Title: "Textile treatment plant with modular structure and control process for such plant"

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The present invention relates to a textile treat- ment plant with modular structure and control process for such plant.

In particular, the present invention refers to treatment plants in which textiles in the form of yarns, staples or the like to be treated with batch dyeing processes are dyed.

A known type of textile treatment plant is generally represented by a treatment vessel in which the material to be treated is contained.

To the treatment vessel are also associated heat- ing means, for instance an electric or steam coil or other suitable means; and such plants also provide a process fluid circulation circuit supplied by a circulation pump.

In some cases, a secondary circulation is pro- vided connected to an expansion tank, in order to al- low process fluid expansion.

The textile treatment occurs by holding the material wrapped on a suited support into the bath in the treatment vessel, which vessel is normally at high temperatures and pressures higher than atmospheric

pressure (overheated water) and circulating the bath

trough the material .

However, it is known that in most cases the lot sizes of material to be dyed tends to be highly vari- able, particularly, but not exclusively, in the production range from 10 to 500 kg.

For this reason, there is an increasing demand for air pressurized machines able to dye variable lots thanks to the possibility to be used partially

charged by reducing the bath level .

However, such solutions are not completely satisfying since they reduce the production efficiency of the machine, defined as the ratio between the nominal load capacity of the machine and the effective use thereof.

In this context it becomes necessary to have a greater number of dyeing devices (with their costs and plant complexity drawbacks) to reach production

targets . Another possibility is to circulate the same bath trough multiple machines in a "coupled" way increasing or decrasing the number of connected machines according to production needs .

In particular, in the prior art, solutions are known where up to 4 machines are coupled even though

only a limited set of coupling arrangements is possible, thus limiting the flexibility and versatility of the plant.

Moreover, in such prior art plants, the control system is conceived in a master-slave mode, such that

the variable controls (temperature, flow rate, ecc.) related to each treatment kier are based on the changes of such variables in a master kier. This control logic does not consider the variations of the properties of the circulating bath due to asymmetric behavior of the circuits. This includes, for instance different hydrodynamic properties (e.g. conduit and charge loss arrangements) and different thermal behaviors (e.g. different dissipations). The object of the present invention is therefore to meet said requirements by means of a modular textile treatment plant that can be used always at a high production efficiency level, maximizing the ratio between the nominal load capacity and the effec- tive use thereof.

Other objects of the invention are the possibil¬

ity to expand a plant proportionally to production increases and to control the use every module or module assembly to perform different processing pro- grams , according to production demands .

Such objects are reached by a modular textile treatment plant. The invention has also as an object a procedure for controlling such a textile treatment

plant . The invention is also described in the annexed claims to which reference is made.

The invention is hereafter described in detail, in an exemplary and not limiting way, with reference to the attached drawings, in which: - figure 1 shows a diagram of a modular textile treatment plant according to the present invention;

- figure 2 shows a diagram of the plant according to the invention from figure 1 , in which the modules being part of the plant and having an odd subscript are represented as reflections on the vertical axis, in such a way as to avoid superimposition of circuit legs and to ease understanding; and

- figure 3 shows the diagram of a generic module of the invention treatment plant, the relevant ele- ments of said module being indicated in the figure by means of symbols more suitable to show the control logic of the system.

First referring to figure 1, the invention treat¬

ment plant will be now described, which plant has a modular structure formed by an assembly of modules,

all identical, which can be mutually connected by means of a suitable piping set and valve system which will be described more in detail later.

Figure 1 shows schematically the basic elements of the invention forming the single modules, with a specific reference to an exemplary arrangement having 6 modules, indicated by the numeric references 1, 2, 3, 4, 5 and 6, respectively.

However, in order to better describe the complex- ity of the circuit connections, reference will be made to figure 2, in which, for instance, the module indicated as a whole with numerical reference 1 provides a treatment vessel 1.4, in which the material to be treated is contained, and a process fluid cir- culation circuit 1.1 generated by a circulation pump 1.2, which pump is used to convey the process fluid to the vessel 1.4 through the pipe 1.3.

The process fluid flowing out from the treatment vessel 1.4 is conveyed through the pipe 1.5 to a tem- perature adjustment actuator 1.6 (typically, but not necessarily, a shell and tube heat exchanger) .

In case of a single module, the process fluid is conveyed back to the circulation pump 1.2 by means of a single pipe.

However, in case module 1 is placed side by side

with and connected to a corresponding module, three pipe legs are provided, that are 1.7, 1.7 ' and 1.7 ^{1 1} .

In particular, leg 1.7 connects the heat exchange element 1.6 to a first three-way valve 1.8, leg 1.7' connects said three-way valve 1.8 to a second three- way valve 1.8', and leg 1.7 ' ' connects the three-way valve 1.8' to the pump 1.2 thus completing the circulation circuit 1.1.

