A wet spraying elastic reduction and dust reduction device

Abstract

The application discloses a wet-spraying elastic-reducing dust-settling device, which comprises a device body, the device body is a cylinder with a through hole along an axis, an inner cavity is formed in the device body, the inner cavity is composed of a medium inlet, a flow guide cavity, an internal confluence cavity, a rectifier cavity, an acceleration cavity and a medium ring outlet which are sequentially communicated, the through hole is used for accommodating a nozzle of concrete wet-spraying, and the medium accelerated by the acceleration cavity passes through the medium ring outlet to form a medium curtain at the front end of the device body. The device is integrally printed by using a 3D printing process, has a small volume, high integration, is convenient to install and ensures uniform and good sealing performance, reduces a jet diffusion angle of concrete wet-spraying operation and effectively reduces and separates dust.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shotcrete, in particular to a wet-type shotcrete rebound reduction and dust reduction device. BACKGROUND

[0002] Shotcrete, also known as sprayed concrete, is a construction technology that sprays pre-mixed concrete material to the surface that needs to be reinforced, repaired or protected through a spraying device, and is widely used in underground engineering, tunnels, rock support, slope protection, repair engineering and other fields. However, during the shotcrete process, the on-site dust concentration is often high, and due to its high allergenicity, high fineness and corrosive characteristics, it seriously threatens the health of on-site construction personnel, and also affects the service life of on-site mechanical equipment, increases equipment maintenance costs, and hinders construction progress. The existing patent CN 220791248 U discloses a nozzle for spraying concrete and a concrete spraying device for spraying concrete, which can simultaneously spray and remove dust by arranging multiple spray nozzles around the shotcrete nozzle. However, the above-mentioned patent adopts the traditional water mist dust removal form to spray and wet the dust kicked up during shotcrete to reduce dust. This scheme requires a high-pressure water pump, a ring-shaped water pipe and multiple spray nozzles. The connection of multiple components has a high leakage rate, and it is difficult to ensure that all the multiple spray nozzles can work normally. In addition, the ring-shaped water pipe cannot guarantee that the spray amount and pressure of each spray nozzle are uniform, which may result in that some areas cannot obtain the effect of wet dust reduction.

[0003] How to effectively suppress shotcrete dust production, improve dust reduction effect, improve the working environment of on-site personnel, and reduce the adverse effects on overall construction quality and progress is a problem that needs to be solved by those skilled in the art. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provides a wet-type shotcrete rebound reduction and dust reduction device to solve the problems mentioned in the technical background.

[0005] A wet-type shotcrete rebound reduction and dust reduction device, comprising a device body, the device body being a cylinder with a through hole along an axis, an inner cavity is formed inside the device body, the inner cavity is composed of a medium inlet, a flow guide cavity, an internal convergence cavity, a rectifier cavity, an acceleration cavity and a medium ring outlet connected in sequence; the through hole is used to accommodate the nozzle of the wet-type shotcrete;

[0006] The number of medium inlets is multiple, and the medium inlets are arranged in a ring array on one end surface of the device body; the main reason for arranging the medium inlets in the above form is that, when the nozzle of the concrete wet spraying is sleeved into the through hole, if the medium inlets are arranged in the form of a ring sleeve, the feeding pipe of the nozzle of the concrete wet spraying needs to be improved, which increases the technical complexity, and the dust falling device cannot be used for other nozzles of the concrete wet spraying, and it is difficult to control the uniformity of the flow velocity and pressure of the medium on the ring interface, if the number of the medium inlets is only one, since the subsequent internal collecting cavity, the rectifying cavity and the accelerating cavity are all ring chambers, even if a rectifying device is arranged in the middle, it is difficult to adjust the uniform flow velocity and pressure of the medium on the cross section of the accelerating cavity, and turbulence is easily formed. Therefore, the number of the medium inlets is multiple, and the medium inlets are arranged in a ring array on one end surface of the device body, and the axial distance from the medium inlets to the through hole is the same.

[0007] The number of the flow guide cavities is the same as that of the medium inlets;

[0008] The side opening of the flow guide cavity is communicated with the internal collecting cavity;

[0009] The internal collecting cavity, the rectifying cavity and the accelerating cavity are ring chambers;

[0010] The medium ring outlet is arranged in a ring on the other end surface of the device body.

