EP0679754B1 - Method and device for treating textile products during drying - Google Patents

Description

The present invention relates to a method and an apparatus for treatment of textile goods during the drying process in dry cleaning machines, Washing machines, tumble dryers and similar devices, as well as special facilities for chemical surface treatment of Textiles that use a circulating air flow and a solvent, or Facilities that only remove water and therefore no solvent and where the Airflow in the circuit or open and those that have a heating register.

In the case of dry cleaning machines, the work sequence generally consists of the Steps cleaning, spinning and drying of textile goods, whereby for the present invention, only the drying process is important. For Washing machines that provide drying is also just the drying process of interest.

The invention relates to the current state of the art of machines open operation or closed circuit based on the course of the Drying airflow required. An open company is to be understood as when the air is sucked in from the environment and blown back into the environment , where indoor air or outdoor air can be used. The closed cycle points a closed circulating air flow with a condensation phase a subsequent so-called reduction phase in an associated one Activated carbon plant is subjected to, in which the solvent content of the air flow is reduced becomes. To understand the invention, the devices mentioned at the beginning also referred to as machines that include the drying process.

After the spinning process of the goods (textiles) has ended, Drying process including machines with the drying process moisture disposed of by air with an inlet temperature of about 90 ° C in the Drum of the machine over the textiles to be treated and thereby the Solvents such as PER are converted into gaseous form. The airflow temperature drops at the drum outlet to about 20 to 25 ° C, for example by piping the Air flow through a cold register, e.g. by means of a blower, from where the gas comes from condensed to the air flow. Up to now, inlet temperatures higher than 90-95 ° C have been considered harmful to textiles. This was believed to be the top one The temperature limit is exposed to the textile goods without being damaged can be. In addition, it is usually required that the temperature of the goods The temperature must not drop below 35 ° C to prevent recondensation. If the temperature of the goods fell below 35 ° C, the textile would Take the solvent back out of the air and store it to a certain extent achieve a filter effect that is not desired.

The temperature of the air in the drum becomes a drying process in modern including machines with metal sensors (e.g. PT100; thermocouples) that are located within the device system and included in the control electronics supplied, whereby not the temperature of the goods is measured, but the Airflow temperature. Because at the beginning of drying more than 20,000 ppm (Particles per million) solvent concentrations in the drum area can be reached, that drop to a fraction of it at the end of drying are subject to this Temperature sensor a heat withdrawal, which inevitably leads to measurement errors. This an attempt is made to compensate for the fact that the inlet and outlet temperatures set accordingly low.

The condensed solvent is particularly useful in dry cleaning machines derived and collected via the cold register and via an associated dry control device fed to a so-called contact water device. In the contact water device the resulting solvent from the distillator with the resulting Solvent from the cold register mixed from drying to get a rough one To get pre-separation of dissolved water. This so-called contact water will be disposed of later via a contact water system. A return of the goods withdrawn water in the drying process is not possible because the water arises from the distillator as an azeotropic mixture and usually only very rarely is changed and therefore experience has shown that it smells unpleasantly strong.

Has the drying process progressed so far that only very small quantities are left Solvents in liquid form are obtained via the dry control device Drying process ended and the so-called reduction phase initiated. Such a Process is in a chemical cleaning machine from DE-AS-22 36 683 known. This means that the heating register on the dry cleaning machine is switched off. At this point there are still solvent gas concentrations from 1200 to 3000 ppm in the drum room and up to 8% solvent in the Were good. During the reduction phase, the drum is therefore not heated more fed only to reduce the solvent content in the air flow to reach.

In order to achieve the lowest possible temperature in the cold register, one as possible complete condensation of the solvent in the cold register is achieved with some dry-cleaning machines, the speed of the blower reduces what is difficult to solve from a control point of view because suitable precise parameters for this are missing. For an environmentally friendly desired or required value To get as close as possible from less than 280 ppm, the air flow, as from the DE-AS-22 36 683 known, guided over an activated carbon plant and there to the given Value reduced.

The parameters that influence drying are: air flow, gas concentration, Temperature gas measurement at the drum outlet or inlet, temperature before or according to the condenser, moisture content of the air, gas pressure, temperature of the goods, Additional heating, drying time, reduction time, loading weight of the drum, type of goods (Diffusion behavior), lint trap load, spin time, cold register (Condensation performance), activated carbon filter, air humidity.

