Device for solidifying a coating layer hot-deposited on a wire, and corresponding installation and procedure

Abstract

Device for solidifying a coating layer hot deposited on a wire-, corresponding installation and method. The device comprises a cooling liquid injection chamber with a liquid inlet and a wire inlet, a cooling chamber with a liquid outlet and a wire outlet, and a partition arranged between the injection and cooling chambers, comprising a wire passage. It also has a conduit for separating the wire. The partition comprises channels fluidically connecting the injection chamber with the cooling chamber and leading into the center of the wire passage in an eccentric manner and being inclined forming an angle with respect to a longitudinal direction-. This directs a jet of cooling liquid on the wire in the direction from the injection chamber towards the cooling chamber.

Claims

1. A device for solidifying a coating layer hot deposited on a wire, said device extending along a longitudinal direction defining the path of passage of said wire, characterized in that it comprises [a] a cooling liquid injection chamber with a cooling liquid inlet and a wire inlet, said injection chamber being cylindrical, [b] a cooling chamber with a cooling liquid outlet and a wire outlet, [c] a partition arranged between said injection and cooling chambers, comprising a wire passage communicating said injection chamber and said cooling chamber with one another, [d] a conduit for separating said wire, extending between said wire inlet and said wire passage, [e] said partition comprises a plurality of channels fluidically connecting said injection chamber with said cooling chamber, said plurality of channels leading into the center of said wire passage in an eccentric manner such that each channel of said plurality of channels seen on a plane perpendicular to said longitudinal direction has a first side wall and a second side wall, said first and second side walls being configured such that at least one of them is eccentric to said longitudinal axis, and the other one is at least radial, the prolongation of said first and second side walls being on one and the same side of said longitudinal axis and [f] said plurality of channels being inclined forming an angle with respect to said longitudinal direction which is comprised between 10 and 40° for aiming a jet of cooling liquid on said wire in the direction from said injection chamber towards said cooling chamber.

2. The device according to claim 1, wherein each channel of said plurality of channels forms an angle with respect to the longitudinal direction between 12 and 30º.

3. The device according to claim 1, wherein on the side of said cooling chamber, said partitioning wall forms a projection in said cooling chamber tapering in the direction from said injection chamber towards said cooling chamber and ending in said wire passage conduit.

4. The device according to claim 1, wherein said inlet is eccentric with respect to said longitudinal axis, such that it is at least tangent to the outer diameter of the conduit for separating said wire.

5. The device according to claim 1, wherein the walls of said cooling chamber, at the end of said wire outlet, taper between said cooling chamber and said wire outlet in the form of a Coanda surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and features of the invention will become apparent from the following description, in which, without any limiting character, preferred embodiments of the invention are disclosed, with reference to the accompanying drawings in which:

(2) FIG. 1 shows a bottom side perspective view of the device according to the invention.

(3) FIG. 2 shows a bottom a side perspective view of the device of FIG. 1.

(4) FIG. 3 shows a longitudinally sectioned view of the device of FIG. 1.

(5) FIG. 4 shows an exploded, longitudinally sectioned view of the device of FIG. 1.

(6) FIG. 5 shows a cross-section through a plane perpendicular to the longitudinal direction of the device, in the area of the plurality of channels fluidically connecting said injection chamber with said cooling chamber.

(7) FIG. 6 shows a schematic view of the installation according to the invention.

(8) FIG. 7 shows a detailed side view of the installation according to the invention provided with a plurality of devices connected in series.

(9) FIG. 8 shows a longitudinally sectioned view of a plurality of devices according to the invention connected in series.

(10) FIGS. 9A to 9C show a simulation of the flow lines on the wire at different levels of flow rate.

(11) FIG. 10 shows a perspective view of a computer-assisted simulation in which the vortex formed on the wire can be seen.

(12) FIG. 11 shows a front view of a computer-assisted simulation in which the vortex formed on the wire can be seen.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

(13) FIGS. 1 to 4 show a device 1 according to the invention for solidifying a coating layer hot deposited on a wire 108. This coating layer can be, for example but in a non-limiting manner, a zinc layer, a Zn and Al alloy in proportions between 0.5 and 20% of Al, Zn, Al, and Mg alloys, polymers, paints, copper, and other coatings hot deposited on the wire 108.

