JP6108225B2 - Slurry concentration measuring apparatus and slurry concentration measuring method using the apparatus - Google Patents

Description

  The present invention relates to an apparatus for measuring the concentration of slurry injected from a nozzle in a wet blasting apparatus, and a method for measuring the concentration of slurry using the apparatus.

  Blasting is widely used in fine processing such as deburring, scale removal, surface roughness adjustment, thin film layer removal, and etching. For blasting, a dry blasting process in which a spray material such as fine particles or shot is sprayed from a nozzle onto a workpiece together with a high-pressure gas such as compressed air, and a slurry in which the spray material is dispersed in a liquid such as water. And wet blasting in which a high-pressure gas such as compressed air is jetted from a nozzle toward a workpiece. Compared to dry blasting, wet blasting has less scattering of fine particles such as spray material and cutting powder generated by blasting, so the work environment is good and the spraying material to the surface of the workpiece Since there is little adhesion, it is excellent in that it is easy to clean the workpiece after processing, and it is expected that opportunities to use wet blasting will increase in the future.

  The processing performance in the wet blast processing varies depending on the concentration of the slurry indicating the proportion of the content of the injection material in the slurry. Therefore, in order to manage the finishing accuracy of the workpiece, it is necessary to manage the slurry concentration and perform blasting. As an apparatus for managing the concentration of slurry, for example, in Patent Document 1, after the slurry is allowed to flow into a flexible tube, this weight is measured, and the concentration of the slurry is measured by calculating the measurement result. An apparatus is disclosed.

Japanese Utility Model Publication No. 06-066952

  The slurry concentration measuring device disclosed in Patent Document 1 is provided in a path branched from a path from the slurry tank to the nozzle. This slurry concentration measuring apparatus has an advantage that the concentration of slurry can be measured even during blasting. However, since the concentration of the slurry injected from the nozzle is affected by the high-pressure gas introduced into the nozzle, it does not necessarily match the concentration of the slurry flowing through the branched path, that is, the concentration of the slurry measured by the concentration measuring device. do not do. Therefore, the slurry concentration measuring device disclosed in Patent Document 1 cannot manage the slurry concentration with sufficient accuracy. An object of the present invention is to provide a slurry concentration measuring device for measuring the concentration of slurry ejected from a nozzle, and a slurry concentration measuring method using the slurry concentration measuring device.

  In the following description, “blasting” means “wet blasting” unless otherwise specified. The “slurry concentration” indicates the content of the injection material with respect to the slurry, and is expressed by mass%, volume%, or the like.

  The present invention relates to a slurry concentration measuring device for measuring the concentration of slurry injected with high-pressure gas from a nozzle of a wet blasting device and in which a propellant is dispersed in a liquid, and the slurry is contained therein. A concentration measuring container having an opening for introduction; and an opening / closing member having one end connected to the opening of the concentration measuring container and having a mechanism for opening and closing a path through which the slurry injected from the nozzle passes. The concentration measuring container is provided with an exhaust unit for discharging the high-pressure gas injected from the nozzle. According to the present invention, since the concentration of the slurry sprayed from the nozzle can be measured in advance before blasting, the finish accuracy of the workpiece can be managed. Furthermore, since the exhaust unit is provided in the concentration measuring container, the concentration of the slurry can be measured without being affected by the high pressure gas.

  In the present invention, preferably, a hollow introduction member having one end connected to the other end of the opening / closing member and introducing the slurry into the opening / closing member, the introduction member including an outer periphery of the one end, Connection for connecting the introduction member connected to the opening / closing member so that a gap is provided between the other end of the opening / closing member, the other end of the introduction member, and the nozzle outlet of the nozzle A member. According to this invention, even when the opening / closing member is closed, the high-pressure gas can be discharged from the gap between the outer periphery of the introduction member and the inner periphery of the opening member.

  In the present invention, preferably, a rectifying member for rectifying the flow of the slurry introduced into the concentration measuring container is connected to the opening of the concentration measuring container. Inside the concentration measurement container, an air flow toward the exhaust part is generated. In the present invention having such a configuration, the flow of the slurry introduced into the concentration measuring container is rectified by the rectifying member, so that the introduced slurry is carried on the airflow and leaked outside from the exhaust part. Can be prevented.

  In the present invention, preferably, a scattering prevention member for preventing the introduced slurry from rebounding is disposed inside the concentration measuring container. If the slurry bounces back as a drop when it falls to the bottom of the slurry concentration measurement container, it may leak out of the exhaust section on the airflow generated in the slurry concentration measurement container. In the present invention having such a configuration, since the scattering prevention member is provided, it is possible to prevent the slurry bounced back as a droplet from being obstructed by the scattering prevention member and getting on the airflow.

  In this invention, Preferably, the sedimentation speed | velocity | rate of the injection material in the said slurry is 0.20-200 mm / sec. According to the present invention having such a configuration, the injection material in the slurry concentration measurement container can be allowed to settle without separating the time, and the injection material and the liquid can be separated.

