JP3797658B2 - Liquefied gas flow nozzle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the production of container-packed beverage products such as canned beverages, the present invention is inactive in the headspace of each container during the continuous transportation of the top-opened container that has been filled with the beverage and before sealing to the sealing device. The present invention relates to a liquefied gas flow nozzle that is used to flow a low-temperature liquefied gas at a predetermined rate.
[0002]
[Prior art]
Non-carbonated beverages such as coffee, black tea, green tea, oolong tea, sports drinks, and fruit juice are filled into cans with thin wall walls such as DI (squeezed iron) cans and filled with beverages. Add a small amount of inert low-temperature liquefied gas such as liquid nitrogen or liquefied argon to the liquid level of the head space inside the can (the space where there is no beverage in the upper part of the can), and then into the opening of the can By tightening and sealing the can lid, the internal pressure of the can after sealing is increased to prevent deformation of the can due to external pressure, or the air in the can is replaced with an inert gas to reduce the amount of residual oxygen In the past, it has generally been practiced to prevent beverage deterioration due to oxidation.
[0003]
On the other hand, as a can lid wrapping device used for manufacturing canned foods, in addition to the type that switches between the low speed operation and the high speed operation (twice the speed of the low speed operation), recently, from the low speed operation to the high speed operation. Has been developed that can be changed steplessly (curved or sloped), and cans can be accommodated to the transfer speed of cans on the production line according to the operating speed of the can lid clamping device. As for the liquefied gas flow down device for adding liquefied gas to the head space inside, the flow rate of liquefied gas per unit time is continuously and steplessly following the stepless speed change of the production line. It has been proposed by the applicant of the present invention to make this change possible, and is already known from JP-A-10-250711.
[0004]
That is, in Japanese Patent Laid-Open No. 10-250711, a liquefied gas flow nozzle composed of a cylinder and a plug is used to pass liquefied gas from the upper end to the lower end of the cylinder on the inner peripheral surface of the cylinder that is in sliding contact with the outer peripheral surface of the plug. And at least one of each groove is inclined from the upper end toward the lower end so that the width is substantially constant and the groove depth gradually decreases. Thus, it is disclosed that the flow amount of liquefied gas through each groove portion (flow amount per unit time) can be changed continuously and steplessly by changing the rising position of the plug with respect to the cylinder. Has been.
[0005]
[Problems to be solved by the invention]
By the way, according to the liquefied gas flow nozzle as described above, the liquefied gas is divided into a plurality of strips from the plurality of grooves, so that the collision with the beverage liquid surface when the liquefied gas flows is reduced. The impact can be mitigated, the liquefied gas can be prevented from scattering outside the can, and a plurality of nozzles with different numbers and sizes of nozzle holes can be prepared to replace the nozzle itself. Without changing the ascending position of the plug, the flow rate of the liquefied gas can be finely adjusted steplessly or continuously, following the stepless speed change of the canned production line. The flow rate per unit time can be changed continuously and steplessly.
[0006]
However, when the liquefied gas flow nozzle is further examined, there is almost no problem in the production of canned beverages using ordinary cylindrical cans such as DI cans. It turns out that the following problems may occur when manufacturing canned beverages with a bottle-shaped can (a metal can with a screwed neck and neck and a thin body) did.
[0007]
That is, in the case of a bottle-type can having a threaded mouth and neck, the inner diameter of the opening is considerably smaller than that of a normal cylindrical can (the normal inner diameter of the opening is about 48 to (The inside diameter of the opening is about 20 to 30 mm in the case of a bottle-type can, whereas the nozzle for liquefied gas flow to be used must be downsized, including the groove bottom portion.) The inner diameter of the cylinder needs to be 15 mm or less (preferably 10 mm or less).
