JP2013245111A - Granular material fluidizing nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stir solid-gas mixture with carrier gas supplied from a nozzle in storing and carrying powder, while vibrating the nozzle with the flow of the blown gas to vibrate a powder container and a carrying passage, thereby increasing efficiency of excitation to be applied for the stirring with the blown gas, resulting in preventing a bridge phenomenon of the powder and a settling phenomenon on a container wall, to significantly improve powder transportation.SOLUTION: An opening/closing member (a bell) constituting a movable side of an annular blown gas slit of a nozzle is closed with a biasing force of a resilient body. The slit is opened with the static pressure of supplied compressed gas for blowing. A flow path for the compressed gas is bent in the bell so that dynamic pressure at a bending point is applied in a direction where the blown gas slit is closed. Opening/closing operation is continued by slit opening operation with the static pressure and closing operation with the dynamic pressure, to mechanically vibrate a container wall. The flow of the blown gas is increased as wells as exciting force, to enhance energy efficiency.

Description

  This invention is for pressurized gas injection suitable for fluidizing powders such as grain powder, cement, ceramic materials, powder materials for powder metallurgy as a solid-gas mixture in a storage tank or a transfer path. Relates to the nozzle.

  In order to fluidize a solid-gas mixture, it is most effective to blow a gas constituting the mixture, and various fluidizing nozzles have been proposed for that purpose. For example, Patent Document 1 proposes a type of nozzle in which the pressure air introduction hole is covered with a cap made of an elastic material, and when the air is introduced, the cap is widened by the pressure of the air to release the blockage, and necessary air is blown. Further, in Patent Document 2, the injection valve of the injection port is closed with a magnetic adhesion force and a biasing force of a coil spring so that it can effectively cope with the conditions in the container.

  Further, when vibration is applied to the container or the transport path of the solid-gas mixture in addition to the blowing of the gas, the mixture moves without being caught on the wall surface of the container or the transport path, so that the working efficiency is further increased. For this reason, a method using a striking means apart from the blowing nozzle is widely used, and is proposed in, for example, Patent Document 3.

  However, if a vibrating device is provided separately from the blowing nozzle, the configuration and operation control of the device become complicated, which is not economical. In the patent document 4, the present applicant has disclosed a technique for imparting a vibration function to the blowing nozzle itself. In this application, the ejection slit of the nozzle is closed by the urging force of the projectile, and while the compressed gas is supplied, the opening operation by the gas pressure and the closing operation by the urging force are alternately continued to oscillate. Is generated.

No. 4-30156 Japanese Patent No. 3559344 JP 2002-104062 A Utility Kaihei 6-39796

  In the nozzle of Patent Document 4, when a cylindrical member that performs an on-off valve function is closed by the urging force of a projectile, impact vibration generated by hitting a slit seat on the nozzle body side is transmitted to the container wall. As a result, vibration was added to the stirring by the jet gas, and the frictional resistance between the container wall and the contents was lowered, and the conveyance efficiency was improved. However, the exciting force is still not sufficient, and a large number of nozzles must be provided to sufficiently vibrate the container wall. Moreover, since the amount of compressed gas used is increased if an attempt is made to increase the excitation effect, it may be inferior to a system equipped with an excitation mechanism separately from the nozzle from the viewpoint of energy efficiency. It is an object of the present invention to further enhance fluidization performance by suppressing the size of the nozzle and exhibiting a vibration function balanced with the stirring function without increasing the amount of compressed gas consumption.

In order to solve the above-described problem, a conventionally known nozzle, that is, a nozzle that collides a bell, which is a blow-off port closing body, with a reciprocating holding mechanism against a slit seat on a container wall, is supplied from the center of the nozzle and flows in the bell. Then, the compressed gas ejected from the slit has a bell internal shape that generates a dynamic pressure that presses the bell against the slit seat during the flow process. That is, the dynamic pressure at which the high-speed flow of compressed gas acts on the bell is urged by the urging force of the projectile causing the bell to collide with the slit seat.