  The slurry concentration measuring method of the present invention includes a step of closing the path of the opening / closing member, a step of sending slurry to the nozzle, a high pressure gas being introduced into the nozzle, and a mixture of the slurry and the high pressure gas mixed together. A step of jetting from the nozzle as a gas-liquid three-phase flow, a step of opening the path of the opening / closing member after a predetermined time has elapsed after jetting the solid-gas-liquid three-phase flow, and measuring the concentration of the slurry. A step of collecting by the container and exhausting the high-pressure gas flowing into the concentration measuring container together with the slurry by the exhaust part; and a step of obtaining the concentration of the slurry using the slurry collected by the concentration measuring container; . According to the present invention, since the concentration of the slurry sprayed from the nozzle can be measured in advance before blasting, the processing accuracy of the workpiece can be managed.

  In the present invention, preferably, the speed of the solid-gas / liquid three-phase flow is reduced until the solid-gas / liquid three-phase flow injected from the nozzle reaches the opening / closing member. According to the present invention having such a configuration, the opening / closing portion can be prevented from being worn by the cutting force of the solid-gas-liquid three-phase flow.

  In the present invention, preferably, at least one of the mass and volume of the slurry collected in the concentration measurement container and the spray material is measured, and the concentration of the slurry is calculated based on the result. According to the present invention having such a configuration, the concentration of slurry can be measured by a simple method.

  In the present invention, preferably, an initial measurement step of measuring at least one of a mass or a volume of the slurry deposited on the opening / closing member while the path of the opening / closing member is closed, a slurry deposited on the opening / closing member, and A stationary phase measuring step of measuring at least one of the mass or volume of the slurry jetted from the nozzle for a predetermined time, and the slurry jetted from the nozzle based on the values measured in the initial measuring step and the stationary phase measuring step. Calculate the concentration. In the present invention having such a configuration, since the influence of the slurry accumulated on the opening / closing portion can be excluded, the concentration of the slurry can be measured more accurately.

  The present invention also relates to a slurry concentration measuring device for measuring the concentration of slurry ejected from a nozzle in a wet blasting apparatus in which a slurry in which a propellant is dispersed in a liquid is ejected from a nozzle together with a high-pressure gas. And closing the upper end of the slurry collecting container provided with a slurry collecting container for collecting the slurry sprayed from the nozzle and an opening for introducing the slurry into the slurry collecting container. A concentration measuring container having a ceiling, and an open / close member that is connected to the opening and that introduces slurry into the slurry collecting container, and that opens and closes a path through which the slurry passes. An opening / closing member provided, and one end connected to the other end of the opening / closing member, for introducing the slurry into the opening / closing member, between an outer periphery of the introducing member and the inside of the opening / closing member Gap And a connecting member for connecting the other end of the introducing member and the injection port of the nozzle, and discharging the high pressure gas injected from the nozzle to the concentration measuring container. An exhaust part is provided for this purpose. In this invention, since the density | concentration of the slurry injected from a nozzle can be measured beforehand before performing blasting, the finishing precision of a workpiece can be managed.

  The processing capability of blasting depends on the concentration of slurry in the injected solid-gas-liquid three-phase flow. Measuring the concentration of the slurry injected from the nozzle is very important in managing the finishing accuracy of the workpiece. The concentration of the slurry can be measured more accurately by directly measuring the slurry injected from the nozzle than in the slurry tank or in the path from the slurry tank to the nozzle. According to the present invention, since the concentration of the slurry that is actually injected can be measured before blasting, the processing accuracy of the workpiece can be managed and stable blasting can be performed.

It is a figure which shows an example of a wet blast processing apparatus. It is a schematic diagram for demonstrating embodiment of this invention. It is a flowchart explaining the process of measuring the density | concentration of the slurry in embodiment of this invention. It is explanatory drawing which shows the state of the injection amount (discharge amount) of the slurry from the nozzle in embodiment of this invention, a pump, an air compressor, and an opening-and-closing member.

  An embodiment of a slurry concentration measuring apparatus of the present invention will be described with reference to the drawings. In the following description, up, down, left, and right directions are directions in the figure unless otherwise specified.

  FIG. 1 is a diagram showing a blasting apparatus 20 of the present embodiment. As shown in the figure, the blast processing apparatus 20 includes a blast processing chamber 21 and a slurry tank 22 provided below the blast processing chamber 21. The slurry storage tank is a tank for storing the slurry and is filled with the slurry. The slurry is formed by dispersing the propellant in a liquid (in this embodiment, water). The slurry tank 22 is connected to the nozzle N via the pump P2. The slurry in the slurry tank 22 is sent to the nozzle N by driving the pump P2.

  In addition, an injection material is an abrasive grain (abrasive material) for performing blasting. The abrasive grains can be generally used for blasting regardless of whether dry or wet, such as iron and non-ferrous metal particles (shots, grids, cut wires, etc.), ceramic particles, plant particles, and resin particles. If it is a particle | grain, it will not specifically limit.

