JP4628562B2 - Method and apparatus for filling liquid nitrogen into container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for filling liquefied nitrogen into a container filled with liquefied nitrogen, for example, liquefied nitrogen, so that it can withstand external pressure, oxidation, etc. in containers such as beverage cans, PET bottles, and bottles. .
[0002]
[Prior art]
In general, in a method for filling liquefied nitrogen, which is liquefied nitrogen, into a beverage can, the liquefied nitrogen L is dropped in accordance with the timing in consideration of the transport speed of the conveyor that transports the can C and the interval between the cans. A dropping type (FIG. 4) and a flowing type (FIG. 5) in which the liquefied nitrogen L is allowed to flow down at a constant amount and the can C is conveyed at a constant speed are known. The dropping method is advantageous when the conveyance speed is 1000 cpm (can per minute) or less, and the flow-down method is advantageous when the conveying speed is more than 1000 cpm (can per minute).
[0003]
[Problems to be solved by the invention]
However, the conventional liquefied nitrogen filling method has the following problems.
First, in the case of a dripping type, an unstable element exists at the start of dripping of liquefied nitrogen.
For example, when back pressure is applied to the stored liquefied nitrogen of the dropping injector, there is an unstable element in which a large amount of liquefied nitrogen L flows out immediately after the valve is opened and the dropping amount is stabilized after a predetermined time.
[0004]
On the other hand, when the stored liquefied nitrogen in the dropping injector is opened to the atmosphere without applying back pressure, there is a problem that the dropping amount of the liquefied nitrogen L is small immediately after the valve opening, and the dropping amount is stabilized after a predetermined time has elapsed.
Furthermore, in the case of the dripping type, since La is produced at the end of the dropwise addition of the liquefied nitrogen L, the filling amount becomes unstable depending on how the La enters, and one of the factors that the can internal pressure after sealing varies. It was.
[0005]
For this reason, in the dripping method, the filling amount of liquefied nitrogen L becomes unstable, the internal pressure of the can after sealing varies, the discharge rate removed from the line because the internal pressure test result is inappropriate, There were times when it reached about 10 times.
Therefore, in order to stabilize the filling amount of the liquefied nitrogen L in the dropping method, for example, an apparatus capable of accurately filling the liquefied nitrogen L into the beverage can as disclosed in JP-A-6-127506. Has been proposed.
[0006]
On the other hand, in the case of the flow-down type, since the constant liquefied nitrogen L always flows out, the filling amount of the liquefied nitrogen L is stabilized, but since the liquefied nitrogen L falls between the cans, the liquefied nitrogen L There is a problem that waste occurs.
In particular, in the case of a so-called bottle can in which the can opening has a smaller diameter than the can body, and a lid can be screwed into the can opening, the can opening can be made with respect to the can body diameter. This tendency is remarkable because the diameter is small.
[0007]
The present invention has been made in view of the above circumstances, and the object thereof is to fill the container with liquefied nitrogen that can stabilize the amount of liquefied nitrogen to be filled in the container while reducing waste of liquefied nitrogen to be used. It is to provide a method and apparatus.
[0008]
[Means for Solving the Problems]
The present invention employs the following configuration in order to solve the above problems.
The invention according to claim 1 is a method for filling liquefied nitrogen into a container which is filled with liquefied nitrogen from a nozzle which is opened and closed by a valve in a container being transported, wherein the front end of the container opening in the transport direction is below the nozzle. Before flowing, the liquefied nitrogen is allowed to flow down in advance, and after the quantified flow is maintained at least until the rear end of the container opening in the transport direction passes below the nozzle, the flow of the liquefied nitrogen is stopped. It is characterized by.
[0009]
The invention according to claim 2 is the method for filling liquid nitrogen in the container according to claim 1, wherein the container is a bottle-shaped container in which the container opening has a smaller diameter than the container body. It is characterized by.