[0011] Optionally, the medium inlet is inlaid with a steel inner ring to connect the medium input pipe.

[0012] Optionally, in order to reduce energy loss, the flow dividing bead is in the form of a hemisphere and is integrated on the upper wall of the flow guide cavity, the spherical surface is opposite to the medium inlet, and the diameter of the flow dividing bead is greater than or equal to the diameter of the medium inlet.

[0013] Optionally, the profile line of the cross section of the accelerating cavity adopts a Vitousevskiy shift axis curve, and the preferred curve equation is:

[0014]

[0015]

[0016] R0 is half of the width of the medium ring outlet (9), and the preferred value is 0.25-0.75 mm;

[0017] R h is a shift axis value, and the preferred value is 0.05R1-0.45R1;

[0018] R1 is half of the width of the rectifying cavity (7), and the preferred value is 40-50 mm;

[0019] X0 is the axial length of the accelerating cavity (6), and the preferred value is 40-50 mm;

[0020] X is the axial length of the self-accelerating cavity entrance, mm;

[0021] R is half of the width of the accelerating cavity (6) at the axial distance X, mm

[0022] N is the shrinkage ratio.

[0023] The purpose of using the Vitoshinsky shift axis curve is to obtain a suitable smooth accelerating medium flow.

[0024] Further, a shunt bead is fixed in the flow guide cavity, and the diameter of the shunt bead is greater than or equal to the diameter of the medium inlet, so that the inflow can be uniformly distributed to the internal flow convergence cavity, and the energy consumption is reduced.

[0025] Optionally, a rectifying honeycomb plate is arranged between the internal flow convergence cavity and the rectifying cavity. Since the internal flow convergence cavity inflow is a convergence of multiple inflows, in order to make the medium inflow flow rate and pressure entering the accelerating cavity relatively consistent, turbulence is avoided,

[0026] Optionally, the radius of the through hole should be greater than or equal to the radius of the concrete wet spraying nozzle, so that the through hole can accommodate the concrete wet spraying nozzle.

[0027] Optionally, the medium is introduced from the medium inlet, sequentially passes through the flow guide cavity, the internal flow convergence cavity, the rectifying cavity, and the accelerating cavity, and is sprayed from the medium ring outlet to form a ring-shaped jet curtain, and the medium is a gaseous medium. The high-speed ring-shaped jet curtain cannot directly wet the dust, but compresses and bundles the concrete spraying jet through the high-speed gaseous medium in a ring shape, reduces the jet diffusion angle in the wet spraying process, thereby improves the spraying thickness, thereby reduces the rebound rate and dust, and the dust is isolated inside the ring-shaped jet curtain, reduces the amount of outward escape, and also plays a dust suppression role.

[0028] Optionally, the device body is integrally formed by 3D printing, preferably by FDM / SLA / MJF 3D printing integration, and the printing material is set to black nylon, photosensitive resin, and PETG-CF, so as to ensure the lightness, sealing property and strength of the device body.

[0029] The beneficial effects of the present application are:

[0030] 1. The medium introduced from the plurality of medium inlets opened in the one end surface of the device body in a ring array enters the internal flow convergence cavity, and the turbulence intensity of the medium is reduced through the rectifying honeycomb plate and the rectifying cavity, and then the flow rate of the medium is increased through the accelerating cavity, and finally a continuous high-speed ring-shaped medium curtain is sprayed from the medium ring outlet, which effectively enhances the bundling of the spraying jet, thereby improving the spraying thickness, reducing the rebound rate and material loss, and the dust is isolated inside the ring-shaped jet curtain, and the dust concentration suppression effect is remarkable.

