Textile machine with a suction device and method for controlling the suction device of a textile machine

Abstract

Method for controlling an extraction device (17) of a textile machine, in particular a spinning or spinning preparation machine, such as a drawing, carding or combing machine, wherein the extraction device (17) comprises a fan (12) for generating an airflow, a filter element (13) for filtering the airflow and a cleaning device (14) for cleaning the filter element (13), characterized in that the speed of the fan (12) and the operating status of the cleaning device (14) are coordinated by means of a control (15).

Description

[0001] The present invention relates to a method for controlling an extraction device of a textile machine, in particular a spinning or spinning preparation machine, such as a draw frame, carding machine, or combing machine. The extraction device comprises a fan for generating an air flow, a filter element for filtering the air flow, and a cleaning device for cleaning the filter element. Furthermore, a textile machine, in particular a spinning or spinning preparation machine, such as a draw frame, carding machine, or combing machine, with a corresponding extraction device is proposed.

[0002] Extraction systems are used on a wide variety of textile machines to remove dust, lint, or other contaminants that arise during the processing of fiber material. Typically, an airflow is generated in the area of ​​dirt-sensitive system components, with the corresponding extraction ducts connected either to individual fans or to a centrally located vacuum source. Examples of such system components include the spinning stations of spinning machines or the drafting systems of corresponding spinning or spinning preparation machines. In order to separate the extracted contaminants, the extraction systems typically incorporate filter elements through which the airflow must pass. However, as the contaminants build up on the filter surface, a significant pressure loss occurs over time, resulting in reduced extraction performance.For this reason, the filter surfaces of the filter elements must be cleaned at certain intervals, which can be done manually or with the help of automatic cleaning devices.

[0003] For example, DE 29 41 612 A1 proposes detecting the air pressure on both sides of a filter using pressure sensors and triggering an optical or acoustic signal when a defined pressure difference is exceeded in order to alert the operating personnel to the need to clean the filter.

[0004] Furthermore, DE 101 45 443 A1 describes a spinning machine whose exhaust fan can be controlled by means of a controller during normal operation of the system in order to be able to adjust its speed and thus also the resulting suction power in the entire spinning machine or individual sectors thereof accordingly.

[0005] While the aforementioned processes already contribute to energy-efficient operation of the respective textile machines, there is still a demand for further energy savings, particularly since the extraction devices can contribute significantly to the overall energy consumption of textile machines.

[0006] The document DE 198 51 020 A1 relates to a line equipped with a fan and a control device. The control device is connected to another control device for reversing the fan's direction of rotation. This document does not provide any information on how the extraction device can be operated efficiently.

[0007] A device for extracting fiber-laden air from textile machines is known from the prior art of DE 10 2006 035 729 A1. A vacuum sensor in the pre-filter area measures the vacuum and transmits it to a control unit. The control signals from the measured pressure values ​​and setpoints are transmitted to the filter cleaning drive. Here, too, there is no indication of how the extraction device can be operated more efficiently.

[0008] The prior art of DE 197 13 747 A1 discloses a method for filtering fibers from an air stream, wherein a vacuum monitor is assigned to an extraction box, which is connected to the linear drive of a scraper via a control device. Consideration of the operating status of the cleaning device and the speed of the fan is not disclosed here.

[0009] DE 37 34 246 A1 discloses that the control system includes a timer that limits the cleaning duration. There is also no mention of fan speed control.

[0010] It is therefore an object of the invention to propose a textile machine and a method for its operation which, through particularly efficient operation of the suction device, enable significant energy savings compared to already known systems and methods.

[0011] With regard to the method, this problem is solved by the fact that the speed of the fan and the operating status of the cleaning device are coordinated with one another using a control system. In contrast, it is already known in the prior art to adapt the speed to specific machine parameters or characteristics of the fiber material to be processed. However, this speed is usually set once manually or based on corresponding measured values ​​to a defined value that remains unchanged during or after the cleaning process. However, particularly during cleaning of the filter element, significant changes in the flow conditions and pressure loss occur. Therefore, especially at this stage, correct regulation of the fan speed makes it possible to optimize not only energy consumption but also the flow conditions within the textile machine.On the other hand, the speed of the fan, especially if it is controlled as a function of the pressure loss at the filter element, can also be an indication of the degree of occupancy of the filter surface, so that a mutual dependency in this direction can also be taken into account by the control system, as described in more detail below.

