Dry ice forming device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an apparatus for producing dry ice for cooling take-out products and the like.

【0002】

[Conventional technology]

In the past, clerk crushed solid dry ice appropriately and attached the required amount to products that need to be refrigerated as take-out products from stores, but solid dry ice causes frostbite etc. when touched directly. There is a danger and care must be taken when handling it. Although over-the-counter sales require particularly quickness, every time dry ice is attached to a product, gloves must be worn, which has been an obstacle to over-the-counter sales, especially at retail stores.

【0003】

In order to solve such a problem, the applicant stated in Patent Application No. 362597 of 1997 that "an expansion cylinder is erected and fixed on the upper part of a work room having a door, and dry ice is generated on the upper end of the expansion cylinder. Dry ice generation is characterized by providing a nozzle for ejecting liquefied carbon dioxide gas for use and a control device for controlling the generated dry ice to be supplied to a container opened at the lower end of the expansion cylinder for a certain period of time. "Device" was proposed. This has made it possible to quickly and safely spray powdered dry ice around products that require refrigeration at stores.

【0004】

[Problems to be Solved by the Invention]

In the above-mentioned dry ice generator, the supply time of the liquefied carbon dioxide gas was kept constant, but it was found that the amount of dry ice produced was not always constant due to various conditions. The present invention has been made to solve this new problem.

【0005】

[Means for solving problems]

The first dry ice generator according to the present invention, which has been made to solve the above problems, has an expansion cylinder erected and fixed on the upper part of the supply chamber, and the dry ice generation apparatus is installed on the upper end of the expansion cylinder. In a dry ice generator in which a nozzle for ejecting carbon dioxide gas is provided to supply the generated dry ice to a container opened at the lower end of an expansion cylinder, an ambient temperature detecting means for detecting the ambient temperature and an ambient temperature detecting means. It is characterized by comprising an ejection time determining means for determining the ejection time of carbon dioxide gas so that the amount of dry ice produced becomes a predetermined amount according to the detected ambient temperature.

【0006】

When the temperature around the place where this dry ice generator is installed is high, the ejected carbon dioxide gas is unlikely to become dry ice, so the same amount will be obtained if it is not ejected for a longer time than when the ambient temperature is low. Unable to produce dry ice. Therefore, the ejection time determining means determines the ejection time of carbon dioxide gas so that a predetermined amount of dry ice is produced according to the detected ambient temperature. In determining the ejection time, the function or reference table obtained in advance by experiments or the like is used. The predetermined amount is a predetermined fixed amount or a target dry ice production amount input from the outside for each use.

【0007】

Further, the second dry ice generator according to the present invention is a similar dry ice generator, in which a gas pressure detecting means for detecting the pressure of the raw material carbon dioxide gas and the dry ice according to the detected gas pressure are used. It is characterized by comprising an ejection time determining means for determining the ejection time of carbon dioxide gas so that the amount of carbon dioxide produced becomes a predetermined amount.

【0008】

When carbon dioxide gas, which is a raw material, is supplied from a cylinder (tank), for example, when the pressure of carbon dioxide gas in the cylinder is low, the amount of dry ice produced even if it is ejected for the same time as compared with the case where it is high. Is few. The same applies when it is supplied from another source (for example, when it is sent directly from the factory by pipeline). That is, the gas pressure is also one of the factors that change the amount of dry ice produced. Therefore, similarly to the above, the ejection time determining means determines the ejection time of carbon dioxide gas according to the detected gas pressure so that a predetermined amount of dry ice is produced. Here, too, when determining the ejection time, the function or reference table obtained in advance by experiments or the like is used.

【0009】

The third type of the dry ice generator according to the present invention is the same dry ice generator, in accordance with the elapsed time calculation means for calculating the elapsed time from the end of the previous carbon dioxide gas ejection and the calculated elapsed time. The present invention is characterized by comprising an ejection time determining means for determining the ejection time of carbon dioxide gas so that the amount of dry ice produced becomes a predetermined amount.

【0010】

Immediately after the carbon dioxide gas is ejected to generate dry ice, the temperature of the carbon dioxide gas flow path and the expansion cylinder, etc., decreases, but after the carbon dioxide gas ejection is stopped, those temperatures rise as time passes. It gradually rises to the ambient temperature (room temperature). While the temperature of the flow path, expansion cylinder, etc. is low, the amount of dry ice produced is large, but as the temperature rises, the amount of dry ice produced decreases. Therefore, the ejection time determining means determines the ejection time of carbon dioxide gas in consideration of the ejection interval as described above, so that a predetermined amount of dry ice is produced. Similarly, when determining the ejection time, the function or reference table obtained in advance by experiments or the like is used.

