can in turn determine an actual differential temperature between the current temperature and the wet bulb temperature of the drying device 02, which also enters the PID controller K 2 14 as a controlled variable y 2 '.
  • the PID controller K 2 14 determines therefrom a manipulated variable u 2 , which directly controls the flap position 03 of the dryer 02 and thus influences the controlled system (drying device 02).
  • the second controller K 2 after reaching the Schwindungsendides, the reflected u 1 at a constant value of the manipulated variable, On regulated by the temperature differential between the cooling limit temperature and temperature of the drying device 2 as a control variable y. Since the differential temperature is generally not parallel to the signals temperature and relative humidity at the sensor outputs, the current temperature y 21 and the relative humidity y 22 are determined in the drying device 02 and by means of a mathematical relationship to the actual differential temperature between the cooling limit temperature and temperature in the drying device formed by a computing unit 15. Thus, the difference between the output of the PID controller K 1 12 serves as a reference variable w 2 and the actual differential temperature y 2 'as Trocknungs Fischs-control difference 13 of the downstream controller 14, which carries out a temperature control.
  • the shrinkage setpoints result from the choice of the reference section, the mix of raw materials, the shape size and geometry and the planned drying time. These easy-to-classify curves have a high similarity, with the most significant difference being the component or molding geometry (surface or sphere model). As in Fig. 2 illustrated, the point of contact moisture determines the time in which the shrinkage of the component is no longer suitable to serve as a reference variable for the control of the drying process. Visually, the moisture of the breakpoint is recognizable when the shape changes its color, because the moisture level sinks below the surface of the molding.
  • the moisture point of the break point is always reproducible. Therefore, a predefinition of the value of the breakpoint humidity at which the shrinkage control is switched to the temperature control is possible and advantageous.
  • the in Fig. 5 illustrated cascade control automatic switching because after the components have reached their Schwindungstalk according to the Knick Vietnamesesfeuchte, is switched by the Schwindungsregler 12 to a parameter set for specifying the manipulated variable curve u 2 , so that only the predetermined change in the differential temperature of the drying device 02 as a controlled variable the behavior of the temperature controller 14 determined.
  • a predefinition of the break point value for example, at approximately 5% of the shrinkage end dimension, can ensure that a reliable switchover is made between shrinkage control and temperature control.
  • the output u 1 of the Schwindungsreglers 12 has a control value of 0 to 100%, but which can also be issued in a size from 0 to 100 Kelvin and thus can be defined as the differential temperature of air temperature to the cooling limit temperature (wet bulb temperature).
  • a lower shrinkage than specified by the setpoint increases the control value (differential temperature from the air temperature to the cooling limit temperature), and an excessively high shrinkage is reduced the control value.
  • the larger the difference temperature between the air temperature and the cooling limit temperature the stronger the drying effect of the air. For a non-oscillatory behavior of the control, only the controller must be parameterized accordingly.
  • the absorption capacity of the dry medium therefore, for example, the difference between the measured air partial pressure and the saturation partial pressure in Pascal, the water vapor absorption capacity in kilograms of steam per kilogram of dry air or the water absorption capacity in kilograms of water per kilogram of dry air or just the difference temperature of air temperature used to the cooling limit temperature be, with the above sizes, for example, for the building material ceramic behaves in conventional temperature ranges sufficiently linear and thus excellently offers as a controlled variable. All of the four variables listed above can be calculated from the measured temperature and the relative humidity, wherein this conversion carries out the arithmetic unit 15.
  • Fig. 6 schematically shows an embodiment of a drying device 01, with the aid of an inventive drying method can be performed.
  • the drying device 01 comprises a drying device 02 in which components, in this case roof tiles, are dried by means of dry, warm air (for example, furnace waste heat).
  • dry, warm air for example, furnace waste heat
  • the dry, warm air, in particular the waste heat from outside the drying device 01 come, ie the oven does not have to be part of the drying device.
  • the supply air volume and an air circulation can be actuated by means of an adjusting device 03.
  • sensors are arranged 05. These sensors 05 comprise a first shrinkage measuring sensor 07 and a second shrinkage measuring sensor 08, wherein the first shrinkage measuring sensor 07 is arranged on the molding, which according to experience dries fastest.
  • the second Schwindungsmessauf choir 08 is located on the molding that dries from experiments or experience known to slowest. Furthermore, the sensors 05 include a temperature sensor 10 and a sensor of the relative humidity 11.
  • the measured variables of the shrinkage sensors 07, 08 are controlled variables y 1 and the temperature of the temperature sensor 10 and the relative humidity of the air inside the drying device 02 by means of the relative humidity sensor 11 entered as a control variable y 2 in a control device 04.
  • the control device 04 comprises a shrinkage setpoint progression unit 06 which determines a setpoint shrinkage course, which is component-specific and depends on the material, shape and other parameters of the component (s), outputs. Furthermore, the control device 04 comprises two slave controllers K 1 12 and K 2 14, which are connected in a control cascade. In addition, a computing unit 15 is provided which generates a derived controlled variable y 2 'from the controlled variables y 2 by arithmetic calculations. Finally, the control device 04 comprises a protocol unit 16, which can log the output manipulated variable u 2 of the control device 04 in addition to the two controlled variables y 1 and y 2 . This protocol unit 16 is in turn connected to a control device 17 and, after repeatedly carrying out a drying operation and finding optimized drying parameters, allows a pure control of the drying device 02 by means of the control device 17 and the adjusting device 03.
  • the values logged during a first drying process by the logging unit 16 can be optimized in a second drying process, wherein in a third downstream drying process the quality of the dried components can be verified again.
  • the protocol unit 16 optimized values should be stored in the protocol unit 16 optimized values, so that by means of the control device 17 and the controller 03 subsequent drying operations can be performed only controlled with optimal control parameters with a consistent quality.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Drying Of Solid Materials (AREA)
EP09173190.1A 2008-11-24 2009-10-15 Procédé et dispositif de séchage et établissement de programmes de séchage Withdrawn EP2189741A3 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102008058793 2008-11-24

