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(11) | EP 2 653 423 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Separation device of dust from pieces of yarn for the collection and recovery of winding waste and winding machine wih such device |
| (57) A winding machine of the type comprising a plurality of winding units (23) and at
least one aspirator (22) able to intake impurities and hair of the yarn, that is the
dusts, or pieces of yarn deriving from the restoration and junction interventions
of the yarn, said at least one aspirator (22) being connected through a common duct
(70) to a common multi-cyclone type general filter (80) for collecting the winding
waste, comprising in series and in depression with an aspirator (71), a double cyclone
device (81) for separating the pieces of yarn from the dusts and a filter device of
said dusts exiting from said double cyclone device, characterized in that said double
cyclone device (81) of the pieces of yarn from the dusts comprises an annular central
portion (84) and two frustum-conical portions (82A, 82B) respectively lower and upper
arranged at the opposite sides of said annular portion (84) for generating two cyclones
respectively of the pieces of yarn and of the dusts and for conveying the same from
said central portion (84) to the reduced-diameter mouths (86, 89) of said two frustum-conical
portions {82A, 82B), wherein said double cyclone device comprises primary nozzles
(88) for injecting tangential flows of compressed air into said double cyclone device
(81).
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[0001] The present invention relates to a separation device of dusts from pieces of yarn for the collection and recovery of waste produced during winding processing by the units composing the automatic winder.
[0002] In particular the purpose of the present invention is to make a particularly functional device and alternative to the known devices suitable for separating dust from the pieces of yarn for the collection and recovery of the waste producing during winding.
[0003] In industrial practice the method of producing yarns in a spinning phase followed by a winding phase in which the yarn is unwound from the feeding bobbing, purified of its defects and rewound onto a package is widespread. The winders are in fact composed of a plurality of winding units aligned along the front of the machine and provided with communal control and service equipment. Among such communal service equipment are the devices for preparing the feeding bobbing to be unwound in the winding units.
[0004] The essential components of a winding unit are shown in the diagram in figure 1, which shows the path of the yarn 2 from the lower feeding bobbing 1 to the upper collection feeding bobbing 12, as follows:
[0008] - 6 splicer device served by 9, 10 suction inlets for catching and consigning the ends of the yarn,
[0014] - 20 one or more suction inlets in the vicinity of the feeding bobbing 1 to eliminate the impurities, substantially consisting of the hair and fibrils produced when the feeding bobbing 1 is functioning, known as "dust removal".
[0015] According to an embodiment of the present invention, the winding machine comprises a plurality of winding units 23 and at least one aspirator 22 able to intake impurities and hair of the yarn, that is the dusts, or pieces of yarn deriving from the restoration and junction interventions of the yarn.
[0016] According to another embodiment of the present invention, both the discontinuous high pressure service for the recovery of the ends with the inlets 9 and 10, and the continuous low pressure service for the dust removal with the inlets 20, are performed by an individual aspirator 22 for each of the winding units aligned along the front of the machine. In other words, each winding unit 23 comprises an individual aspirator 22 which provides both the discontinuous high pressure service for the recovery of the ends with the inlets 9 and 10, and the continuous low pressure service for the dust removal with the inlets 20.
[0017] According to an embodiment, such aspirator 22 consists of a rotary aspirator with a centrifugal rotor 25 operated by an electric brushless motor 26 driven in frequency by the control unit 16 of the winding unit.
[0018] The inlet 20 of the dust removal service with continuous and low depression suction is connected by a duct 30 to the suction unit of the winding unit intercepted by a gate valve 31, controlled by the control unit 16 of the winding unit and normally kept open during the normal winding process.
[0019] The inlets 9 and 10 work discontinuously with high depression suction during the interruptions of normal winding. They are respectively connected by a duct 34 to the suction unit 22 of the winding unit, intercepted by a gate valve 35, controlled by the control unit 16 of the winding unit and normally kept closed during the normal winding process. The gate valve 35 is only opened during the joining operations. Ultimately, the individual suction unit 22 which equips the single winding unit 23 serves either the duct 30 of the low depression dust removal service or the duct 34 of the high depression suction.
[0020] The different depression values required for the two alternative suction services are obtained by driving the centrifugal aspirator 22 at different speeds, which has characteristic curves of the suction depression ΔP which vary in inverse proportion to the flow volume, according to a sheaf of parallel curves growing as the speed of rotation increases.
