Apparatus with a firing device incorporated to dye fabrics

Abstract

 Dyeing apparatus (20) to dye fabrics (11) or any other surface of textile piece goods, which consists of a body (31) equipped with means (12-13-14) to circulate the fabrics within the body (31) and of means (17-18) to circulate a dyebath (15) within the body (31), the apparatus (20) incorporating a firing device (21) immersed in the flow of the dyebath (15) so as to heat the dyebath (15), the firing device (21) being equipped with its own independently fed (25-26) gas burner (22) and with its own discharge (29) for the products of combustion.

Description

[0001] This invention concerns an apparatus with a firing device incorporated to dye fabrics. To be more exact, the invention concerns a dyeing apparatus having its own independent energy supply and structurally compact which is able to obtain a very high energy efficiency and dyeing yield in general.

[0002] The apparatus of the invention is employed advantageously in dyeing processes that provide for the use of dyeing machines for fabrics, whether these machines treat goods in movement in a non-circulating bath or goods in movement in a circulating bath.

[0003] The state of the art covers a plurality of dyeing apparatuses of the type with which this invention is concerned. A plurality of units of such apparatuses is generally included in the dyehouse but all of them are never working at one and the same time.

[0004] However, they always have available the heat-carrying fluid, whether superheated water or steam, to heat the dyebath.

[0005] So as to provide this service without downtimes, the dyehouse is equipped with a great heating plant and a network, often very long, to distribute the heat-carrying fluid.

[0006] The above equipment entails a low overall heat efficiency of the dyehouse, normally of between 60% and 65%, together with the relative high costs arising therefrom.

[0007] Among the apparatuses normally employed in the dyeing of fabrics we must mention the well known Jigger and Foulard equipment in which the dyebath remains still, whereas the fabrics are circulated, normally several times, within the dyebath itself.

[0008] The category of apparatuses operating with circulation of the fabrics and of the dyebath includes the equally well known Jet equipment or nozzle-type dyeing machines and the Overflow equipment.

[0009] In Jet equipment the dyebath is injected against the fabric whereas with the Overflow system the fabric is carried by spontaneously/falling together with the current of the dyebath.

[0010] All the above apparatuses are equipped with devices, normally heat exchangers, suitable to achieve the required heat condition in the dyebath and generally in all the steps of the dyeing process.

[0011] For this purpose these apparatuses are linked, as we said earlier, to a central heating plant with the resulting limitations from the point of view of the yield of dyeing and the overall energy balance.

[0012] Attempts have been made in the dyeing of wound bodies with a view to providing embodiments in which a dyeing apparatus is installed in an independent circuit connected to a boiler providing direct heat of the dyebath.

[0013] Various plant lay-outs have been proposed but have not been applied in practice as they are industrially too bulky and very expensive.

[0014] The present applicants have set themselves the objective of providing a dyeing apparatus that overcomes the problems of the state of the art and can offer a compact structure which is independent from an energy point of view and makes possible modest dyebath liquor ratios and high yields of dyeing.

[0015] The invention is set forth in the main claim, while the dependent claims describe various features of the invention.

[0016] The apparatus of the invention comprises a system for direct heating of the dyebath with firing in the apparatus, that is to say, the heating device is wholly sunk in the means which has to be heated.

[0017] This apparatus containing its own firing means according to the invention may be a Jigger or Overflow apparatus or another suitable for dyeing purposes.

[0018] By modulating the quantity of the fuel mixture immitted into the combustion chamber it is possible to carry out the dyeing operation with various speeds of increase of the temperature of the dyebath.

[0019] The speed of increase of the temperature is selected by the dyer, depending on the type of material, type of dye and the results to be obtained.

[0020] The apparatus of the invention can also provide for a recovery of heat by means of the cooling of the fumes of combustion in the stack. This cooling can be performed by means of water, which can be used thereafter to fill the dyeing apparatus and therefore takes on a given value of temperature beforehand.

[0021] The heat efficiency found by the applicants with the apparatus of the invention is contained substantially within a range between 93% and 98% calculated on the net calorific value.

[0022] The overall efficiency may be even higher where the cooling of the fumes of combustion at the stack is used.

[0023] These and other special features of the invention will be made clearer in the description that follows.

[0024] The attached figures, which are given as a non-restrictive example, show the following:-

Fig.1

is a diagram of a known apparatus of the Overflow type to dye fabrics;

Fig.2

is a diagram of an apparatus of the Overflow type according to the invention to dye fabrics.

[0025] Fig.1 is a diagram of an apparatus 10 of the Overflow type to dye fabrics.