  The nozzle N is connected to a high-pressure gas generation mechanism (in this embodiment, an air compressor 27), and high-pressure gas (in this embodiment, compressed air) is sent from the air compressor 27 to the nozzle N. Slurry and compressed air sent to the nozzle N are mixed inside the nozzle N and injected toward the workpiece W as a solid-gas-liquid three-phase flow. Blasting is performed by the slurry in the injected solid-gas-liquid three-phase flow colliding with the workpiece W. Then, the slurry injected toward the workpiece W flows into the slurry tank 22 and is collected.

  Further, the blasting apparatus 20 includes a sorting mechanism 23 and a separation mechanism 24. The sorting mechanism 23 includes a pump P <b> 1 for pumping up the slurry from the slurry tank 22. When blasting is performed, fine particles are generated by the collision between the spray material and the workpiece, and these fine particles flow into the slurry tank 22. As such fine particles, a part of the injection material is cracked or chipped, and the injection material has a size that is not suitable for blasting, or the workpiece W caused by the collision between the injection material and the workpiece W. Examples thereof include cutting powder.

  The slurry in the slurry tank 22 is sent to the sorting mechanism 23 by the pump P1 while containing fine particles. The sorting mechanism 23 separates the fine particles contained in the sent slurry from the reusable spray material suitable for blasting. The spray material suitable for blasting sorted by the sorting mechanism 23 is returned to the slurry tank 22. The fine particles selected by the selection mechanism 23 are sent to the separation mechanism 24. The fine particles sent to the separation mechanism 24 are subjected to solid-liquid separation, and the solid matter is recovered as sludge in the sludge tank 25 and the liquid is recovered in the liquid storage tank 26.

  The path extending from the pump P2 to the nozzle N is branched in the middle, and a part of the slurry pumped up by the pump P2 is returned to the slurry tank 22 by this branched path. In this way, when the pump P2 is driven, a part of the slurry returns to the slurry tank 22, so that the slurry in the slurry tank 22 is agitated.

  FIG. 2 is a cross-sectional view showing the concentration measuring apparatus 10 for measuring the concentration of the slurry according to the present embodiment. The concentration measuring apparatus 10 of the present embodiment is attached to the tip of the nozzle N, and directly collects the slurry injected from the nozzle N and measures the concentration. The concentration measuring device 10 includes a concentration measuring container 11, an exhaust part 12 provided on the side wall of the concentration measuring container 11, a cylindrical opening / closing member 13 connected to the upper part of the concentration measuring container 11, and an opening / closing member 13. An introduction member 14 connected to the upper portion, and a connecting member 15 that connects the introduction member 14 and the nozzle N are provided. The opening / closing member 13 is a cylindrical member, and the lower end of the introduction member 14 is inserted into the upper portion thereof. As will be described in detail later, a gap S is formed between the upper end of the opening / closing member 13 and the lower end of the introduction member 14.

The concentration measuring container 11 is a slurry collecting container 11a having a cylindrical upper casing 11a _{1 with} both upper and lower ends opened and a bottomed cylindrical lower casing 11a ₂ removably attached to the lower end of the upper casing 11a _1. And a lid 11b that forms the ceiling of the slurry collecting container 11a. A plurality of openings 11c are provided on the upper side surface of the upper casing 11a _1.

When the solid-gas-liquid three-phase flow is ejected from the nozzle N, the compressed air in the solid-gas-liquid three-phase flow is exhausted (outflowed) to the outside from the opening 11c. However, the cross-sectional area A ₁ of the opening 11c is too small, the pressure in the slurry collection vessel 11a is increased from the nozzle N in a solid-gas-liquid three phases flow is injected, the closing member 13 and the introduction member 14 Compressed air is also exhausted from the gap S formed between the two. As a result, part of the slurry rides on the flow of compressed air exhausted from the gap S and leaks out. For this reason, in this embodiment, the sum of the cross-sectional areas of the openings 11c is set to be larger than 2.2 × 10 ⁻³ m ² .

Further, the total A ₁ of the cross-sectional area of the opening 11c is too small with respect to the cross-sectional area A ₂ of the introduction member outlet 14b, when the gas-solid-liquid three phases flow is introduced into the concentration measuring vessel 11, the concentration measuring vessel 11 is increased in pressure. As a result, the slurry cannot be satisfactorily introduced into the concentration measuring container 11. Conversely, if the total A ₁ of the area of the opening 11c is too large for the area A ₂ of the introduction member outlet 14b, density measurement container 11 becomes large. Therefore, it is preferable to the ratio of the sum _{A 1} of the cross-sectional area of the opening 11c of the _(A 1 / _{A 2)} 10 to 45 to the cross-sectional area _{A 2} of the introduction member outlet 14b, in the range of 10 to 25 Further preferred.