[0008]
Therefore, as a liquefied gas flow nozzle that can also be applied to bottle-shaped cans, specifically, the upper end surface is a bowl-shaped concave curved surface, and there are eight grooves (groove width of about 1 mm) parallel to the axis on the inner peripheral surface. The diameter of the imaginary circle that is formed and connects the groove bottom of each groove at the upper end of the groove is about 9 mm, the diameter of the imaginary circle that connects the groove bottom of each groove at the lower end of the groove is about 7 mm, and the groove in each groove Create a cylinder so that the angle of inclination with respect to the axis of the bottom is about 3 ° and the diameter of the imaginary circle connecting the parts of the inner peripheral surface where no groove is formed is about 5.5 mm. has a vertically movable sliding contact rod-like (columnar shape) portion to the surface, and create a plug having a closure made of resin convex surface that matches the concave surface of the upper end surface of the cylinder above the rod-like portion did.
[0009]
Then, a liquefied gas flow device is used in which a liquefied gas passage is communicated with the lower end portion of the liquefied gas storage tank, and a liquefied gas flow nozzle comprising the cylinder and the plug is disposed at the lower end portion of the liquefied gas passage. The open / close valve provided in the liquefied gas supply pipe connecting the liquefied gas storage tank of the apparatus and the liquefied gas original tank is opened / closed by detecting the liquid level height of the storage tank. By maintaining the liquid level almost constant and communicating the inside of the storage tank with the outside, the pressure on the liquid level in the storage tank is maintained at atmospheric pressure, and the cylinder of the liquefied gas flow nozzle While continuing to flow a certain amount (per unit time) of liquid nitrogen through each groove part (eight groove parts) on the inner peripheral surface, a bottle-shaped can for an inner volume of 500 ml with an inner diameter of the opening of the mouth and neck part of about 20 mm, Liquefied gas with 491 g of water filled An experiment in which a predetermined amount of liquid nitrogen is added into the bottle-shaped can after passing through the lower nozzle, the cap is sealed with the cap, and then the pressure inside the can is measured with a tactile pressure tester. Went.
[0010]
As a result, the flowing state of the liquid nitrogen from the liquefied gas flow nozzle is dispersed and flowed into the same number (eight) of yarns as the number of groove portions of the cylinder immediately below the nozzle as shown in FIG. However, since the groove bottom of each groove part of the cylinder is inclined in the direction toward the center, multiple (8) thread-like flows gradually approach along the way and eventually merge into one flow. As a result, the impact when liquid nitrogen falls on the liquid level in the can increases, and the view on the liquid level in the can increases, causing liquid nitrogen to scatter. As a result, it has been found that there is a problem that the variation in the internal pressure of each can increases.
[0011]
An object of the present invention is to solve the above-mentioned problems. Specifically, the liquefied gas is divided into a plurality of flows through a groove portion having an inclined groove bottom formed on the inner peripheral surface of the cylinder. In the liquefied gas flow nozzle, which allows the flow of liquefied gas to be finely adjusted steplessly or continuously, the liquefied gas that has been flowed down into multiple streams is joined in the middle. Therefore, it is an object to drop the liquid onto the liquid level in the container while being reliably dispersed.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention includes a cylinder having an axial line in the vertical direction, a plug including a rod-shaped portion inserted into the cylinder from above, and a closing portion positioned above the rod-shaped portion. A plurality of grooves for passing the liquefied gas are formed in parallel to the axial direction of the cylinder from the upper end to the lower end of the inner peripheral surface of the cylinder that is in sliding contact with the outer peripheral surface of the rod-shaped portion of the plug. At least one or more of the opposing pairs have a substantially constant width from the upper end to the lower end, and the groove bottom is inclined so that the depth of the groove gradually decreases. When rotatably plug reaches its lowest position, that the lower surface of the closure portion of the plug is brought into close contact with the upper end surface of the cylinder, the upper end opening of each groove of the cylinder all being configured to be closed by a plug In the liquefied gas flow nozzle, at the lower end of the groove having a groove bottom of the cylinder is inclined, the corner portions of the lower end of the groove bottom is characterized in that it is chamfered.