This shows the difficulties involved in finding suitable parameters to control the air flow in the dry phase of the goods to find the reliable enough to dry textile goods under economic conditions perform. For example, the dry control device detects the known ones Dry cleaning machines only the already condensed solvent behind the cold register and does not take into account which textile quantities or textile types are dried, the actual residual solvent content in the air stream and in the goods. Therefore undesirable different degrees of dryness reached.

In particular, the dry control or regulating device does not detect any temperature fluctuations the air flow in the drum area, which inevitably at Drying process occur, also not the influences of temperatures outside the chemical cleaning machine, which depending on the season and location Influence the drying time factor during gas phase formation up to 30%. She controls moreover, not the air humidity, based on the water content of the air flow, which is of particular importance. Naturally, this is true also to other machines that include a drying process. The requirements the clothing industry, which do not allow dimensional changes of the textiles cannot be satisfied by such measuring methods. If the goods overdry Excessively high temperatures cause irreversible damage due to water withdrawal from the fiber, which is particularly useful for delicate textiles such as mohair and pure wool is the case.

From DE-A1-32 34 105 a chemical cleaning machine with a circulating, closed air flow known at which the solvent concentration in the washing drum housing after completion of the washing process and before opening the unloading door is reduced in that drying air through the goods and cleaning or recovery equipment is recycled until a solvent vapor concentration has been reached which allows the unloading door to be opened, without exposing the environment to excessive solvent vapor concentration becomes. The cleaning device can consist of an activated carbon filter, while recovery can be done by freezing. There are also flaps described for controlling the air flow, for reversing gas flows provided when changing the operating states from closed to open unloading door are.

By reducing the amount of solvent in the goods during their drying, the drum outlet temperature gradually increases, and with it the temperature Temperature of the goods, while at the same time the evaporative cooling capacity in the drum on the textile fibers decreases. This in turn means a higher one Energy input to the cold register in chemical cleaning machines and leads automatically to the fact that the temperature increases on the output side of the cold register, which a means higher solvent concentration in the air flow and is not desired. Measurements have shown that up to 8 minutes of drying time are wasted because during this phase the gas concentration at the entrance to the cold register is compared shows almost no gradient to the cold register exit.

This drying process control has so far not been able to influence the gas-forming To take condensation processes in the air flow since this control just that Already liquid condensed solvent is detected, which from the cold register Chemical cleaning machine emerges.

In the case of previously known drying control methods, the drum outlet is generally located a gas meter attached. This is required or prescribed to to prevent the loading door from being opened while there is more than 280 ppm solvent gas concentration in the drum room.

The residual solvent content in the textiles is not recorded here. Furthermore are these devices are technically designed so that they either in the range of 0 - 800 ppm, or can measure in the range of 800 - 20000 ppm. Such devices can therefore do not measure the entire drying process and control it optimally. In practice these devices are also not used for regulation. A gas measuring device is preferred with a more precise measuring range of 0 - 800 ppm. An optimal measurement the course of drying through these devices at a gas concentration above 800 ppm is not possible. Thus, a single gas meter will not entire measurable gas concentration range within the drying process.

For dryers that remove water from textiles, the drying process takes place in simplest form through a pure time control. The heating power for heating the Air is set to a fixed value and the goods are set to a fixed value Duration treated. Because the type and moisture content of the goods are common Fluctuations are subject to energy-efficient and gentle washing Using this type of control requires a great deal of experience and care from the operating personnel. Therefore, a regulation is often used in which the air humidity is measured at the drum outlet. If this falls below a certain one Value, drying is complete. So different humidity levels, but not directly the residual moisture in the textile fiber.

Air temperature control also takes place. Depending on the sensitivity of the laundry is a corresponding target temperature for the air in the drying drum set. This temperature is at the drum inlet or outlet or both measured using conventional temperature measurements (PT100, thermocouples) and set via a heating register.

The problem with the control system is that drying is generally less than optimal becomes. Basically, the drying performance is at the highest possible air temperature preferably. However, as mentioned, the temperature of the goods may have a maximum value Do not exceed, otherwise excessive wear and damage to the Textiles occur.