  In the nozzle whose bell internal shape has been improved as described above, a compressed gas supply path is provided in the shaft portion protruding from the nozzle central portion into the container to supply air into the bell, and a boss hole is provided in the center of the bell. It is preferable to cause the bell to reciprocate by inserting and holding an elastic body between the bell presser provided at the tip of the shaft and the bell.

  Further, as a different form from the above, the bell may wrap around the engaging portion that fits the nozzle central portion without penetrating the bell. That is, an engaging portion is provided at the inner central portion of the bell, a bell receiving portion is provided at the nozzle central portion, and an elastic body is mounted between the bell and the nozzle central portion to mount the bell. Make reciprocating motion.

  Furthermore, in any of the above-mentioned forms, if the shape and dimensions are such that the portion located inside the granular container in use can be taken in and out through the mounting hole of the granular fluidizing nozzle provided on the container wall. Convenient for maintenance management. By doing so, even if powder is present inside the container at the time of repair / inspection, construction can be performed from the outside as it is.

  According to the product of the present invention, when the compressed gas is ejected from the slit at a high speed, the bell constituting one side of the slit is vibrated by the high-speed air flow, so that the blow applied to the container wall when the gas ejection flow rate increases. Energy also increases. As a result, the container wall vibrates simultaneously with the fluidization of the solid-gas mixture by the jet stream, so that the contents are less likely to stick and no cross-linking phenomenon occurs.

  It was confirmed that the range in which the product of the present invention vibrates the container wall is sufficiently wider than the fluidization range of the contents by the ejection of the compressed gas. Therefore, for example, if the nozzles are installed in an appropriate arrangement on the conical bottom of the silo, the entire cone can be vibrated even with a relatively small number of nozzles. As a result, the contents do not stay at the connection point between the cylindrical portion and the conical portion, and complete first-in first-out management becomes possible.

  Since the product of the present invention exhibits fluidization performance equivalent to or better than that of the conventional product even in a relatively small size compared to the conventional product, the size of the nozzle internal structure portion can be reduced to the size passing through the mounting hole of the container wall. Even if it is small, it works well. As a result, there is no need to enter the container at the time of installation work or repair / inspection work. Further, depending on the properties of the contents, there are many cases in which the nozzle can be attached and detached even when the container is filled. These things ensure safety, reduce construction costs, and shorten the construction period.

  In the product of the present invention, a stable excitation force was obtained, and an unexpected effect was obtained by the sound accompanying the vibration. The sound generated when the nozzle of the embodiment is driven and mounted on a cement silo is low when the powder filling degree in the container is high, becomes high as the filling degree decreases, and the container wall strongly resonates when the remaining amount is low. . This makes it possible to measure the filling height equivalent to the hammer test, and can also be used as a simple inventory management means.

  In addition, the product of the present invention has a very simple structure that does not require an electrical or complicated mechanism as compared with other vibration means, and therefore has extremely high durability. In the example manufactured for the cement silo, there is almost no wear even though the container is hit by more than 180 Hz. As a result, it is expected that the maintenance cost at the nozzle usage site can be greatly reduced.

  It is a longitudinal cross-sectional view of the granular material fluidization nozzle of 1st Example of this invention.   It is a longitudinal cross-sectional view of the conventional granular material fluidization nozzle.   It is explanatory drawing of the jet stream in the slit part of this invention product.   It is an arrangement plan of an actual machine performance test of a powder body fluidizing nozzle.   It is a vibration waveform in the conventional granular material fluidization nozzle.   It is a vibration waveform in the granular material fluidization nozzle of 1st Example of this invention.   It is a longitudinal cross-sectional view of the granular material fluidization nozzle of 2nd Example of this invention.   It is a fragmentary sectional view in the 3rd example of the present invention.   It is explanatory drawing of the bell part in 4th Example of this invention.

  First, in the powder fluidization technique, the basic technique that is the starting point of the present invention will be described with reference to FIG. FIG. 2 shows a granular material fluidizing nozzle (hereinafter referred to as a nozzle) according to the idea of Patent Document 4 by the present inventor. In the figure, a nozzle mounting hole 41 provided in the wall 42 of the powder container is reinforced by a nozzle mounting seat 43 on the outer surface side of the powder container. The nozzle body 1 fits into the nozzle mounting hole at the step portion 12, and the base portion 11 is flange-connected to the nozzle mounting seat by a bolt (not shown). A slit seat 13 is attached to the end surface of the stepped portion 12, and the surface of the slit seat is set to a position that is flush with the inner surface of the powder container or slightly protrudes. In this way, the nozzle is mounted in such a posture that it protrudes toward the inner surface of the container perpendicular to the wall surface of the powder container.

