JPH022988B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method and apparatus for controlling the supply of steam into a steam processor housing. It is well known that in order to obtain optimal results when continuously processing textile products in a steam treatment device, it is necessary to create a steam atmosphere as homogeneous as possible within the steam treatment device housing. For this purpose, sufficient steam is added to the steam processor so that the temperature required for an optimal reaction is always present in the steam processor and so that the steam processor housing is completely filled with steam and contains as little air as possible. Control is required to feed into the steam processor housing. This objective is best achieved by maintaining a certain vapor pressure within the steam processor housing at all times above atmospheric pressure.

PRIOR ART However, the control of the steam supply and thus the steam pressure within the steam treatment equipment housing is
Accurate measurements of current conditions within the steam processor housing are difficult because they are extremely difficult. Due to the continuous operating method of the steam treatment device, which requires insertion through the inlet opening and withdrawal from the outlet opening, only a slight overpressure can build up in the steam treatment device housing. If an overpressure is to be created, a considerable amount of steam must be discharged from the steam processor housing, which is undesirable due to the associated environmental pollution and energy losses. On the one hand, a small amount of overpressure makes it difficult to measure, and on the other hand, pressure fluctuations based on operating conditions cause errors in control, making it difficult to use pressure as a control variable. However, temperature measurements within the steam processor housing are similarly difficult as turbulence occurs which introduces errors into the measurement results. Furthermore, the temperature measured anywhere within the steam treatment equipment housing is
It does not provide an indication of the true steam filling within the steam processor housing.

A comparable device of this kind was published in West German patent no.
1937100, in which the state of the steam atmosphere in the steam treatment device housing is obtained via a water container in the steam treatment device housing;
Water is constantly supplied to the water container from the outside. The amount of water supplied to the water container is measured with a flow meter. The liquid temperature in the container and the evaporation rate calculated from the inflow form the control variables for the supply of steam and heat to the steam treatment device. This measurement method is obviously complex and does not always ensure that an optimum degree of steam filling inside the steam treatment device housing is maintained.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and a device as mentioned in the opening paragraph in order to maintain an optimum degree of filling and as constant a temperature as possible in the steam treatment device housing. be. This problem is solved according to the invention by a method having the features of claim 1 and a device having the features of claim 4.

The invention is based on the physical phenomenon that media with different temperatures form layers depending on their density. Hotter and therefore lighter steam fills the steam processor housing upwardly, thereby displacing heavier air downwardly. This phenomenon is exploited in an optimal and simple manner by means of the method and device according to the invention in order to determine the pressure or the degree of steam filling in a steam treatment plant by means of temperature measurements. Since the temperature is measured in the lowest vapor layer, an optimum degree of filling can always be maintained. Since a sudden drop in temperature can be measured in the boundary region between the lowest and therefore heaviest vapor layer and the surrounding air, it is possible to determine the lower vapor level by temperature measurements.

The measurement is carried out particularly reliably and simply when the temperature is measured in a conduit which is arranged outside the steam treatment device housing and which communicates freely between the steam atmosphere inside the steam treatment device housing and the external atmosphere.
Measuring the temperature within the conduit outside the steam processor housing further has the advantage that the stratification within the conduit is more constant than elsewhere inside the steam processor housing. The dividing position between the hot steam and the cooler ambient air is always kept at a constant level under optimal conditions, unaffected by disturbances under operating conditions. In this way, no complex measuring devices are required inside the steam treatment device housing. Due to the differential pressure, the steam
Since it is possible to escape freely into the external atmosphere via the conduit, the temperature at the measuring point increases only when steam passes past the measuring point instead of the displaced air. The degree of filling can be controlled in a very simple manner by supplying steam to the steam treatment device housing when the temperature at the measuring point falls until the temperature at the measuring point rises again.

Complete filling of the steam processor housing with steam is ensured by the conduit extending below the steam processor housing; and the temperature sensor being provided at a location below the steam processor housing. The steam reaches the temperature sensor only when the entire steam treatment device housing is filled with steam and a steam layer has also formed in the conduit.

It is also possible for the conduit to have a straight cross section with a plurality of joint positions for temperature sensors spaced from each other. Depending on the current conditions obtained in the steam treatment device housing, or depending on the measurement range of the temperature sensor, the temperature sensor can be mounted at different positions on the conduit. It would also be conceivable to equip the conduit with more than one temperature sensor for precise control or to ensure a higher safety factor.