[0013]
According to the above configuration, when the liquefied gas is caused to flow down through each groove of the cylinder by raising the plug from the lowermost position, the raising position of the plug is changed in accordance with the speed of the production line. It is possible to continuously and steplessly change the flow rate of the liquefied gas (flow rate per unit time) through each groove portion where the groove bottom is inclined.
[0014]
In addition, the groove bottom is inclined so that the depth of the groove gradually decreases from the upper end to the lower end of the groove part at least a pair of the groove parts facing each other so that the flow amount of the liquefied gas can be changed. On the other hand, by chamfering the corners at the bottom of the groove bottom at the lower ends of the grooves, as shown in FIG. 4, the flow flows slightly toward the center along the inclined surface of the groove bottom. The liquefied gas that has flowed along the rounded surface (the chamfered corner) chamfered at the lower end of the groove is slightly drawn outward and changed to a downward (vertical) flow. Therefore, the same number of grooves as the number of grooves are formed without any disturbance, and always flow downward stably.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the liquefied gas flow nozzle of the present invention will be described in detail with reference to the drawings. In addition, about the nozzle for liquefied gas flow of this embodiment, FIG. 1 shows the lower end part of the liquefied gas flow apparatus with which the nozzle is arrange | positioned, FIG. 2 shows the state by which the nozzle is opened by the desired opening degree. 3A and 3B show the structure of the cylinder constituting the nozzle, and FIGS. 4A and 4B show the state where the liquefied gas flows down through the groove of the cylinder. It is. FIG. 5 shows a state in which the liquefied gas flows through the groove portion of the cylinder in the liquefied gas flow nozzle of the comparative example.
[0016]
Although the entire structure of the liquefied gas flow apparatus using the liquefied gas flow nozzle of the present embodiment (the structure of other parts excluding the structure of the nozzle part) is not shown, for example, Japanese Utility Model Publication No. 63-35933. No. 1-10331, No. 1-59170, JP-A-10-250711, and the like, which have an appropriate structure conventionally known, and a liquefied gas flow down device The liquefied gas that has flowed down through the nozzle disposed at the lower end of the bottle is added from above to the head space of the can that has been filled with the beverage and has not yet been sealed.
[0017]
In such a liquefied gas flow down device, a vacuum heat insulation chamber for insulating the low-temperature liquefied gas (inert low-temperature liquefied gas such as nitrogen gas or argon gas) supplied from the liquefied gas original tank from the outside temperature. The liquid level of the liquefied gas stored in the storage tank is always kept constant and the liquid level is opened to the atmosphere (on the liquid level). Is almost the same as the atmospheric pressure), and it is allowed to flow down through the liquefied gas flow nozzle under constant pressure due to its own weight.
[0018]
The liquefied gas flow nozzle of this embodiment used in such a liquefied gas flow device will be described. The lower end portion of the liquefied gas flow device is entirely surrounded by a vacuum heat insulating chamber 6 as shown in FIG. In this state, a liquefied gas passage 5 is formed so as to communicate with the bottom of the storage tank 4, and a liquefied gas flow nozzle 1 including a cylinder 2 and a plug 3 is arranged at the lower end of the liquefied gas passage 5. It is installed. Corresponding to this nozzle 1, in order to prevent water vapor from the beverage in the atmosphere and in the can from rising in the vicinity of the outlet of the nozzle 1 and freezing and adhering as the low-temperature liquefied gas flows. The frost protection cover 7 is detachably attached to the outer cylinder portion 8 surrounding the liquefied gas passage 5 as a part of the outer wall of the vacuum heat insulation chamber 6. The dried nitrogen gas is introduced into the gap with the outer cylinder portion 8 so as to flow out from the opening at the lower end of the defrosting cover 7. Although not shown, a heater is attached to the defrosting cover 7 to prevent frost from adhering to the vicinity of the opening.
[0019]
In the liquefied gas flow nozzle 1, the cylinder 2 is fastened together with the packing by the cylinder cap 9 that is screwed to the lower outer peripheral surface of the outer cylinder portion 8 at the flange portion 21 formed on the outer peripheral surface near the lower end. In this state, the plug 3 is fixed to the bottom wall of the long rod 10 extending in the up-down direction, and a universal joint 11 having a structure generally known per se is provided. Thus, the plug 3 inserted in the cylinder 2 from above is fixed by the vertical movement of the rod 10. The cylinder 2 moves up and down.