  The shaft portion 21 of the nozzle body 1, the bell presser 22 at the tip of the shaft portion, the urging screw 23, and the elastic body 24 constitute a bell holding portion. The bell 3 inserted into the shaft portion by the boss portion 31 is held by the elastic body 24 so that the bell slit portion 33 is pressed against the slit seat 13 so as to be able to reciprocate in and away from the slit seat. The compressed gas supply part composed of the center hole 16 and the communication hole 17 of the shaft part is covered with a bell to form a pressure accumulation chamber 35.

  Next, the effect of the nozzle in the above configuration will be described. When the pressurized gas is fed, the gas reaches the pressure accumulating chamber 35 and increases its internal pressure. Then, when the internal pressure of the pressure accumulating chamber exceeds the urging force of the elastic body 24, the bell 3 is pushed back, and a slight gap of the slit 36 is opened between the bell slit portion 33 and the slit seat 13, and the pressure is increased. Gas is ejected from the slit. The jet flow forms a disc-like jet stream that radiates from the center of the nozzle and stirs the contents (powder) around the nozzle.

  When the pressurized gas is discharged from the slit, the internal pressure of the pressure accumulating chamber decreases, and the bell 3 is pushed back by the urging force of the projectile and the slit 36 is closed. Here, when the bell slit portion of the bell collides with the slit seat, sound and vibration are emitted. It is a feature of this nozzle that the vibration of the container wall is added to the stirring by the jet flow. Since this vibration mainly vibrates the container wall, the contact resistance between the contents and the container wall is significantly reduced simultaneously with the fluidization of the contents. This makes it difficult for the bridging phenomenon that occurs during the cutting of the contents.

  The slit seat is preferably made of a material different from that of the bell in order to exhibit a sealing function at the time of pressure accumulation and a vibration function in response to the collision of the bell slit portion. Since this material needs to have appropriate flexibility and hardness, for example, in the case of a cement silo, hard rubber is suitable.

  Thus, while the pressurized gas is supplied, the reciprocating motion of the bell is repeated. However, in an actual powder container, it is not always necessary to maintain fluidity, and it may flow when being cut out. . Therefore, at the site where this nozzle is used, the use efficiency of the pressurized gas is increased by sending the pressurized gas into pulses at an appropriate interval for a short time only when necessary.

  The above is the structure and operation effect of the conventional nozzle. This type of nozzle greatly improved performance by adding a new action of vibration that was not available in previous nozzles. However, it is still not enough to meet even more demanding requirements. For example, if the cone angle of the lower hopper part is increased (obtuse angle) in order to increase the volumetric efficiency of the powder container, it is easy to cause seizure in this part, so it is necessary to increase the nozzle deployment density. There is a need for further improvement in fluidization performance.

  In order to improve the performance of the nozzle, it is only necessary to improve the shape and flow velocity of the ejected airflow and to enhance the vibration by striking. On the other hand, since the nozzle is an obstacle to the movement of the contents as a protrusion on the wall of the container, there is a restriction that a smaller size is desirable. Under these restrictions, the present invention has been achieved as a result of repeated trials with various changes in the shape of the nozzle, particularly the shape of the bell.

  Next, the invention relating to the first claim of the present application will be described with reference to FIGS. What has been noticed when improving the nozzle is that the vibration effect of the impact is relatively small compared to the stirring effect of the fumarole. Accordingly, the shape of the flow path of the compressed gas was variously changed to search for a shape that increases the vibration of the bell. As a result, when the inner diameter side of the bell slit portion was protruded in a cross-sectional tongue shape as shown in FIG. 1, the vibration was remarkably increased.