[0031] 2, the device body is integrally formed by 3D printing, small in size, high in integration, good in sealing, light in weight and high in strength, is sleeved on the nozzle of the concrete wet spraying machine through the through hole, is convenient to install, and has low interference to the existing concrete wet spraying machine. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 it is a schematic view of the appearance of the wet-mix shotcrete rebound-dust-reducing device of the present application

[0033] Figure 2 it is a schematic view of the cross section of the wet-mix shotcrete rebound-dust-reducing device of the present application

[0034] Figure 3 it is a schematic view of the cross section of the wet-mix shotcrete rebound-dust-reducing device of the present application

[0035] Figure 4a 、 4b , 4c, 4d, 4e are the flow field simulation result diagrams of the device described in the embodiments of the present application

[0036] Figure 5 it is a result diagram of the wet-mix shotcrete rebound-dust-reducing experiment under the laboratory scale of the wet-mix shotcrete rebound-dust-reducing device of the present application

[0037] Figure 6a 、 6b it is a result diagram of the wet-mix shotcrete rebound-dust-reducing experiment under the field scale of the wet-mix shotcrete rebound-dust-reducing device of the present application

[0038] Figure 7 it is a comparison diagram of the field operation effect of the wet-mix shotcrete rebound-dust-reducing device of the present application

[0039] In the figure: 1-device body; 2-medium inlet; 3-flow guide cavity; 4-shunt bead; 5-internal flow convergence cavity; 6-flow regulation honeycomb plate; 7-flow regulation cavity; 8-acceleration cavity; 9-medium ring outlet; 10-through hole; L x is the axial distance from the nozzle outlet of the concrete wet spraying machine to a certain point, mm; D0 is the nozzle diameter of the concrete wet spraying machine, mm. DETAILED DESCRIPTION

[0040] The embodiments of the present application are described below through specific specific examples. It should be noted that the examples described herein are only used to explain the present application and are not used to limit the present application. The following examples and features in the examples can be combined with each other without conflict.

[0041] Example 1

[0042] As Figure 1 、 2As shown, the wet spraying and rebounding dust reducing device of the embodiment of the application comprises a device body 1, the device body 1 is a cylinder with a through hole 10 along an axis, an inner cavity is formed in the device body 1, and the inner cavity is composed of a medium inlet 2, a flow guide cavity 3, an internal flow collecting cavity 5, a rectifying cavity 7, an accelerating cavity 8 and a medium ring outlet 9 which are sequentially communicated.

[0043] The through hole 10 is used to accommodate a nozzle of the wet concrete spraying. The radius of the through hole is set to 55 mm, so that the rebounding dust reducing device can be sleeved on the nozzle of the wet concrete spraying.

[0044] The number of the medium inlets is set to 4, and the medium inlets are arranged in an annular array at the rear of the device body. The medium inlets are inlaid with steel inner rings to connect the medium input pipes. The radius of the medium inlet is set to 20 mm, and the axial length of the medium inlet is the same as that of the flow guide cavity, and both are half of the axial length of the internal flow collecting cavity.

[0045] The top of each flow guide cavity is fixed with a flow dividing bead, the flow dividing bead is hemispherical, the spherical interface faces the medium inlet, and the diameter of the flow dividing bead is greater than or equal to the diameter of the medium inlet to reduce energy consumption. The radius of the flow guide cavity is slightly greater than the radius of the medium inlet, and is set to 25 mm in this embodiment.

[0046] The rectifying honeycomb plate is arranged between the internal flow collecting cavity and the rectifying cavity. Since the inflow of the internal flow collecting cavity is the convergence of multiple inflows, in order to make the flow rate and pressure of the medium inflow entering the accelerating cavity relatively consistent, and avoid turbulence. The axial length ratio of the internal flow collecting cavity to the rectifying cavity is 1:2.

[0047] The medium is introduced from the medium inlet, sequentially passes through the flow guide cavity, the internal flow collecting cavity, the rectifying cavity and the accelerating cavity, and is sprayed from the medium ring outlet to form an annular jet curtain. The medium is gaseous medium.

[0048] The device needs to form a high-speed gaseous medium ring at the medium ring outlet 9 to compress and bundle the concrete spraying jet, so it is necessary to try to improve the flow rate of the medium and the uniformity of the medium flow, and avoid turbulence to destroy the bundling of the spraying jet.

[0049] The profile line of the cross section of the accelerating cavity adopts the Vitousevskiy shift curve to ensure the outlet flow rate and turbulence degree, and the equation of the curve is:

[0050]

[0051]

[0052] Since the dust-settling device is used in combination with the nozzle of the concrete wet-mixing gunite, the size of the medium inlet and outlet, the acceleration cavity and the rectification cavity needs to be adapted to the size of the nozzle, wherein R0 is half the width of the medium ring outlet (9), and the value is preferably 0.25-0.75 mm;

[0053] R1 is half the width of the rectification cavity (7), and the value is preferably 40-50 mm;

[0054] X0 is the axial length of the acceleration cavity (6), and the value is preferably 40-50 mm;

[0055] X is the axial length from the inlet of the acceleration cavity, mm;

[0056] R is half the width of the acceleration cavity (6) at the axial distance X, mm

[0057] N is the contraction ratio.

