Abstract:
An apparatus for injecting two fluids is provided with a first elongated header which extends in a straight line and is supplied with a first fluid, a second elongated header which extends along the first header and is fixed to the backside of the first header, a nozzle lead-in member for leading the first fluid from the first header and the second fluid from the second header, and a nozzle for mixing and injecting the fluids from the nozzle lead-in member. Such apparatus for injecting two fluids has a simple construction and can be produced efficiently. In using this apparatus for injecting two fluids in manufacturing minimized spangle molten plated steel plate, for which water atomized by compressed air is injected toward a surface of the steel plate strip running from bottom to top while passing through a plating bath, a main spangle removing mechanism and a spare spangle removing mechanism are provided and operated selectively and alternately, so that operation can be continued even when either of the mechanisms breaks down.

Description:
FIELD OF THE INVENTION 
     This invention relates to a two-fluid injecting apparatus, and more particularly to a two-fluid injecting apparatus for mixing and injecting air and various treatment fluids on the surface of a strip to be treated, such as steel strip, plastic or paper. 
     This invention also relates to a manufacturing apparatus of minimized spangle molten plated steel plate. 
     DESCRIPTION OF THE PRIOR ART 
     A typical prior art apparatus is disclosed, for example, in Japanese Laid-Open Patent Pub. 137628/1976, in which a pair of spangle removing apparatus are disposed across a strip in a casing having a passage for a steel strip running from bottom to top while passing through the plating bath. In this apparatus, air headers elongated in the strip widthwise direction, water headers elongated in the strip widthwise direction, and multiple branch pipes extending in the vertical direction are disposed at equal intervals along the strip widthwise direction, and nozzles are attached to these branch pipes. 
     In this prior art, since the intervals between the nozzles are narrow, it is very difficult to replace the nozzles when clogged. This nozzle replacing job is done by slowing down the strip running speed. As a result the working efficiency is lowered, defective products may be produced, and steam is blown out from nozzles such that the working environment becomes extremely impaired. 
     Besides, in the prior art, there are many constituent elements, and the size is increased, the weight is increased, and maintenance is troublesome. 
     In order to solve the above problems, it is a primary object of this invention to present an injecting apparatus which is light and compact, and arranged such that a clogged nozzle can be easily replaced, as well as a manufacturing apparatus of minimized spangle molten plated steel plate which utilizes such injecting apparatus. 
     SUMMARY OF THE INVENTION 
     To achieve the above object, a two-fluid injecting apparatus of this invention comprises: 
     a first elongated header which extends in a straight line and is supplied with a first fluid; 
     a second elongated header which extends along the first header, is fixed to a first side of the header, and is supplied with a second fluid; plural nozzle lead-in members penetrating from a second side of the first header to the first side of the first header and having a first path for leading the first fluid in the first header and a second path for leading the second fluid in the second header; and 
     a nozzle, for mixing and injecting the first fluid and the second fluid, detachably installed in the nozzle lead-in member, and having passages individually communicating with the first and second paths. 
     According to the invention, the first fluid supplied to the first header is lead through the first path to a passage provided in the nozzle. The second fluid supplied to the second header is lead through the second path of the nozzle lead-in member to the passage provided in the nozzle. Since the passage communicates with the first and second paths individually, the first and second fluids supplied are mixed and injected from the nozzle. When the nozzle is clogged, the first and second headers can be removed and the clogged nozzle, can be replaced with a new one, or the headers can be replaced immediately with spare headers provided with a nozzle which is not clogged. 
     According to the invention, the first header which leads the first fluid and the second header which leads the second fluid are generally connected so that if the nozzle is clogged, it is easy to take out the headers and replace the nozzle with a spare one, which enables prompt replacement work, a reduction in the work required for maintenance, and an improvement in efficiency. Since it is not necessary to provide a branch tube in each respective nozzle, the construction may be simplified and light and compact. 
     In a preferred embodiment of this invention, in the nozzle lead-in members, plural first paths are formed on the outer circumference of the second path and are spaced apart in the peripheral direction. 
     In a different preferred embodiment, the first fluid is air, and the second fluid is water or a liquid including water, and the second fluid is atomized and injected by the nozzle, using the first fluid. 