[0012] It is advantageous to reduce the fan speed during cleaning. During cleaning of the filter element, there is a deliberate reduction in pressure loss, so that at the same fan speed an increased volume flow is recorded in the corresponding extraction ducts of the textile machine. Although this improves the extraction effect, an excessive increase or the resulting fluctuations in volume flow can be undesirable in many cases. In this case, it is more advantageous to reduce the fan speed by a certain amount, so that during or after the cleaning process a speed is set that ensures reliable extraction while still being characterized by low energy consumption. The fan can therefore be operated during normal operation orIf the filter element is only slightly dirty, it can be operated at a low basic speed, which is then gradually increased as the filter surface becomes clogged.

[0013] In this context, it is advantageous if cleaning is started when the fan reaches a defined speed, in particular the maximum speed. This takes into account the fact that not only does it make sense to regulate the speed depending on the filter occupancy, but also the opposite case, in which the speed serves as an indication of the filter occupancy and thus as a trigger signal for starting the cleaning process. For this purpose, it can be advantageous, for example, to assign the fan a base speed and a maximum speed, whereby the base speed is selected when the filter element is clean and the maximum speed corresponds to the maximum permissible filter occupancy. Thus, by evaluating the fan speed, which can be controlled, for example, by appropriate pressure sensors, it is always possible to make a statement about the condition of the filter element and thus, in particular, about its degree of contamination.If this and thus also the speed reaches a certain maximum value, the cleaning is finally started, whereby at this stage the speed can again be regulated depending on the cleaning progress or generally the operating status of the cleaning device, as described above.

[0014] It is also advantageous if cleaning is initiated after a reduction in production speed or a production stoppage of the textile machine. Since cleaning the filter element usually causes a change in the flow conditions, which can always have a negative impact on the production process or the quality of the final product, it may be advisable to schedule cleaning during the aforementioned periods, as a lower amount of material can be expected during these periods due to the process. Furthermore, it is also advisable to perform cleaning during these stages regardless of the actual degree of contamination of the filter element, thus ensuring that a clean filter surface is available when the textile machine returns to normal production speed.

[0015] It is also advantageous if the fan speed is throttled down when the production speed is reduced or when the textile machine is stopped. In the latter case in particular, the suggested speed reduction ensures that as few good fibers as possible are sucked away and that there is no change in the surface structure of the fiber slivers fed through the textile machine that come to a standstill when production is stopped. Likewise, it is therefore also advisable to reduce the fan speed when the production speed is throttled down, as this will also result in a lower throughput of fiber material and therefore a lower accumulation of contaminants. The reduction in speed is in turn initiated or at least registered by the control system and taken into account when initiating the next cleaning process of the filter element.For example, it is conceivable that cleaning normally occurs at specific intervals, whereby these intervals can be extended after a reduction in fan speed is detected. Furthermore, it is also possible to increase or reduce the fan speed in the event of a sliver or thread break in the product being processed by the textile machine, so that the cleaning intervals can also be changed in this case.

[0016] Advantageously, cleaning is initiated at the time of changing a feed and / or spinning can assigned to the textile machine. Such a change is usually accompanied by a reduction in the production speed of the textile machine, so that the aforementioned advantages of appropriate cleaning can be realized here as well. Naturally, the speed of the exhaust fan is also adjusted according to the invention, so that minimal energy consumption can be achieved.

[0017] In a particularly advantageous development of the invention, the fan speed is throttled during the change of a feed and / or spinning can assigned to the textile machine. In this case, the throttling occurs either in response to the cleaning process initiated by the can change, or the can change serves as a start signal for regulating the fan speed, whereby the cleaning process can also be initiated simultaneously.

