JP2003080307A - Method for setting flow speed of emulsion in conduit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for setting the flow speed of emulsion in a conduit in which the flow speed of the emulsion in the conduit where the emulsion consisting of oil diluted with water flows is adjusted under a prescribed condition, and adhesion of any foreign matters to a conduit wall due to oil composition can be prevented. SOLUTION: In the method for setting the flow speed of the emulsion in the conduit in which the emulsion consisting of oil diluted with water flows in the conduit 20, and a part of the emulsion is ejected from a nozzle 3 provided in the conduit 20, the flow speed of the emulsion is adjusted so that the low laminator flow thickness δis smaller than the oil particle diameter R.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which an emulsion obtained by diluting oil with water flows in a pipeline, and a part of the emulsion is provided in the pipeline. The method of setting the flow rate of the emulsion in the pipeline that is to be sprayed from the nozzle, particularly, the outer pipe of the spray header used when the rolling oil is diluted with water and supplied in the emulsion state in cold rolling. The present invention relates to a method for setting a flow rate of an emulsion flowing in a pipe between the inner pipe and the inner pipe. 2. Description of the Related Art In cold rolling, the friction between a rolling roll of a rolling mill and a material to be rolled is reduced to facilitate the processing of the material to be rolled, or a product having a clean surface of the material to be rolled. For example, a rolling oil supply device shown in FIG. 5 is used (see Japanese Patent Publication No. 7-90251). In this rolling oil supply apparatus, rolling oil is supplied from an oil supply pipe 104 via oil supply control pumps 106, 106 'to inner pipes 109, 1 of spray headers 102, 102'.
09 'is supplied directly to the center. On the other hand, the dilution water is supplied from the water supply pipe 105 to the water supply control pump 11.
1 through the inner pipe 10 of the spray headers 102, 102 '.
9, 109 'is supplied directly to both ends. [0004] The spray header 10
As shown in FIG. 6, the dilution water supplied to 2, 102 'passes through end portion 113, ejector portion 114, body portion 118, and throttle portion 116, and reaches central enlarged portion 117. On the other hand, the rolling oil reaches the central enlarged portion 117 via the narrowing portion 116, where it is mixed with dilution water to form an emulsion. [0005] The emulsion passes through communication holes 110 formed in the central enlarged portion 117 to form outer tubes 108 and 108 '.
And the inner pipes 109 and 109 ′, and flow through the pipes, and a part thereof is jetted from the nozzles 103 and 103 ′ to the front and back surfaces of the material to be rolled 101. Also, the nozzle 10
Emulsion not jetted from 3, 103 'is guided to the body 118 through the hole 115 by the function of the ejector 114. The emulsion guided to the body 118 is mixed with dilution water, and then guided again to the central enlarged portion 117 via the squeezing section 116, where it is mixed with rolling oil to form a new emulsion. Thereafter, the same circulating operation is repeated so that emulsions having substantially the same concentration are ejected from all the nozzles 103, 103 'mounted on the spray headers 102, 102'. By jetting the emulsions having substantially the same concentration from all the nozzles 103 and 103 ', the rolling oil is uniformly applied in the width direction of the material to be rolled 101 so that the shape of the material to be rolled 101 becomes appropriate. Besides, it is possible to prevent the occurrence of seizure flaws between the material to be rolled 101 and the rolling roll. In FIG. 5, reference numerals 107 and 107 'denote a refueling control motor, and 112 denotes a water supply control motor. [0006] However, the conventional rolling oil supply apparatus has the following problems. That is, when the emulsion flows from the center to the end in the conduit between the outer pipes 108, 108 'and the inner pipes 109, 109' through the communication hole 110 formed in the central enlarged portion 117, Part of each nozzle 103,
103 ', the flow rate of the emulsion decreases from the center to the end, and the inner pipes 109 and 109' and the outer pipe 10
In some cases, foreign matter caused by an oil component adhered to the end pipe wall of the end portion of the pipe 108, 108 ', causing clogging of the pipe. When this pipe clogging occurs, the circulation operation of the emulsion is not performed smoothly, and it has been difficult to jet the emulsion from the nozzles 103 and 103 'at a uniform concentration. Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to adjust the flow rate of an emulsion in a pipeline through which an emulsion obtained by diluting oil with water flows under predetermined conditions. Accordingly, it is an object of the present invention to provide a method for setting the flow rate of an emulsion in a pipe, which can prevent foreign substances from adhering to a pipe wall due to an oil component. Means for Solving the Problems The present inventors can satisfactorily prevent foreign matter from adhering to a pipe wall due to a decrease in flow velocity.
