Patent Application
20060180182
In the wet processing of hank-formed textile goods on JET-Processing Machines, for instance, on JET-Piece Dyeing Machines, the textile goods are to be in circulation in the form of an endless fabric rope in a closed vessel by means of a transport (or conveyance) JET-System in the form of a JET-Nozzle, which is impinged to a conveyance current, which provides to the fabric rope its feed movement in the prescribed rotation context. The transport medium, in this context, in most machines, is a processing bath or liquor to which additives can be mixed depending upon the process-specific parameters and which can be brought to different temperatures during the course of the process.
In each of such wet finishing processes, flushing operations are necessary, in which substances, which have an affinity to the textile goods or get attached to their surfaces are found, and must be flushed out, after they have been subjected to preparatory processes such as desizing or scouring, bleaching, washing, saponification etc., and are brought, to start with or simultaneously to the flushing operations in solution, emulsion or dispersion. For the purpose of flushing textile products, which, if minutely examined, is a thinning process in the course of which the concentration of the flushed out dirt particles are sunk in the flushing liquid, three different process methods are adopted in the actual process. This is for example explained in Melliland Textileberichte 6/1997, Pages 428 to 433:
In respect of the so-called batch flushing, in the vessels a flushing liquid bath is filled, the fabric rope is set in motion and after a predetermined number of circulations of the fabric rope; the detergent bath is again discharged. Thereby a mixture of the dirt-loaded processing liquor on the product with the flushing liquid in the flushing bath. After repetition of a few baths, the desired flushing result is obtained.
Under a different process method the flushing takes place between two different levels of the scouring liquor in the vessel. In this method, the circulation movement of the fabric rope during the flushing operation is not interrupted through a filling and discharging operation of the finishing/processing liquor. Instead, the rinsing/flushing liquid is circulated through a circulation pump, generally the floatation pump, during the processing period, whereby, using corresponding control of the flushing liquid inflow in the vessel and of the flushing liquids discharge from the vessel, a flushing liquid level is maintained in the vessel, which oscillates or fluctuates between an upper and a lower level (the minimum level for a perfect operation of the circulation pump). The success of the flushing can be determined similar to the case of batch flushing, through ascertaining the dirt content of the discharged flushing liquid.
A third process is finally the flushing or rinsing with overflow. In this case, under a circulating fabric rope, the dirt-loaded processing liquor contained in the vessel is continuously added with scouring liquid, general water, while the excess processing bath, made thinner by the scouring liquid, is discharged continuously up to a certain level, which level is determined by means of an overflow tube. The success of the flushing is obtained in this case through a continuous thinning of the process bath; it can be ascertained through corresponding monitoring of the processing bath, made increasingly thinner, that gushes out through the overflow pipe.
Of these process methods for flushing, the batch flushing and the flushing between two different levels are the most efficient in the context of the scouring liquid consumption; that means generally water consumption. By the very principle the flushing liquid consumption under the overflow rinsing process is the maximum, with the result that this flushing or rinsing process is inefficient, in the context of flushing/scouring liquid consumption.
The water consumption of a dyeing machine, in many industrialized countries, is an important criterion for the economy of a wet finishing process. The flushing time required for achieving the respectively prescribed success rate for the rinsing, among others, however, also influences the economic viability. Comparatively, long flushing periods result in correspondingly long total processing time and thus limit the product throughput that can be realized on the machine.
For the reason that in a JET processing machine of this type also during the flushing operation, the drive of the endless product rope is achieved by the hydraulic path through the liquor current impinging on the nozzle, the processing liquor quantity necessary per time-unit, irrespective of the flushing processes adopted, heavily depends on the liquid quantity essential for driving the fabric rope. In other words, a significantly high quantity of flushing liquid, that means generally rinsing water, is needed simply for the purpose of driving the product flow. Of course attempts were already made to dispense with (compare Melliland Textileberichte, among others) the idea of driving the fabric rope through the liquor circulated by the circulation pump during the flushing operation, and to convey or move the product rope thereby that exclusively fresh rinsing water is fed as transport medium in to the jet nozzle, so as to achieve both the flushing as well as the material transport. However, such a process is uneconomical because of the high volume of rinsing water required, and the bad or inefficient replacement or exchange of the liquid between the fresh water streaming from the jet and the dirty water from the processing liquor brought along by the fabric rope.
The task of the invention is therefore to design a flushing or rinsing process for hank formed textile products on JET-Processing machines, which allows to keep the minimum the flushing liquid consumption to the minimum, that means generally the rinsing water consumption, and the time required for carrying out the flushing operation, and to dovetail or match them corresponding to the respectively applicable conditions and peculiarities in such a manner that the production cost for the entire wet finishing process requiring a flushing operation is minimized.