A confirmation window (not shown) for confirming the capacity of the slurry from the outside is provided on the side surface of the lower casing 11 a ₂ , and a scale is marked on the confirmation window. Below the opening portion 11c of the inner wall of the upper casing 11a _1, splash prevention member 11f is provided. An opening 11 d for introducing slurry into the concentration measuring container 11 is provided at the center of the lid 11 b.

  The exhaust part 12 is formed by connecting a hollow exhaust member having both ends opened to the opening part 11c. The exhaust unit 12 defines a path for exhausting the compressed air introduced into the concentration measuring container 11 together with the slurry. The shape of the exhaust member is not particularly limited, but in this embodiment, it is a curved L-shape.

A rectifying member 11e that rectifies the flow of the slurry when it is introduced into the concentration measuring container 11 is provided at the peripheral edge of the opening 11d of the lid 11b so as to extend downward. In the present embodiment, a cylindrical member having the same inner diameter as the opening 11d is used as the rectifying member 11e. Here, if the ratio (L / D ₁ ) of the length L of the rectifying member 11e to the diameter D ₁ of the opening 11d is too small, the effect of rectifying is small. Conversely, if the ratio (L / D ₁ ) of the length L of the rectifying member 11e to the diameter D ₁ of the opening 11d is too large, the straightness of the slurry introduced into the concentration measuring container 11 increases, so concentration measurement The force with which the slurry collides with the bottom of the container 11 increases. For this reason, the amount of slurry that rebounds at the bottom increases, and the amount of slurry that leaks to the outside from the exhaust port 12a that is the outlet of the exhaust unit 12 increases as described later. For these reasons, the ratio of the length L of the flow control member 11e to the diameter _{D 1} of the opening 11d (L / _{D 1)} is preferably a 0.1 to 6.5, and 0.2 to 5.0 More preferably.

  An opening / closing member 13 is connected to the upper side of the opening 11d. The opening / closing member 13 defines a path through which the slurry passes and has a mechanism that can open and close the path. The mechanism of the opening / closing member 13 is not particularly limited as long as it can open and close the path. However, it is preferable that the opening / closing member 13 is made of an abrasion-resistant material because the slurry passes therethrough. The opening / closing member 13 according to the present embodiment includes a cylindrical casing 13c having both ends opened, and an abrasion-resistant elastic tubular body 13d that is disposed inside the casing 13c and has a through passage inside. . Flange portions are provided at both ends of the casing 13c, and one end thereof is fixed to the lid 11b. Thereby, one end (opening / closing member outlet 13b) of the opening / closing member 13 is connected to the opening 11d formed in the lid 11b of the concentration measuring container 11.

  A gap is provided between the casing 13c and the elastic tubular body 13d. The gap is connected to the air compressor 27 via a connector 13e connected to the casing 13c, a hose (not shown), and an on-off valve (not shown). When compressed air is pressed into the gap, the elastic tubular body 13d swells toward the center as the pressure in the gap increases. As a result, the through path inside the elastic tubular body 13d is closed, and the opening / closing member 13 is closed. Since the opening / closing member 13 functions as a path through which the through passage inside the elastic tube flows, the path of the slurry can be opened and closed by press-fitting and discharging compressed air into the gap.

  An introduction member 14 is disposed at the upper end of the opening / closing member 13 (opening / closing member inlet 13a). The introduction member 14 is formed of a hollow member having both ends opened. The introduction member 14 is fixed by a base 16 fixed to the upper end of the opening / closing member 13 so that the lower end (introduction member outlet 14b) of the introduction member 14 is disposed in the upper portion of the slurry path of the opening / closing member 13. .

The outer diameter of the introduction member outlet 14b is smaller than the inner diameter of the opening / closing member inlet 13a. For this reason, the lower end of the introduction member 14 is inserted into the opening / closing member inlet 13a, and a gap S is formed between the opening / closing member inlet 13a and the introduction member outlet 14b. The height position h of the introduction member outlet 14b relative to the opening / closing member inlet 13a (in FIG. 2, the height position of the opening / closing member inlet 13a is 0 and the upward direction is positive) can be arbitrarily set. the ratio of the height h of the introduction member outlet 14b to the diameter _{D 2} of the inlet 13a (h / _{D 2)} is it is preferable to be -0.5 to 0.5, to the -0.3～0.3 Is more preferable. This is for the following reason. When the ratio of the height position h of the introduction member outlet 14b to the diameter D ₂ of the opening and closing member inlet 13a (h / D ₂₎ is too small, since the introduction member outlet 14b is penetrated than necessary closing member 13, the opening and closing member It is difficult for the slurry to flow out of the gap S when 13 is closed. Also, wider than necessary spacing between the ratio of the height h of the introduction member outlet 14b to the diameter D ₂ of the opening and closing member inlet 13a (h / D ₂₎ is too large and the opening and closing member inlet 13a and the introduction member outlet 14b Therefore, when the opening / closing member 13 is opened, the slurry leaks outside through the gap S formed between the opening / closing member inlet 13a and the introduction member outlet 14b, and it becomes impossible to introduce all the slurry into the introduction member 14. .

