This application claims priority from German Patent Application No. 10 2004 030 967.1 dated Jun. 26, 2004, the entire disclosure of which is incorporated herein by reference.
The invention relates to an apparatus for measuring the mass of fibre material passing through a spinning preparation machine or system or through a nonwoven production device.
In a known apparatus (WO 00/12974), a carding machine is provided wherein unprocessed crude fibre material enters the carding machine at a slow speed and carded fibre material in the form of a fibre sliver or fibre web leaves the carding machine at a high speed. The carded fibre material passes through a microwave resonator, which is arranged at the exit from the carding machine and which measures the mass (density) of the fibre material. That measurement value is suitable for fine regulation of the carded fibre material, which forms an intermediate product. Furthermore, at the entrance to the carding machine there is optionally provided a measuring device for the moisture content of the unprocessed crude fibre material; this is intended to allow rough regulation. A substantial disadvantage is that rough regulation does not allow precise and uniform flows of fibre material to be accomplished in the cleaning system upstream of the carding machine. For example, the production of fibre blends having exact proportions of different fibre components is not possible using the known apparatus.
It is an aim of the invention to provide an apparatus of the kind described at the beginning that avoids or mitigates the mentioned disadvantages and, especially, that makes it possible to improve measurement of the mass of fibre material in a cleaning system, especially between a bale opener and carding machine, and to use that measurement for closed-loop and/or open-loop control.
The invention provides an apparatus for determining the mass of textile fibre material in the form of fibre flocks, comprising:
a measurement pathway for the fibre flocks; and
a measuring device comprising at least one microwave resonator for monitoring flocks in the measurement pathway.
The measures according to the invention make it possible to accomplish precise and uniform flows of fibre material in a cleaning machine or cleaning system. The measurement of the mass of the fibre flocks, especially with compensation for the moisture content, can be used for open-loop and/or closed-loop control. It is possible, especially, for relatively large to large amounts of fibre material, as are processed in a cleaning system, to be measured precisely. Furthermore, the invention makes it possible for fibre material to be dispensed in exact amounts. A particular advantage is that the apparatus according to the invention makes it possible, by simple means, for the fibre mass of different fibre components to be ascertained in non-contacting manner, as a result of which fibre blends of exact proportions, for example 60% cotton and 40% polyester, can be produced.
Advantageously, the moisture content of the fibre flocks can be measured. Advantageously, it is possible to compensate for the moisture content when measuring the mass of the fibre flocks. Advantageously, the measurement value of the mass of the fibre flocks is used for open-loop control of at least one spinning preparation machine. Advantageously, the measurement value of the mass of the fibre flocks is used for closed-loop control of at least one spinning preparation machine. Advantageously, the measurement value of the mass of the fibre flocks is used for dispensing in metered amounts in the course of feeding a spinning preparation machine. Advantageously, the measurement value of the mass of the fibre flocks is used for feeding a conveying device, for example, a conveyor belt, chute or the like. Advantageously, the measurement value of the mass of the fibre flock is used for feeding a transporting device, for example, a pneumatic flock-transporting device, pipeline, shaft or the like. Advantageously, the measuring device is arranged at the exit from a hopper feeder. The hopper feeder may have a driven conveyor belt, for example, an ascending needled lattice. A driven stripping device, for example, a smoothing cylinder, may be associated with the conveyor belt of the hopper feeder. The speed of the inclined lattice of the hopper feeder may be adjustable. The speed of the stripper roller of the hopper feeder may be adjustable. The measuring device may be associated with a conveying device, for example, a conveyor belt, chute or the like. The measuring device may be arranged at the exit from a condenser. The measuring device may be associated with a flock charging shaft. The measuring device may be arranged downstream of at least one slow-speed take-off roller of the condenser and/or of the flock charging shaft. The speed of the at least one take-off roller of the flock charging shaft may be adjustable. Advantageously, the measuring device is arranged downstream of a high-speed opener roller. Advantageously, the opener roller is arranged downstream of the at least one take-off roller. Advantageously, a driven conveyor belt is arranged downstream of the hopper feeder. The speed of a conveyor belt arranged downstream of the at least one hopper feeder may be adjustable. Advantageously, a driven conveyor belt is arranged downstream of the flock charging shaft. The speed of the conveyor belt arranged downstream of the at least one flock charging shaft may be adjustable.
