The cracking resistance line valve board assembly of molten metal slide gate
Background of invention
The present invention relates in general to and is used to control the valve plate that motlten metal flows on the slide gate nozzle, is specifically related to prevent under thermal stress the valve board assembly that cracks.
In steel-making and other metallurgical process, slide gate nozzle is commonly used to control molten metal flow.This class mouth of a river has comprised a scaffold; Last fixedly valve plate, its eyelet that has eyelet aligns with the mouth of a river of tundish or ladle so that motlten metal flows; And a choke block that has the metal flow hole, it can be in fixing valve plate slip underneath.In the slide gate nozzle that matches with continuous cast mold, removable eliminator plate following also has a fixing valve plate down, and this fixedly equally also has the metal flow hole on the valve plate, and this eyelet aligns with the eyelet of last fixedly valve plate basically.Molten metal flow speed depends on the registration of eyelet on the slidably choke block and upper mounted plate.Removable eliminator plate is longer than fixed restriction plate usually, so that can all can regulate molten metal flow from the front and the back of its eyelet, and, can not overlap fully with the eyelet of fixed head by the eyelet that makes oneself and cut off molten metal flow.Usually, can rely on the hydraulic connecting rod device to make choke block slide between fixed head.
Choke block on this class slide gate nozzle and fixed head are made by heat-resisting and corrosion resistant refractory material, as aluminium oxide, aluminium carbide, zirconia.Yet no matter the heat-resisting and corrosion resistance of these refractory materials how, the serious thermal stress that they bear causes crackle generation in various degree the most at last.For example in STEELMAKING PRODUCTION, the temperature near the zone of its mobile eyelet on each slide gate nozzle approximately is 2900 ℃, and the temperature of slide gate nozzle neighboring only is an environment temperature.Owing to expand with remarkable speed greater than the valve plate balance in every valve plate eyelet zone on every side, formed huge thermograde has just produced very big mechanical stress.These stress have just formed from the radially abducent crackle of valve plate eyelet.If do not take any measure to suppress the expansion of these crackles, crackle will expand to the periphery of valve plate always, finally causes the valve plate fracture.
For expansion that prevents this class crackle and the valve plate fracture that causes thus, various clamp mechanism have been developed in the prior art.The effect of these mechanisms is that the periphery at valve plate applies enough big pressure, and the crackle of rising in eyelet like this just can not be to the circumferential expansion of valve plate.In such clamp mechanism, all twining a stirrup on the periphery of each valve plate.Regrettably, the applicant finds to adopt this stirrup type clamp mechanism to have three shortcomings at least.At first, be better than being centered around originally the valve plate ambient air owing to make the thermal conductivity of the steel of band, in fact the use stirrup has increased the thermograde on valve plate length and the width, thereby causes the more generation of multiple cracks.Secondly, after stirrup was heated because of contiguous motlten metal, the speed that stirrup expands was greater than the speed of expansion of the refractory material that constitutes valve plate, and this has reduced and acts on the valve plate periphery in order to reduce the thrust of crack propagation velocity.The 3rd, if the bight of valve plate is not circular, this clamping stirrup will act on local mechanical stress in the bight of valve plate, and this will produce beyond thought crackle in these zones.
In order to overcome these and other shortcoming, clamping system to be improved, it has comprised a framework that is threaded the sphenoid of manipulation, the engagement of the bight of this sphenoid and valve plate, and the bight of valve plate is cut into the angle with the complementation of sphenoid angle.Though the clamp mechanism of this framework wedge shape build obviously is better than only adopting the clamp mechanism of stirrup around valve plate, the inventor points out further that also there are two shortcomings at least in this design and have hindered it to delay the possibility of crackle fully.In the various modification of this design, the China invites the person recognizes: no matter along the position of valve plate longitudinal centre line how eyelet, the angle of being cut top rake portion corresponding to each of valve plate length or width is the same.Therefore, depart from the valve plate of valve plate longitudinal centre line (in fact having comprised all valve plates) at eyelet, the maximum zone of crackle can not stepless action take place in clamping force, near the zone the eyelet of maximum thermal stress promptly occurs.And even eyelet is positioned at the center of valve plate, the applicant has found that at valve plate and cut on the angle orientation of top rake portion, can not resemble the imagination prevent the crackle expansion best.The formation that this non-optimal results comes from crackle is not evenly to distribute along 360 ° around eyelet, no matter fixedly valve plate or movable valve plate, the distribution of crackle all is to setover along the longitudinal centre line of valve plate.This crackle is considered to around the distribution or asymmetrical distribution of valve plate eyelet because choke block causes along the fixing longitudinal sliding motion on valve plate surface.Also there is another shortcoming in the clamp mechanism of prior art, promptly under some occasion, they with respect to the angle on the vertical limit of valve plate less than 20 °.Except provide inappropriate clamping force with closure along the crackle of valve plate axis of pitch, because the clamping wedge body also can produce huge local stress when, using this low-angle to being cut the huge thrust of top rake portion effect.This local stress can crack and the crack at the valve plate folding corner region, and this has just directly deviated from the whole purpose of clamp mechanism.Generally speaking, the final shortcoming of this class valve plate is the optimization that lacks the length of being cut top rake portion, or to the optimization with respect to eye diameter of the length of valve plate and width.Though the length in bight must have minimum size, to concentrate to avoid producing undesirable local mechanical stress in these zones of valve plate, they can not do too greatly.