Prior to setting the conditions of the flow rate of the emulsion in the pipe, a detailed study was conducted on what causes the foreign matter to adhere to the pipe wall due to the decrease in the flow rate. As a result, the thickness of the laminar bottom layer near the pipe wall is reduced by the oil particle diameter in the emulsion at the end where the flow velocity in the pipe in which the oil is diluted with water and the oil is diluted with water flows. It was found that when the thickness was larger than that, the foreign matter adhered to the tube wall. That is, as shown in FIG. 7, when the emulsion flows from the central portion to the end portion of the conduit between the outer tube 108 and the inner tube 109 through the communication hole 110, a part of the emulsion is removed. Since the liquid is ejected from each nozzle 103, the flow velocity of the emulsion decreases from the center to the end.
That is, the flow velocity V of the emulsion, a longitudinal that decreases toward the end portion from V ₁ in the longitudinal direction position P ₁ corresponding to the nozzle 103 ₁ of spray header central portion corresponding to the nozzle 103 _2, 103 ₃ endmost Direction position P ₂ , P ₃
, V ₂ and V ₃ . Flow rate V of this emulsion
Conversely, the thickness δ of the laminar flow bottom layer increases, and this thickness δ increases from δ ₁ at the longitudinal position P ₁ corresponding to the nozzle 103 ₁ at the center of the spray header toward the end, End nozzles 103 ₂ , 103 ₃
Δ ₂ , δ _{3 at} the longitudinal positions P ₂ , P ₃ corresponding to
It becomes. Here, the “laminar flow bottom layer” refers to a region where a laminar flow is maintained due to a decrease in flow velocity near the inner wall of the pipe. This flow velocity V
7 at the longitudinal positions P ₂ and P _{3 where}
As shown in (B), when the laminar flow bottom layer thicknesses δ ₂ and δ ₃ were larger than the oil particle diameter R in the emulsion, foreign matter adhered to the pipe wall. Here, the “oil particle diameter” refers to the emulsion particle diameter of oil (rolling oil) supplied to a pipeline as a water emulsion. Accordingly, the present invention has been made based on this finding. According to the first aspect of the present invention, an emulsion obtained by diluting oil with water flows in a pipeline, and a part of the emulsion is provided in the pipeline. A method for setting the flow velocity of an emulsion in a pipeline adapted to be ejected from a given nozzle, wherein the flow velocity of the emulsion is such that the laminar low layer thickness in the pipeline is smaller than the oil particle diameter. It is characterized by adjustment. According to this flow velocity setting method, at every part in the pipeline, particularly at the end in the pipeline where the flow velocity decreases,
The flow velocity of the emulsion is adjusted so that the laminar low-layer thickness in the pipeline becomes smaller than the oil particle diameter, foreign matter caused by the oil component is prevented from adhering to the wall of the pipeline, and clogging of the pipeline is avoided. Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a rolling oil supply device to which a method for setting a flow rate of an emulsion in a pipeline according to the present invention is applied. FIG. 2 is a sectional view of a spray header used in the rolling oil supply device shown in FIG. 3 (A) is a schematic view of the spray header shown in FIG. 2, and FIG. 3 (B) is a relation between the flow velocity of the emulsion and the thickness of the laminar bottom layer with respect to the longitudinal position of the spray header according to the present invention, and the laminar bottom layer thickness. 4 is a graph showing the relationship between the particle size and the oil particle diameter. The rolling oil supply device shown in FIG. 1 includes a rolling roll (not shown) of a rolling mill and a material 1 to be rolled in cold rolling.