  One end of a hollow connection member 15 having both ends opened is connected to the upper end of the introduction member 14 (introduction member inlet 14a). The other end of the connecting member 15 is connected to the nozzle N. Since the solid-gas-liquid three-phase flow injected from the nozzle N passes through the connecting member 15 when measuring the slurry concentration, the connecting member 15 is preferably made of an abrasion-resistant material. In this embodiment, a member that is a flexible tube made of polyvinyl chloride (PVC) is used.

Introducing the member outlet 14b sectional area A ₂ is too small with respect to the cross-sectional area A ₃ of the injection port of the nozzle N, can not be satisfactorily introduced into the slurry density measurement container 11 be opened closing member 13 Slurry accumulates on the introduction member 14 and the connecting member 15. Further, it is necessary to enlarge the size of the introducing member outlet 14b of the cross-sectional area A ₂ is too large and the opening and closing member 13 with respect to the cross-sectional area A ₃ of the injection port of the nozzle N, as a result the concentration measuring apparatus itself large Become. For this reason, the ratio (A ₂ / A ₃ ) of the cross-sectional area A ₂ of the introduction member outlet 14b to the cross-sectional area A ₃ of the injection port of the nozzle N is preferably 3.5 to 25.0, and preferably 5 to 15 More preferably, it is in the range.

  Hereinafter, a method for measuring the concentration of the slurry ejected from the nozzle N using the concentration measuring apparatus 10 will be further described with reference to FIGS. FIG. 3 is a flowchart for explaining the process of measuring the concentration of the slurry according to the present embodiment. FIG. 4 shows the amount of slurry injected from the nozzle (discharge amount), the pump, the air compressor, and the opening / closing in the present embodiment. It is explanatory drawing which shows the state of a member. The following slurry concentration measurement is performed before or during blasting.

As shown in FIG. 3, the opening / closing member 13 is closed (S01), the injection port of the nozzle N is connected to the connecting member 15 (S02), and then the pump P2 is driven (S03). When the pump P2 is driven, the slurry in the slurry tank 22 is stirred and the slurry is sent to the nozzle N. The slurry sent to the nozzle N is discharged from the injection port of the nozzle N. At this time, the path of the slurry in the opening / closing member 13 is closed. As a result, the slurry does not flow into the concentration measurement container 11 but flows out through the gap S formed between the opening / closing member 13 and the introduction member 14. Incidentally, the cross-sectional area A ₄ is too small gap S formed between the closing member 13 and the introduction member 14 with respect to the cross-sectional area A ₂ of the introduction member outlet 14b, that slurry flows out from the gap S The slurry stays in the opening / closing member 13, the introducing member 14, and the connecting member 15. Further, the flow velocity of the slurry discharged when there is formed a cross-sectional area A ₄ of the clearance S is too large from the gap S between the opening and closing member 13 with respect to the cross-sectional area A ₂ and the introduction member 14 of the introducing member outlet 14b The injection material in the slurry stays in the opening / closing member 13 as it becomes late. If the cross-sectional area of the gap S is too large or too small, the propellant in the slurry settles in the slurry path in the closing member 13 due to the retention of the slurry, and the slurry path is closed by the accumulated propellant. The Therefore, the ratio (A ₄ / A ₂ ) of the cross-sectional area A ₄ of the gap S formed between the opening / closing member 13 and the introduction member 14 to the cross-sectional area A ₂ of the introduction member outlet 14 b is 0. It is preferably 2 to 6.0, more preferably 0.5 to 3.5.

After driving the pump P2, the amount of slurry discharged from the nozzle N of a predetermined time t ₁ has elapsed is constant. However, since the slurry is not sufficiently stirred at this time, the concentration of the slurry sent to the nozzle N is unstable. Therefore, it further waits for a predetermined time t ₂ in this state. As a result, the concentration of slurry and the discharge amount from the nozzle N become constant.

When the predetermined time (t ₁ + t ₂ ) has elapsed (Yes in S04), compressed air is supplied to the nozzle by the air compressor 27 (S05), and the slurry is injected from the nozzle N as a solid-gas-liquid three-phase flow. At this time, the slurry may collide with the opening / closing member 13 and the opening / closing member 13 may be worn out. In order to prevent such wear and tear, it is necessary to sufficiently decelerate until the solid-gas-liquid three-phase flow reaches the opening / closing member 13. For this reason, in this embodiment, when the pressure of compressed air is 0.3 to 0.5 MPa, the length of the connecting member 15 is about 300 mm. Moreover, when it is necessary to further decelerate, it can decelerate by flow resistance by curving the connection member 15. At that time, in order to prevent wear caused by the collision of the solid-gas liquid three-phase flow with the curved portion, it is preferable to reinforce the portion where the solid-gas liquid three-phase flow collides with an abrasion resistant material (for example, abrasion resistant rubber). .