From module 1, two legs A and B of the circuit branch, connecting module 1 to the next module 2. In particular, leg A ends with a three-way valve 2.8, and leg B ends with three-way valve 2.8', said valves being associated to module 2.

The assembly comprising valves 1.8, 1.8', 2.8, 2.8' and legs A and B forms the coupling assembly between module 1 and module 2.

In its turn, module 2 provides a treatment vessel 2.4 in which the material to be treated is contained, and a process fluid circulation circuit 2.1 generated by a circulation pump 2.2, which pump is used to convey the process fluid to the vessel 2.4 through a pipe divided into three legs 2.3, 2.3' and 2.3'', respectively, by three-way valves 2.9, 2.9' from which two pipes C and D branch, connecting module 2 to the next module 3.

In particular, leg C ends with a three-way valve

3.9' and leg D ends with a three-way valve 3.9, said valves being associated to module 3.

The assembly comprising valves 2.9, 2.9', 3.9, 3.9', and legs C and D forms the coupling assembly between modules 2 and 3.

The process fluid flowing out from the treatment vessel 2.4 is conveyed through pipe 2.5 to a temperature adjusting actuator 2.6 (typically, but not nec- essarily, a shell and tube heat exchanger) .

Module 2 also provides three pipe legs 2.7, 2.7' and 2.7' ', where in particular leg 2.7 connects the heat exchanging element 2.6 to the three-way valve 2.8, leg 2.7' connects said three-way valve 2.8 to the second three-way valve 2.8', and leg 2.7' ' connects the three-way valve 2.8' to pump 2.2.

In brief, module 3 is basically identical to module 1 and provides a treatment vessel 3.4, in which the material to be treated is contained, and a proc- ess fluid circulation circuit 3.1, which circuit is supplied by a circulation pump 3.2 used to convey the process fluid to the vessel 3.4 through a pipe divided into three legs 3.3, 3.3' and 3.3'', respectively, by three-way valves 3.9' and 3.9. The process fluid flowing out from the treatment

vessel is conveyed through pipe 3.5 to a temperature adjusting actuator 3.6 (typically, but not necessarily, a shell and tube heat exchanger) .

Module 3 also provides three pipe legs 3.7, 3.7' and 3.7'', where in particular leg 3.7 connects the heat exchanging element 3.6 to the three-way valve

3.8, leg 3.7' connects said three-way valve 3.8 to the second three-way valve 3.8', and leg 3.7' ' connects the three-way valve 3.8' to pump 3.2, respec- tively.

From the three-way valves 3.8' and 3.8, at last, two pipes E and F branch, connecting module 3 to next module 4, and contributing to form the coupling assembly between modules 3 and 4. The above described arrangement shows how each successive module can be connected to the preceding one.

All the connections above have been described in mere exemplary form, with reference to three-way valves .

Such connections can alternatively be performed by suitably positioning two-way valves, in case for costs or practical reasons two-way valves are preferred to three-way valves . Each module provides a certain number of sensors

Sl...Sn, and actuators Al...An, each acting on the physical quantity measured by the corresponding sensor (for instance, but not in a limiting way, differential pressure, flow rate, temperature, levels) . The above-said coupling assemblies provided with valves allow, by opening or closing the valves, to define separated plant sections, which can be dedicated each to the processing of a different dyeing lot.

For instance, by closing valves 2.3' and 2.3' ', the plant of figures 1-2 can be divided in two separated sections, the former comprising modules 1-2 and the latter comprising modules 3-4, so that each section can be dedicated to the processing of a differ- ent dyeing lot.

Figure 3 shows the generic module "i" belonging to the treatment plant of the invention, the relevant elements of the module having been indicated in said figure by means of symbols allowing to better show the system control logic.

In particular E(i) and I(i) indicate the module

coupling assemblies (tubes and valves) which hydrau- lically connect the i-th module to the next modules in the following way:

If i=2n+l (odd), assembly E(i) is connected to

E(i+1), and I(i) is connected to I(i-l);

If i=2n (even), assembly E(i) is connected to E(i-l), and I(i) is connected to I(i+1).

Of course, the starting module to which following modules are connected can be identified by i=l, or in an alternative embodiment of the invention the starting module can be identified by i=0.

As an example, in the figure, the sensors are indicated by Sl, S2 and S3, respectively referring to differential pressure, flow rate and temperature sensors, and Al, A2 and A3 indicate the actuators acting on the values measured by the corresponding sensor.

The modular structure of the plant according to the present invention is designed to independently process different dyeing lots, even in view of the fact that in a single dyeing lot, which as said above can involve several coupled machines, the required process conditions (for instance: flow rate, temperature) must be maintained as uniform as possible dur- ing the process, as if the assembly of coupled modules was functioning as a single module, so as to avoid, among other things, non uniform dyeing re¬

sults .