In one preferred embodiment, the fibre flocks pass through the microwave resonator in flight, for example, they may be carried through the resonator by a pneumatic transport system. In another preferred embodiment, the fibre flocks fall through the microwave resonator.
In the case of formation of a fibre blend, means for dispensing prespecifiable amounts of fibre flocks of different grades may be provided. Advantageously, the fibre flocks of the blend components are introduced into charging shafts of a mixing apparatus and are in each case deposited at the lower end of a charging shaft onto a conveyor belt (mixing belt) by at least one take-off roller. Advantageously, the conveyor belt (mixing belt) is arranged to be driven in variable manner.
Advantageously, the fibre mass is arranged to be measured continuously. Advantageously, the fibre feed is carried out continuously. For mixing, closed-loop volumetric flow control may be provided.
In one embodiment, the measurement value of the mass of the fibre flocks is used for open-loop control and/or closed-loop control of a cleaning system having at least two cleaning machines, preferably a plurality of cleaning machines.
In a second embodiment, the measurement value of the mass of the fibre flocks is used for open-loop control and/or closed-loop control of a carding system having at least one carding machine, preferably a plurality of carding machines.
In a third embodiment, the measurement value of the mass of the fibre flocks is used for determining the through-flow rate in a pipeline or the like for conveying fibre material. Conveying of the fibre flocks may be carried out pneumatically. The apparatus may be used for determining the through-flow rate in a pipeline or the like for fibre waste.
The measurement value of the mass of the fibre flock may be used for determining production in a flock charging shaft. The measurement value of the mass of the fibre flocks may be used for determining production in a flock mixer, for example, a multi-mixer. The measurement value of the mass of the fibre flocks may be used for determining production in a flock feeder, for example, having an upper reserve shaft and a lower feeding shaft. Mixing of the fibre material components may be carried out in the air flow.
The invention also provides an apparatus for measuring the mass of fibre material passing through a spinning preparation machine or system or through a nonwoven production device, wherein at least one microwave resonator and an associated measurement electronics unit matched thereto are provided, in which the fibre material is present in the form of fibre flocks and the fibre flocks pass through a measurement pathway having a measuring device having the at least one microwave resonator.
Moreover, the invention provides a method for measuring the mass of fibre material in flock form, comprising causing the fibre flocks to pass through a measurement zone and determining a parameter relating to mass of the fibre in the measurement zone by means of a measuring device comprising at least one microwave resonator.
The terms “measurement of the fibre mass”, “fibre flock mass” or the like also include the measurement of equivalent parameters such as, especially, the flock density, the flock weight and the like and also variations in those parameters.
a is a diagrammatic side view of a bale opener (hopper feeder) with a delivery conveyor belt, wherein a first embodiment of the invention is arranged downstream of the inclined lattice and stripping roller;
b shows a bale opener (hopper feeder) and delivery conveyor belt, wherein a second embodiment of the invention is associated with the delivery conveyor belt;
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The apparatus according to the invention comprises at least one microwave sensor 12, 12′, 12″, 121 to 126 for measuring a dielectric property, especially a property related to the mass of the fibre flocks, using a microwave resonator, the flocks 16, 19, 21, 25′, 25″, 33 introduced into the resonator interacting with a resonant microwave field produced in the resonator in order to ascertain suitable measurement parameters indicative of the mass of the fibre flocks.
A “resonator” refers to a spatial region in which a standing microwave field can propagate and can be an enclosed or substantially enclosed cavity resonator.
The fibre material whose density is measured is arranged in a spatial region 12a designated a “product space”, which in operation of the sensor 12, 12′, 12″, 121 to 126 is in a fixed spatial relationship with the spatial region of the resonator. The microwaves enter the product space in order to interact with the fibre material. The microwave resonator is permeable to the microwaves in the direction of the product space. The fibre material can be a continuous and/or unending product flow, for example fibre flocks in the form of a fibre/air flow 19, 21, 25′, 25″, 33 or in the form of a flock layer 16 in spinning preparation machines, especially cleaning machines.
Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.
Number | Date | Country | Kind |
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10 2004 030 967.1 | Jun 2004 | DE | national |