[0020]
The plug 1 of the nozzle 1 has cold resistance, wear resistance, and slipping, such as fluororesin and polyamide resin, above a cylindrical rod-shaped portion 31 that is in sliding contact with the cylindrical inner peripheral surface (cylinder hole) of the cylinder 2. A plastic packing member (closing portion) 32 having excellent properties is integrally attached, and is inserted completely until the lower end of the rod-like portion 31 of the plug 3 reaches the lower end of the cylinder 2 as shown in FIG. In a state where the plug 3 is in the lowest end position, the packing member 32 of the plug 3 is opposed to the upper end surface 23 of the cylinder 2 formed in a bowl-shaped concave curved surface (or a bowl-shaped tapered surface). The lower surface (formed in a convex shape that matches the concave shape of the upper end surface 23 of the cylinder 2) is in close contact.
[0021]
As shown in FIGS. 3 (A) and 3 (B), the cylinder 2 of the nozzle 1 has a flange portion 21 formed on the outer peripheral surface near the lower end thereof, and slides on the outer peripheral surface of the rod-shaped portion 31 of the plug 3. On the inner peripheral surface 20 of the cylinder 2 in contact, the width is substantially constant from the upper end to the lower end, the depth of the groove bottom gradually decreases from the top to the bottom, and the depth is extremely small near the lower end. In addition, a plurality of groove portions 22 inclined at the bottom of the groove are formed radially at equal intervals with respect to the axial center of the cylinder 2 (eight in the illustrated case), and are formed in parallel with the axial direction of the cylinder 2, respectively. .
[0022]
In the liquefied gas flow nozzle 1 composed of the cylinder 2 and the plug 3 as described above, as shown in FIG. 1, the plug 3 is completely inserted into the cylinder 2 until it reaches its lowest end position. Since the lower surface of the packing member 32 of the plug 3 is in close contact with the upper end surface 23 of the cylinder 2, all the upper end open portions of the respective groove portions 22 of the cylinder 2 are blocked by the packing member 32 of the plug 3. Since it is in a completely closed state, the liquefied gas stored in the storage tank 4 does not flow down from the liquefied gas passage 5 through the nozzle 1.
[0023]
When the rod 10 is lifted by a desired amount of movement from such a state, as shown in FIG. 2, when the plug 3 is moved upward by a desired height relative to the cylinder 2 and stopped, The packing member 32 of the plug 3 is separated upward from the upper end surface 23, the upper end open portion of each groove portion 22 of the cylinder 2 communicates with the liquefied gas passage 5, and the cylinder 2 at the lower end position of the rod-shaped portion 31 of the plug 3 stopped. Each groove portion 22 is opened downward so that the liquefied gas passes in accordance with the depth of the groove bottom of each groove portion 22 (cross-sectional area of the groove portion).
[0024]
Therefore, the liquefied gas stored in the storage tank 4 passes through each groove portion 22 of the cylinder 2 from the liquefied gas passage 5 at a flow rate corresponding to the cross-sectional area of each groove portion 22 of the cylinder 2 at the lower end position of the plug 3. Accordingly, the plug 3 flows downward in a state where it is dispersed in a plurality (eight) of uniform yarns. Therefore, the ascending position of the plug 3 with respect to the cylinder 2 is adjusted by the amount of movement of the rod 10 to be opened downward. By changing the cross-sectional area of each groove 22, the amount of liquefied gas flowing down through each groove 22 (the opening degree of the nozzle 1) can be continuously changed steplessly.