     In a further different preferred embodiment, the first and second headers are disposed along the widthwise direction of the strip to be treated, and the plural nozzle lead-in members and the nozzles individually corresponding to each of the plural nozzle lead-in members are spaced apart along the widthwise direction. 
     In a still different preferred embodiment, the apparatus further comprises a first pipe connection tube attached to one longitudinal end of the first header, and a second pipe connection tube attached to one longitudinal end of the second header. 
     Moreover, in order to achieve the above object, a manufacturing apparatus for manufacturing minimized spangle molten plated steel plate according to this invention has a pair of spangle removing apparatus mounted in opposing relation to one another across a steel plate strip in a casing having a passage for the strip running from bottom to top while passing through a plating bath, wherein 
     the spangle removing apparatus comprises a main spangle removing means and a spare spangle removing means disposed downwardly of the main spangle removing means, 
     each of the main spangle removing means and spare spangle removing means comprising: 
     a first elongated header which extends in a widthwise direction of the strip and is supplied with a first fluid comprising one of a gas and a liquid; 
     a second elongated header which extends along the first header, is fixed at a first side of the header, and is supplied with a second fluid comprising the other one of the gas and the liquid; 
     plural spaced apart nozzle lead-in members mounted along the widthwise direction through the first header, and including a first path for leading the first fluid from the first header and a second path for leading the second fluid from the second header; and 
     a nozzle, for mixing, atomizing and injecting the first and second fluids, detachably installed in each of the nozzle lead-in members and having passages individually communicating with the first and second paths. 
     The main spangle removing means and spare spangle removing means being operated alternately. 
     According to the invention, a pair of spangle removing apparatus are disposed at both sides of the strip running from the bottom to top while passing through the plating bath. The spangle removing apparatus includes the main spangle removing means and the spare spangle removing means which are operated alternately and selectively. 
     Referring to the main and spare spangle removing means operated alternately and selectively, upon operating the main spangle removing means, the first fluid supplied to the first header is led through the first path of the nozzle lead-in members into a passage provided in the nozzle. The second fluid supplied to the second header is led through the second path of the nozzle lead-in member into the passage provided in the nozzle. The passage communicates with the first and second paths individually, so that the supplied and first and second fluids are mixed and injected from the nozzle. The first and second fluids thus mixed are sprayed in an atomized state from the nozzle of the main spangle removing means onto the strip running from bottom to top in the passage. During injection of the first and second fluids by the main spangle removing means, when the nozzle becomes clogged, the first and second headers can be taken out and the clogged nozzle can be replaced with a new one or a spare header provided with a nozzle which is not clogged can be immediately disposed at the position of the removed header. 
     During such replacing of the nozzle or header, the spare spangle removing means is operated, and by means of such operation as the main spangle removing means, the first and second fluid may be mixed and injected from the nozzle. 
     According to the invention, when the nozzle is clogged, the header can be taken out and the nozzle or the header can be replaced immediately with spare ones. Moreover, since the main and spare spangle removing means can be properly exchanged and used, the first and second fluids can be injected by at least either of the main and spare spangle removing means. Accordingly, it is not necessary to lower the running speed of the strip, thereby improving work efficiency. 
     In a preferred embodiment, the manufacturing apparatus comprises also a main convection preventing plate which is spaced from the strip, extends down from below the main spangle removing means, and reaches the rear part of the nozzle header of the spare spangle removing means; and 
     a spare convection preventing plate which is spaced from the strip, extends down from below the nozzle of the spare spangle removing means, and reaches the drain trap. 
     In a different preferred embodiment, the main spangle removing means and spare spangle removing means are set on rails which guide them in the longitudinal direction, in which  the main spangle removing means and spare spangle removing means are each movable in the longitudinal direction along each rail. 
     In a further different preferred embodiment, the main spangle removing means and spare spangle removing means are each provided with means for angularly adjusting the nozzles about an axial line parallel to the first header. 