  The effect of changing the inner diameter side shape of the bell slit portion was measured and compared. Two types of test nozzles shown in FIG. 1 and FIG. 2 were produced by changing the shape of the bells that were used in cement silos for practical use. For the bell slit part, the outer diameter is 35 mm, the conventional product has an inner diameter of 25 mm, the radial length of the slit is 5 mm, and the product of the present invention has an inner diameter of 30 mm and the radial length of the tongue piece is 2.5 mm. The length in the radial direction is 5 mm. As shown in FIG. 4, these nozzles were attached to the same height position of the lower hopper of the cement silo so as to face each other by 180 degrees, and Portland cement was loaded from the nozzle position to a height of 2 m. The pressure of the compressed air was switched to three stages, and both nozzles were alternately supplied in a pulsed manner to drive, and the vibration of the outer end face of the nozzle base was measured with a laser Doppler velocimeter. FIG. 5 shows the measurement results of the conventional product shown in FIG. 2, and FIG. 6 shows the measurement results of the product of the present invention shown in FIG.

  5 and FIG. 6 are obtained by cutting out 0.20 seconds to 0.05 seconds in the vibration waveform obtained by supplying compressed air in a pulsed form for 0.5 seconds. The vertical axis represents the measured vibration velocity (cm / second) of the laser Doppler velocimeter, and the compressed air pressure is 10 Pa in the upper stage, 20 Pa in the middle stage, and 60 Pa in the lower stage. As observed from the waveform of FIG. 5, the conventional product can clearly read a regular vibration waveform at a pressure of 10 Pa. However, when the pressure increases to 20 Pa and 60 Pa, the regularity becomes unclear, and the amplitude of the vibration speed is increased. Has also decreased.

  FIG. 6 shows the vibration waveform obtained by sending a compressed air pulse to the nozzle of Example 1 of the present invention in the same manner as described above. Comparing this result with the conventional product, the amplitude of the vibration velocity is first increased from the conventional product at any air pressure, about 5 times at 10 Pa, 15 times at 20 Pa, and about 60 times at 60 Pa. . Next, as for the waveform, unlike the conventional product, the amplitude remarkably increases as the air pressure increases, and even when the amplitude increases, the regularity of vibration is not lost, and the center frequency slightly increases.

  Considering the mechanism of this remarkable excitation force enhancement, as shown in FIG. 3, the airflow flowing into the bell reaches the slit along the inverted S-shaped path along the bell inner wall forming the pressurizing flow path 37. It ejects from the slit at high speed. Here, the major difference from the prior art is that the dynamic pressure P shown in the figure is applied to the back surface of the tongue piece 34, which urges the urging force of the projectile. When the pressure of the compressed gas increases, the flow velocity increases, and the dynamic pressure due to this P also increases and becomes larger than the urging force of the projectile, which is assumed to be the main driving force for the reciprocating motion of the bell. . That is, the opening operation driven by the static pressure based on the pressure difference between the inside of the nozzle and the container and the closing operation driven by the dynamic pressure of the jet flow continue. In contrast, in the conventional product, the collision of the bell is based only on the urging force of the projectile, so that the excitation force is not increased even if the gas pressure is increased. Rather, when the pressure of the compressed gas increases, this acts to prevent the collision movement of the bell due to the urging force, and as a result, it is considered that the amplitude slightly decreases as the pressure increases.

  Since it is considered that the dynamic pressure P increases as the area of the back surface of the tongue piece increases, the nozzle was driven by changing the radial length of the tongue piece. As a result, it was found that if a nozzle having an outer diameter of 35 mm has a tongue piece portion of at least about 2 mm in the radial direction, a practical vibration strengthening effect appears. Further, when the tongue piece is lengthened, it can be extended as long as the airflow on the inner diameter side is not obstructed. In an example of a nozzle applied to a cement silo, a sufficient excitation force is exhibited at about 2.5 mm. In the specimen of FIG. 6, it is 2.5 mm.

  Next, the details of the bell holding part according to claim 2 will be described. In FIG. 1, a compressed gas supply portion is formed in the shaft portion 21 of the nozzle body 1. The compressed gas supply portion includes a central hole 16 and a communication hole 17 that penetrates radially outward from the hole bottom. The central hole is screwed to the compressed gas supply line by a tap machined at its inlet. Four communication holes 17 are opened at equal intervals, and the reciprocating motion of the bell can be controlled by adjusting the flow rate of the compressed gas according to the hole diameter.