[0021] According to a possible embodiment, the two ducts 30 and 34 of each winding station are connected to a common filter 50, one for each winding station, which retains the material aspirated and transported by the suction and in particular retains both the dust removal impurities collected with the winding on, and the bits of yarn, the so-called "pieces of yarn" removed by the suction of the aspirator 22 when connected to the inlets 9 and 10 and driven at a high depression with the winding off.
[0022] In each winding station, the individual filter 50 may be fitted with a single filtering septum of fine mesh which retains all the material: both the impurities and the pieces of yarn. The presence of an individual filter 50 for each winding unit is not obliged.
[0023] As shown in the embodiment shown in the detail of figure 2 in axonometric view, the individual filter 50 is made with a filtering chamber, with a hopper 55 underneath for collecting the separated pieces of yarn. The filtering chamber is fitted with a coarse mesh filtering septum 51 which retains the "pieces of yarn", removed by the high depression suction by the aspirator 22, when connected to the inlets 9 and 10 and operated at high depression.
[0025] As shown, the filtering septum 51 of the filter 50 is preferably positioned to receive from below the flow of fluid containing the material to be separated so that, when the high depression suction flow ceases, most of the coarse material intercepted and retained by the filtering septum 51 falls spontaneously downwards into the hopper 55 underneath, freeing the filtering septum 51.
[0026] Generally speaking, the quantity of material to be retained is composed mainly of pieces of yarn. The linear dimension of the pieces of yarn may in fact range from several centimetres, in normal yarn joining preparation, up to tens of metres and even more, for the long defects of the yarn purity detected by the yarn clearer 11. Again generally speaking, the impurities of the dust removal have an average dimension to the order of a millimetre or little more.
[0027] In industrial practice the material separated and recovered with the filters is generally recycled to the carding machine, to recover the fibres which compose the pieces of yarn. In such processing, the impurities and the short fibres present if any in the recovered material are separated and removed, leaving only the fibres of acceptable length to be processed.
[0028] From the bottom of the filters 50 which equip the winding stations, the accumulated material is periodically emptied, respectively by ducts 53, intercepted by a gate valve 54, which join a common emptying collector 70. On the opposite upper side, the filters 50 are fitted with a pressure relief valve 57, which is opened for the emptying operations of the material accumulated in the filters 50. The opening of such pressure relief valves 57 preferably isolates the filter 50 from its aspirator 22.
[0029] Figure 3 shows the collection system of winding waste in its entirety. All the individual output ducts 53 of the winding units 23 are connected to a common collector 70, which collects all the material separated in the respective filters 50. The presence of the respective filters is not obliged: therefore the winding units 23 can be directly connected to said common collector or common duct 70.
[0030] The feeding bobbing preparation devices 63 shown here only schematically may advantageously be connected to the collector 70. Such devices generate a significant quantity of residues of bits of yarn, aspirated by an individual aspirator 64, deposited in mesh filters 65 and emptied by a duct 68, with a system provided with drain valves 66 and pressure relief valves 67 entirely analogous to that of the filters 50 of the winding unit according to figure 1.
[0031] All the filters 50 and 65 are connected with the collector 70 to a collective collection system of their waste, consisting of a duct of a small size which is positioned along the machine and which receives the flow from all the winding units 23 and, preferably, also from the feeding bobbing preparation devices 63. The collector 70 is served by a high depression aspirator 71, which periodically empties the material of the filters with pneumatic transport to a general filter 80 which is described in more detail in figures 4 and 5. To prevent blockages, the transport speed in the duct 70 is kept at a speed of around 20 m/sec.
[0032] The need to empty the material retained by the filters is extremely variable, depending on the yarns processed in the winding machine. Generally speaking, the greatest emptying frequency is required by the feeding bobbing preparation devices 63 which require cleaning of the filters 65 as often as every 10-20 minutes, to the order of magnitude of several hundred feeding bobbing prepared.
[0033] The filters 50 equipping the winding stations 23 require, instead, generally speaking, cleaning at intervals to the order of an hour, in the case of filters with a single, fine mesh filtering septum which retains all the material: both the dust and the pieces of yarn. In the case in which the filters 50 are made with a double filtering chamber in series, such cleaning frequency is reduced increasing the intervals between one cycle and the other by about 40-50%, unless processing very hairy yarns.