【0011】

Since the device according to the present invention can generate a predetermined amount of dry ice regardless of various conditions in this way, it is suitable for automatic sales in stores and the like in combination with its convenience and safety. ing. Therefore, a money (coin and / or banknote) identification device is provided in these dry ice generators, and when a predetermined amount of money is inserted, the ejection time determining means starts operating and starts producing and supplying dry ice. You may try to do so.

【0012】

BEST MODE FOR CARRYING OUT THE INVENTION

In the above, the devices that determine the carbon dioxide gas ejection time according to the three parameters of the ambient temperature, the gas pressure of the raw carbon dioxide gas, and the elapsed time (ejection interval) since the end of the previous ejection have been shown, but of course these parameters are used. It may be provided in an appropriate combination according to the environment and the like. For example, when the most accurate control is desired, as shown in FIG. 1, an ambient temperature detecting means 2, a gas pressure detecting means 3, and an elapsed time calculating means 4 are provided, and the ejection time determining means 1 has three parameters. It is advisable to use all of them to determine the carbon dioxide ejection time. In the example of FIG. 1, the ejection time determined by the ejection time determining means 1 is sent to the ejection valve control device 6, and the ejection valve control device 6 opens the ejection nozzle 7 for that time to generate a predetermined amount of dry ice. To do. The ejection valve control device 6 sends the time when the ejection nozzle 7 is closed to the time storage means 5 and stores it there. The elapsed time calculation means 4 reads out the ejection stop time stored in the time storage means 5, and calculates the elapsed time from the end of the previous ejection by taking the difference from the current time.

【0013】

On the other hand, when used in an environment where the ambient temperature hardly changes, only two parameters, gas pressure and ejection interval, need to be considered. Further, when a constant pressure of carbon dioxide gas is always supplied, or when the capacity of the cylinder (tank) is sufficiently large and the gas pressure changes very slowly, the gas pressure detecting means 3 is not provided. Alternatively, the change in gas pressure may be transmitted to the ejection time determining means 1 by a simple manual changeover switch.

【0014】

[Example]

An over-the-counter dry ice generator, which is an embodiment of the present invention, will be described. In FIGS. 5 and 6, reference numeral 10 denotes a main body, which constitutes a frame by angles and the like, and is surrounded by an iron or plastic plate to form a housing. When using plastic, it is desirable to use a material that does not embrittle or deteriorate at low temperatures. Reference numeral 11 is a supply chamber, which is provided in the middle of the main body 10. Reference numeral 12 denotes a door of the supply chamber 11, which slides up and down in this embodiment. 13 is the handle of the door 12, and 14 is the door switch that operates when the door 12 is closed. When the door 12 is slid upward by holding the handle 13, the door 12 is fixed to the upper frame by, for example, a magnet catch or a latch mechanism (not shown).

【0015】

Reference numeral 15 denotes a horn (expansion cylinder), the upper part of which is fixed to the upper part of the supply chamber 11, and the lower part is open. A nozzle 16 is provided above and inside the horn 15, and the nozzle 16 communicates with a gas supply pipe 18 (FIG. 6) via a solenoid valve 17. The gas supply pipe 18 is connected to a cylinder of liquefied carbon dioxide gas (not shown).

【0016】

The main body 10 is provided with a temperature sensor 19 for measuring the ambient temperature. If the temperature sensor 19 can measure the outside air temperature around the gas supply pipe 18, its location is not specified.

【0017】

Further, a gas pressure sensor 23 is provided on the upstream side (gas supply side) of the gas supply pipe 18 with respect to the solenoid valve 17. Again, the position is not limited as long as the pressure of carbon dioxide gas can be measured, and it may be provided at the mouth of the cylinder of liquefied carbon dioxide gas.

【0018】

A main switch 21 is provided on the side surface of the main body 10, and a supply button 25 and a coin slot of the coin identification device 24 are provided on the front surface of the main body 10 (the side where the door 12 of the supply chamber 11 is provided). .. A type that is not equipped with the coin identification device 24 is also possible. A control device 20 for controlling the operation of the entire device is provided inside the main body 10, and the door switch 14, the solenoid valve 17, the temperature sensor 19, the gas pressure sensor 23, the supply button 25, and the coin identification device 24 ( When equipped), etc. are all connected to the control device 20.