Publications (2)

Publication Number Publication Date
EP2189741A2 true EP2189741A2 (fr) 2010-05-26
EP2189741A3 EP2189741A3 (fr) 2014-07-02

Family

ID=41698031

Family Applications (1)

Application Number Title Priority Date Filing Date
EP09173190.1A Withdrawn EP2189741A3 (fr) 2008-11-24 2009-10-15 Procédé et dispositif de séchage et établissement de programmes de séchage

Country Status (1)

Country Link
EP (1) EP2189741A3 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115157481A (zh) * 2022-06-20 2022-10-11 沈阳华控科技发展有限公司 一种pvc干燥装置的热量控制方法
CN119320283A (zh) * 2023-07-17 2025-01-17 北京国资环境保护技术有限公司 一种把餐厅剩余食物处理成肥料的方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2767484A (en) * 1954-11-09 1956-10-23 Gilson Pierre Charles Jean Device for measuring and regulating the drying of wet products inside a drier
JP4051074B2 (ja) * 2005-10-31 2008-02-20 住友林業株式会社 木材の乾燥方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115157481A (zh) * 2022-06-20 2022-10-11 沈阳华控科技发展有限公司 一种pvc干燥装置的热量控制方法
CN119320283A (zh) * 2023-07-17 2025-01-17 北京国资环境保护技术有限公司 一种把餐厅剩余食物处理成肥料的方法

Also Published As

Publication number Publication date
EP2189741A3 (fr) 2014-07-02

Similar Documents

Publication Publication Date Title
DE69616076T2 (de) Verfahren zur holztrocknung
DE102019121658A1 (de) Vorrichtung mit einer Klimakammeranordnung zum Ausführen eines Schmelzschichtungsverfahrens
CH684965A5 (de) Verfahren und Vorrichtung zur Erhöhung des Wirkungsgrades von Kompressionsvorrichtungen.
DE102015205338A1 (de) Trocknungsvorrichtung
EP3309294A1 (fr) Systeme d'air de traitement
EP0376175B1 (fr) Procédé et dispositif pour contrôler la compression et/ou pour créer une zone marginale avec une surface modifiée pendant l'extrusion de particules, notamment de particules végétales avec des agents liants
EP2189741A2 (fr) Procédé et dispositif de séchage et établissement de programmes de séchage
DE69416726T2 (de) Verfahren und Vorrichtung zur thermischen Reinigung von Objekten
DE19513547C2 (de) Verfahren zum Steuern des Wärmebehandlungsprozesses in einer Pelletieranlage
DE3041958A1 (de) Verfahren zur steuerung einer pelletieranlage fuer feinkoernige erze
WO2018033491A1 (fr) Procédé de calcination en deux étapes ainsi qu'installation correspondante
DE1408996B2 (de) Verfahren zur automatischen Steuerung eines Wanderrostkühlers
DE3611563A1 (de) Verfahren und einrichtung zur trocknung von keramikrohlingen
WO1997017131A1 (fr) Procede de durcissement hydrothermal et de sechage de corps moules lies par hydrate de silicate de calcium (csh) et dispositif de mise en ×uvre dudit procede
DE2119136C3 (de) Regelkreis zur Regelung einer Kunststoffschneckenpresse
DE3114711A1 (de) "verfahren und vorrichtung zur verhinderung der ansammlung von material in einer rohrleitung"
DE102021000618A1 (de) Verfahren zur Regelung eines Trocknungsverlaufes eines Produktes in einem Trockner
EP0541982A1 (fr) Procédé pour la conduite d'un four tunnel
EP0656515B1 (fr) Procédé pour commander des sécheurs dans les manufactures de briques
EP1182413A1 (fr) Dispositif et procédé pour le traitement de bandes continues
WO2016116185A1 (fr) Procédé pour faire fonctionner un système de pile(s) à combustible et système de pile(s) à combustible associé
EP0429947A1 (fr) Procédé de régulation pour le séchage du bois
DE102015005500B4 (de) Vorrichtung zur Herstellung eines faserverstärkten Kunststoffbauteils
EP3752350B1 (fr) Procédé et dispositif pour la commande d'une soupape et utilisation du dispositif dans une presse de vulcanisation de pneus
DE102006037127B4 (de) Verfahren zur Regelung klimatischer Parameter in einer Spritzkabine

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

RIC1 Information provided on ipc code assigned before grant

Ipc: F26B 21/06 20060101AFI20140210BHEP

Ipc: F26B 25/22 20060101ALI20140210BHEP

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

RIC1 Information provided on ipc code assigned before grant

Ipc: F26B 25/22 20060101ALI20140526BHEP

Ipc: F26B 21/06 20060101AFI20140526BHEP

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20150106