In order to do so, the action of actuators must be adjusted as a function of the values measured by

the sensors, and in particular it must be determined the number of actuator and the module containing the actuator that must retroact on specific sensors.

It is clear that, in case of a single module functioning without being connected to others, each sensor Sn will read the corresponding physical quan¬

tity as it is determined by the action of the actuator An, thus showing that a solution to the control problem is already known. This preamble allows to show that the present invention has also as an object a control process for a textile treatment plant.

In order to understand the control process operation logic of the present invention, define d(t) as the "distance" between the actuator At and the sensor St into a single module, that is the number of coupling assemblies that need to be passed through to reach the sensor from the actuator (processing fluid circulation). In figure 2, such circulating direction is indicated as clockwise.

Considering as an example figure 2, d(l) = 1; d(3) = 2.

According to the present invention, is thus provided a control procedure whose function is to con- trol the plant operation parameters into the plant

itself or suitable sections thereof dedicated to different dyeing lots .

The process control acts on the actuators into the several modules in reply to the following: which actuator At of module "c" must be acted upon, considering that said actuator manages the quantities measured by the sensor St in module "i" to be controlled, when the assembly of connected modules, coupled to form a specific plant section, comprises the modules from "j" to "k"?

In the procedure of the present invention, module "c" is determined as follows:

The invention procedure will thus perform a control loop to control each actuator of the modules involved in a single dyeing program, optionally acting on an actuator the does not belong to the same module containing the sensor measuring the corresponding quantity to be controlled. The module "c" which must be acted upon is therefore determined by the control logic indicated by the above eq. (1) .

Example 1

Assume a six modules plant and a process with a dyeing lot involving only modules 2 to 5 (j = 2 and k

= 5) . In other words, modules 2 to 5 are used for a single color by closing the end valves connecting

said modules to the contiguous modules .

As we need to control the value of the physical quantity measured by S3 in module 4 (i = 4) , a corresponding actuator A3 will be acted upon, which is lo- cated in a module "c" determined according to the invention.

For A3 and S3 whe have d(3) = 2 and C is determined as follows: C = 4 + (-l) ^λ 4 * 2 = 4 + 2 = 6.

Therefore, c' > k is the case. By applying the formula 2k - c' + 1, we obtain 2 * 5 - 6 + 1 = 10 - 6 + 1 = 5.

Concluding, it will be the actuator A3 of module 5 to act on the quantities measured by the sensor S3 within module 4. In the procedure of the invention, such calculations are repeated at suited time slots for all modules and all sensors in order to determine the corre¬

sponding actuators on which to act each time.

The present invention provides the following im-

portant benefits:

First of all, it allows to expand a plant proportionally to production increases, since it allows to use identical modules which can be coupled in a potentially unlimited way, even in subsequent time steps.

Moreover, the invention allows to have a plant in which a dyeing machine performs a treatment program independently from other machines .

The invention also allows to treat different lots at the same time and asynchronousIy according to production requirements based on customer demands .

Differently from solutions of the prior art, the invention allows to have coupling circuits with the same length, thus providing a more uniform process- ing.

A further example, which is not limiting at all with regard to the invention potential, is now provided with the sole aim to point out the invention adaptability. Example 2

This example is based on the hypothesis of a plant formed by 4 dyeing modules, with a capacity of

40 kg each. According to the present invention, such plant can be configured to function as : - a single 160 kg machine dyeing with a single

color (all modules are connected) ;

- a 40 kg machine dyeing with a color + a 120 kg machine dyeing with a second color (modules 1 to 3 are connected and module 4 works independently, or modules 2 to 4 are connected and module 1 works inde¬

pendently) ;

- two 80 kg machines dyeing independently with two different colors (modules 1 and 2 are connected each other, as well as modules 3 and 4) ; - two 40 kg machines dyeing with two different colors + a 80 kg machine dyeing with a third different color (1 and 2 coupled, with 3 and 4 being independent, or 2 and 3 coupled, with 1 and 4 being independent, or 3 and 4 coupled, with 1 and 2 being inde- pendent) ;

- four machines, 40 kg each, dyeing independently with four different colors (all four modules disconnected) .

The arrangements indicated in the above example are clearly only some of all possible configurations.

A further benefit of the present invention is

that by using a repeated module, the production and certification operations are simplified, different certifications not being needed for each treatment vessel, with consequent savings for producers.

From the above, it is clear that the inventive concepts described are not limited to the application examples shown, but they can be beneficially adapted to other similar applications.

The usage field of the invention is not limited to the examples shown in the above description.

The present invention is therefore subjected to many changes and modifications, all included in the inventive concepts defined in the attached claims, while technical details can change as necessary.

All measures and values of parameters and physical quantities cited are to be considered as merely exemplary and not limiting in any way the invention features .