[0034] Such cleaning is performed for a few winding stations at a time and preferably for one filter 50 at a time, while the winding unit 23 is on. The operation takes a few seconds and is performed, for the winding units 23, by first opening the pressure relief valves 57, preferably isolating the filter 50 from the aspirator 22, closing the valves 31, 35 towards the winding unit 23 and then opening the drain valve 54 on the duct 53, with the aspirator 71 on. Cleaning of the filter is thus prevented from affecting winding during its normal running. The suction with the aspirator 71 attracts air from the pressure relief valves 57 and empties the filters 50 of the accumulated material, taking it to the general filter 80 by means of the collector 70.
[0035] According to the invention the general filter 80 is made with classification of the material in a multi-cyclone system.
[0036] In particular as shown in more detail in figure 4 as an overall diagram, such multi-cyclone system comprises a double cyclone device 81 separating the dust from the pieces of yarn and a mono cyclone device 91 processing the current coming out of the double cyclone 81 to remove the dust.
[0038] With reference to figures 4 and 5, the double cyclone 81 upstream and the mono cyclone 91 downstream are placed in depression with the aspirator 71.
[0039] The double cyclone device 81 comprises an annular central portion 84 and two cone or frustum-conical portions 82A, 82B positioned above and below the annular portion 84.
[0040] As will be described in more detail below, in the cone portion 82A positioned under the central annular portion 84 the pieces of yarn is are given a downward cyclonic movement while in the cone portion 82B positioned above the central annular portion 84 the dust is given an upward cyclonic movement, thereby de facto dividing the dust from the pieces of yarn.
[0041] The double cyclone device 81 is fed by the duct 70 with a current of aspirated air containing both pieces of yarn and other impurities coming from the filters 50 and 65 which are successively cleaned, opening their pressure relief valves 57 and 67 and their gate valves 54 and 66.
[0042] The current to be filtered is introduced discontinuously into the double cyclone device 81 in the lower cone portion 82A immediately below the central annular portion 84.
[0043] In particular the duct 70 feeds the current to be filtered into the double cyclone device 81 with a tangential direction, generating a descending spiral movement by effect of the gravity towards the lower cone portion 82A.
[0045] As already said above the cleaning operation of the filters is performed for one or more filters at a time. The arrival of the material to be classified is thus discontinuous and pulsating.
[0046] By effect of the centrifugal force, the pieces of yarn and larger sized particulate, on account of its greater inertia compared to the dust, comes into contact with the inner conical walls of the lower cone portion 82A.
[0047] After hitting against the walls the pieces of yarn slows down its cyclonic movement and by effect of the gravity slides down and accumulates on the bottom of the lower cone 82A, which thus acts as a conical hopper, from which it is periodically emptied with the gate valve 83.
[0049] As a result of the pressure difference between the tangential entrance aperture 85 and the upper exit aperture 86, the dust, much lighter than the pieces of yarn, inverts its direction of movement and rises up again with an ascending spiral movement along the upper cone 82B as far as the exit aperture 86 in axis with the cyclone 81 as far as the duct 87.
[0050] The cone shape of the upper portion 82B has the dual technical effect of helping to create an ascending vortex responsible for capturing the dust and, once created, stabilising said vortex.
[0051] In fact dust particles rising with a spiral movement with directrixes not perfectly aligned with the exit duct 86 are channelled towards said exit 86.
[0052] However it may still happen that the undesired downward movement of the dust occurs where the dust pollutants have a high molecular cohesive force, or where there has not been a complete separation of the inverse coaxial inner vortexes.
[0053] Moreover such undesired downward movement of the dust occurs when vortexes are created with an axis misaligned with the main exit axis.
[0054] Obviously, even in the case in which intensity and turbulence of the vortex decrease, there may be a return downward of the dust gas.
[0055] Bearing in mind the pulsating and discontinuous feeding of the material to be separated and classified the formation of the cyclonic vortexes is not immediate and may take a certain amount of time to stabilise and function correctly.
[0056] In order to prevent such undesired downward movements of the dust portion towards the lower cone portion 82A and to achieve the rapid formation of a stable vortex, according to the present invention the upper cone portion 82B immediately above the annular portion 84 comprises primary nozzles 88 for the input of flows of compressed air into the double cyclone 81.
[0057] By way of example the supply pressure of the compressed air nozzle is 4 - 6 bar and has a flow rate for each separation cycle of approximately 250 Nl.