(14) The device 1 has an elongated outer casing 24 extending along a longitudinal direction L. This longitudinal direction defines the path of passage of the wire 108.

(15) The casing 24 forms therein a cooling liquid injection chamber 2. The injection chamber 2 has a cooling liquid inlet 6 and a wire inlet 4.

(16) On the other hand, FIG. 2 also shows how the device 1 has a cooling chamber 8 with a cooling liquid outlet 12 and a wire outlet 10.

(17) A partition 14 is provided between the injection chamber 2 and the cooling chamber 8. This partition has a wire passage 16 communicating the injection chamber 2 and the cooling chamber 8 with one another.

(18) There is also provided in the injection chamber 2 a conduit 22 for separating the wire 108, extending between the wire inlet 4 and the wire passage 16. This conduit 22 prevents the wire 108 from being subjected to the effects of the cooling liquid when it is injected into the injection chamber 2 through the liquid inlet 6. The cooling liquid directly hitting the surface of the wire 108 in a perpendicular direction while the coating is still hot may damage the quality of the coating.

(19) FIG. 3 shows that the liquid inlet 6, which in this case is formed by a cylindrical conduit, is eccentric with respect to the longitudinal axis L. Also for avoiding turbulences inside the injection chamber, in a preferred embodiment the inlet is tangent to the outer diameter of the conduit 22 for separating the wire 108. This favours the formation of a vortex inside the injection chamber 2.

(20) FIG. 4 also shows how the partition 14 has a plurality of channels 18 fluidically connecting the injection chamber 2 with the cooling chamber 8. It can be seen in FIG. 5 how this plurality of channels 18 leads in an eccentric manner relative to the centre of the wire passage 16. On the other hand, these channels 18 are furthermore inclined forming an angle α with respect to the longitudinal direction L for directing a jet of cooling liquid on the wire 108 in the direction from the injection chamber 2 towards the cooling chamber 8.

(21) The combination of these two features causes the formation of a vortex at the outlet of the wire passage 16 in the partition seen in FIGS. 10 and 11. This vortex surrounds the wire 108, cooling it more efficiently than the known devices. This also means that the length of the coating solidification step can be significantly shortened.

(22) On the other hand, the way in which the channels 18 lead into the cooling chamber 8 plays a significant role in terms of device efficiency. Thus, in a particularly preferred manner each channel of the plurality of channels 18, seen on a plane P perpendicular to the longitudinal direction L, has a first side wall 26 and a second side wall 28, both seen in FIG. 5. These first and second side walls 26, 28 are configured such that at least one of them is eccentric to the longitudinal axis L, whereas the other one is at least radial. The drawing shows through the dash-dotted lines that, in this case, the first side wall 26 is the radial one, whereas the second side wall 28 is clearly eccentric. The prolongation of these first and second side walls 26, 28 is therefore on one and the same side of said longitudinal axis L. This avoids the formation of liquid streams in opposing directions and obtains a more regular vortex, reducing turbulences. The direction of rotation of the stream is indicated in FIG. 5 by means of arrow A.

(23) On the other hand, also with the movement to improve the deformation-free finishing of the coating layer, each channel of the plurality of channels 18 forms an angle α with respect to the longitudinal direction L which is comprised between 10 and 40° and preferably between 12 and 30°. For example, in FIG. 3 the channels form an angle α of 16° with respect to the longitudinal direction.

(24) This same FIG. 3 also shows how, on the side of the cooling chamber 8, the partitioning wall 14 of the device 1 forms a projection 20 in the cooling chamber 8 tapering in the direction from the injection chamber 2 towards the cooling chamber 8, ending in the wire passage conduit 16. This projection 20 has a substantially frustoconical shape. Thus, in the preferred operating direction of the device 1, which is when the longitudinal direction L is in the vertical direction, it allows collecting the pouring cooling liquid and preventing it from entering the injection chamber 2 again. Also in this same direction and to prevent the pouring water from being led to the wire passage 16, the device 1 of the drawing has walls of the cooling chamber 8 which, at the end of the wire outlet 10, taper between the cooling chamber and the wire outlet 10 in the form of a Coanda surface. This surface helps to collect the cooling liquid and leads it to the side walls of the cooling chamber 8, facilitating the exit thereof through the liquid outlet 12.