Discharge amount of the slurry from the nozzle N, i.e. the injection amount is reduced by the flow of compressed air, comprising after the driving of the air compressor 27, the predetermined time t ₃ has elapsed constant. However, immediately after the predetermined time t ₃ has elapsed which may be injected by pulsating injection material. Thus, further opening the passage opening and closing section 13 after a predetermined time _{t 4} has passed (Yes at S06) (S07), thereby introducing the solid-gas-liquid three phases flow into the concentration measuring container 11. At this time, the compressed air introduced as a solid-gas liquid three-phase flow is exhausted from the exhaust unit 12.

  Inside the concentration measurement container 11, an air flow toward the exhaust unit 12 is generated. For this reason, the solid-gas-liquid three-phase flow introduced from the opening portion 11d of the lid 11b is dispersed in the left-right direction in FIG. 2, and the slurry rides on this air flow and is external to the exhaust port 12a that is the outlet of the exhaust unit 12. There is a risk of leakage. In contrast, in the present embodiment, the flow of the solid-gas-liquid three-phase flow introduced into the introduction member 11 is rectified by the rectification member 11e provided in the opening 11d, so that the introduced slurry is internally It can be prevented from being leaked to the outside by the airflow.

When a solid-gas-liquid three-phase flow is introduced into the concentration measuring container 11, slurry accumulates at the bottom of the concentration measuring container 11. At this time, when the newly introduced slurry collides with the slurry accumulated in the concentration measuring container 11 and bounces back as a droplet, the bounced slurry rides on the airflow inside the introduction member 14 as described above and exhausts. There is a risk of leakage from the mouth 12a to the outside. In contrast, in the present embodiment, since the inner wall splash prevention member 11f of the upper casing 11a ₁ is provided, by this rebound, can prevent leakage to the outside of the slurry. Scattering prevention member 11f is a ring-shaped plate member in the present embodiment, as the inner is inclined toward the bottom surface direction (e.g., the angle α is 45 to 75 degrees with the side wall of the upper casing 11a _1), a slurry catching It fixed along the inner wall of the collection container 11a. The length of the anti-scattering member 11f may be selected as appropriate so that the slurry bounced off at the bottom does not get on the air flow and does not prevent the slurry introduced into the concentration measuring container 11 from dropping.

When the opening / closing member 13 is opened, the slurry accumulated on the opening / closing member 13 is also introduced into the concentration measuring container 11. For this reason, it is necessary to eliminate this influence. Therefore, first, an “initial measurement process” is performed to measure the initial slurry (“initial measurement” in S08). That is, the slurry is introduced into the concentration measuring container 11 while the opening / closing member 13 is opened in S07. After the slurry deposited in the path of the closing member 13 has passed sufficient time _{t 5} for being introduced into the concentration measuring vessel 11 (Yes in S09), it closes the closing member 13 (S10). after that. The operation of the pump P2 is stopped (S11), and the supply of compressed air to the nozzle is stopped (S12).

Remove the lower casing 11a _2, it is calculated from the scale of the confirmation window volume Vs ₁ of the slurry of the lower casing 11a _2. Further, measuring the mass Ms ₁ of the slurry at a mass meter (S13). After the measurement, the lower casing 11a ₂ is emptied and again connected to the upper casing 11a ₁ (S15).

Next, a “stationary period measurement step” is performed to measure the concentration of the slurry that is actually injected (“stationary period measurement” in S08). The above-described steps S03 to S07 are performed again to open the path of the opening / closing member 13 and introduce the slurry into the concentration measuring container 11. After the predetermined time (t ₅ + t ₆ ) has elapsed (Yes in S16), the opening / closing member 13 is closed (S17). The predetermined time (t ₅ + t ₆ ) is appropriately selected so that the amount of slurry introduced into the concentration measurement container 11 does not exceed the upper limit value of the confirmation window.

After removal of the lower casing 11a _2, to calculate the volume Vs ₂ of the slurry of the lower casing 11a in ₂ from the scale of the confirmation window. Further, measuring the mass Ms ₂ at a mass meter (S18). The slurry in the lower casing 11a ₂ includes slurry that has accumulated in the opening / closing member 13 before the opening / closing member 13 is opened.

The true specific gravity of the solid can be calculated as ρ, and the concentration of the slurry can be calculated as mass% from the following formula (1). In the formula (1), V represents Vs ₂ -Vs ₁ and M represents Ms ₂ -Ms ₁ . The true specific gravity ρ of the solid matter may be the true specific gravity of the propellant, but in order to measure more accurately, the lower casing 11a ₂ is allowed to stand and the solid matter is allowed to settle in step S15. The true specific gravity may be measured by sampling. If the sedimentation rate of the solid matter is too slow, it takes a lot of time to measure, and if it is too fast, it will be difficult to supply a constant concentration of slurry to the nozzle. It is preferable that it is 0.2-200 mm / sec. In terms of conversion, the particle diameter is 30 to 1,000 μm and the specific gravity is 1.2 to 9.0.