[0058] Such nozzles 88, also defined as over feeders, feed compressed air in tangential motion into the upper cone portion 82B, so as to trigger, feed and generate new vortex flows of a tangential turbulent nature, during the functioning cycle.
[0059] Such over feeding of a vortex nature increases the vortex movement generated by the duct 70 optimising the separation of the pieces of yarn, pushed with more force towards the inner walls of the lower cone portion 82A, and of the dust, separated further from the pieces of yarn as a result of the turbulence. Once the cyclone has been correctly formed the input of air from the nozzles 88 may even be suspended.
[0060] Lastly, the upper cone portion 82B next to the exit 86 comprises a compressed exhaust air diffuser 104 of the double cyclone 81.
[0061] Such diffuser 104 is operated only at the end of the processing cycle to facilitate the emptying by pneumatic thrust of the pieces of yarn from the hopper.
[0062] As shown in Figure 5, the flow from the duct 87 is into the mono cyclone device 91, in particular into its lower conical part 92 and with a direction tangential to the aperture 94. In the same way as described above, here too a downward spiral movement is generated. As a result of the centrifugal force, the medium size particulate leaves the flow, comes into contact and slows down against the inner conical walls of the cyclone as a result of inertia: by effect of the gravity the medium particulate slides down and accumulates on the bottom of the conical hopper 92, from which it is periodically emptied with the gate valve 95. Here too, the flow of air containing the finer particulate inverts its direction of movement and rises upwards in a spiral movement to the upper part 93 of the cyclone 91. Such upper part 93 is a cylindrical shape and, in its central part, is occupied by a filtering cartridge 96, which intercepts the upward flow and removes and retains the residual particulate.
[0063] According to another embodiment, the filtering cartridge 96 is removed and the filtering chamber is fitted with a coarse mesh filtering septum 51 which retains the "pieces of yarn".
[0064] The hole size of the filtering cartridge is to the order of 15 µm. Such filtering cartridge is preferably cylindrical, aligned in common with the cyclone 91, provided with a blind bottom and upper blind crown, so as to force the air flow to pass over its cylindrical filtering surface, with the flows indicated by the arrows, and then to come out of the upper opening 100 towards the aspirator 71 and empty into the atmosphere.
[0065] A compressed air diffuser for washing the cartridge, connected to the service compressed air, may be placed above the cartridge 96.
[0066] During the cleaning operations of the individual filters 50 and 65 of the winding machine the pressure drop, namely the differential pressure upstream and downstream of the cartridge 96 is constantly controlled, for example with a differential pressure gauge. When such measure arrives at a predefined value at the end of the cleaning cycle the aspirator 71 is stopped and its output is closed. The cartridge 96 is then cleaned, simultaneously opening the solenoid valve and the gate valve 95 of the hopper 92 and injecting compressed air with the diffuser. This way a reverse washing from the inside to the outside is performed which frees the particulate from the outer surface of the cartridge 96.
[0067] The individual filters 50 are cleaned one at a time by opening in succession their valves 54 and respective pressure relief valves 57. For the filters 65 of the preparation devices 63 the procedure is exactly the same. With the aspirator 71 a suction depression of 10-13 kPa or 1000-1300 mm of water column is exerted, such depression values refer to the depression exerted in the filters 50 and 65 to be cleaned, while the depression values in the parts downstream are affected by the pressure drop of the overall circuit.
[0068] The device according to the present invention for separating the dust from the pieces of yarn for the collection and recovery of the waste produced during winding processing proves an alternative and particularly functional solution compared to the known devices provided for such purpose.
[0069] The device according to the present invention is self-cleaning and, therefore, it is not necessary to switch off the device during its cleaning, on the contrary of known prior art devices, both for the relative loss of pressure, and for the depression exerted on the head door. In this way the device according to the present invention is self-cleaning and, therefore, it is not necessary, to switch off the device during its cleaning, just like it happens in prior art devices both for pressure losses, due to filter obstruction, and for the depression exerted on the head door. In this way, the productivity is increased because the filter never obstructs and, therefore, there is no loss of pressure.
[0070] Moreover, the filtering device according to the invention, can be easily modified and applied to prior art winding machines.
[0071] Moreover, the filtering device of the present invention can be easily positioned outside the room containing the winding machine, thus reducing the overall dimension of the winding machine itself.