  A bell presser 22 is held at the tip of the shaft portion 21 by an urging screw 23, and between the bell presser 22 and the slit seat 13, an elastic body 24 and the bell 3 are overlapped and inserted into the shaft portion 21. ing. The material of the elastic body 24 is preferably a fine rubber sponge, and the elastic force (biasing force) can be adjusted by the material type and bubble density. The bell 3 fits into the shaft portion 21 with a slight play at the boss portion 31 and is slidable along the shaft portion. The bell portion of the bell extends in a cylindrical shape toward the container wall, and the tip bell slit portion 33 is in contact with and closely contacts the slit seat 13.

  Both end surfaces of the bullet member 24 are bonded to the end surface of the bell 3 and the bell presser 22, respectively, and by tightening the urging screw 23, the bell slit portion 33 and the slit seat 13 are brought into close contact with each other to have a pressure accumulation function. A pressure channel 37 is formed. Since the pressing force to the slit seat, that is, the closing force of the pressure channel is generated by the compression deformation of the elastic body, the internal pressure of the pressure channel can be adjusted by tightening the urging screw 23.

  The feature of the structure of the present embodiment is that the urging mechanism by the projectile is made as small as possible and accommodated at the tip of the nozzle. Compared to the type often seen in the prior art, ie, a biasing structure equipped with a coil spring outside the container, there is very little protrusion out of the container. In the cone part at the bottom of the silo, this is often welcomed because there is little space for people to move around.

  Next, a second format in the present invention will be described with reference to FIG. As shown in the figure, the bell 5 has a dome shape and covers all the portions located in the container of the nozzle. The part from the trunk part of the bell to the slit part is the same as in the first embodiment. A central shaft 51 protrudes from the center of the bell, and an urging rod 52 is fixed to the central shaft by a screw and fixed integrally with the bell. A large-diameter head 54 is formed at the lower end of the biasing rod.

  The center hole 16 of the nozzle shaft portion 21 penetrates to the tip of the shaft, and the bell center shaft is slidably fitted into the open end. The center hole has a large diameter on the outer side of the container, the end surface of the stepped portion forms a spring receiving seat 14, and a coil spring 55 is inserted between the spring receiving seat and the biasing rod head 54. . There is a gap between the biasing rod head and the center hole large diameter portion, and the biasing rod head is slidable along the center hole. The coil spring is a compression spring, and the bell slit portion 33 is pressed against the slit seat 13 by a spring biasing force to close the slit. This is the bell holding part in this embodiment.

  The head 54 of the urging rod 52 is provided with four axial vent holes 56 on a concentric circle, and serves as a passage for the supplied compressed gas. The compressed gas passes from the central hole to the pressurizing flow path 37 through the communication hole, and in the same manner as in the first embodiment, the bell is vibrated and ejected from the slit into the container to stir the contents. Compared with nozzles having the same mounting hole size, the present embodiment has a larger bell mass than the first embodiment, and the impact force during vibration is relatively large.

  In Example 1, the sponge projectile is exposed in the container, and the projectile may be eroded by the granular material of the contents or the carrier gas. This means that the contents are contaminated by the projectile at the same time, and therefore, this embodiment is welcomed from the viewpoint of preventing contamination.

  In this embodiment, the bell is held by a compression spring, but a tension spring may be used. However, when the tension spring is passed through the center hole and stretched between the bell and the nozzle base, a locking mechanism is added to prevent the bell from falling into the container when the tension spring is fully extended. There is a need to. In this embodiment, since the compression spring has the function of the limiter, a separate locking mechanism is not required, and the practicality is high.

  Although Embodiments 1 and 2 have been described above, the features of the present invention common to both of them will be mentioned. In FIGS. 1 and 7, the maximum diameter of the nozzle internal structure is a bell, a bell presser, or a bullet. On the other hand, the nozzle mounting hole provided in the container is larger than the maximum diameter of these internal structures in any of the embodiments. With this structure, the work can be completed without entering the container when the nozzle is inspected or replaced. This not only eliminates dangerous work entering and exiting the container, but also does not contaminate the inside of the container, so that no cleaning work is generated.