Obviously, the bight of valve plate need be cut to cut and have a certain degree, so that clamping force acts on the zone that is easy to generate crackle most rightly, so that farthest block the extension of any this crackle.Ideally, the bight of valve plate should have enough length to avoid producing undesirable local mechanical stress in the bight.
Summary of the invention
In general, the present invention is a kind of cracking resistance line valve board assembly that is used on the slide gate nozzle, and it overcomes or has improved all shortcomings in the prior art at least.Described assembly has comprised a fire-resistant valve plate, this valve plate has the eyelet that is used to guide motlten metal and distributes along the valve plate center line, and by a section bight of cutting, so that clamping force near center line concentrates on eyelet in case the crack arrest line in this generation and expansion, wherein each angle orientation that is cut top rake portion changes along the position on the center line with eyelet.This assembly also comprises a clamping frames, is used for that required clamping force is affacted each and is cut on the bight of cutting.
In order to realize that above-mentioned clamping force concentrates effect, each is cut the bight of cutting all with to fall into the straight line in the angle vertical mutually, and the summit of this angle is a point of contact of eye diameter.The point of contact of passing center line is originated from the one side at this angle, and is cut the intersection point of cutting preceding valve plate intersection edges by the bight.The another side at this angle originates from the point of contact of passing center line, also through being parallel to the intersection point that valve plate intersection edges and distance should intersect the straight line of the eye diameter distance in edge.
In preferred embodiments, each quilt section bight of cutting is all perpendicular to straight line, this line passes center line, at the point of contact of the eyelet of maximum gauge that valve plate operation has and be parallel between the intersection point of straight line of valve plate intersection edges and extend, these parallel lines are half of eyelet maximum gauge apart from the distance at valve plate edge.When the profile of valve plate was rectangle, each bight was cut along cutting perpendicular to above-mentioned straight line and by the straight line of the intersection point on parallel lines and the long limit of valve plate wherein.
Valve board assembly can be along an axial-movement in slide gate nozzle, and this axis can be coaxial with the longitudinal centre line of valve plate, perhaps, valve board assembly also relatively slide gate nozzle fix.In both cases, valve plate has comprised an eyelet of arranging along center line, and cuts the bight of cutting according to the described identical geometric formula of front first valve plate.In both cases, come to be applied required clamping force with a clamping frames to cutting the bight of cutting.
In order to provide the minimum ceramic material of a kind of usefulness to make and to possess the various required closing motions and the moving valve board component of forward and backward throttling function, the valve plate profile of movable component preferably adopts rectangle, its length is 5.5~5.75 times of eye diameter, and its width is 2.9~3.1 times of eye diameter.In preferred embodiments, the length of movable valve plate and width are respectively 5.66 times and 3.0 times of eye diameter.Close and the standing valve board component of forward and backward throttling action so that finish in order to provide to match with movable valve plate, the plate of standing valve board component equally also is preferably rectangle, its length is 4.5~4.75 times of eye diameter, and its width is 2.9~3.1 times of eye diameter.In preferred embodiments, fixedly the length of valve plate and width are respectively 4.66 times and 3.0 times of eye diameter.
No matter be movable valve plate or fixing valve plate, valve board assembly of the present invention all provides one to possess and close and the cracking resistance line valve plate of forward and backward throttling capacity, and makes the ceramic material of its consumption minimum.
The accompanying drawing summary
Fig. 1 is a side cross-sectional schematic diagram that is installed in the slide gate nozzle on the tundish, and slide gate nozzle has adopted valve board assembly of the present invention;
Fig. 2 is the vertical view of throttle plate assembly of the present invention;
Fig. 3 is the vertical view of standing valve board component down of the present invention;
Fig. 4~Figure 10 is the upward view of the used valve plate of standing valve board component down of the present invention, and they illustrate the various preferred versions of suitable this valve plate and how to be determined by the angle of section top rake portion;
Figure 11~Figure 13 is the vertical view of used valve plate in the throttle plate assembly, and they illustrate the various preferred versions of suitable this valve plate and how to be determined by the angle of section top rake portion;
Figure 14 is the last fixedly vertical view of valve plate in the closed position that is stacked on the throttle plate; And
Figure 15 is the vertical view identical with valve plate shown in Figure 14, and only this moment, throttle plate arrived the back throttle position with respect to last fixedly valve plate straight skidding.