In the previous control and regulation procedures of the chemical cleaning machine or machines that include a drying process normally the temperature at the drum outlet is taken into account, which with the decrease the amount of solvent increases and can cause the goods to overheat, however, as mentioned, the actual temperature of the goods is not measured.

JP-A-5177091 is a drying machine known, the actual temperature of the goodsputes for controlling the heating register were measured becomes.

It is therefore an object of the present invention, a method and an apparatus for the treatment of textile goods during the drying process in dry cleaning machines, Washing machines, tumble dryers and the like To create facilities that keep the drying process going over the entire period optimize the drying process to ensure a sufficiently low water content reach or a low solvent concentration of less than 280 ppm reach the output side of the drum, which significantly shortens the drying time and energy is saved.

According to the invention, the object is achieved by a method which is characterized in that is that the temperature or the humidity of the surface of the textile Goods measured without contact and depending on the measured values the air flow, air temperature or humidity during the Drying process is affected.

Furthermore, the air volume flow and / or the air temperature is dependent of the contactlessly measured temperature or moisture on the surface of the goods and depending on the gas concentration of the solvent constantly changing in the air flow, at least the gas concentration of the solvent from the temperature and pressure of the air flow on the outlet side of the Drum determined and the temperature on the input side of the drum lowered when the temperature is on the outlet side of the drum or on the surface of the goods exceeds a predetermined value.

In addition to the temperature and pressure, the output side of the drum the humidity content of the air flow can be measured.

Furthermore, the heating register is dependent on the temperature or humidity the surface of the goods is regulated and switched off by means of a control device, if the gas concentration of the air flow is below a predetermined value drops to end the drying process.

In a further embodiment of the method according to the invention, the airflow during the course of drying in addition to solvent, the amount of water from the Goods are collected and returned to the drum in gas form to the goods, when the moisture content of the goods drops below a specified value.

Furthermore, the task according to the invention is achieved by a device, in particular Dry cleaning machine, washing machine, dryer or the like Device for performing the method according to the invention solved the one circulating air flow and an organic solvent or water, or just one circulating or an open airflow used, and a drum for recording of the goods, a heating register, a control device and if necessary has a blower and a cold register, in that in the area of Drum a measuring device for non-contact measurement of the surface temperature or the moisture of the goods is arranged with the control device is in operative connection, which depends on the measured values Air volume flow, the air temperature or the humidity during the Drying process by means of a throttle device located in the air conveying path steplessly regulates that between the output side of the drum and the input side of the Cooling fan provided is arranged. The task continues at Devices that are not equipped with a movable drum, e.g. Tunnel finishers and baking ovens, solved by one installed on the room wall, for example Measuring device that in the manner described above by a non-contact measurement Regulation of the air volume flow enables.

In a preferred embodiment of the invention, the measuring device is on the loading and unloading door attached to the drum. The measuring device is expediently located essentially in the plane of the axis of rotation of the drum. With systems without a drum, the measuring device is generally at the level of the hanging or lying textiles attached.

Furthermore, the throttle device is arranged in the air conveying path. The throttle device can be, for example, a throttle valve or a throttle valve.

Finally, on the output side of the drum there is a temperature sensor, a pressure sensor and / or a moisture sensor arranged in the air conveying path with the control device are connected.

The invention first of all provides a measuring method for non-contact measurement the temperature of the goods. It is a Measuring device based on the principle of the optical radiation pyrometer, for example an infrared or other radiation measuring device. Here, the radiation emission of textiles in the infrared range. The between goods and measuring device Air or the air-water mixture has the degree of absorption α = 0. So there is no heat radiation from the air and it only becomes the actual one Surface temperature of the goods measured.

The surface temperature may differ from the temperature inside the goods distinguish, but this is irrelevant because of the physical Process of drying with a corresponding need for heat of vaporization and due to the convective supply of this heat from the outside via the heated one Airflow in the goods is always a temperature below the surface temperature will set. Possible damage to textiles due to overtemperature can therefore only be carried out on the surface and this is precisely where the invention is based recorded the temperature.