[0010]
According to a third aspect of the present invention, in the apparatus for filling liquid nitrogen into a container, a nozzle for filling liquid nitrogen into the container being transported, a valve for opening and closing the nozzle, and the container being transported at a predetermined position. After the container is detected by the container detecting means to be detected and the container detecting means, the valve is opened in advance for a predetermined time before the front end of the container opening in the conveying direction is below the nozzle. And a control means for closing the valve after maintaining the valve state at least until the rear end in the transport direction of the container opening passes below the nozzle.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram showing a method and apparatus for filling liquefied nitrogen into a can according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing the overall configuration of the apparatus. Beverage can (container), L indicates liquefied nitrogen.
[0012]
In FIG. 2, the liquefied nitrogen filling apparatus for cans according to the present embodiment includes an injector 2, a can conveyance mechanism (conveyor) 3 for conveying cans C, and a can lid C filled with liquefied nitrogen L. A capper 4 to be screwed and a can detection means (container detection means) 10 for detecting a can C being conveyed by the can conveyance mechanism 3 at a predetermined position are provided.
[0013]
The injector 2 is provided with a tank 9 for storing liquefied nitrogen L, a nozzle 1 provided at the bottom of the tank 9, a valve 7 for opening and closing the nozzle 1, and a solenoid 8 for driving the valve 7. It has been.
A filler (not shown) provided with a star wheel is provided on the upstream side of the liquefying injector 2, and the cans C are sequentially filled with beverages.
[0014]
The capper 4 is fixed to the rotating shaft thereof, and a gear-shaped encoder 5 in which the passage time between teeth is set equal to the conveyance interval time of the can C, and a proximity disposed opposite to the encoder 5. And a switch 6.
The encoder 5 and the proximity switch 6 constitute speed detecting means for detecting the rotational speed of the rotating shaft of the capper 4, that is, the conveyance speed of the can C.
[0015]
After the can C is detected by the can detection means 10, the valve 7 is opened in advance for a predetermined time before the conveyance direction front end 11 a of the can opening (container opening) 11 reaches below the nozzle 1. Control means (not shown) for closing the valve 7 is provided after the valve opening state is maintained at least until the rear end 11b in the conveyance direction of the can opening 11 passes below the nozzle 1.
[0016]
This control means uses a timer (not shown) to monitor an elapsed time after the can detection means 10 detects the can C (hereinafter referred to as “elapsed time t after can detection”), and can detection When the can 10 is detected by the means 10 and thereafter “elapsed time after detection of can t = power supply start time ts”, power supply to the solenoid 8 is started, and “elapsed time after detection of can t = power supply stop time tf”. When this happens, power supply to the solenoid 8 is stopped.
[0017]
The power supply start time ts is the time t1 required from the time when the can C is detected by the can detection means 10 until it reaches the nozzle 1, and after the power supply to the solenoid 8, the valve 7 is driven and the liquefied nitrogen is discharged from the nozzle 1. Using the delay time t2 required for L to flow out and the outflow amount to be sufficiently stabilized (becomes a constant flow), it is obtained from the equation of ts = t1-t2. In the present embodiment, the delay time t2 is set to 45 to 50 [msec], for example.
[0018]
The reason for the setting is that, after supplying power to the solenoid 8, it takes 35 to 40 [msec] for the liquefied nitrogen L to reach the upper end of the opening of the can C after the valve 7 is opened. This is because it is necessary to allow for an unstable flow time of the liquefied nitrogen L.
Accordingly, the delay time t2 is appropriately set according to the distance from the tip of the nozzle 1 to the upper end of the opening of the can C, the sectional shape of the tip of the nozzle 1, and the like.
[0019]
On the other hand, the power supply stop time tf is the passage time t3 required from the time when the can C is detected by the can detection means 10 until the rear end 11b in the transport direction of the can opening 11 passes below the nozzle 1, and the can opening Using an allowance time t4 that allows for a manufacturing error in diameter, it is obtained from an equation of tf = t3 + t4.
The passage time t3 is obtained from t3 = t1 + t5 using the arrival time t1 and the crossing time t5 required for the can opening 11 approaching below the nozzle 1 to completely pass (cross) the nozzle 1.
[0020]
These arrival time t1 and crossing time t5 are obtained from the following equations.