DESCRIPTION OF THE PREFERRED
In all accompanying drawings, identical numeral components identical.Referring now to Fig. 1, present invention includes movable and standing valve board component 1, it uses on the slide gate nozzle 2 of the molten steel of regulating outflow from tundish 3 or other motlten metal.Slide gate nozzle 1 is fixed on the installing plate 5, and installing plate 5 is connected on the tundish shell 7 accordingly by the erecting device that does not show.Valve plate 1 has comprised a mouth of a river 9 of being made by ceramic material, and the mouth of a river has funnel type vestibule 10 flows out from tundish 3 with aimming circle cylindricality motlten metal stream, and the mouth of a river 9 utilizes heat-resistant filler, particularly tamping material 11 mechanically to be installed on the diapire of tundish.
The main application of valve board assembly 1 of the present invention is to regulate from the mouth of a river flow of molten metal that 9 vestibule 10 flows out.For this reason, present invention includes upper and lower fixing plate assembly 13 and 17, but and choke block assembly 23 that is clipped in their centres and lateral sliding.Upper mounted plate assembly 13 has comprised a fixed head 14 that ceramic material is made, and fixed head 14 has circular eyelet 15 so that the guiding motlten metal flows out from vestibule 10.Bottom plate assembly 17 equally also comprises the fixed head 18 that a refractory material is made, and fixed head 18 has eyelet 15 eyelets 19 onesize and centering with it with upper mounted plate 14.Upper and lower fixing plate 14 preferably has identical length and width with 18.Being installed on bottom plate 18 bottom surfaces is tubulose fixture 20, and it can be used for for example guiding motlten metal to enter the crystallizer of conticaster.Tubulose fixture 20 has comprised that an integral body is connected to the installing plate 21 on the sleeve pipe 22.The erecting device (not shown) guarantees that the plate 21 of tubulose fixture 20 is installed to position shown in Figure 1.Tubulose fixture 20 makes the motlten metal and the surrounding air that flow out from slide gate nozzle system 1 completely cut off, thereby prevents that motlten metal and oxygen on every side from reacting.But be installed between upper and lower fixing plate assembly 13 and 17 choke block assembly 23 lateral slidings.Choke block assembly 23 comprises a plate 24 of being made and had eyelet 25 by ceramic material equally, eyelet 25 be circular and diameter identical with eyelet 15 on the upper mounted plate 14.Eyelet 19 on the bottom plate 18 is greater than eyelet 25 and 15, and this is for fear of choke block 24 stifled steel to take place in the operation of closing.Yet, when possessing leading edge throttling (front edge throttling) and closing ability fully, also possessing the back edge throttling capacity in order to make slide gate nozzle system 1, choke block 23 is than upper and lower fixing plate 13 and 17 length.In the operating process of slide gate nozzle 2, make choke block 24 along axis A side direction back and forth movement by hydraulic connecting rod mechanism (not shown), the direction of axis A is consistent with the longitudinal centre line of valve plate 13,17 and 24.
Referring now to Fig. 2, on general rectangular choke block 24, make and cut the bight 30a~30d that cuts, to guarantee the clamping force close eyelet 25 of center line 92 (it and axis A conllinear shown in Figure 1) longitudinally.Peripheral tensioning at choke block 24 is provided with the globality of annular stirrup 31 with reinforcement plate.Clamping frames 33 is looped around the periphery of choke block 24 and stirrup 31 to guarantee having enough clamping forces to affact foregoing being cut on the bight 30a~30d that cuts.For this reason, fix to clamp clamp jaw 37a and the 37b that element 35 has positioned opposite on the clamping frames 30, clamp jaw is arranged to avoid producing local stress with identical angle with 30b with respect to being cut a bight 30a who cuts in the left side of plate 34.Clamping frames 33 also comprises a pair of framework leg 39 that separates but be arranged in parallel, and a mobilizable clamp assembly 41 is housed on this framework leg.Clamp assembly 41 has comprised a mobilizable clamping element 43, and this clamping element 43 has two relative clamp feet 45a and 45b equally, and they cut the 30c of the top rake portion angle setting identical with 30d with the quilt with valve plate 24 right sides.Pass the clamping screw 49 of the core hole (not shown) on the clamping supporting member 47 and core hole (also not shown) threaded engagement on the active clamping piece 43, thereby when rotary screw 49, the quilt on clamp jaw 45a on the movable clamping element 43 and 45b and valve plate 34 right sides cuts 30c of top rake portion and 30d engagement.Accordingly, this operation can make clamp jaw 37a and 37b on the fixed clamping piece 35 that the quilt that clamping force is applied to valve plate 24 left sides is cut on 30a of top rake portion and the 30b.