[0025]
A detailed example of the control of the opening degree of the nozzle 1 by controlling the raising position of the plug 3 will be described in detail when applied to an actual can manufacturing line. The position of the plug 3 and liquefaction per unit time are described. The relationship between the gas flow rate and the speed of the can production line and the flow rate of liquefied gas per unit time required to produce cans at that speed (the amount that can provide the internal pressure required for the cans produced) ) In advance and input them to the computer, while monitoring the speed of the canning production line and sending it to the computer, calculating the position of the plug 3 that matches the speed, 3 is sent to a servo motor (not shown) attached to the upper end of the rod 10 to send a signal for instructing the position movement of the rod 10 to produce the canned food at the speed of the line. By moving the plug 3 to a position where the flow rate of gas per unit time can be obtained, the flow rate of the liquefied gas flowing down from the nozzle 1 is changed steplessly corresponding to the stepless change of the line speed. Can be made.
[0026]
By the way, when the groove bottom of each groove formed in the cylinder of the nozzle for flowing liquefied gas is inclined so that the depth gradually decreases from the upper end toward the lower end (inclination toward the axis of the cylinder 2) As shown in FIG. 5, the flowing state of the liquefied gas is dispersed and flowing in the same number (eight) as the number of the groove portions 22 immediately below the nozzles. As a result, the liquefied gas is formed on the liquid surface in the can depending on the distance between the liquid level of the head space in the can and the nozzle. The impact at the time of dropping is large, and the view on the liquid level becomes large, and there is a possibility that the liquefied gas is scattered.
[0027]
In order to cope with such a problem, in the liquefied gas flow nozzle 1 of the present embodiment, as shown in FIG. 4A, the corner 22a at the lower end of the groove 22 is chamfered. 4B, on the lower end surface of the cylinder 2, the nozzle outlet portion 24 by the respective lower ends of the groove portions 22 and the portion between them is protruded downward from the peripheral portion 25. The lower end of the nozzle outlet portion 24 is formed in a substantially flat portion, and the corner portion 22a at the lower end of the groove bottom of the groove portion 22 is chamfered so that the curvature radius R becomes 0.1 to 0.5 mm. The corners at the lower end of the portion between the groove portions 22 (inner peripheral surface 20 of the cylinder 2) are also chamfered so as not to cause burrs.
[0028]
According to the liquefied gas flow nozzle 1 of this embodiment as described above, the nozzle 1 passes through each groove portion 22 of the cylinder 2 only by controlling the amount of movement of the rod 10 and changing the rising position (fixed position) of the plug 3. The flow rate of the liquefied gas flowing down from the production line can be changed steplessly step by step so that it can respond to, for example, a stepless change in the speed of the canning production line. Regardless of the above, an amount of liquefied gas necessary for obtaining a constant pressure in the can can be added to the can.
[0029]
Further, the liquefied gas that has flowed down through each of the plurality of groove portions 22 of the cylinder 2 can be allowed to flow into the lower can while being dispersed in a uniform thread shape without being merged in the middle. Because the impact of the liquefied gas that has flowed down on the beverage surface in the can can be mitigated, the liquefied gas can be effectively prevented from splashing outside the container due to the impact caused by the collision with the liquid surface. Can do.
[0030]
That is, as shown in FIG. 4A, by chamfering the corner 22a at the lower end of each groove portion 22 of the cylinder 2, it flows down slightly toward the center along the inclined surface of the groove bottom of the groove portion 22. The liquefied gas that has flowed along the curved surface of the corner portion 22a chamfered at the lower end of the groove portion 22 is slightly drawn outward and changed to a downward flow (vertical direction). The liquefied gas that has flowed down through each groove portion 22 of the cylinder 2 does not merge into a single flow on the way, and is dispersed in a uniform thread shape in the lower can. Will flow down.
[0031]
In the present embodiment, the curvature radius of the chamfered corner portion 22a at the lower end of the groove bottom of the groove portion 22 is set to 0.1 to 0.5 mm so that the groove 22 flows along the inclined surface of the groove bottom. Thus, the liquefied gas can be effectively changed to a downward (vertical) flow along the curved surface of the corner 22a. Further, by making the nozzle outlet portion 24 protrude downward from the peripheral portion 25 at the lower end surface of the cylinder 2, it is relatively easy to chamfer the corner portion 22 a at the lower end of each groove portion 22 of the cylinder 2. In addition to this, the liquefied gas can be easily removed (the liquefied gas does not flow from the lower end of each groove portion 22 to the peripheral portion).