For solving this problem, reference is made to the characteristics of the Patent claim 1 of the Invention-related Process.
The invention proceeds from the knowledge that in jet processing machines based on aerodynamic principle the transport of the endless product flow is independent of the processing liquor, because the fabric flow takes place through the impingement of the Venturi-Nozzle with a gaseous transport medium, where applicable, supported by an externally driven roller, and therefore offer new possibilities for the flushing operation.
Under the new process for flushing or rinsing of hank-formed textile products, the procedure adopted, in accordance with the invention, is therefore the following: the textile product in the form of an endless fabric rope is set in motion by means of a Venturi-Nozzle in a closed vessel through a gaseous transport medium. The textile product is subjected to the effect of a flushing or scouring liquor/liquid in such a manner that the rinsing/flushing is undertaken with continuously flowing scouring liquor. In this context, the rinsing liquid application per time-unit is controlled optimally through and/or the speed of fabric rope movement, which depends on products-specific-data of the textile article, the machine-specific-data and the process-specific-data. The dirty rinsing liquid exiting from the nozzle is discharged from the vessel.
What it means practically is that for instance fresh rinsing water is brought on to the product from a water pipe, where applicable, through a pump and a heat exchanger in the course of the movement of the fabric rope before and/or in the nozzle and/or after the nozzle in the manner described. The exiting dirt particles-loaded rinsing water is discharged immediately thereafter. Thereby what is achieved, in comparison to the hydraulic JET-processing machine described earlier, is a relatively significantly lower rinsing water quantity requirement while simultaneously shortening the rinsing time.
Thus possibilities open up to optimize the flushing or rinsing water consumption per time unit as well as the rinsing time depending on the criteria described above. In an especially advantageous design of the new process this objective can be achieved in the following fashion: From product-specific data of the textile article, for example, weight, substrate and the making-up of the fabric rope, from design-dependent data of the nozzle such as jet diameter, jet length etc. and from specific data relating to the processing such as circulation speed of the fabric rope and such other factors, a computer model is evolved which images or simulates flushing or rinsing process and its success. The control of the throughput of the flushing liquid per unit through nozzle and the rope circulation speed is effected through a computer based on the prescribed computer model.
The computer model can be analyzed through the data obtained during the flushing operation. Apart from this, the computer model can be compared and calibrated through simple tests with data obtained in actual rinsing exercise.
In actual practice, the success of a flushing process is determined either with a colour appreciation or through simple tests carried out with hand. These tests could for instance be by twisting of a fabric rope and the capturing of the dripping water, for the purpose of determining residual colour fastness. Another possibility is for instance, the measurement of the pH value or the electric conductivity of the impure flushing liquid being drained. These tests are generally carried out directly on the machine, in which either the liquor is taken out or the machine is stopped. In the finished products after the wet processing, mostly consequential and standardized quality controls are carried out (friction fastness, wash-proof, perspiration fastness, etc.) which are known worldwide and results of which are comparable with each other.
The invention-related process under which a direct rinsing or flushing of the product with scouring liquor takes place, can now be so designed that the success of the rinsing operation can be continuously monitored online or in prescribed time intervals. The data so obtained for the respective success of the flushing can flow into the control and particularly in the computer model in order to modify the flushing operation automatically or to specify the end of the rinsing operation. The modification of the rinsing operation, for instance, can be done in such a manner that the application of the rinsing liquid on the rope is different, particularly higher at the beginning of the flushing operation, that means during the first rotation or circulation of the rope, than towards the end of the rinsing operation.
Because of the fact that under the new rinsing process a direct rinsing of the product takes place in the rinsing liquid flowing into the vessel, the dirt-load of the dirty rinsing liquid represents a measure or a yardstick of the rinsing effect achieved. For measuring this impurity extent, for instance, following sensors can be used:
The measurement of the dirt extent can be done in the rinsing water exiting from the vessel and/or directly on the fabric rope.
For determining the end of the rinsing time, among others, the following criteria, measured through among corresponding sensors and/or calculated through the computer, can be used.
The combination of theoretically calculated values and practically measured values in the computer model mentioned above enables a further optimization of the flushing operations. For instance, it is plausible that at the start of the flushing process where with higher flushing liquid quantities a more intensive dilution of the concentration reached, the rinsing or flushing time is optimized. Towards the end of the flushing process, if the concentration's differentials in the dirt containing outflow of the flushing liquid from the product (fabric rope) rotation to product rotation are not significantly large, it is of advantage to work with a lesser flushing liquid quantity, however with somewhat higher time allotted. The result is in any case a flushing operation, which is optimized both in respect of the required rinsing liquid quantity as well as with reference to the required rinsing time.