[0018] It can also be advantageous if the speed and / or the cleaning progress are controlled taking into account the pressure loss at the filter element. Even though it is part of the invention that the speed is controlled in coordination with the cleaning process, other parameters can also be taken into account when determining the speed. For example, it is conceivable that the start of cleaning causes a reduction in the fan speed. At the same time, however, the control system can also ensure that the speed is always high enough to ensure a minimal pressure loss at the filter element, which ensures an appropriate volume flow of the extracted air-pollutant mixture.The speed of the fan can of course also be regulated at times when no cleaning is carried out, whereby in this case the speed is advantageously always selected so that the pressure loss at the filter element remains constant.

[0019] It is also extremely advantageous if the speed and / or the progress of the cleaning process are controlled taking into account the air volume flow, particularly in the area of ​​the extraction device. While the pressure loss at the filter element already allows statements to be made about the degree of contamination, the effectiveness of the removal of contaminants depends essentially on the actual volume flow at the respective components, such as the cleaning lips of a drafting system. However, this volume flow is not necessarily directly proportional to the aforementioned pressure loss. It can therefore be extremely useful to additionally or alternatively detect the volume flow of the extracted air stream at one or more points on the textile machine and to take the determined values ​​into account either generally when controlling the speed of the fan or specifically during cleaning of the filter element.In this case, it may be particularly useful to increase the speed as the filter load increases, so that the flow rate remains constant. Of course, a defined flow rate can also be used as a starting signal for the cleaning process.

[0020] It is also advantageous if production data, such as the type of fiber material processed by the textile machine, the production speed of the textile machine or machine-specific parameters, such as the position of the cleaning lips of a drafting system, are taken into account when regulating the fan speed. This has the main advantage that the cleaning performance of the extraction device can be optimally adapted to the existing conditions, whereby, in addition to a satisfactory cleaning effect, energy consumption can also be kept as low as possible. If the textile machine also has several identical or similar production units, as is the case with a 2-head drafting system, for example, barrier flaps are usually present which, in the event of a production error (e.g.In the event of a belt break, or during a can change, the corresponding extraction ducts of the affected production unit can be closed using shut-off valves. It is particularly advantageous if the fan speed is controlled in such a way that the volume flow at the unaffected production unit remains constant despite the blocking of individual extraction ducts.

[0021] Furthermore, it is advantageous if the speed of the fan is controlled using a frequency converter, which enables quick and reliable adjustment of the speed in the presence of a central power supply.

[0022] Finally, the textile machine according to the invention is characterized in that the fan and the cleaning device are connected to a control system of the textile machine, with the aid of which the speed of the fan and the operating status of the cleaning device can be coordinated with one another, in particular in accordance with the above explanations. While it is known to generally and usually manually adjust the speed, for example to specific assortments to be processed, the textile machine according to the invention provides a system that can be optimally adapted with regard to energy consumption and cleaning conditions. On the one hand, it is possible to start cleaning at specific speeds and thus flow conditions in the system. On the other hand, the speed of the fan can be regulated at the beginning of or during cleaning of the filter element in such a way that defined flow conditions can be created.It can be extremely advantageous if the volume flow in the respective extraction ducts is kept constant, for example by reducing the fan speed, while the filter element is being cleaned. It may also be desirable to increase the volume flow, particularly if other system components are to be cleaned at the same time as the filter element(s). For example, it would be advantageous if the cleaning lips of a drafting system were raised at the same time as the filter is being cleaned in order to free them of contaminants using an increased volume flow. In this context, it is also advantageous if the fan speed is increased when the cleaning lips are raised in order to further improve the desired cleaning effect.

[0023] Advantageously, the control system is designed so that the fan speed can be reduced during cleaning, as a reduction in pressure loss is expected during this phase, particularly due to the clearing of the filter surface. This allows for significant energy savings, as reliable extraction can be ensured despite the reduced speed.