The evaporation or drying process takes place at the interface between Goods and air take place complex heat and mass transfer processes. For this Basically, the temperature of the goods is generally not the same as the temperature the surrounding drying air. In general, it can be assumed that the temperature of the goods is significantly lower at the start of the drying process than the air temperature. According to the invention, however, it is possible, especially at the beginning drying at high temperatures. This high temperature is now via a suitable control system with the surface temperature of the goods as Control variable and the output of the heating register for the drying air as a control variable adjusted. Due to the complex conditions on the surface of the goods are mostly non-linear controllers for this application, for example based on fuzzy logic. The non-contact temperature and humidity measurement the surface of the textile goods in the drum in connection with The fuzzy logic allows the different sensitivities of the textile goods to differentiate and thus the drying process of the type and - adjust sensitivity.

Depending on the system conditions, a simple regulation of the heating register is not sufficient, to achieve the desired product temperature, so that in addition Adjustments in the form of a throttle valve in the air conveying path are required. Their Regulation is also carried out automatically by the control device.

The desired low solvent concentrations of less than 280 ppm, in particular in a dry cleaning machine, can now, as tests show have to be achieved even without activated carbon plant, so that a technical and cost very complex part of the machine is eliminated. Because of economical reasons an activated carbon filter can still be provided to reduce the solvent content in the Further reduce air flow. In particular, the new process achieves that the residual solvent concentration in the textiles again of about 1% of Goods weight is reduced to less than 0.4% of the goods weight.

To achieve this goal and to achieve the object of the present invention therefore needs the control device, which is the central control device of the Chemical cleaning machine or machine including a drying process forms, the information about the gas pressure, the gas temperature, the gas volume flow, and possibly the air humidity on the outlet side of the drum. This Data are from the appropriate measuring devices, namely temperature, pressure and Humidity sensor, recorded at the drum outlet and to the control device passed on.

The control device exercises via the throttle device, which is preferably a throttle valve is influence between the drum outlet and the cold register input the temperature and the air pressure in the drum by reducing or increasing of the air volume flow.

Furthermore, the control device with that installed on the window of the drum Connected measuring device, the contactless the actual temperature of the goods measures. The non-contact measurement of the temperature of the goods has the particularly great advantage is that the actual temperature and moisture content of the goods is recorded, so that a really realistic value is obtained becomes. The control device monitors whether the temperature of the goods is a set or exceeds the specified limit. It switches the heat supply in the heating register when the limit is exceeded and controls in parallel the throttle device and thus immediately the temperature and the volume of the air flow. It is also possible that the non-contact measuring device alone does the operations the control device, i.e. that the entire control and regulating electronics is housed in the measuring device.

To get an optimal drying time, there is one at the beginning of the drying to strive for high gas concentration. This is only possible with very high temperatures to reach. At about 25 ° C outlet temperature of the air flow at the outlet of the There are about 280 grams of solvent in the air flow per cubic meter of drum. At 60 ° C, this is already 800 grams, more than double. Until you reach it the optimum inlet temperature on the drum often takes 4-5 minutes, since the self-losses of the heating register and the drum walls require a lot of energy consume. A fixed temperature value of, for example, 90 ° C would mean significantly more drying time than a regulated value of 120 ° C. At the same time, however, 120 ° C surface temperature would be damaged of the goods, namely the textiles.

An inventive regulation of the surface temperature prevents this damage, since it rules out any possibility of the goods overheating. This is it is possible to expose the goods to air temperatures above 95 ° C.

The method according to the invention simultaneously adjusts the air flow temperature on the outlet side of the drum, the gas pressure of the air flow and, if necessary the humidity level measured by with the cold register on Actuate the throttle device or switch the heating register on and off To regulate the temperature on the inlet side of the drum. The temperature therefore rises on the output side of the drum above a predetermined value, is by means of Control device automatically lowers the temperature on the input side of the drum, because the throttle device reduces the air flow and the heating register is switched off. However, the temperature on the outlet side of the drum drops to a predetermined value, the control device is enlarged using the throttle device the cross section of the air flow and turns on the heating coil, so that the temperature on the inlet side of the drum rises.

The moisture content of the also plays an important role in the drying process Airflow. Due to the particularly high requirements for emissions reduction will be a disadvantageous reduction in the current state of the art the natural residual moisture of the goods to be dried.