  After calculating the slurry concentration (S19), the nozzle N is removed from the connecting member 15 (S20), and the measurement of the slurry concentration is terminated.

(Example of change)
It is also possible to calculate the concentration of slurry in mass% only from the mass of the slurry and the propellant. For example, in step S13 and step S18, the slurry is separated into a solid (that is, a propellant) and a liquid, and the steps of measuring the masses Mp ₁ and Mp ₂ of the solid are performed, respectively, using formula (2) It is also possible to calculate the concentration (mass%). Incidentally, Mp in the formula (2) represents an _Mp 2 -Mp _1, Mp ₂ is the mass of solids in the "stationary phase measurement step", Mp ₁ is solid in the "initial measurement step" mass And M represents Ms ₂ -Ms ₁ as described above. The method for separating the solids from the slurry is, for example, by allowing the lower casing 11a ₂ to stand and allowing the solids to settle, and then discharging the supernatant liquid, and then filtering the remaining solids and liquids by sieving, specific gravity separation, suction filtration, etc. By separating each by a known technique, it can be separated efficiently.

In the above embodiment, the slurry concentration is calculated by mass%, but may be calculated by volume%. For example, in steps S13 and S18, the lower casing 11a ₂ is allowed to stand still to settle the solid matter, and then the step of calculating the volume Vp ₁ and Vp ₂ of the solid matter that has settled is further performed, and Vp ₂ −Vp ₁ is calculated. If Vp, it can be calculated using equation (3). Vp ₁ and Vp ₂ indicate the volume of the solid in the “initial measurement step” and the “stationary phase measurement step”, respectively. Alternatively, a conversion coefficient for converting from volume% to mass% may be calculated in advance, and the slurry concentration may be calculated as mass% from the equation (3) and the conversion coefficient.

  A reference mass and a threshold value may be set in advance, and a reference value and a measured value may be compared. If the measured value is outside the threshold value of the reference value, it is determined that the concentration of the slurry sprayed from the nozzle N is not suitable for the target blasting, and it is determined to be rejected, and the concentration of the slurry in the slurry tank 22 is determined. adjust. Thereafter, the slurry injected from the nozzle N is measured again. This process may be repeated until the measured value is within the threshold range. Further, the reference value and the threshold value may be a volume.

  According to this embodiment, since the concentration of the slurry ejected from the nozzle can be measured in advance before blasting, the finishing accuracy of the workpiece can be managed. Furthermore, since the exhaust unit 12 is provided in the concentration measurement container 11, the slurry concentration can be measured without being affected by the compressed air.

(Effect of embodiment)
According to this embodiment, since the concentration of the slurry ejected from the nozzle can be measured in advance before blasting, the finishing accuracy of the workpiece can be managed. Furthermore, since the exhaust unit 12 is provided in the concentration measurement container 11, the slurry concentration can be measured without being affected by the compressed air.

And since the density | concentration of the slurry injected from a blast processing apparatus can be measured correctly in this way, the processing precision of the to-be-processed object in blast processing can be managed. Thus, by being able to manage the processing accuracy of the workpiece in blasting, for example, the following effects can be obtained.
(1) The surface roughness for each processing is stabilized.
(2) Since processing time can be predicted, useless processing time is not required.
(3) The present invention can also be applied to processing that requires high processing accuracy, such as etching.

  Further, according to the present embodiment, since the gap S is formed between the outer periphery of the introduction member 14 and the inner periphery of the opening / closing member 13, the compressed air is removed even when the opening / closing member 13 is closed. S can flow out to the outside.

  Further, according to this embodiment, the flow regulating member 11e is provided in the opening 11d of the concentration measuring container 11, and the flow of the slurry introduced into the concentration measuring container 11 is rectified by the rectifying member 11e. It is possible to prevent the slurried slurry from leaking out of the exhaust section 12 by riding on this airflow.

  Moreover, according to this embodiment, since the settling speed of the injection material in the slurry is 0.20 to 200 mm / s, the injection material in the slurry concentration measurement container 11 is allowed to settle without requiring much time. The propellant and the liquid can be separated.

  Further, according to the present embodiment, since the slurry is injected as a solid-gas-liquid three-phase flow, the opening / closing member 13 may be worn when the slurry collides with the opening / closing member 13, but the slurry is sufficiently decelerated. Therefore, wear of the opening / closing member 13 can be prevented.

  Further, according to the present embodiment, the concentration of the slurry is calculated based on at least one of the mass or volume of the slurry measured in the initial measurement step and at least one of the mass or volume of the slurry measured in the stationary phase measurement step. Therefore, since the influence of the slurry staying in the opening / closing member 13 can be excluded, the concentration of the slurry can be measured more accurately.