Arrival time t1 = X / V / W
Crossing time t5 = D / V / W
X: Distance from can detection means 10 to nozzle 1 [mm]
V: Conveying speed of can C detected by speed detecting means [can / sec]
D: Can opening diameter [mm]
W: transport pitch of can C [mm]
[0021]
From the above, the power supply stop time tf is obtained by the following equation.
tf = t3 + t4
= (T1 + t5) + t4
= (X + D) / V / W + t4
That is, if the rear end 11b in the conveyance direction of the can opening 11 has passed directly under the nozzle 1, even if the flow amount of the liquefied nitrogen L subsequently fluctuates, the filling amount is not affected at all. The power supply stop time tf is set based on the conveyance speed V of the can C, the can opening diameter D, the conveyance pitch W, and the manufacturing error of the can opening 11.
[0022]
Incidentally, when the transport speed V = 6 [can / sec], the transport pitch W = 126 [mm], the opening diameter D = 32 [mm], and the margin time t4 = 5 [msec],
Passing time per can = 1 / V≈0.166 [sec],
Transit time per mm = 0.166 / W≈0.0013 [sec / mm],
Crossing time t5 = D × 0.0013≈42 [msec]
Thus, the time from when the can C reaches below the nozzle 1 until the power supply is stopped becomes 47 [msec] by adding a margin time t4 = 5 [msec] to the crossing time t5.
[0023]
FIG. 3 is a diagram showing the relationship between the flow of liquefied nitrogen L flowing along with the opening and closing of the valve and the nitrogen filling area of the can C. In FIG. 3, the symbol T ₀ indicates the start of opening of the valve 7, T ₁ Is the end of valve 7 opening, T ₄ is the start of closing of valve 7, T ₅ is the end of closing valve 7, T _{0 to} T ₁ are regions where the flow rate of liquefied nitrogen L is unstable at the time of opening, T ₁ T ₄ to T ₄ indicate a fixed flow area of the liquefied nitrogen L, T _{2 to} T ₃ indicate a nitrogen filling area to the can C, and T _{4 to} T ₅ indicate a flow quantity unstable area of the liquefied nitrogen L when the valve is closed.
[0024]
Next, the filling method of liquefied nitrogen is demonstrated according to FIGS.
First, since the detection signal is sent to the control means when the can detection means 10 detects the can C, the control means activates a timer and starts measuring the elapsed time t after detection of the can.
When the elapsed time t after can detection reaches a preset power supply start time ts, the control means supplies power to the solenoid 8 and opens the valve 7.
[0025]
When power is supplied to the solenoid 8 at this timing, a mechanical delay until the valve 7 opens, a delay until the liquefied nitrogen L that has come out of the nozzle 1 reaches the can C, and an outflow amount of the liquefied nitrogen L Since the delay until it is sufficiently stabilized is taken into consideration, before the front end 11a in the transport direction of the can opening 11 reaches below the nozzle 1, that is, the liquefied nitrogen L flows down to the shoulder 12a on the front side in the transport direction of the can C. At that time, the outflow amount is already stable, and a constant flow is ensured for the can opening 11.
[0026]
Thus, in FIG. 3, remove the falling amount unstable area at the time of opening from T ₀ to T _1, at yet a T ₁ became quantitative flow down state of the predetermined delay elapsed time T ₂ timing, cans opening The part 11 is located below the nozzle 1 and is filled with liquefied nitrogen L.
Thereafter, when the power supply stop time tf elapses after the can C is detected by the can detection means 10, the control means stops power supply to the solenoid 8 and starts closing the valve 7.
[0027]
The timing for stopping the power supply to the solenoid 8 is after the rear end 11b in the transport direction of the can opening 11 has completely passed under the nozzle 1, and the constant flow is maintained until this point.
[0028]
When power supply to the solenoid 8 is stopped after the rear end 11b in the transport direction of the can opening 11 has completely passed under the nozzle 1, the mechanical delay until the valve 7 is completely closed, that is, 3, the flow amount unstable region at the time of closing the valve from T ₄ to T ₅ in FIG. 3 can be surely removed, and the flow down until the liquefied nitrogen L flows down to the shoulder 12b on the rear side in the conveying direction of the can C. Is maintained.