The air humidity sensor provided can also be used to return water to the goods be used in the drum. The amount of humidity drops below the water volume is automatically returned in gaseous form on the goods and thereby prevents their over-drying. If the gas concentration drops to the specified value, the drying process automatically ended. By automatically controlling the temperature the input or output side of the drum, the drying process, as mentioned, optimized. By early detection of low gas concentrations then the temperature on the input side of the drum and the speed of the solvent-air mixture is reduced, so that a reduction the gas concentration of the solvent to below 280 ppm without activated carbon system becomes

The relationship between airflow, air pressure, drum inlet and drum outlet temperature and possibly the air humidity is with regard to the cold register input or exit of chemical cleaning machines of the greatest importance. When the air flow and thus the energy input before the cold register input is too strong, the condensation performance is reduced because the interface temperature of the cold register rises. This is the reason for a reduction the condensation. To optimize the drying performance, you need to at the same time higher temperatures in the drum area, because an air flow with low temperature means low condensation on the cold register. It follows the necessary regulation of the ideal conditions for optimal control of the Drying process.

The drying is accelerated by the fact that a vacuum in the drum in relation to the external pressure. So in conjunction with an improved Condensation of the solvent-saturated air flow at the cold register is an air flow generated, which is due to the negative pressure, is able to a higher proportion of solvent air to transport to the cold register than usual. In particular at the end of drying a necessary ratio of the diffusion rate created within the voluminous textiles (winter goods); but in summer also automatically takes light textiles into account.

This process step is based on the following control process. Because it an airtight system that includes a drying process Machine is the mass of air during the drying process constant. At the end of drying, the control device can be operated via the throttle valve reduce the passage of air in the air path. This builds between Blower and throttle valve an increased pressure. Because the mass of air in the circuit remains constant, the air volume and thus the air pressure on the rest decrease Part of the system, especially in the drum. According to the type of textiles the throttle valve is closed more or less. Install accordingly different pressure drop and thus a more or less large negative pressure in the drum.

Contrary to expectations, it has been shown that despite the high temperatures of, for example 120 ° C at the entrance to the drum no damage to the goods, as in a high evaporation cold is generated in the corresponding time range. This can also the total drying time can be significantly reduced if the temperature control already carried out in an optimal way at the beginning of the drying process a high air flow is required right at the start of drying, to ensure adequate ventilation and heating of the goods for gas phase formation to reach in a short time.

This can be done at the beginning of the drying process Temperatures up to 150 ° C can be reached on the inlet side of the drum. Such high inlet temperatures have so far not been considered feasible, however, are made possible by the present invention.

The natural fibers, such as cotton, contain depending on the moisture content the air up to 35% and more natural water. Will this water withdrawn from the fibers, there is a shrinkage in the textile fabric, which is not desirable is. However, this contradicts the attempt to keep the solvent concentration as low as possible to achieve in the air flow. Therefore, as mentioned above, the water returned to this drying time.

It should also be emphasized that the parameters mentioned above, namely inlet / outlet temperature on the drum, pressure and humidity of the air flow, Temperature before and after the cold register and solvent concentration in narrower Relationship to the drying time, the reduction time, the loading weight of the Drum, the type of goods, the fluff catcher and the spin time before Drying process stand.

The non-contact measurement of the surface of the goods is also a matter of principle Laundry ironers applicable to regulate the drying air volume. Even with so-called Ovens in which a surface finishing of the textiles or the Textile fabric takes place, is the non-contact temperature measurement according to the present invention applicable.

Fig. 1:

eine allgemeine schematischer Darstellung des Grundprinzips einer einen Trocknungsprozeß einschließenden Maschine mit geschlossenen Luftkreislauf; und

Fig. 2:

ein Ausführungsbeispiel einer Chemisch-Reinigungsmaschine mit geschlossenen Luftkreislauf.

The invention is described in exemplary embodiments with reference to the accompanying drawings. The drawings show in

Fig. 1:

a general schematic representation of the basic principle of a machine including a drying process with a closed air circuit; and

Fig. 2:

an embodiment of a dry cleaning machine with a closed air circuit.

The schematic representation in Fig. 1 shows the general execution of a Drying system in which the air is circulated. In open operation however, the cold register represented by the dash-dot-dash line over which the Exhaust air is not required and the air is not circulated. However, this is not important for the present invention.