DESCRIPTION OF SYMBOLS 10 Concentration measuring device 11 Concentration measuring container 11a Slurry collection container 11a ₁ Upper casing 11a ₂ Lower casing 11b Lid 11c Opening (side surface)
11d Opening (lid)
11e Rectification member 11f Spattering prevention member 12 Exhaust part 12a Exhaust port 13 Opening / closing part 13a Opening / closing member inlet 13b Opening / closing member outlet 14 Introducing member 14a Introducing member inlet 14b Introducing member outlet 15 Connecting member 16 Mounting base 20 Blast processing device 21 Blasting chamber 22 Tank 23 Sorting mechanism 24 Separating mechanism 25 Sludge tank 26 Liquid storage tank 27 Air compressor N Nozzle P1, P2 Pump W Workpiece S Clearance

Claims (10)

A slurry concentration measuring device for measuring the concentration of slurry injected with high-pressure gas from a nozzle of a wet blasting device and in which a propellant is dispersed in a liquid,
A concentration measuring container having an opening for introducing the slurry therein;
An opening / closing member having one end connected to the opening of the concentration measurement container and having a mechanism for opening / closing a path through which the slurry injected from the nozzle passes,
An apparatus for measuring the concentration of a slurry, wherein the concentration measuring container is provided with an exhaust part for discharging high-pressure gas ejected from a nozzle. Furthermore, one end is connected to the other end of the opening / closing member, and the hollow introducing member introduces the slurry into the opening / closing member, the introduction member including an outer periphery of the one end and the other end of the opening / closing member. An introduction member connected to the opening and closing member such that a gap is provided between the inner periphery and the inner periphery;
The slurry concentration measuring apparatus according to claim 1, further comprising: a connecting member for connecting the other end of the introduction member and an injection port of the nozzle.   The rectification member for rectifying | straightening the flow of the slurry introduce | transduced into the inside of this concentration measurement container is connected with the opening part of the said concentration measurement container, The Claim 1 or Claim 2 characterized by the above-mentioned. Slurry concentration measuring device.   4. The slurry preventing member according to claim 1, wherein a scattering preventing member is disposed inside the concentration measuring container to prevent the introduced slurry from bouncing back. 5. Concentration measuring device.   The slurry concentration measuring apparatus according to any one of claims 1 to 4, wherein a settling velocity of the spray material in the slurry is 0.20 to 200 mm / sec. A slurry concentration measuring method using the slurry concentration measuring apparatus according to any one of claims 1 to 5,
Closing the path of the opening and closing member;
Sending slurry to the nozzle;
Introducing a high-pressure gas into the nozzle and mixing the slurry and the high-pressure gas and injecting from the nozzle as a solid-gas-liquid three-phase flow;
Opening the path of the opening and closing member after a predetermined time has elapsed since jetting the solid-gas-liquid three-phase flow;
Collecting the slurry by the concentration measuring container and exhausting the high pressure gas flowing into the concentration measuring container together with the slurry by the exhaust unit;
Determining the concentration of the slurry using the slurry collected by the concentration measuring vessel;
A method for measuring the concentration of a slurry, comprising:   In the step of mixing the slurry and the high-pressure gas and injecting it from the nozzle as a solid-gas-liquid three-phase flow, the solid-gas-liquid three-phase flow injected from the nozzle reaches the opening / closing member until the opening / closing member is reached. The method for measuring the concentration of slurry according to claim 6, wherein the speed of the solid-gas-liquid three-phase flow is reduced.   The step of determining the concentration of the slurry is characterized in that at least one of the mass and volume of the slurry and the spray material collected in the concentration measuring container is measured, and the concentration of the slurry is calculated based on the result. The method for measuring the concentration of the slurry according to claim 6 or 7. The step of determining the concentration of the slurry includes an initial measurement step of measuring at least one of a mass and a volume of the slurry deposited on the opening / closing member while the path of the opening / closing member is closed, and a deposition on the opening / closing member. A stationary phase measuring step of measuring at least one of the slurry and the mass or volume of the slurry sprayed from the nozzle for a predetermined time, and
9. The slurry concentration measuring method according to claim 8, wherein the concentration of the slurry injected from the nozzle is calculated from the values measured in the initial measurement step and the stationary phase measurement step. In a wet blasting apparatus for injecting a slurry in which a propellant is dispersed in a liquid together with a high-pressure gas from a nozzle, a slurry concentration measuring apparatus for measuring the concentration of slurry injected from the nozzle,
A slurry collecting container for collecting the slurry sprayed from the nozzle; and a ceiling part for closing the upper end of the slurry collecting container provided with an opening for introducing the slurry into the slurry collecting container; A concentration measuring container comprising:
One end is connected to the opening, and an opening / closing member for introducing slurry into the slurry collecting container, the opening / closing member having a mechanism for opening / closing a path through which the slurry passes;
One end is connected to the other end of the opening / closing member, and is an introduction member for introducing the slurry into the opening / closing member, and is connected with a gap provided between the outer periphery of the introduction member and the inside of the opening / closing member. Introduction member,
A connection member for connecting the other end of the introduction member and the injection port of the nozzle,
An apparatus for measuring the concentration of a slurry, wherein the concentration measuring container is provided with an exhaust part for discharging high-pressure gas ejected from a nozzle.

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