     In a still different preferred embodiment, the main spangle removing means and spare spangle removing means are each provided with means for approaching and retracting away from the strip. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a manufacturing apparatus of minimized spangle molten plated steel plate in one of the embodiments of this invention, as seen from the front side; 
     FIG. 2 is a plan view showing an embodiment of the same manufacturing apparatus; 
     FIG. 3 is a right side elevation view of the manufacturing apparatus; 
     FIG. 4 is a sectional view of a header in a direction transverse to the lengthwise direction; 
     FIG. 5 is a front elevation of the header; 
     FIG. 6 is a right side elevation of the header; 
     FIG. 7 is a sectional view taken along line VII-VII in FIG. 4; 
     FIG. 8 is a sectional view of a nozzle; 
     FIG. 9 is a front elevation of the nozzle; 
     FIG. 10 is a schematic longitudinal sectional view showing a part of the manufacturing apparatus in FIG. 1; and 
     FIG. 11 is a schematic horizontal sectional view showing a part of the manufacturing apparatus in simplified form. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, embodiments of this invention are described below. In FIG. 1, in a casing 1 having a rectangular parallelepiped contour and including a passage 1a for a steel strip A moving from bottom to top while passing through a plating bath, main spangle removing means B are disposed across the strip A. A passage door 1b is provided at one side of the strip passage 1a, and an opening cylinder 1c of the door 1b is disposed on the casing outer wall as shown in FIG. 2. In the upper part of the casing, there is an opening 1d for adjusting the mist suction volume as shown in FIG. 3. Inside the casing 1, a mist chamber 2 is formed by a mist guide wall 2a extending from above the spangle removing means B to the upper end of the casing 1, and an opening 2b for sucking the mist is provided in the upper part of the wall 2a in such a manner that the opening area may be adjusted by a damper. 
     In this apparatus, a spangle removing apparatus comprises the main spangle removing means B and a spare spangle removing means C spaced beneath it. The spangle removing means C is mounted above a drain trap 16 located at the bottom of the casing 1. The main spangle removing means B and the spare spangle removing means C have substantially the same construction. 
     FIG. 4 shows the main spangle removing means B. The main spangle removing means B possesses plural nozzles N disposed at equal intervals along the strip widthwise direction, and a nozzle header 3 mounting them detachably as shown clearly in FIG. 5. 
     The nozzle header 3 comprises an air header 31 which is a first header and is elongated in the widthwise direction of the strip A, and a liquid header 32 which is a second header and is elongated in a direction parallel to the air header 31, and attached to the rear side of the air header 31 (i.e. the side opposite to the strip A with respect to the air header 31). At one end of the headers 31, 32 in the lengthwise direction, individual pipe connection tube ports 33, 34 are attached, and extend parallel in the lengthwise direction of the headers 31, 32 and are directed away from one end thereof (rightward in FIG. 5). The air header 31 has plural nozzle lead-in members 35 mounted along the air header 31 at intervals, for example, equal intervals. The lead-in members 35 are mounted through the air header 31 in the longitudinal direction of the lead-in members 35 (i.e. the direction perpendicular to the strip A in FIG. 4). Each of these members 35 is approximately cylindrical, and as clear from FIG. 7, includes a liquid passage 35a extending longitudinally therethrough along the central axis thereof, and a nozzle N is detachably fitted to an end of each of the members 35, whereas the rear end of the fluid passage 35a opens into the liquid header 32. As clear from FIG. 7, each of the members 35 is provided with plural air passages 35b formed at, for example, equal intervals about the liquid passage 35a through the portion of the member 35 connected to the nozzle N. 
     FIG. 8 is a sectional view of nozzle N, and FIG. 9 is its front view as seen from the left side of nozzle N in FIG. 8. As shown in these drawings, the nozzle N includes a nozzle tip 38, and a cap 39 which is screwed onto the end of this nozzle tip 38. The external threads 40 of the nozzle tip 38 are engaged with the internal threads formed in the liquid passage 35a of the nozzle lead-in member 35, and the nozzle N is detachably fitted to the nozzle lead-in member 35 as stated above. The axial line of the nozzle tip 38 is on a straight line common to the axial line of the nozzle lead-in member 35, and a liquid passage 42 is formed on this axial line. The liquid passage 42 communicates with a valve chamber 43 formed at a rear end part 41 of the nozzle tip 38. In this valve chamber 43 are incorporated a valve disc (or ball) 45 to be seated on a valve seat 44, and a spring 46 for elastically thrusting the valve disc 45 by resisting the pressure of the liquid from the passage 35a, thereby composing a check valve 47. When the liquid from the liquid header 32 is pressure-fed, the valve disc 45 is displaced leftward in FIG. 8 against the spring force of the spring 45 such that it is spaced from the valve seat 44, so that the liquid is pressure-fed into the liquid passage 42. 