It should be noted that after T ₅ , drooping La occurs as shown in FIG. 1 (d). However, no drooling La is caused since the can opening 11 is removed from below the nozzle 1.
[0029]
As described above, according to the present embodiment, it is possible to avoid an unstable period of the flow rate of liquefied nitrogen when the valve is opened and closed, and to eliminate unstable factors due to drooping after the valve is closed. As a result, the internal pressure in the can C can be set within a desired range.
Moreover, since the liquefied nitrogen L does not always flow out from the nozzle 1 as in the conventional flow-down type, waste reduction of the liquefied nitrogen L can be achieved.
[0030]
As in the present embodiment, the can opening 11 is narrower than the can body (container body) 13, and the lid Ca can be screwed to the can opening 11 so as to be liquefied into a so-called bottle can. Particularly in the case of nitrogen filling, the waste reduction effect of the liquefied nitrogen L is great.
Needless to say, since the opening area is small in the case of a bottle can, the amount of liquefied nitrogen L that is wasted when the flow-down method is adopted becomes enormous.
[0031]
It should be noted that the present invention is not limited to the above embodiment, and the specific numerical values described above are merely examples, and the present invention is not limited thereto.
For example, in the above-described embodiment, the bottle can in which the can opening 11 has a smaller diameter than the can body 13 has been described. However, the can opening 11 and the can body 13 have substantially the same diameter. Can also be applied to cans.
[0032]
Moreover, as a bottle-shaped container, what is called a plastic bottle and a bottle are not restricted to a bottle can.
Further, the container is not limited to beverages, but includes containers used for other purposes.
[0033]
【The invention's effect】
As described above, according to the filling method and filling apparatus of liquefied nitrogen of the present invention, the container can always be filled with a fixed amount of liquefied nitrogen, and the low pressure container due to insufficient liquefied nitrogen filling amount or the high pressure due to excessive liquefied nitrogen filling. While preventing generation | occurrence | production of a container, the waste of liquefied nitrogen can also be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a method and apparatus for filling liquefied nitrogen in a can according to an embodiment of the present invention.
FIG. 2 is a schematic view showing the overall configuration of the liquefied nitrogen filling apparatus shown in FIG.
FIG. 3 is an explanatory diagram showing a relationship between a change in the flow amount of liquefied nitrogen L accompanying opening and closing of the valve in the liquefied nitrogen filling apparatus shown in FIG.
FIG. 4 is an explanatory view showing a conventional dripping type liquefied nitrogen filling method.
FIG. 5 is an explanatory view showing a conventional flow-down type liquefied nitrogen filling method.
[Explanation of symbols]
1 Nozzle 7 Valve 10 Can detection means (container detection means)
11 Can opening (container opening)
11a Transport direction front end 11b Transport direction rear end 13 Can body part (container body part)
C can (container)
L Liquid nitrogen

Claims (3)

A method for filling liquefied nitrogen into a container filled with liquefied nitrogen from a nozzle that is opened and closed by a valve in a container being conveyed,
Before the front end of the container opening in the transport direction reaches below the nozzle, the liquefied nitrogen is allowed to flow in a predetermined amount, and at least until the rear end in the transport direction of the container opening passes below the nozzle. After maintaining, the flow of the liquefied nitrogen is stopped, and the liquefied nitrogen filling method into the container is characterized. The method for filling liquid nitrogen into a container according to claim 1, wherein the container is a bottle-shaped container in which the container opening has a smaller diameter than the container body. A nozzle for filling liquefied nitrogen in a container being transported;
A valve that opens and closes this nozzle;
Container detecting means for detecting the container being conveyed at a predetermined position;
After the container is detected by the container detection means, the valve is opened in advance for a predetermined time before the front end of the container opening in the transport direction is below the nozzle, and the opened state is at least the container opening. And a control means for closing the valve after maintaining the rear end in the transport direction of the section under the nozzle, and a liquefied nitrogen filling device for a container.

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