(25) After having described the device 1 according to the invention in detail, an installation 100 according to the invention for solidifying a coating layer hot deposited on a wire 108 is described below.

(26) FIG. 6 shows a schematic installation having six devices 1 according to the invention connected in series arranged such that their longitudinal direction L corresponds to the vertical direction.

(27) The lower device 1 has the wire outlet 10 connected with the wire inlet 4 of the adjacent device 1 and so on and so forth all the way to the upper device 1, the wire outlet 10 of which is free.

(28) The installation has a cooling liquid tank 102 and thrusting means 104. In this embodiment, the thrusting means are a fan. Alternatively, they may be a hydraulic pump. The thrusting means 104 fluidically connect the tank 102 with each of the liquid inlets 6 of each of the six devices 1 through a main conduit 110. Thanks to the thrusting means 104, the cooling liquid is thrust into each of the injection chambers 2.

(29) The injection chamber 2 is separated from the wire passage 16 through the conduit 22. A plenum which allows balancing the injection pressure in each of the devices 1 is thereby formed. The injection chamber 2 must be filled upon starting up the installation. Thus, when the injection chamber 2 is full, at a certain pressure, the cooling liquid is then introduced in the channels 18 and it moves upward to the cooling chamber 8.

(30) FIGS. 9A to 9C show the effect achieved through the angle α of inclination of the channels 18. As can be seen, as the flow rate circulating through the channels 18 increases from 6 l/min to 21 l/m, the speed with which the cooling liquid “rubs against” the surface of the wire to be cooled increases. An angle perpendicular to the wire 108 would cause significant deformations on the coating surface, whereas a non-parallel angle would not provide efficient cooling. Thanks to the flow having a longitudinal component in the same direction as the forward movement of the wire 108, an optimum operating range is achieved, in which the formation of irregularities on the surface of the wire 108 is avoided and a very efficient cooling is achieved.

(31) Then, FIGS. 10 and 11 show the effect achieved thanks to the eccentricity of the channels 18 with respect to the wire 108 to be cooled. The direction of the velocity vectors shows how the vortex is formed around the wire 108. This vortex causes a particularly efficient cooling and hardening of the coating layer, but without damaging the coating surface or causing irregularities.

(32) The installation 100 according to the invention also has suction means 106. In this embodiment, the suction means are a fan. These suction means 106 are in charge of keeping the tank 102 under vacuum. A closed circuit is thereby created in which the circuit between the liquid outlet 12 and the inlet of the tank 102 is under negative pressure for discharging the cooling liquid from the cooling chamber of each of the devices 1 to the tank 102. Once in the tank 102, the cooling liquid is again thrust by the fan 104. A closed cooling circuit is thereby formed.

(33) The installation 100 according to the invention therefore allows putting into practice the method according to the invention for solidifying a coating layer hot deposited on a wire 108 at a high speed, in an efficient manner, but with a better-quality surface finish.

(34) In the method, the wire 108 is moved forward along the longitudinal direction L. A plurality of jets of cooling liquid is projected through each of the devices 1 in a manner that eccentric with respect to the center of the wire 16 and transverse to the longitudinal direction L in the forward movement direction of the wire 108. During the forward movement of the wire 108, the suction means 106 create a negative pressure downstream of the liquid outlet 12 which returns the liquid to the tank 102.

(35) To achieve optimum results in the solidification of the coating layer in the step of projecting, said liquid is injected into the injection chamber with a flow rate between 2 and 25 l/min, which provides injection speeds between 6 and 25 m/s at the outlet of the channels 18.

(36) Finally, it must be mentioned that the installation according to the invention can be installed in wire processing lines of any type in which there is a step of coating using a coating to be solidified.

(37) By way of example, the invention contemplates assembling the installation according to the invention at the end of a line for continuously processing wire by galvanization. Installations of this type can be single-wire or multi-wire installations. Thus, in the event of a multi-wire processing line, the line would include as many coating layer solidification installations as there are wires to be processed.