     An annular recess 48 is formed in the nozzle tip 38, concentric with the axial line of the nozzle tip 38, and air passages 49 communicating with this annular recess 48 are formed peripherally about the liquid passage 42. These air passages 49 are inclined toward the center as it approaches the end (the left end in FIG. 8) of the nozzle tip 38. The annular recess 48 communicates with the air passage 35b formed in the nozzle lead-in member 35. 
     The cap 39 fitted to the nozzle tip 38, together with the nozzle tip 38, forms a mixing chamber 50 for mixing liquid and air. This cap 39 posses a flat nozzle hole 51 extending in the widthwise direction of the strip A on the extension of the axial line of nozzle tip 38. 
     The pressure of the air pressure-fed into the air header 31 is, for example, 4 kg/cm 2 , and the pressure of the liquid pressure-fed into the liquid header 32 is, for example, 1.5 kg/cm 2 . The ratio α(=S1/S2) is preferably about 50/1, where S1 is the sum of the sectional areas of the plural air passages 49 formed in the nozzle tip 38 and S2 is the sum of the sectional areas of the plural liquid passages 42 formed in the nozzle tip 38. Therefore, the air pressure-fed into the air header 31 is injected into the mixing chamber 50 from the air passage 35b of the nozzle lead-in member 35 through the air passage 49 of the nozzle N. The liquid pressure-fed into the liquid header 32 at this time is introduced into the liquid passage 42 of the nozzle N from the liquid passage 35a of the nozzle lead-in member 35 into the liquid passage 42 of the nozzle N through the check valve 47, and is then injected from the liquid passage 42. In this way, the liquid is injected from the nozzle hole 51 in an atomized state, and is sprayed onto the surface of the strip A which is flat along its widthwise direction. 
     Compressed air is supplied into the tube connection port 33 connected to the air header 31 from the air pressure source 52 by way of a switching valve 53 as shown in FIG. 5. Liquid is pressure-fed into the tube connection cylinder 34 attached to the liquid header 32 from the liquid supply source 54 through a switching valve 55. When the switching valve 55 is closed, in order to prevent dropping of the liquid from the liquid passage 42 of the nozzle tip 38 and the nozzle hole 51, the check valve 47 is closed as the valve disc 45 is pressed by the spring force of the spring 46 against the valve seat 44. 
     A slide guide means 36 is provided for guiding and supporting both the headers 31, 33 slidably in their lengthwise direction. In this slide guide means 36, rails 36e are fixed on a lower wall 36b which is formed by an irregular shaped grooved steel web 36a, and wheels 57 of the header 31 are supported by the rails 36e, such that the headers 31, 32 are positioned and guided in the longitudinal direction between the front wall 36c which is a short flange and the rear wall 36d which is a long flange. The rails 36e extend in the widthwise direction of the strip A. 
     Next, as shown in FIGS. 10 and 11, the header 3 is fixed to the header support rod 4 which is parallel to the strip A and is horizontal, by way of the bracket 5, and is pushed down from above by the header fixing arm 6. Both ends of the support rod 4 are rotatably supported by a rod receiving plate 7. 
     A nozzle withdrawal means 8 is provided for drawing back the nozzle N from the strip A, and includes a rectangular horizontal slide plate 8a which the rod receiving plate 7 is mounted to and extends up from. The slide plate 8a is supported rotatably in the longitudinal direction on the upper surface of a horizontal base board 8b, and its vertical position is defined by a horizontal guide bar 8j which is elongated in the longitudinal direction. A nut member 8d is affixed to the upper surface of the slide plate 8a, and a guide pin 8h extends down from the lower surface of the nut member 8d. This pin 8h is guided so as to be movable in the longitudinal direction (the lateral direction as viewed in FIGS. 10 and 11), penetrating through the slit 8c of the base board 8b. In order to withdraw the nut member 8d, a nozzle withdrawal screw shaft 8e is extended horizontally in the longitudinal direction. The screw shaft 8e is rotatably supported by bearing plates 8f at both its ends, and one end of the screw shaft 8e is rotated and driven by a driving means 59 which projects through the casing 1. Between the bearing plate 8f and not member 8d, a protective bellows tube 8i is mounted about the circumference of the screw shaft 8e in order to prevent mist from depositing on the screw shaft. Instead of the driving means 59, a handle to be turned manually may be attached to the screw shaft 8e. 