[0026] A fabric 11 to be dyed is made to circulate according to the arrow 12 within a body 31 of the apparatus 10, firstly in a conduit 13 and thereafter in a curved dyeing channel 14.

[0027] The fabric 11 slides straight and is immersed in a dyebath 15 in the conduit 13, whereas in the dyeing channel 14 the fabric 11 is folded and is carried forward instead by falling spontaneously together with the current of the dyebath 15.

[0028] Next, the dyebath 15 reaches a collection vessel 16 located in the lower part of the apparatus 10 and is taken thence, by a pump 17 for instance, and returned to the cycle by a feed line 18.

[0029] The required temperature conditions of the dyebath 15 on entering the apparatus 10 are re-established by circulating the dyebath 15 in a heat exchanger 19, in which there is circulated steam or superheated water coming from a suitable heat generator (not shown in the figure).

[0030] Fig.2 gives a diagram of an embodiment according to the invention, in this example on the basis of a dyeing apparatus with the Overflow system 10 of the type shown in Fig. 1, but the apparatus could be any other apparatus to dye fabrics which contains adaptations suited to the purpose.

[0031] A dyeing apparatus 20 according to the invention also comprises the body 31 which includes the conduit 13 for immersion of the fabric 11 in the dyebath 15, the dyeing channel 14 and the dyebath collection vessel 16 connected to means 17 that recirculate the dyebath 15.

[0032] The apparatus 20 according to the invention includes a firing device 21 in the feed line 18 of the dyebath 15.

[0033] This firing device 21, which is sunk in the flow of the dyebath 15 circulated by the pump 17, includes a burner 22 cooperating with a combustion chamber, the burner 22 being of the type with injected air for instance.

[0034] The present applicants have found very advantageous, but not restrictive, the employment of a dry chamber 23 cooperating with the burner 22 and in conjunction with a wet combustion chamber 24.

[0035] The air of combustion is drawn from the exterior by means of a fan 25 and is mixed at the intake of the burner 22 with gas coming from a valve 26.

[0036] The gas employed may be of various types; the present applicants have found the use of methane especially advantageous, also from the point of view of the plant used in general.

[0037] Liquid propane gas (GPL) too has been used and tried with good results; in any event any other fuel of the state of the art can be employed.

[0038] The fuel gases pass from the dry combustion chamber 23 to the wet combustion chamber 24 and thence to a heat exchanger 27 with tubes for fumes.

[0039] The flue gases from the heat exchanger 27 reach a collector 28, whence they are discharged through a duct 29. The condensation water is collected in the collector 28 and discharged through a discharge 30.

[0040] The dyeing apparatus 20 may be connected advantageously to a unit to cool the fumes of combustion leaving the duct 29.

[0041] The recovered heat can be employed to heat water for use, for instance, in various operations of washing the fabric for all the dyeing operations.

[0042] The firing device 21 of the invention may be installed equally well in any other suitable position in the flow of the dyebath 15.

[0043] Installation of the firing device 21 in the complex of the dyeing apparatus 20 will obviously entail the inclusion in that apparatus 20 of additional control, safety and protective devices, but all of this forms part of the state of the art and can be readily understood, together with many other possible variants, by a person skilled in this field without departing thereby from the scope of the invention as claimed.

Claims

1. Dyeing apparatus (20) to dye fabrics (11) or any other surface of textile piece goods, which consists of a body (31) equipped with means (12-13-14) to circulate the fabrics within the body (31) and of means (17-18) to circulate a dyebath (15) within the body (31), the apparatus (20) being characterized in that it incorporates a firing device (21) immersed in the flow of the dyebath (15) so as to heat the dyebath (15), the firing device (21) being equipped with its own independently fed (25-26) gas burner (22) and with its own discharge (29) for the products of combustion.

2. Apparatus (20) as claimed in Claim 1, in which the firing device (21) is installed advantageously in a recirculation and feed line (18) of the dyebath (15).

3. Apparatus (20) as claimed in Claim 1 or 2, in which the firing device (21) comprises a combustion chamber, advantageously a dry combustion chamber (23), and a wet combustion chamber (24) and a heat exchanger (27) with tubes for fumes and a collector (28) for flue gases.

4. Apparatus (20) as claimed in any claim hereinbefore, in which the feed gas of the burner (22) is advantageously methane.

5. Apparatus (20) as claimed in any claim hereinbefore, in which a duct (29) to discharge products of combustion is connected to a unit which cools such products of combustion.

6. Apparatus (20) as claimed in any claim hereinbefore, in which the products of combustion are cooled with water used in the dyeing apparatus (20).

Drawing