  In Example 1, the problem that the elasticity of sponge deteriorates when the contents of a container penetrate | invade into a bullet made from sponge was left. This intrusion of contents is considered to occur mainly when the nozzle is activated and the surrounding contents are flowing violently. A solution to this by the structure of the nozzle is Example 3, which is shown in FIG. The central hole 16 of the shaft extends to the position of the boss portion of the bell, and a scavenging hole 18 extending from the central hole to the boss inner diameter is provided.

  With this structure, while the compressed gas is supplied to the nozzle, the compressed gas reaches from the scavenging hole to the boss inner diameter and passes through the clearance between the boss portion 31 and the shaft 21 to the sponge as indicated by the broken line arrow in the figure. invade. The compressed gas entering the sponge passes through the pore structure and exits from the outer peripheral surface of the sponge into the container. This flow of compressed gas has the effect of pushing back the contents that are about to enter the sponge from inside the container. This greatly extended the life of the sponge.

  In Example 1, there was a problem that the sponge exposed into the container was eroded by the contents and was worn out. One solution to this is shown in FIG. In this embodiment, the shoulder portion of the bell is extended to form an extension 39 to surround the sponge, and the tip of the bell fits with the bell retainer 22 with a slight gap.

  By doing this, there was almost no possibility that the sponge would be touched and worn out directly. Therefore, the risk of the contents being contaminated by the sponge due to mechanical action was very low. As an additional effect, the extension portion increases the mass of the bell, so that the excitation energy increases when the nozzle is activated.

  Powders are handled in a wide range of fields such as materials, foods, and chemistry. The particle size of the powders is increasing from fine powders to ultrafine powders, and industrial fields that use them are expanding. Along with this, the problems related to the storage and transport technology of powder and granular materials have also been advanced. The present invention is a basic technique for facilitating the transfer of powder particles, and has the potential to greatly reduce logistics costs and management costs, and is expected to be widely used in various fields in the future.

DESCRIPTION OF SYMBOLS 1 Nozzle main body, 12 step part, 13 Slit seat 15 Compressed gas supply part, 16 Center hole, 17 Communication hole 20 Bell holding part, 21 Shaft part, 22 Bell presser, 23 Energizing screw, 24 Bullet 3 bell Boss part, 32 body part, 33 bell slit part, 34 tongue piece part 35 pressure accumulating chamber, 37 pressure passage 36 slit 41 nozzle mounting hole 5 bell, 51 bell central axis, 52 biasing rod, 55 coil spring

Claims (4)

A slit seat located substantially in the same plane as the inner wall of the container;
Inside the slit seat, a compressed gas supply unit provided in the center of the nozzle,
A bell that covers the compressed gas supply part, the edge of the peripheral edge is brought into contact with the slit seat to form a fusible slit;
A bell holding part that makes the bell move freely in and out of contact with the slit seat and presses and holds the bell against the slit seat with an elastic biasing force;
In the powder fluidizing nozzle consisting of
A powder particle fluidizing nozzle characterized in that the internal structure of the bell is shaped to generate fluid pressure that presses the bell against the slit seat by compressed gas passing through the bell. In Claim 1, the compressed gas supply part protrudes into the container from the nozzle center part, is a shaft part having a compressed gas supply path,
The bell has a boss hole in the center,
Powder comprising a bell holding portion comprising a shaft portion through which a bell is inserted and held by a boss hole, a bell press provided at the tip of the shaft portion, and a projectile inserted between the bell press and the bell. Granule fluidizing nozzle. In claim 1, the bell wraps around the engaging portion that fits into the center of the nozzle,
A granular material fluidizing nozzle, wherein the bell holding part comprises a bell receiving part having the engaging part, and an elastic body mounted between the bell and the nozzle center part. In claims 1 to 3,
A granular fluidizing nozzle, wherein a portion located inside the granular container in use can be taken in and out through a mounting hole of a granular fluidizing nozzle provided on the container wall.

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