Since upper and lower fixing plate assembly 13 with 17 all be similar basically aspect main, for avoiding tediously long, only bottom plate assembly 17 is narrated.
Referring now to Fig. 3, following board component 17 has comprised the bottom plate 18 that has eyelet 19, and the rounded and diameter of eyelet 19 is identical with eyelet 25 on the choke block 24.Identical with choke block 24, the quilt on the fixed head 18 cut the 54a~54d of top rake portion make clamping force along valve plate longitudinal centre line 70 concentrate on eyelet 19 near.Bottom plate assembly 17 has comprised that also one affacts by the clamping frames 58 on section bight 54a~54d that cuts clamping force.For this reason, clamping frames 58 has comprised the frame assembly 59 (shown in broken lines) of a rectangle, the left end of frame assembly 59 has comprised a fixed clamping piece 60 that has clamp jaw 62a and 62b, and the function of clamp jaw is identical with clamp jaw 37a, 37b on the clamping element noted earlier 35.Frame assembly 59 has also comprised an active clamping piece 64 on its right side.Clamping element 64 has comprised clamp jaw 66a and 66b, cuts on 54c of top rake portion and the 54d by rotation clamping screw 68 quilt that can make clamp jaw be pressed against plate 18 tightly, and this clamping screw 68 is operated in the mode identical with aforementioned screw 49.In various schemes, angle by section bight 54a~54d that cuts and clamp jaw 62a, 62b and 68a, 68b is identical, thereby between these parts, form bigger contact area, thus avoided causing in the bight of plate 18 the local stress of the crackle of not wishing.
Fig. 4 has represented that the length of each fixed head 14 in the preferred embodiment and 18 and width are the functions of eyelet 19 maximum dimension D that how had by valve plate (under the actual conditions) operation and definite.In order to satisfy the needs with respect to the closed position of choke block 18, the length of plate 18 first halves of counting from eyelet 19 central points should be able to be held the shutoff stroke Ss of 1.5 times of eye diameters at least.Though shutoff stroke only need be a bit larger tham single eye diameter theoretically, so little stroke is not considered the effect owing to corrosion, and eyelet 19 can significant extension take place along the longitudinal centre line 70 of plate 18.Therefore, in practice, shutoff stroke is 1.5 times of eye diameter at least.Such stroke will make eyelet 25 on the choke block 24 in the location, position at as shown in the figure valve plate 18 tops.When choke block 24 arrives as shown in the figure closed position, in order to guarantee that fixed head has enough length with supporting choke block 24, fixed head must have the extra length D that exceeds eyelet 25 centers, and this is 1.5D+1D=2.5D with regard to the total length that makes plate 18 and count from eyelet 19 centers.
For all the other length of determining that fixed head 18 is counted from eyelet 19 centers, a need is considered throttle position after between the eyelet 25 ' of the eyelet 19 of fixed head and choke block 24, because fixed head 18 need not to hold two independent shutoff strokes.Therefore, the Lower Half length of fixed head 18 is the additional length that 0.66D (it allows that choke block eyelet 25 ' arrives maximum back throttle position as shown in Figure 4) adds 1.5 times of eye diameters, has so just guaranteed that fixed head 18 provides enough supportings to choke block 24 in slide gate nozzle 2.Therefore fixed head Lower Half length overall is 0.66D+1.5D=2.16D.Consider the plate length of two parts up and down, the length overall of fixed head 18 (identical with the length overall of upper mounted plate 14) should be 2.16D+2.5D=4.66D.In order to guarantee that fixed head 18 has enough width in slide gate nozzle 2, bear the mechanical stress that molten steel stream is applied to it so that have enough structural strengths, simultaneously also in order to provide enough seating surfaces to tubular plates or pocket block, the width of plate 18 in eyelet 19 center line both sides should be 1.5 times of eye diameter, makes that overall width is 1.5D+1.5D=3.0D.Here come the length and the width of display plate with the maximum gauge of eyelet, when eyelet is not circle, also can uses the same method and represent relative dimensions according to the Breadth Maximum of eyelet.