[0032]
Furthermore, in the present embodiment, the rod 10 and the plug 3 are connected via the universal joint 11, so that the mounting position of the rod 10 and the mounting position of the cylinder 2 are slightly shifted, or the rod 10 is slightly tilted. Even if the axial center of the rod 10 and the axial center of the cylinder 2 do not exactly match, the inclination of the rod 10 with respect to the cylinder 2 is affected when the plug 3 is inserted into the cylinder 2. The plug 3 is inserted without tilting with respect to the cylinder 2, and as a result, the outer peripheral surface of the plug 3 (rod-like portion 31) and the inner peripheral surface 20 of the cylinder 2 (cylinder hole) that are in sliding contact with each other. No so-called galling phenomenon occurs between them, and the sealing performance at the close contact portion between the upper end surface 23 of the cylinder 2 and the lower surface of the packing member 32 of the plug 3 is deteriorated. Unakoto is not.
[0033]
Moreover, in this embodiment, as shown in FIG. 3 (B), the upper end surface 23 of the cylinder 2 is formed in a bowl-shaped concave curved surface (or a bowl-shaped tapered surface), whereby the plug 3 When the rod 10 is inserted into the cylinder 2 from above, the shaft cores of the rod 10 and the cylinder 2 are not precisely aligned, so that the position of the lower end of the plug 3 (the lower end of the rod-shaped portion 31) and the cylinder hole of the cylinder 2 Even if the relationship is deviated, the plug 3 can be easily inserted into the cylinder 2.
[0034]
That is, the shape of the upper end surface of the cylinder 2 may be any shape including a flat surface as long as the shape of the lower surface of the packing member 32 of the plug 3 is matched with that. If the end surface is formed into an inclined surface that inclines downward from the outer peripheral portion toward the central portion, such as a tapered surface or a concave curved surface inclined in a bowl shape, the plug 3 is inserted into the cylinder 2 from above. At this time, even if the positional relationship between the lower end of the plug 3 (the lower end of the rod-shaped portion 31) and the cylinder hole of the cylinder 2 is shifted, the lower end of the plug 3 is simply lowered by the rod 10 as it is. Therefore, the plug 3 can be easily inserted into the cylinder 2.
[0035]
As shown in FIG. 3B, in order to form the upper end surface 23 of the cylinder 2 in a bowl-like inclined surface, it is formed in a concave curved surface instead of a simple tapered surface and coincides with this concave curved surface. As described above, if the lower surface of the packing member 32 of the plug 3 is formed in a convex curved surface, the contact area between the upper end surface 23 of the cylinder 2 and the lower surface of the packing member 32 of the plug 3 is smaller than that in the case of a simple tapered surface. Can be increased as much as possible, and the sealing performance when the nozzle is closed can be improved by the close contact between the upper end surface 23 of the cylinder 2 and the packing member 32 of the plug 3.
[0036]
As mentioned above, although one embodiment of the liquefied gas flow nozzle of the present invention has been described, the present invention is not limited to the specific structure as shown in the above embodiment. The shape of the peripheral surface (and the outer peripheral surface of the rod-shaped portion of the plug) is not limited to the shape having a perfect circular cross section as shown in the above embodiment, but is an oval shape having a pair of opposed planar walls. As a cross-sectional shape, a plurality of groove portions may be formed in parallel on each of the flat walls from the upper end to the lower end of the cylinder. By installing the liquefied gas flow nozzles so that they are parallel to each other, it is possible to collect a plurality of liquefied gas flows to be dispersed and flowed in a narrow range. Against liquefied gas It becomes suitable for flow down.