The rolling oil supply device is used for reducing the friction between the rolling material 1 and facilitating the processing of the material 1 to be rolled, or finishing the surface of the material 1 to be a clean product. , The rolling oil is supplied from the oil supply pipe 4 via the oil supply control pumps 6 and 6 'to the inner pipe 1 of the spray headers 2 and 2'.
1, 11 'is supplied directly to the central part. On the other hand, the dilution water is supplied from the water supply pipe 5 to the water supply control pump 8.
Are supplied directly to both ends of the inner tubes 11, 11 'of the spray headers 2, 2'. Then, the spray header 2,
As shown in FIG. 2, the dilution water supplied to 2 ′
3, through the ejector section 14, the body section 16 and the throttle section 17 to reach the central enlarged section 18. On the other hand, the rolling oil reaches the central enlarged portion 18 via the squeezing portion 17, where it is mixed with dilution water to form an emulsion. The emulsion passes through the communication hole 12 formed in the central enlarged portion 18 and reaches the pipe 20 between the outer pipes 10 and 10 ′ and the inner pipes 11 and 11 ′. A part is sprayed from the nozzles 3 and 3 'onto the front and back surfaces of the material 1 to be rolled.
Emulsion not jetted from the nozzles 3 and 3 ′ is guided to the body 16 through the hole 15 by the function of the ejector 14. The emulsion guided to the body 16 is mixed with dilution water, and then guided again to the central enlarged section 18 via the squeezing section 17, where it is mixed with rolling oil to form a new emulsion. Thereafter, the same circulating operation is repeated so that emulsions having substantially the same concentration are ejected from all the nozzles 3, 3 'mounted on the spray headers 2, 2'. Here, the emulsion is supplied to the central enlarged portion 18.
When flowing from the center to the end of the conduit 20 between the outer pipes 10, 10 'and the inner pipes 11, 11' through the communication holes 12 formed in the
Since the liquid is ejected from 3 ', the flow velocity of the emulsion in the pipeline 20 decreases from the center to the end. For this reason, the inner tubes 11, 1
Foreign matter due to the oil component may adhere to the end pipe walls of the end pipes 1 ′ and the outer pipes 10 and 10 ′, which may cause pipe clogging. However, in this embodiment, FIG.
As shown in FIG. 3A and FIG.
Is adjusted so that the laminar flow low layer thickness δ in the pipe is smaller than the oil particle diameter R in any of the longitudinal directions. Like that. That is, the flow velocity V of the emulsion, a longitudinal that decreases toward the end portion from V ₁ in the longitudinal direction position P ₁ corresponding to the nozzle 3 ₁ of spray header central portion corresponding to the nozzle 3 _2, 3 ₃ endmost Direction position P ₂ ,
V _2, V ₃ becomes in P _3, when the flow velocity V of the emulsion is lowered, becomes thicker thickness δ of the laminar bottom layer conversely,
The thickness [delta], becomes thicker toward the end portion from [delta] ₁ in the longitudinal direction position P ₁ corresponding to the nozzle 3 ₁ of spray header central, longitudinal position P that corresponds to the nozzle 3 _2, 3 ₃ endmost ₂ and P ₃ are δ ₂ and δ _3, and the flow velocity V is adjusted so that the thickest laminar low layer thickness δ ₂ and δ ₃ is smaller than the oil particle diameter R. The flow rate V of the emulsion is adjusted by the flow rate control device 19 connected to the oil supply control motors 7, 7 'of the oil supply control pumps 6, 6' and the water supply control motor 8 'of the water supply control pump 8. This is achieved by controlling the rotation speed of the pumps 6, 6 'and the water supply control pump 8. Hereinafter, the adjustment of the flow velocity V of the emulsion by the flow velocity control device 19 will be described in detail. In general, the "laminar bottom layer" is defined as a region near the inner wall of the pipe where the laminar flow is maintained due to a decrease in flow velocity.
As shown in the flow velocity distribution in the pipe of FIG. 4, the laminar bottom layer thickness (distance from the inner wall of the pipe 20) δ is given by ## EQU1 ## Here, a is the average fluid depth (m) / 4, and Re is the number of Reynolds nozzles. FIG.