The air in the air conveying path 5 is sucked in by the blower 7 and in with it the heating register 13, and optionally via the cold register 11 to the drum 1 transported. The goods are dried in drum 1. The one with steam or solvent-enriched air leaves the drum 1 and gets back into the Air conveyor 5.

The drying is controlled by a control device 23. The surface temperature of the goods to be dried is with the non-contact measuring device 41st detected. In the control device 23 it is compared with a target value and accordingly the heating register 13 is set. Furthermore, the blower 7 also provided to achieve the desired surface temperature of the goods.

With the temperature measurement by the temperature sensor 25, limit value monitoring takes place, to avoid overheating of the goods in drum 1.

The non-contact temperature measuring device 41 serves as well as the temperature measurement by the temperature sensor 25 and the humidity measurement by the Humidity sensor 29 for recognizing the end of the drying process. Of the Drying process is finished when at the temperature measuring points, namely the non-contact Temperature measuring device 41 and the temperature sensor 25, respectively the measuring points, namely the humidity sensor 29 and the non-contact Temperature measuring device 41, the corresponding temperature or air humidity is measured.

Fig. 2 shows a dry cleaning machine with a closed air circuit is explained in more detail below. The central part of the dry cleaning machine is the drum 1, which merges into an air conveying path 5 on the output side 3, which, as from the drawing is easy to see, forms a closed cycle. The direction of circulation of the air flow is indicated by the corresponding arrows in the air conveying path 5 featured.

In the air conveying path 5, a blower 7 is arranged, which is the organic solvent containing air flow from the drum 1, so that in front of the blower 7 Negative pressure in the air conveyor path 5 arises. The blower 7 promotes the solvent-air mixture in the air conveying path to a throttle valve 9, wherein between blowers 7 and the throttle valve 9 creates an overpressure area. Downstream of the throttle valve 9 is a cold register 11, which is followed by a heating register 13.

The air conveying path 5 continues from the heating register 13 to the input side 15 of the Drum 1. On the cold register 11 there is a dry control device on the input side 17 arranged, in which condensed solvent and water runs and in the usual Way (not shown) is supplied to the contact water device 31. The dry control device 17 contains a conventional known unspecified and not level control belonging to the subject matter of the invention, via a corresponding Float 19 works.

The float 19 located in the dry control device 17 actuates one Switch 21 when no more solvent condensate flows out of the cold register 11. This Switch 21 is connected to a control device 23. This control device 23 controls the circulating air flow during the entire drying process. For this purpose, it contains all the control electronics required for this. A temperature sensor is located in the air conveying path 5 on the outlet side 3 of the drum 1 25, a pressure sensor 27 and a humidity sensor 29, each with Control device 23 are connected. The control device 23 is on the other hand with the Throttle valve 9 and the heating register 13 connected.

A contact water device 31 is arranged behind the dry control device 17, which on the input side via an access line 33 with the dry control device 17 and on the output side with a derivative to a not shown here Clean tank for the solvent is connected. The contact water device also contains 31 a derivative 35 for the introduction of contact water into the drum 1 in the Derivation 35 of the contact water device 31, a valve 37 is also introduced. The Control device 23 is connected on the output side to the valve 37 for control purposes.

Furthermore, the access door of the drum 1 is in approximately the same plane as the The axis of rotation 39 of the drum 1 is a measuring device 41 for non-contact measurement attached to the temperature of the goods. This measuring device 41 is controlled connected to the control device 23.

After the spinning process, the drying process begins in the dry cleaning machine. The air flow is through that located in the air conveying path 5 Fan 7 moves in the direction of the arrow. Output side 3 of the drum 1 is over the Temperature sensor 25, the pressure sensor 27 and the humidity sensor 29 each the temperature, pressure and humidity measured in the air flow and the Measurement data is forwarded to the control device 23 via the corresponding control lines. The values of temperature, pressure and humidity are used in the control device 23 determines the gas concentration of the solvent in the air flow and in Depending on this, the throttle valve 9 via the corresponding control lines actuated by opening or closing it in a controlled manner so that the air volume flow is reduced or enlarged. Falls below the gas concentration of the Solvent in the air flow a certain predetermined value, the control device switches 23 from the corresponding control line, the heating register 13, so that the drying process is ended.