[0037]
Further, the plurality of groove portions formed on the inner peripheral surface of the cylinder are not limited to those having the same shape with the groove bottom inclined as shown in the above embodiment, It is sufficient that the groove bottom is inclined at least at a pair of opposed grooves, and the number and size of the groove parts can be appropriately changed. The smaller the amount of the liquefied gas flowing down, the less the amount of liquefied gas flowing down even if the plug position is changed. Therefore, in order to increase the range of change in the amount of liquefied gas flowing down, it is suitable for dispersing the liquefied gas and flowing down. It is preferable to provide a number of grooves and to incline all (or most) groove bottoms.
[0038]
Further, regarding the plug of the liquefied gas flow nozzle, in the above embodiment, the lower end of the rod for moving the plug and the plug are connected via a universal joint, but the axis of the rod supporting the plug and the cylinder If the shaft core can be precisely matched, the rod and the plug may be directly connected, and the shape of the upper end surface of the cylinder is inclined downward from the outer peripheral portion toward the central portion in the above embodiment. However, it is needless to say that the design can be changed as appropriate, such as a flat surface or other shapes.
[0039]
【The invention's effect】
According to the liquefied gas flow nozzle of the present invention as described above, the flow amount of liquefied gas per unit time to flow down can be changed steplessly with a simple structure, and the production line can be stepped steplessly. The flow rate of liquefied gas per unit time can be increased or decreased following the speed change, so that the desired amount of liquefied gas can always be added to the container regardless of the speed of the production line. In addition, the liquefied gas dispersed and flowing down from the nozzle can be flowed downward in the state of being dispersed in a uniform string without being merged in the middle, and the liquefied gas flowing down in the container It is possible to prevent the liquefied gas from scattering due to the collision with the liquid surface.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a lower end portion of a liquefied gas flowing-down apparatus provided with a liquefied gas flowing-down nozzle according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a state in which the liquefied gas flow nozzle shown in FIG. 1 is opened at a desired opening degree.
3A is a top view showing the structure of a cylinder of the liquefied gas flow nozzle shown in FIG. 1, and FIG. 3B is a longitudinal sectional view taken along line BB in FIG.
4A is a longitudinal cross-sectional explanatory view of the cylinder of the liquefied gas flow nozzle shown in FIG. 3, and FIG. 4B is a vertical cross-sectional explanatory view showing a state in which the liquefied gas flows through the groove of the cylinder, and FIG. FIG.
FIG. 5 is a longitudinal sectional explanatory view showing a state in which liquefied gas flows down through a groove portion of a cylinder in a comparative example of a liquefied gas flowing nozzle.
[Explanation of symbols]
1 (for liquefied gas flow down) Nozzle 2 Cylinder 3 Plug 22 Groove 22a Corner (at the bottom of the groove bottom) 24 Nozzle outlet

Claims (3)

The cylinder has a vertical axis, a plug having a rod- like portion inserted into the cylinder from above, and a closing portion located above the rod-like portion. The cylinder is in sliding contact with the outer peripheral surface of the rod-like portion of the plug. A plurality of grooves for passing the liquefied gas are formed in parallel to the axial direction of the cylinder from the upper end to the lower end of the peripheral surface, and at least one pair or more of each groove is directed from the upper end to the lower end. When the bottom of the groove is inclined so that the width is substantially constant and the depth of the groove gradually decreases, and the plug that can move up and down relative to the cylinder reaches its lowest end position, by lower surface of the closure portion is in close contact with the upper end surface of the cylinder, the upper end opening of each groove of the cylinder in the liquefied gas flow nozzle that is configured to be closed by all the plug, the cylinder At the lower end of the groove bottom is inclined, liquefied gas flow nozzle corner portion of the lower end of the groove bottom is characterized in that it is chamfered. 2. The liquefied gas flow nozzle according to claim 1, wherein a radius of curvature of a chamfered corner portion at a lower end of the groove bottom of the groove portion is 0.1 to 0.5 mm. 3. The liquefied gas flow nozzle according to claim 1, wherein a nozzle outlet portion formed by each lower end of each groove portion and a portion between the grooves protrudes downward from the peripheral portion on the lower end surface of the cylinder. .

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