Referring now to Fig. 5, Fig. 6 and Fig. 7, they have been described an angle of being cut the bight 54a~54d that cuts and have determined method, and the first step of this method is neighboring and and this neighboring structural line of half eyelet or 0.5D apart of making to be parallel to this plate interior week along plate 18.These structural lines are represented as 72a~72d in Fig. 5.These structural lines intersect at bight 74a~74d.Fig. 6 represented angle determine method second the step.At the intersection point 74a~74d of structural line and have between the point of contact 76a~76d of eyelet 19 of maximum gauge and make tangent line 78a~78d, each bar among tangent line 78a~78d all passes longitudinal centre line 70.The 3rd step of this method is not only determined angle, but also determines to be cut the length of top rake portion.Make straight line 80a~80d in this step in poly-, they not only intersect perpendicular to tangent line 78a~78d but also with horizontal tectonics line 72b and 72d.These straight lines 80a~80d is used for guiding and cuts the bight of cutting processing tile 18, is cut the 54a~54d of top rake portion to form.
Fig. 6 has represented that also a kind of more common definite quilt cuts the method for the angle of the bight 54a~54d that cuts.In this common method, structural line line segment 82a~82b (no matter whether eye diameter is maximum on the valve plate, its length is an eye diameter D) draws perpendicular to the length and the width of valve plate, thereby forms a square as shown in the figure.In this more common method, the angle of being cut the 54a~54d of top rake portion is according to any straight line that falls into angle B and definite, the summit of angle B is point of contact 76c, extend by the intersection point 84 of structural line line segment 82a recited above and 82b on one side of this angle, its another side by cut in the bight cut before the intersection point 86 of plate 18 long limits and broadside.Arbitrary the straight line that falls into angle B all can be used to determine one and cuts the top rake degree that its method is to realize as vertical line by arbitrary straight line in this family of straight lines.Every vertical line extends through the intersection point of horizontal tectonics line 72b and 72d, thereby all can be determined by the length and the angle of section top rake portion.
Fig. 8 has represented to cut according to a kind of more specifically embodiment of this method the plate 18 of the 54a~54d of top rake portion, and vertical with tangent line 78a~78d herein straight line is used for determining concrete section top rake degree.After the bight was cut off, as shown in Figure 9, preferably the end with them was rounded to 90 such fillets.The bight of this rounding helps to prevent that the folding corner region at plate 18 from producing local stress.
Figure 10 has represented that size of the present invention is determined and the final products of cutting method are cut in the bight.Special needs to be pointed out is that the width of the 3.0D of plate 18 makes it can hold tubulose fixture 20, the width of the installing plate 21 of tubulose fixture and length are 2.5 times of eye diameters.
Figure 11 has described with respect to maximum aperture diameter D to Figure 13 and has determined the respective length of choke block 24 and the method for cutting the top rake degree of width dimensions and definite bight 30a~30d.With respect to the first half of choke block 24, as in fixed head 18, shutoff stroke is the half as much again or the 1.5D of maximum aperture diameter at least.During this external closed position, the center of eyelet 19 also needs to increase the refractory slab of 1.5D on fixed head 18, so that provide enough plate length feed flows to press the assembling and the operation of linkage.Therefore, the length of choke block 24 first halves must be 1.5D+1.5D=3.0D.Now,, need 2/3 eye diameter or 0.66D at least in order to adapt to the back throttle position referring to the latter half of plate 24.And, also need the length of 2 eye diameters outside the throttle position in the back, prevent to produce between the plate air-breathing unexpectedly to guarantee supporting fully and enough sealings.So the total length of choke block Lower Half must be 0.66D+2.0D=2.66D.The total length of the upper and lower two halves addition of choke block 24 is 3.0D+2.66D=5.66D.The choke block width is identical with definite method of fixed head 18 width, uniformity that is beneficial to make and convenience.Thereby the width of choke block 24 also is 1.5D+1.5D=3.0D.
Referring now to Figure 13, the angle of being cut the 30a~30d of top rake portion on the choke block 24 can be used with the same method of aforementioned fixation plate 18 (particularly Fig. 6) and accurately determine.Therefore, do not need to repeat the details of this method step.But it is to be noted, except utilize described in Fig. 6 determine by the concrete grammar of the angle of section top rake portion perpendicular to the structural line of aforementioned tangent line 78a~78d, also can utilize bight more common, determine choke block 24 with reference to the method in 18 upper right corner of plate among Fig. 6.
Though only in the mode of single preferred embodiment the present invention is narrated, to those skilled in the art, different improvement, increase and variation are conspicuous.All such improvement, increase and variation all drop within the scope of the present invention defined in the appended claims book.