This optimization in vertical wet processing/finishing operation, that means in the dyeing units, is of great economic significance. For example, in certain industrial economies, the dyeing units work generally with relatively lesser production and higher water costs, while in other countries a higher production and a very low water costs are obtained. There are also regions in which the processed water is allocated to the dyeing units, and therefore production enhancement is only possible if with the allotted water remaining constant a higher production and thereby a higher income can be achieved.
The invention based process enables, with the knowledge of the data required for the flushing process, to optimize the flushing process. Particularly under application of the computer model, the control of the water consumption and/or the required production time itself can be calculated, depending upon the production conditions, such as price of water, magnitude of production and such similar parameters respectively applicable. The control system needs from the operator or the programmer of the wet processing/finishing machine only information whether the flushing process should be optimized in the context of the water consumption or with reference to the production time.
Further design versions of the invention-based process are the objects of the sub-claims. They emerge also from the following description of a design example of the invention-based process, which is elucidated here below on the basis of the following drawings.
The following are illustrated in the drawing:
The high temperature (HT) piece dyeing machine schematically illustrated in
The nozzle 6 is impinged to a gaseous transport medium current, which puts the fabric rope 4 in circulation, in the rotation context illustrated through arrow 10. The transport medium in the above case is air or steam-air compound, which is sucked through a blower 11 and a suction pipe 12 from the vessel 1 and is conveyed through a compression pipe 13 in the nozzle 6.
On the vessel 1 at the bottom, a focus pipe 14 is arranged which includes a liquor filter 15 and is connected with a suction pipe 16 of a liquor circulation pump 17, the compressed pipe 18 of which has a heat exchanger 19 and converges through a regulating valve 20 in the nozzle 6. The liquor circulation pump 17 enables to have the liquor sucked from the vessel 1 circulated through the nozzle 6 and the vessel 1. Parallel to the heat exchanger 19 and the liquor circulation pump a bye pass pipe 22 is provided, which includes a shut-off valve 23 and connects the focus pipe 14 with the compressed pipe 21. Additionally an dosing tank 24 is visualized which contains in watery solution, emulsions or dispersions a chemical additive material, which can be supplied through a dosing pump 25 and a jointing pipe 26 in the suction pipe 16 of the liquor circulation pump 17. The piece dyeing machine described hitherto, working in accordance with aerodynamic principle is perse known. If in the course of a processing operation it is necessary to rinse or flush the fabric rope 4, the process adopted is as follows:
A discharge valve 17 of the focus pipe 14 and an inlet valve 28 in the suction pipe 16 of the liquor circulation pump 17 are opened. Through the inlet valve 28 rinsing water gushes into the suction pipe 16, as denoted through an arrow 29. The incoming rinsing water can be added from the dosing tank 24, where applicable, with the additive, which simplifies or supports the flushing operation, and is brought to the heat exchanger 19 at a purpose specific rinsing temperature, before it enters the nozzle 6. The blower 11 is switched on and conveys the transport/conveying air stream circulating through the pipe 12, 13, the nozzle 6 and the vessel 1, which drives the fabric rope 4 in the direction of the rotation.
The rinsing water entering the nozzle 6 is brought to the product, which builds the fabric rope, in the nozzle 6. The fabric rope 4 pulled out by the roller 5 from the storage 8 is drenched at the entry in the nozzle 6 with the dirt particle-loaded liquor, which is brought to the nozzle 6 through the fabric rope. In the nozzle 6, there takes place a mixing of the dirt-loaded liquor, which lands into the nozzle through the fabric rope and the rinsing water quantity added through the injection using the compressed pipe 21. The dirty rinsing water exiting from the nozzle 6 is captured in the vessel 1, and is let out through the focus pipe 14 and the outlet valve 27, as denoted through the arrow 30. The suction pipe 15 is shut-off through a shut-off valve 31 against the suctions side of the liquor circulation pump 17.
With the increasing number in the circulation of the fabric rope 4, the dirty liquor contained in the fabric rope is diluted in an increasing measure through the rinsing water injected through the nozzle 6, till finally the respectively endeavoured flushing success is reached. The entry of this flushing success can be determined through sensor device 31 online, through which the dirty rinsing water gushing from the vessel 1 flows. The sensor device 32 monitored for instance the pH value, the electrical conductivity and the turbidity of the outgoing rinsing water and transmits electrical signals, which characterize and corresponds to these parameters, as data to a computer 33 of the control system.