During the drying process, the solvent condenses at the entrance to the cold register 11 and is together with the amount of water that occurs when Drying process of the goods occurs, derived in the drying control device 17 and collected there first. This reaches in the dry control device 17 located swimmers 19 a certain level. The switch 21 will actuated when no more solvent condensate flows from the cold register 11. This Switch 21 then sends a signal to the control device via its associated control line 23, which receives this signal and stores it for further control operations.

The control device 23 operates on the basis of the values determined by the Sensor 25 to 29 via the corresponding control line valve 37, which opens around the water 45 accumulated in the contact water device 31 via the discharge line 35 Feed drum 1 when the moisture content of the goods drops, while the temperature of the goods increases. The rise of the The temperature of the goods is measured by the measuring device 41 without contact and the determined value is forwarded to the control device 23. On the On the basis of these measured values, the control device 23 controls the Throttle valve 9 or the heating register 13.

The present invention e.g. the drying process of a dry cleaning machine optimized over the entire duration of the drying process, by a low solvent concentration of less than 280 ppm on the output side reach the drum, which significantly shortens the drying time and one environmentally friendly drying process is carried out.

Claims (10)

1. Process for treatment of textile goods during the drying process in dry-cleaning machines, washing machines, clothes dryers and similar devices, as well as in special devices for chemical treatment of textile surfaces which employ a circulating airflow and a solvent, and devices which remove only water and thus no solvent and in which the airflow is either recirculates or flows openly; those that have a heating register are characterized in that the temperature or the humidity of the surface of the textile goods is measured without contact and the air temperature or humidity influenced during the drying process in dependence on the values measured in the airflow.
2. Process according to claim 1 characterized in that the airflow volume and/or the air temperature are constantly changed in dependence on the temperature or moisture on the surface of the goods as determined by contact-free measurement, as well as in dependence on the gas concentration of the solvent in the airflow, the gas concentration of the solvent being determined at least from the temperature and pressure of the airflow at the output side of the drum and the temperature being lowered, if the temperature exceeds a preset value at the output side of the drum or at the surface of the goods.
3. Process according to claims 1 and 2 characterized in that, in addition to the temperature and the pressure at the output side of the drum, the moisture content of the airflow is measured.
4. Process according to claims 1 to 3 characterized in that the heating register is controlled and shut off in dependence on the temperature or surface moisture of the goods by means of a control device to end the drying process, if the gas concentration of the airflow drops below a preset value.
5. Process according to claims 1 to 4 characterized in that the amount of water from the goods present in the airflow during the drying process is collected and returned to the goods in the drum in gaseous form, if the moisture content of the goods drops below a preset value.
6. Device, particularly a dry-cleaning machine, a washing machine, a clothes dryer or similar device for carrying out the process according to claim 1 which uses a circulating airflow and a solvent or uses a circulating or an open airflow and has a drum for receiving the goods, a heating register, a control device and, optionally, a blower and a cooling register, characterized in that a measuring device (41) is associated with the region of the drum (1) for contact-free measurement of the surface temperature or the moisture content of the goods and stands in operative connection with the control device (23) which, in dependence on the values measured in the airflow, is in continuous adjustable control of the airflow, the air temperature, or the humidity during the drying process by means of a throttle device (9) located in the path conveying the air (5) and is associated with the blower (7) which is disposed with output side toward the drum (1) and input side toward the cooling register (11).
7. Device according to claim 6 characterized in that the measuring device (41) is attached to the loading and unloading door of the drum (1).
8. Device according to claims 6 and 7 characterized in that the measuring device (41) is attached essentially in the plane of the rotational axis (39) of the drum (1).
9. Device according to claims 6 to 8 characterized in that a temperature sensor (25), a pressure sensor (27) and/or a humidity sensor (29) in the path conveying the air (5) are associated with the output side of the drum (1) and are connected to the control device (23).
10. Device without a drum, in particular, special devices for chemical treatment of surfaces for carrying out the process according to claim 1, characterized in that a measuring device (41) for contact-free measurement of the surface temperature of the goods is employed through which the air temperature or the humidity can be influenced during the treatment of the goods in dependence on the measured values of the airflow volume.

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