[0024] It is also advantageous if the control system is designed so that cleaning can be started when a defined speed, especially the maximum speed, of the fan is reached, since an increase in speed is usually a reliable indication of increasing contamination of the filter surface. In this case, the speed can be regulated based on the pressure loss or the volume flow in the area of ​​the extraction device or correspondingly assigned system components.

[0025] In an advantageous development of the invention, the control system is designed such that cleaning can be started after the production speed has been reduced or the textile machine has been stopped. Cleaning is particularly useful in the latter case, as no contamination occurs and any interruption or throttling of the suction due to the activation of the cleaning device has no negative consequences.

[0026] It can also be advantageous if the control system is designed so that the fan speed can be throttled when the production speed is reduced or the textile machine is stopped. During these times, a smaller amount of contaminants is generally generated, as correspondingly less fiber material is being processed. Thus, a lower fan speed is sufficient to ensure satisfactory extraction.

[0027] Advantageously, the control system is further designed such that the cleaning can be started at the time of changing a feed can and / or spinning can assigned to the textile machine, since the fiber material transported through the system is generally reduced in these production stages as well, which also reduces the load caused by impurities to be extracted.

[0028] Furthermore, it is advantageous if the control is designed in such a way that the speed of the fan can be throttled during the change of a feed can and / or spinning can assigned to the textile machine in order to prevent the suction of good fibers, particularly at this stage.

[0029] It is also advantageous if the control system is designed in such a way that production data, such as the type of fiber material processed by the textile machine, the production speed of the textile machine, or machine-specific parameters, such as the position of the cleaning lips of a drafting system or the position of the previously described barrier flaps, can be taken into account when regulating the fan speed. This ensures particularly advantageous control of the fan speed, since all of the aforementioned data influences the flow conditions within the system and the smooth operation of the extraction device.

[0030] In any case, it is advantageous if the filter element is equipped with a sensor to measure the pressure drop across the filter element. The measured values ​​can be used to regulate the fan speed during, before, and / or after the filter element cleaning process. It is also possible to regulate the fan speed depending on the pressure drop, whereby the cleaning progress or the general operating status of the cleaning device can be regulated depending on the fan speed.

[0031] It is also advantageous if the fan is connected to a frequency converter to control the speed, since such components are available in a wide variety of designs and are also inexpensive.

[0032] Last but not least, it is advantageous if the fan is assigned a separate drive, particularly in the form of an electric or compressed air motor, to enable individual and easily controllable fan speed regulation. While it is also possible to control the fan speed(s) via a central drive and the interposition of appropriate gears, individual drives have the advantage that they can be controlled easily and reliably. Furthermore, the failure of one drive does not affect multiple fans, so their pressure loss can potentially be compensated for by other fans.

[0033] Further advantages of the invention are described in connection with the following figure. It shows: Fig. 1 a schematic side view of part of a textile machine according to the invention.

[0034] The Fig. The section of a textile machine according to the invention shown in Figure 1 in the form of a draw frame essentially comprises an input area with corresponding feed rollers 1, which draw several of the fiber strands 2 to be drawn from so-called feed cans (not shown). Subsequently, the parallel fiber slivers are guided over a feed table 3 provided with corresponding suction slots running perpendicular to the sheet plane and finally combined into a fiber sliver 5 by a first pair of rollers 4, wherein this pair of rollers 4 simultaneously serves as a measuring device to detect any thickness fluctuations of the fiber strands 2 and to take them into account during the subsequent drafting by the draw frame.

[0035] The drafting system itself comprises an input roller pair 6, a middle roller pair 7, and an output or delivery roller arrangement 8, each of which rotates at increasing peripheral speeds in the sequence mentioned. Due to these different peripheral speeds of the rollers 6, 7, and 8, the fiber sliver 5, which is spread out in the drafting system like a fleece, is ultimately drawn according to the ratio of the respective peripheral speeds. The input roller pair 6 and the middle roller pair form the so-called pre-drafting zone, while the middle roller pair 7 and the delivery roller arrangement 8 form the corresponding main drafting zone.