If the flushing or rinsing effect is striven for is achieved, the addition is again stopped and the piece dyeing machine is made ready for the next following wet finishing/processing step. During the flushing operation, the fabric rope is driven through the air stream conveyed by the blower 11 independent of the rinsing water quantity injected. Through corresponding control of the blower 11, the rotation speed of the fabric rope 4 can be continuously altered, while the control valve 20 allows modifying the rinsing water quantity injected per time unit, with controls from a computer 33.
Alternatively the rotation speed of the fabric rope 4 can be altered also thereby that the computer 33 controls a butterfly valve 34 in the compressed pipe 13 in the downstream of the blower 11. The injected rinsing water quantity can also be modified through a control intervention on the circulation pump 17, as is denoted in
The quantity of the dirt particle-loaded liquor brought into the nozzle 6 with the fabric rope 4 depends primarily on factors such as weight, substrate and the making up of the fabric rope 4. From this a calculation is made how many litres of liquid can be absorbed by the fabric rope. The quantity of the actually consumed liquid, in relation to the weight of the fabric rope, results in the so-called “pick-up A”. Moreover it is dependent on the speed of the fabric rope 4, the dirt particles contained liquor quantity brought in the nozzle 6 with the fabric rope depends therefore directly on the rotation speed of the fabric rope. Building from this knowledge, it is possible to generate a computer model, which simulates the success of the flushing. This computer model can be compared and calibrated through tests with the practical conditions.
The dirt concentration is recorded in gram per litre in the dirt particles loaded rinsing water exiting from the focus pipe 14, depending upon the number of the circulation of the fabric rope 4. Both the curves show that the concentration during the first rotation of the fabric rope steeply falls down and, with increasing number of the rotation of the fabric rope approximates asymptotically a minimal residual value. There is a good agreement between calculation and actual measurement.
The reconciliation between calculation and actual measurement is apparently good. With a computer model so obtained, the parameters for the flushing process can be optimized in the simulation calculations. The result of these calculations is illustrated for a design example in FIGS. 3 to 5.
The design example, which forms the basis for FIGS. 3 to 5 is applicable for a cotton textile product with an average square meter weight of 250/m and with following parameters:
From this emerge the following values for flushing time in minute and flushing water consumption in litre per kilogram, which are illustrated graphically in the visuals of the
These values and the images according to
It can be seen from
The values given in Tables 1 and 2 show that through variation of the rinsing water quantity per time unit (injection quantity) and the speed of rotation of a product, as illustrated through the dark shaded fields of the table, for instance, a time saving by 75% can be achieved, while simultaneously the required rinsing water quantity increases only by 38%.
The illustrated design example shows that under lower rinsing water costs, at the cost of an enhanced flushing/rinsing water consumption, the product quantity produced and thereby the income can be significantly enhanced, because the rinsing time is shortened, while under high flushing water costs by extension of the flushing time and, necessitated by it, through application of additional machine capacity the expenditure could be significantly reduced.
In the above mentioned description, generally flushing/rinsing liquid A was spoken about, which in general is rinsing water, about which reference has already been made. Principally, however even other rinsing liquids, even those of organic type, can be used if it is of advantage in the context of the textile products to be flushed.
In the design example described as above, the rinsing liquid is ejected in nozzle 6 (
This is illustrated in
The pipe 34 need not necessarily converge in the area above the roller 5. Depending upon the respective peculiarities convergence of pipe 34 can happen somewhere between the roller and the annular gap of the Venturi-Nozzle 6. Besides this, even design forms can be thought of in which the convergence of the pipe 34 lies in the movement path of the fabric rope 4 (vertical), located between the storage 8 and roller 5, and the rinsing liquid is brought on the fabric rope 4 already before it reaches the roller 5. In
Moreover for application of the rinsing liquid on the fabrication rope 4, even a compressed pipe 36 can be visualized, converging in the product stream path at the rear of the nozzle 6, which for instance, branches from the compressed pipe 21 and includes a control valve 37, which is controlled by computer 33. In this manner, it is possible to apply rinsing liquid at the rear of the nozzle either alternatively or in addition on the fabric rope 4.
The dirt particles containing flushing liquid emerging from the fabric rope 4 is captured in the vessel 1 and is discharged through the sump and the outlet valve 27. Alternatively, the following method can also be adopted. In that dirt particles containing rinsing liquid are discharged from the vessel branch-wise, that means the rinsing liquid is captured in the vessel in order to be added later for a reuse. In conclusion it may be pointed out that the sensor device 32 for determining the achievement of the flushing success need not necessarily be located at the rear of the outlet valve 27, in order to monitor the exiting rinsing liquid mixed with dirt.
The measurement or determination of the data characterizing the extent of dirt can also take place directly on the fabric rope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 49 375.1-26 | Oct 2003 | DE | national |