[0072] Moreover, the filtering device of the present invention does not require additional equipment, just like aerial or underground canalizations provided in prior art winding machines.
[0073] Moreover, the filtering device, in order to correctly work, needs a flow of about 100/125 mc/h (cubic meters per hour) wherein such flow is reintroduced into the environment of the winding machine without being subjected to relevant changes of temperature and/or humidity.
[0074] On the contrary, in prior art winding machines the flows are about 3500/4000 mc/h (cubic meters per hour), wherein such flows are channelled by means of canalizations and then expelled outside the room containing the winding machine; therefore, in order to grant the correct environment conditions in terms of both temperature and humidity for the winding operations, such flows have to be conditioned. The conditioning, i.e. warming and/or cooling and/or filtering, requires a relevant consumption of energy.
1. A winding machine of the type comprising a plurality of winding units (23) and at
least one aspirator (22) able to intake impurities and hair of the yarn, that is the
dusts, or pieces of yarn deriving from the restoration and junction interventions
of the yarn, said at least one aspirator (22) being connected through a common duct
(70) to a common multi-cyclone type general filter (80) for collecting the winding
waste, comprising in series and in depression with an aspirator (71), a double cyclone
device (81) for separating the pieces of yarn from the dusts and a filter device of
said dusts exiting from said double cyclone device, characterized in that said double cyclone device (81) comprises an annular central portion (84) and two
frustum-conical portions (82A, 82B) respectively lower and upper arranged at the opposite
sides of said annular portion (84) for generating two cyclones respectively of the
pieces of yarn and of the dusts and for conveying the same from said central portion
(84) to the reduced-diameter mouths (86, 89) of said two frustum-conical portions
{82A, 82B), wherein said double cyclone device comprises primary nozzles (88) for
injecting tangential flows of compressed air into said double cyclone device (81).
2. The winding machine according to claim 1, wherein in that said common duct (70) introduces
said residuals into said separating double cyclone device (81) having a tangential
motion at said lower frustum-conical portion (82A).
3. The winding machine according to any preceding claims, wherein the outlet separation
of said duct (70) into said separating double cyclone device (81) has a circular section.
4. The winding machine according to any of the preceding claims, wherein said primary
nozzles (88) inject tangential flows of compressed air at said upper frustum-conical
portion (82B).
5. The winding machine according to any of preceding claims, wherein it comprises a diffuser
for injecting exhaust compressed air (104) into said double cyclone device (81) at
said upper frustum-conical portion (82B) close to said outlet mouth (86).
6. The winding machine according to any of preceding claims, wherein each one of said
winding units (23) comprises at least one aspirator (22), and all of said aspirators
are connected, through the common duct (70), to said common multi-cyclone type general
filter (80) for collecting the winding waste.
7. The winding machine according to any of preceding claims, wherein each one of said
winding units (23) is served by an aspirator (22) which alternately provides a low
depression continuous suction while the winding is functioning, for the removal service
of the impurities and hair of the yarn, that is the dusts, or a high depression discontinuous
suction for eliminating the pieces of yarn deriving from the restoration and junction
interventions of the yarn while the winding is interrupted.
8. The winding machine according to any of preceding claims, wherein each one of said
individual aspirators (22) is equipped with a filter (50), all said filters being
connected through the common duct (70) to said common multi-cyclone type general filter
(80) for collecting the winding waste.
9. A double cyclone device (81) supplied, with a pulsating or a discontinuous feeding,
by winding waste, for separating the dusts from the pieces of yarn comprising an annular
central portion (84) and two frustum-conical portions (82A, 82B) respectively lower
and upper arranged at the opposite sides of said annular portion (84) for favouring
the generation of two cyclones respectively of the pieces of yarn and of the dusts
and for conveying the same from said central portion (84) to the reduced-diameter
mouths (86, 89) of said two frustum-conical portions (82A, 82B), wherein the double
cyclone device (81) comprises primary nozzles (88) for injecting tangential flows
of compressed air into said double cyclone (81).
10. The double cyclone device (81) according to claim 9, wherein said primary nozzles
(88) inject tangential flows of compressed air at said upper frustum-conical portion
(82B).
11. The double cyclone device (81) according to claim 9 or 10, wherein it comprises a
diffuser for injecting exhaust compressed air (104) into the double cyclone (81) at
said upper frustum-conical portion (82B) close to said outlet mouth (86).