     A nozzle angle adjusting means 9 is provided for adjusting the angle of the nozzle N with respect to the strip A and includes an angle adjusting lever 9a fixed to one end of the header support rod 4, and an angle setting plate 9c being set up on the slide plate 8a, such that the relative angle can be adjusted by inserting pins (not shown) into pin holes 9b, 9d disposed in the lever 9a and setting plate 9c, respectively. 
     The operation of the apparatus is described below. In the main spangle removing means B, when air is introduced into the air header 31 and liquid into the liquid header 32, they are mixed at the nozzle N through the nozzle lead-in members 35, and the mixture is sprayed toward the strip A. For example, one or some of the nozzles N of the main spangle removing means B are clogged, (1) the spare spangle removing means C can be operated, or (2) the tube connection cylinders 33, 34 of the main spangle removing means B can be separated, and the header 3 can be guided by the slide guide 36, and moved in the longitudinal direction of the header 3 (perpendicular to the sheet of FIG. 10, parallel to the sheet of FIG. 11) to be replaced with a spare header. 
     At the nozzle withdrawal means 8 for adjusting the distance of the nozzle N from the strip A, when the screw shaft 8e is rotated by the driving means 59, the nut member 8d retreats with respect to the strip A, and the slide plate 8a also retreats, such that the header support rod 4 is retracted rearwardly. As a result, the header retreats together with the slide plate 8a and rod 4, so that the distance between the nozzle N and strip A may be adjusted. 
     To adjust the angle of the nozzle N, the nozzle angle adjusting means 9 is operated, and the lever 9a is turned to change the fitting position of the pin with respect to the angle setting plate 9c. 
     In FIG. 1, at one side of the casing 1, passage doors 11a are disposed. Downwardly from the main spangle removing means B, a main convection preventing plate 12 is provided, and this main convection preventing plate 12 is spaced from the strip A, is mounted downward of the nozzle N, and stretches rearward of the nozzle header of the spare removing means C. Downwardly from the spare removing means C is disposed a spare convection preventing plate 15, and this spare convection preventing plate 15 is spaced from the strip A, is mounted downward of the nozzle of the spare removing means C, and extends above the spare drain trap 16. A main drain trap 13 is installed at the lower side of the main removing means B. 
     Referring again to FIG. 3, maintenance covers 17 are provided at four positions on one side wall of the casing 1 parallel to the strip A. At one side of the casing 1 orthogonal to the strip A, a mist exhaust hood 18 is mounted and communicates with the mist chamber 2, and the mist is exhausted upward by this hood 18. A mist hood cover 19 is disposed on this hood 18, and a drain pipe 20 extends downwardly from its lower end. 
     Here, the mist circulating in the casing is blocked by the main and spare convection preventing plates 12, 15, and drops of mist deposited on these convection preventing plates 12, 15 are received by the main drain trap 13 and spare drain trap 16, and are led to the outside of the casing. Since the main and spare convection preventing plates 12, 15 are disposed in the casing 1, circular flow of mist is blocked, and falling of water drips deposited on the inside of the casing 1 onto the strip A is prevented. Thus, the quality of this strip A is not adversely affected, and the yield is not lowered. 
     Since tube connection cylinders 33, 34 are attached to one end of each header 31, 32, there are few tube junctions, such that the assembly work efficiency is significantly improved, and possible air and liquid leaks are decreased accordingly. Therefore, on the whole, a compact and light weight header can be presented. Incidentally, if the header 3 is long, a partition board may be disposed midway in the longitudinal direction, and tube connection cylinders may be disposed at both ends in the longitudinal direction of the header. 
     Moreover, since the header is supported by slide guide which slidably guides the header in the lengthwise direction, if the nozzle is clogged, the header may be immediately removed and the nozzle replaced, or the header may be quickly replaced with a spare one. 
     The header 3 and the nozzle N of the invention may be utilized with not only manufacturing apparatus for minimized spangle molten plated steel plate, but also with other technical art. Other fluid than air or liquid may be pressure-fed into the header 3. Furthermore, liquid and gas may be pressure-fed into the header 31 and the header 32, respectively.