It is particularly preferred that the means controlled by the controller include a steam control valve in the steam supply conduit leading to the steam treatment device housing, wherein the steam control valve is configured to completely fill the steam with the temperature measured at the temperature sensor. The controller compares the temperature to a target temperature corresponding to the steam treatment equipment housing. This temperature can be obtained by measurement, where the measured value allows an inverse estimation as to the temperature or pressure at any location within the steam treatment device housing. However, the steam atmosphere can also be controlled by other means, controlled by the controller.
Naturally, it is possible that it may be controlled. Thus, for example, it would be possible to inject fresh water into the steam processor housing while simultaneously operating a heating device within the steam processor housing.

Examples Examples of the present invention will be described in more detail with reference to the drawings.

A steam treatment device 8, such as is normally used for treating a textile strip 2 in a steam atmosphere, is shown in a highly simplified diagram in FIG. The fabric strip 2 enters the steam treatment device housing 1 from a pre-treatment device (not shown) through an inlet channel 9 and passes through a lower guide roller 10 and an upper guide roller 11 to steam along the associated strip guide. It is guided in a meandering manner through the processing equipment. In order to minimize energy losses, the steam treatment device housing 1 is coated with a thermal insulation material 12.

The inlet opening 19 in the inlet channel 9 is provided as narrow as possible to prevent leakage of steam as much as possible. Contact at this location is not permissible, since if the textile strip 2 comes into contact with, for example, a flexible lip seal, liquids entrained by the textile strip, such as dyes, bleaches, etc., will be scraped off. In this embodiment, the fabric band 2 is a water seal 13
The water seal 13 exits the steam treatment equipment housing 1 and is provided with a turning roller. The water seal prevents the escape of steam from the outlet location. However, instead of a water seal, an outlet opening designed similarly to the inlet opening 19 may also be provided. The textile strip is then fed to a post-processing machine, for example a washing machine.

Steam is supplied to the steam treatment device housing from a steam source, not shown, via a steam supply conduit 15 for heating up and maintaining the temperature of the steam treatment device housing. Steam reaches the manifold 20 and thence via a plurality of steam distribution pipes 14 to the interior of the steam processor housing. A steam control valve 16 is provided in the steam supply conduit 15 and is provided with a pneumatic, hydraulic or electric control element. The steam control valve 16 is controlled by a controller 17 and is opened or closed depending on the current state obtained within the steam treatment device housing. Temperature maintenance heating in a steam treatment device is usually performed using saturated steam.

Conduit 3 extends below the bottom of the steam processor housing. Since one end of the steam is open to the outside atmosphere, a layer corresponding to the steam density within the steam processor housing can therefore continue into the conduit. A temperature sensor 4 is provided in the conduit 3 in the lower part of the steam treatment device housing 1 and supplies the measured temperature to a controller 17 via a measured value transducer, which is not shown in detail. The predetermined target temperature is set in the controller 17 before the steam processing apparatus starts operating.

In FIG. 2 the preferred shape of the conduit 3 is illustrated in some detail. The conduit is fixed to the side wall 21 of the steam treatment equipment housing 1 by means of a coupling flange 5 .
In theory, the conduit could extend directly downward from the steam processor housing. However, in this case the condensed water would also be discharged, which on the one hand would be undesirable and on the other hand would lead to errors in the measurement results. Therefore, it is preferable to provide it on the side at a certain distance from the bottom. The conduit extends vertically downward from the coupling flange 5 via the bent pipe 23. In both cases, therefore, the outlet opening 22 is located below the lowest position of the steam treatment device housing 1. The diameter of the conduit 3 is dimensioned in such a way that the vapor atmosphere can propagate unhindered in layers.

The temperature sensor 4 is fixed to the joint boss 7 and projects diagonally into the conduit 3 from above. The measured temperature can be read directly with the thermometer 6. In the straight section of the conduit, a plurality of joint bosses 7 may be provided at circumferential intervals, and a temperature sensor 4 or a sealing plug can be installed in the joint boss 7 as required. However, usually only one fitting boss 7
The optimum position of the measuring sensor 4 in the conduit 3 is determined by experiment, so that only the position of the measuring sensor 4 in the conduit 3 is sufficient.

In the region of the stationary steam atmosphere inside the steam treatment equipment housing 1 there is a check measurement sensor 24 which measures the current temperature in the working area of the steam treatment equipment housing.
may be provided. This temperature can be read by the inspection thermometer 25.