[0036] In order to remove impurities contained in the fiber strands 2 as well as fiber components that become detached during passage through the draw frame from the drafting rollers, cleaning lips 16 are assigned to the drafting rollers, which rest on the surface of the rollers and can be lifted off from them for cleaning purposes.

[0037] After passing through the drafting system, the fiber sliver 5 is finally drawn off by means of a pair of calender rollers 9 and deposited in a spinning can 11 by a rotating depositing plate 10.

[0038] In order to remove the above-mentioned impurities and fiber components from the draw frame, individual suction channels run through the system, which finally converge in the area of ​​a suction device 17. While in Fig. 1 only one suction device 17 is shown, a textile machine can of course also have several of these suction devices 17, as indicated by the arrows to the right of the drafting rollers, which indicate an exhaust air flow in the direction of a further suction device 17.

[0039] The suction device 17 in turn comprises a fan 12 for generating an air flow, a filter element 13 for filtering the air flow and a cleaning device 14 for cleaning the filter element 13, the latter being Fig. 1 is shown as an example of a motor-driven cleaning slide. Of course, the filter element 13 can also be a correspondingly mounted and rotating filter surface that is guided past a stationary scraper or brush element.

[0040] According to the invention, the fan 12 and the cleaning device 14 are connected to a controller 15, with the aid of which the operating states of both components can be coordinated. It is generally advantageous if the speed of the fan 12 can be regulated, for example with the aid of a frequency converter, throughout the entire operation of the textile machine. This can be based on the pressure loss at the filter element 13, the volume flow in the area of ​​the fan 12 or individual extraction ducts, or other measured or controlled variables, such as the type of fiber material processed by the textile machine, the production speed of the textile machine, or machine-specific parameters, such as the position of the cleaning lips 16.

[0041] However, especially during the cleaning process of the filter element 13, the textile machine according to the invention also makes it possible to take the progress of the cleaning process, in particular its start and end, into account when regulating the speed. For example, the speed can be throttled at the start of the cleaning process in order to compensate for the increasing volume flow caused by the increase in the free filter area, so that the resulting volume flow remains constant. Following the cleaning process, the fan 12 finally returns to its base speed, which can then be increased as the filter area becomes increasingly full.

[0042] It is also advantageous to start the cleaning process based on the speed of fan 12. Especially if the speed before and after the cleaning step is regulated depending on the pressure loss at the filter element 13 or the aforementioned air flow volumes, an increase in the speed indicates an increasing degree of contamination of the filter surface. Once the speed has finally reached a certain level, the cleaning process should be started. The speed of fan 12 can be throttled back during this stage depending on the progress of the cleaning process.

[0043] Furthermore, it is advantageous if the cleaning, and thus the change in fan speed, is initiated during a production stop or a production slowdown on the draw frame. Such an event can occur, for example, when changing the feed cans or the spinning can 11 that receives the drawn fiber material. It may also be expedient to increase the fan speed synchronously with the lifting of the cleaning lips 16 to enable reliable suction of adhering contaminants.

[0044] Furthermore, the invention is not limited to the illustrated embodiment. Rather, all combinations of the described individual features, as shown or described in the claims, the description, and the figure, and to the extent that such a combination appears technically possible or reasonable, are the subject of the invention. List of reference symbols 1 feed rollers 2 fiber strands 3 Feed table 4 pairs of rollers 5 Sliver 6 input roller pairs 7 middle pair of rollers 8 Delivery roller arrangement 9 pairs of calender rolls 10 storage plates 11 Spinning can 12 Fan 13 Filter element 14 Cleaning device 15 Control 16 Cleaning lip 17 Suction device