[0058] If the shift axis curve is not used, since the value of the contraction ratio N is the ratio of R1 and R0, the maximum can reach 200, which is too large, and will cause the curve to shrink sharply in the front section and hardly shrink in the rear section, and the sharp contraction of the airflow is easy to cause separation and destroy the uniformity of the airflow. Therefore, a suitable shift axis R h The curve is optimized to obtain a large and uniform airflow, and the value is preferably 0.05R1-0.45R1.

[0059] In this embodiment, the flow field of the device using the Vitoshinsky shift axis curve with the above value range is simulated by Ansys Fluent software to determine the optimal implementation parameters, wherein when R0=0.50 mm, R h =0.05-0.45R1, R1=47.50 mm, X0=45 mm, and the medium inlet pressure is set to 0.3 MPa, as shown in Figure 4a , 4b , 4c, 4d, 4e.

[0060] The outlet flow rate corresponding to different shift axis amounts under a constant medium inlet pressure (0.3 MPa) is as shown in Figure 4a When the shift axis amount is 0.25R1, the contraction ratio N=4.8, at this time the medium ring outlet flow rate reaches a peak value of about 47 m / s compared to other shift axis amounts, and the device internal speed solid rendering Figure 4b shows that the speed behind the rectification cavity is basically uniform, as the airflow in the device enters the acceleration cavity, Figure 4c , the airflow speed presents a gradient increase until the medium ring outlet speed reaches the maximum, and the airflow is uniform and does not occur turbulence. At the same time, the device internal pressure solid rendering Figure 4d shows that the device internal pressure is overall uniform, Figure 4eIt can be seen from the figure that the pressure of the accelerating cavity decreases gradually with the increase of the internal airflow, and the airflow is uniform and no turbulence occurs.

[0061] In this embodiment, a PZ-3 type concrete wet spraying machine with a concrete discharge capacity of 5 m 3 / h is used to obtain the relationship between the medium ring outlet velocity and the wet spraying jet diffusion angle. By adjusting different medium inlet pressures, the wet spraying jet diffusion angle variation curve under different medium ring outlet flow rates is obtained in the laboratory scale. The results are shown in Figure 5 , which shows that the medium ring outlet flow rate is negatively correlated with the wet spraying jet diffusion angle. The larger the medium ring outlet flow rate, the smaller the wet spraying jet diffusion angle. When the medium ring outlet flow rate is close to 40 m / s, the minimum wet spraying jet diffusion angle is obtained, so a large medium inlet pressure is selected to obtain the maximum medium ring outlet flow rate.

[0062] It is shown that the device with the above implementation parameters can obtain the maximum medium ring outlet flow rate and uniform medium flow without turbulence under a constant medium inlet pressure of 0.3 MPa, and can be set on the nozzle of the concrete spraying machine for dust reduction.

[0063] After determining the main implementation parameters of the accelerating cavity, the axial length ratio of the accelerating cavity and the rectifying cavity is set to 3:5, and other chamber parameters are set. The device body is integrated by SLA 3D light curing printing, and the printing material is set to photosensitive resin, thereby obtaining the wet spraying and dust reduction device.

[0064] Example 2

[0065] This embodiment is a wet spraying and dust reduction device for wet spraying and dust reduction test in the field scale, as shown in Figure 7 , a CHP25E type concrete wet spraying machine with a concrete discharge capacity of 25 m 3 / h is used. The wet spraying and dust reduction device of example 1 is set on the nozzle of the CHP25E type concrete wet spraying machine, the nozzle diameter is 50 mm, and the sprayed concrete strength is C30.

[0066] Figure 7 The field operation effect of the wet spraying and dust reduction device can be directly shown, Figure 7 the left side is the field operation diagram of the nozzle of the concrete wet spraying machine without setting the wet spraying and dust reduction device, it can be seen that the concrete slurry is sprayed from the nozzle in a diffused manner, forming a large amount of dust, which diffuses in the working space, Figure 7 the right side is the field operation diagram of the nozzle of the concrete wet spraying machine with the wet spraying and dust reduction device set thereon, the concrete slurry is sprayed from the nozzle in a columnar shape, the concrete spraying jet is well bundled in the high-speed annular medium curtain, and the amount of dust in the working space is obviously reduced.