The layering of the steam column 26, which increases in density and therefore decreases in temperature from top to bottom, is illustrated in FIG. 2 relative to the conduit 3. Here, the steam column 26 or conduit 3 is divided into horizontal planes a to h that are equally spaced from each other. The horizontal plane y is located above the outlet opening 22 and the horizontal plane x is located at the level of the inspection measurement sensor 24. Inspections and measurements were carried out on each of the above-mentioned horizontal planes in an experimental apparatus, and the pressure-temperature diagram shown in FIG. 3 was obtained. Here, T is the temperature °C and P is the pressure Pa (Pascal).

As is clear from the temperature curve 27, a sudden drop in temperature is observed between the horizontal planes g and e. This temperature drop corresponds to the boundary area between the steam atmosphere inside the steam treatment device and the outside atmosphere. Here, the temperature within the measurement position area f exists within a range that allows the use of a normal commercially available temperature sensor.

The "hot/cold" division position is always maintained at a substantially constant level via the control system, so that a constant temperature is always obtained on the horizontal plane x and the steam treatment device housing is completely filled with steam.

As can be seen from the pressure curve 28, the pressure decreases with increasing distance from the steam treatment device housing, and its value reaches zero in the horizontal plane y, that is, in the outlet opening 22.

[Brief explanation of drawings]

1 is a simplified diagram of the device according to the invention; FIG. 2 is a conduit to which a temperature sensor is connected; and FIG. 3 is a diagram showing the temperature and pressure relationships within the conduit. DESCRIPTION OF SYMBOLS 1... Steam processing device housing, 2... Fabric band, 3... Conduit, 4... Temperature sensor, 7... Joint position, 8... Steam processing device, 15... Steam supply conduit, 16... Steam control Valve, 17...Controller, 21
...Side wall, 22...Other end (of the conduit), f...Measurement point.

Claims (1)

Claims: 1. Continuously controlling a textile product 2, in which the current state in the steam treatment device housing 1 is measured and the current state is constantly adapted to a setpoint value via means controlled by a controller. In a method for controlling the supply of steam into a steam treatment device housing 1 for processing;
and the means controlled by the controller are activated in the event of a temperature change. A method of controlling the supply of steam into the housing. 2. A method according to claim 1, characterized in that the temperature is measured in a conduit 3 which is outside the steam treatment device housing 1 and is in free communication with the steam atmosphere inside the steam treatment device housing and with the external atmosphere. . 3. A method according to claim 1 or 2, characterized in that when the temperature at the measuring point f falls, steam is supplied to the steam treatment device housing 1 until the temperature at the measuring point rises again. 4. Continuously measuring the textile product 2 with a measuring device for measuring the current state in the steam treatment device housing 1 and means controlled by a controller for adapting the current state to the target value at all times. In the device for controlling the supply of steam into the steam treatment device housing 1 for treatment; the measuring device is a temperature sensor arranged in the area of the lowest steam layer present in the steam treatment device housing; and A device for controlling the supply of steam into a steam processing device housing, characterized in that the means controlled by the device is activated by a temperature change of the temperature sensor. 5 The temperature sensor is located outside the steam treatment equipment housing 1 and has one end connected to the steam treatment equipment housing 1.
5. A device according to claim 4, characterized in that it is provided in a conduit (3) connected to the conduit (3) whose other end (22) is open to the external atmosphere. 6. Device according to claim 5, characterized in that: 6 the conduit 3 and the steam treatment device housing 1 extend downwardly; and the temperature sensor 4 is provided at a lower position of the steam treatment device housing 1. 7. Device according to claim 6, characterized in that the conduit (3) has a straight cross section with a plurality of joint positions (7) for temperature sensors (4) spaced from each other. 8 Conduit 3 connects to side wall 2 of steam treatment equipment housing 1
8. Device according to claim 6 or 7, characterized in that it is connected to 1. 9. The means controlled by the controller comprises a steam control valve 16 in the steam supply conduit 15 leading to the steam treatment device housing 1; and the steam control valve 16 controls the temperature measured at the temperature sensor 4 completely with steam. 9. A device according to any one of claims 4 to 8, characterized in that it is activated by a controller (17) which compares the temperature with a corresponding target temperature of the steam treatment device housing (1) filled with vapor treatment device housing (1).