Claims

[1] Method for controlling a suction device (17) of a textile machine, in particular a spinning or spinning preparation machine, such as a draw frame, carding machine or combing machine, wherein the suction device (17) comprises a fan (12) for generating an air flow, a filter element (13) for filtering the air flow and a cleaning device (14) for cleaning the filter element (13), characterized by that the speed of the fan (12) and the operating status of the cleaning device (14) are coordinated with one another by means of a control (15). [2] Method according to the preceding claim, characterized by that the speed of the fan (12) is reduced during cleaning. [3] Method according to one or more of the preceding claims, characterized by that the cleaning is started when a defined speed, in particular the maximum speed, of the fan (12) is reached. [4] Method according to one or more of the preceding claims, characterized by that cleaning is started after a reduction in production speed or a production stop of the textile machine. [5] Method according to one or more of the preceding claims, characterized by that the speed of the fan (12) is throttled when the production speed is reduced or when production of the textile machine is stopped. [6] Method according to one or more of the preceding claims, characterized by that the cleaning is started at the time of changing a feed can and / or spinning can (11) assigned to the textile machine. [7] Method according to one or more of the preceding claims, characterized by that the speed of the fan (12) and / or the progress of the cleaning is throttled during the change of a feed can and / or spinning can (11) assigned to the textile machine. [8] Method according to one or more of the preceding claims, characterized by that the control of the speed and / or the progress of the cleaning takes into account the pressure loss at the filter element (13). [9] Method according to one or more of the preceding claims, characterized by that the speed is controlled taking into account the air volume flow, particularly in the area of ​​the extraction device (17). [10] Method according to one or more of the preceding claims, characterized by that when controlling the speed of the fan (12), production data such as the type of fiber material processed by the textile machine, the production speed of the textile machine or machine-specific parameters such as the position of the cleaning lips (16) of a drafting system or the position of barrier flaps are taken into account. [11] Method according to one or more of the preceding claims, characterized by that the speed of the fan (12) is controlled by means of a frequency converter. [12] Textile machine, in particular a spinning or spinning preparation machine, such as a draw frame, carding machine or combing machine, wherein the textile machine comprises a suction device (17) with a fan (12) for generating an air flow, a filter element (13) for filtering the air flow and a cleaning device (14) for cleaning the filter element (13), characterized by that the fan (12) and the cleaning device (14) are connected to a control (15) of the textile machine, with the aid of which the speed of the fan (12) and the operating status of the cleaning device (14) can be coordinated with one another. [13] Textile machine according to the preceding claim, characterized bythat the control (15) is designed such that the speed of the fan (12) can be throttled during cleaning. [14] Textile machine according to one or more of claims 12 and 13, characterized by that the control (15) is designed such that the cleaning can be started when a defined speed, in particular the maximum speed, of the fan (12) is reached. [15] Textile machine according to one or more of claims 12 to 14, characterized by that the control (15) is designed such that the cleaning can be started after a reduction in the production speed or a production stop of the textile machine. [16] Textile machine according to one or more of claims 12 to 15, characterized bythat the control (15) is designed such that the speed of the fan (12) can be throttled when the production speed is reduced or when production of the textile machine is stopped. [17] Textile machine according to one or more of claims 12 to 16, characterized by that the control (15) is designed such that the cleaning can be started at the time of changing a feed can and / or spinning can (11) assigned to the textile machine. [18] Textile machine according to one or more of claims 12 to 17, characterized by that the control (15) is designed such that the speed of the fan (12) can be throttled during the change of a feed can and / or spinning can (11) assigned to the textile machine. [19] Textile machine according to one or more of claims 12 to 18, characterized bythat the control (15) is designed in such a way that, when regulating the speed of the fan (12), production data, such as the type of fiber material processed by the textile machine, the production speed of the textile machine or machine-specific parameters, such as the position of the cleaning lips (16) of a drafting system or the position of locking flaps, can be taken into account. [20] Textile machine according to one or more of claims 12 to 19, characterized by that the filter element (13) is assigned a sensor for measuring the pressure loss at the filter element (13). [21] Textile machine according to one or more of claims 12 to 20, characterized by that the fan (12) is operatively connected to a frequency converter for controlling (15) the speed. [22] Textile machine according to one or more of claims 12 to 21, characterized bythat the fan (12) is assigned an individual drive, in particular in the form of an electric or compressed air motor.

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