[0067] The jet diffusion angle contraction effect in the wet-mix process is shown in Figure 6a The results show that under the medium inlet pressure of 0.3 MPa, the average wet-mix jet diffusion angle effective contraction rate reaches 35.7% before and after the wet-mix shotcrete rebound-reducing and dust-settling device of embodiment 1, and the maximum effective contraction rate is 56%, indicating that the wet-mix shotcrete rebound-reducing and dust-settling device has a good contraction effect on the jet diffusion angle in the wet-mix process.

[0068] The dust concentration suppression effect in the wet-mix process is shown in Figure 6b The results show that under the medium inlet pressure of 0.3 MPa, the average effective suppression rate reaches 57.9% before and after the wet-mix shotcrete rebound-reducing and dust-settling device, and the maximum effective suppression rate is 87.6%. The overall maximum dust concentration of the wet-mix process is also not more than 80.41 mg / m 3 , which is basically the trough value of the wet-mix shotcrete rebound-reducing and dust-settling device, indicating that the wet-mix shotcrete rebound-reducing and dust-settling device has an excellent dust suppression effect on the wet-mix process.

[0069] The above is only the preferred embodiment of the present application, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the scope of protection of the present application.

Claims

1. A wet-mix shot reduction and dust suppression device, characterized in that, The device comprises a device body (1), which is a cylinder with a through hole (10) along an axis, and an inner cavity is formed inside the device body (1), and the inner cavity is composed of a medium inlet (2), a flow guide cavity (3), an internal confluence cavity (5), a rectifying cavity (7), an acceleration cavity (8) and a medium ring outlet (9) in sequence; the through hole (10) is used to accommodate a nozzle for wet-type concrete spraying; The number of the medium inlets (2) is multiple, and the medium inlets (2) are arranged in an annular array on one end surface of the device body (1); The number of the flow guide cavities (3) is the same as that of the medium inlets (2); The side opening of the flow guide cavity (3) is communicated with the internal confluence cavity (5); The internal confluence cavity (5), the rectifying cavity (7) and the acceleration cavity (8) are annular chambers; The medium ring outlet (9) is arranged in an annular shape on the other end surface of the device body (1); The flow guide cavity (3) is fixed with a shunt bead (4), the shunt bead is hemispherical and integrated on the upper wall of the flow guide cavity, the spherical surface is perpendicular to the medium inlet, and the diameter of the shunt bead (4) is greater than or equal to the diameter of the medium inlet (2); The rectifying honeycomb plate (6) is arranged between the internal confluence cavity (5) and the rectifying cavity (7); The medium is introduced into the medium inlet (2), sequentially passes through the flow guide cavity (3), the internal confluence cavity (5), the rectifying cavity (7) and the acceleration cavity (8), and is sprayed from the medium ring outlet (9) to form an annular jet curtain, and the medium is a gaseous medium.

2. The wet-mixing shotcrete damping and dust-settling device according to claim 1, characterized in that: The profile line of the cross section of the acceleration cavity (8) adopts a Vitoldinsky moving axis curve, and the curve equation is: ； wherein R0 is half of the width of the medium ring outlet (9), mm; R h is the shift distance, mm; R1 is half of the width of the rectifying cavity (7), mm; R is half of the width of the accelerating cavity (8) at the axial distance X, mm; X0 is the axial length of the accelerating cavity (8), mm; X is the axial length from the inlet of the accelerating cavity, mm; and N is the contraction ratio.

3. The wet-mixing shotcrete elastic reduction and dust-settling device according to claim 1 or 2, characterized in that: The medium inlet (2) is inlaid with a steel inner wire ring.

4. The wet-mix process shotcrete bounce reduction and dust suppression device of claim 1, wherein: The axial length of the rectifying cavity (7) and the acceleration cavity (8) is 5:

3.

5. The wet-mix process shotcrete bounce reduction and dust suppression device of claim 1, wherein: The device body (1) is integrally formed by 3D printing.

Images