The symbol v is the flow velocity of the fluid in the pipe. Then, as shown in FIG. 2 and FIG.
In the case of the double pipe structure having 0 and the inner pipe 11, the above-mentioned a and Re are expressed as follows. a: Fluid average depth (m) / 4 In a double pipe, m = (D−d) / 4 4 (2) Therefore, a = ((D−d) / 4) / 4 = (D−d) / 16 (3) where D is the diameter of the outer tube 10 and d is the diameter of the inner tube 11. Re: (V · L) / ν In a double tube, L = (D−d) (4) Therefore, Re = (V · (D−d)) / ν (5) V is the representative velocity of the flow (in the case of a pipe, the average velocity on the cross section, so-called average flow velocity), L is the representative length (in the case of a pipe, four times the average fluid depth), and ν is the dynamic velocity of the fluid. The viscosity coefficient. Therefore, when the spray header has a double pipe structure having an outer pipe 10 and an inner pipe 11 as shown in FIGS. 2 and 3, the above-mentioned laminar flow bottom layer thickness δ is as follows: Equation 2 The laminar bottom layer thickness δ can be expressed as a function of the average flow velocity V (this average flow velocity V is equivalent to the above-mentioned emulsion flow velocity V). On the other hand, the "oil particle size"
Is defined as the emulsion particle size of the oil (rolling oil) supplied to the pipeline as a water emulsion. The measurement of the emulsion particle size is performed by using an emulsion particle size measuring device such as a Coulter counter. Achieved by measuring. The flow velocity controller 19 controls the laminar flow bottom layer thickness δ expressed by the above equation (6) to be smaller than the average particle size in the particle size distribution measured by the emulsion particle size measuring device. Is determined such that the emulsion flows through the conduit 20 between the outer pipes 10, 10 ′ and the inner pipes 11, 11 ′ at the determined average flow rate V.
The number of rotations of the refueling control pumps 6, 6 'and the water supply control pump 8 is controlled. The diameter D of the outer tubes 10, 10 ', the diameter d of the inner tubes 11, 11', and the kinematic viscosity coefficient ν of the fluid necessary for determining the average flow velocity V of the emulsion are input to the flow rate control device 9 in advance. . Thus, the outer tubes 10, 10 'and the inner tube 1
1 and 11 ', the laminar flow low layer thickness δ is larger than the oil particle diameter R (the value of the above-mentioned average particle diameter) at every part in the pipe line 20, particularly at the end in the pipe line 20 where the flow velocity decreases. The average flow velocity V of the emulsion is adjusted so that the thickness becomes thinner, foreign matter caused by the oil component is prevented from adhering to the pipe wall, and clogging of the pipe is avoided. For this reason, the circulation operation of the emulsion is performed smoothly, and the emulsion from the nozzles 3 and 3 ′ can be reliably ejected at a uniform concentration. The range of the oil particle diameter R in the measured particle diameter distribution is about 3 to 50 μm, and the average particle diameter is 2 μm.
5 μm. For this reason, the flow velocity control device 19 determines the average flow velocity V of the emulsion such that the laminar bottom layer thickness δ represented by the above equation (6) becomes smaller than 25 μm, and the determined average flow velocity V Is the outer tube 10,1
It is preferable to control the rotation speeds of the oil supply control pumps 6, 6 'and the water supply control pump 8 so as to flow in the pipe line 20 between the oil pipes 0' and the inner pipes 11, 11 '. Adhered foreign matter is prevented from adhering to the pipe wall, and pipe clogging is avoided. More preferably, the rotational speeds of the oil supply control pumps 6, 6 'and the water supply control pump 8 are controlled so that the average flow velocity V of the emulsion becomes smaller than 3 μm, which is a value near the minimum particle size. Thereby, the outer tubes 10, 10 '
In the pipe 20 between the inner pipes 11 and 11 ′, particularly at the end of the pipe 20 where the flow velocity decreases, the laminar flow low layer thickness δ is a value near the minimum particle diameter of the oil particle diameter R. 3
The average flow velocity V of the emulsion is adjusted so as to be thinner than μm, so that adhesion of foreign matter due to the oil component to the tube wall is reliably prevented. Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various changes can be made. For example, in the present embodiment, the pipeline through which the emulsion obtained by diluting oil with water flows is the pipeline 20 between the outer pipe 10 and the inner pipe 11, that is, the pipeline of a double pipe. It may be a pipe in one pipe. When the flow velocity V of the emulsion is adjusted by the flow velocity controller 19, the flow velocity of the emulsion in the conduit 20, particularly the flow velocity of the emulsion at the end of the conduit 20, is measured by a flow velocity measuring device. The flow velocity measured by the apparatus may be compared with the determined average flow velocity V, and feedback control may be performed so as to eliminate the deviation of the flow velocity measured by the flow velocity measurement apparatus from the determined average flow velocity V. As described above, according to the method for setting the flow velocity of the emulsion in the conduit according to the first aspect of the present invention, the flow velocity of the emulsion is controlled by the thickness of the laminar bottom layer in the conduit. Since the thickness is adjusted to be smaller than the oil particle diameter, the laminar low-layer thickness in the pipe is smaller than the oil particle diameter in all parts in the pipe, particularly at the end in the pipe where the flow velocity is reduced. Thus, the flow rate of the emulsion is adjusted, foreign substances caused by oil components are prevented from adhering to the pipe wall, and pipe clogging can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a rolling oil supply device to which a method for setting a flow rate of an emulsion in a pipeline according to the present invention is applied. FIG. 2 is a sectional view of a spray header used in the rolling oil supply device shown in FIG. 3 (A) is a schematic view of the spray header shown in FIG. 2, and FIG. 3 (B) is a relation between the flow rate of the emulsion and the laminar bottom layer thickness with respect to the longitudinal position of the spray header according to the present invention, and the laminar bottom layer thickness. 4 is a graph showing the relationship between the particle size and the oil particle diameter. FIG. 4A is a schematic diagram showing a flow velocity distribution in a pipe;
(B) is an enlarged view of an arrow A part of (A). FIG. 5 is a configuration diagram of a conventional rolling oil supply device. 6 is a sectional view of a spray header used in the rolling oil supply device shown in FIG. 7A is a schematic view of the spray header shown in FIG. 6, and FIG. 7B is a diagram showing the relationship between the flow velocity of the emulsion and the laminar bottom layer thickness with respect to the longitudinal position of the conventional spray header, and the laminar bottom layer thickness. 4 is a graph showing the relationship between the particle size and the oil particle diameter. [Description of Signs] 1 Rolled material 2, 2 'Spray header 3, 3' Nozzle 3 ₁ Nozzle 3 at center ₂ Nozzle _{3 at} extreme end ₃ Nozzle at extreme end 4 Oil supply pipe 5 Water supply pipe 6, 6 ' Refueling control pump 7, 7 'Refueling control motor 8 Water supply control pump 9 Water supply control motor 10, 10' Outer pipe 11, 11 'Inner pipe 12 Communication hole 13 End part 14 Ejector part 15 Hole 16 Body part 17 Narrowing part 18 Center enlargement Part 19 Flow velocity control device 20 Pipe line 21 Pipe δ Laminar flow bottom layer thickness R Oil particle diameter

Continuation of front page    (72) Inventor Koji Kawashima             1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba             Inside the Iron Corporation Chiba Works (72) Inventor Katsuhiko Kato             1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba             Inside the Iron Corporation Chiba Works F term (reference) 2F030 CA10 CC01 CD08 CE04 CE13                 3J071 AA11 BB02 CC11 DD33 EE03                       EE23 EE26 FF16

Claims (1)

Claims: 1. An emulsion obtained by diluting oil with water flows in a pipeline, and a part of the emulsion is jetted from a nozzle provided in the pipeline. A method for setting the flow rate of an emulsion in a pipeline, wherein the flow rate of the emulsion is adjusted such that the thickness of the laminar bottom layer in the pipeline is smaller than the oil particle diameter. Flow rate setting method.