【0019】

When using the device of this embodiment, the main switch 21 is operated to turn on the power of the device. After setting the product box or product bag containing the frozen product under the horn 15 in the supply chamber 11, the user pulls up the door 12 by holding the handle 13 to close the supply chamber 11 and closes the supply button 25. push. For safety, the generation of dry ice does not start even if the supply button 25 is pressed until the door switch 14 detects that the door 12 is closed. Further, in the case of the coin insertion type, the generation of dry ice is not started until the coin identification device 24 detects the insertion of a predetermined amount of coins.

【0020】

The control device 20 opens the solenoid valve 17 for a predetermined time by a process described later. As a result, liquefied carbon dioxide gas is discharged from the nozzle 16, and powdered dry ice is generated in the horn 15 and supplied into a product box or a product bag below the horn 15.

【0021】

In this embodiment, the amount of dry ice produced can be arbitrarily set. The amount of generation may be selected by a changeover switch (not shown) provided on the side surface or inside of the main body 10 that can be operated only by the administrator of the apparatus, or a changeover switch is provided on the front surface of the main body. The generation amount may be arbitrarily selected by the user.

【0022】

The ejection time for producing the required amount of dry ice varies depending on the ambient temperature, the pressure of the carbon dioxide gas cylinder, and the elapsed time from the previous ejection. Therefore, an experiment is conducted in advance to determine how long (seconds) carbon dioxide gas should be ejected according to the values of these parameters in order to generate a target amount of dry ice. An example of the relationship thus obtained is shown in FIGS. 3 and 4.

【0023】

Figure 3 shows the carbon dioxide pressure of 26 kg / cm.²In this case, it is a graph for obtaining the carbon dioxide gas ejection time for producing 150 g of dry ice by using the time interval from the end of the previous ejection and the ambient temperature as parameters. In addition, Fig. 4 shows the carbon dioxide gas ejection time for producing 150 g of dry ice when the ambient temperature is 30 ° C, with the time interval and gas pressure from the end of the previous ejection as parameters. It is a graph. A reference table is created based on these data and stored in a non-volatile memory or the like. This memory or the like is provided in the control device 20, and during actual operation, the temperature sensor 19 and the gas pressure sensor 23 (or the manual changeover switch that the administrator or the like appropriately switches according to the gas pressure as described above), the elapsed time. Each parameter value input from the calculation means (described later) is input to this reference table, and the ejection time for generating the desired amount of dry ice is taken out by performing interpolation processing or the like.

【0024】

It should be noted that, instead of storing in the memory or the like in the form of a reference table as described above, a function for calculating the ejection time from each parameter is obtained in advance based on the experimental data and stored in the memory or the like. You may leave it.

【0025】

The following processing is performed inside the device. When the main switch 21 is turned on, the control device 20 starts the process as shown in the flowchart of FIG. Here, when the present device is a coin insertion type, the following operations are enabled after the coin identification device 24 detects that a predetermined amount of coins have been inserted. First, it is checked by an interrupt or the like whether or not the supply button 25 is pressed (step S1). In the case of the coin insertion type, if sufficient safety measures are taken, the supply button 25 may be abolished and the following supply operation may be started at the same time as the predetermined amount of coins is inserted.

【0026】

When the supply button 25 is pressed, the ambient temperature T is first input from the temperature sensor 19 (step S2), the pressure P in the carbon dioxide gas cylinder is input from the gas pressure sensor 23 (step S3), and the control device 20 is inside. The elapsed time from the end of the previous gas ejection is calculated by the elapsed time calculation means 4 (see FIG. 1) provided in (step S4). The operation of the elapsed time calculation means 4 may be performed by the control device 20 itself.

【0027】

The control device 20 applies the data to the reference table stored in the non-volatile memory in the control device 20 to determine the ejection time (step S5). Then, the ejection start signal is output to the ejection valve control device 6 (FIG. 1) (step S6), and the time determined in step S5 is waited for to elapse (step S7). When the set ejection time has elapsed, the ejection stop signal is output to the ejection valve control device 6 (step S8), and the time at that time is stored in the memory (time storage means 5 in FIG. 1) in the control device 20. (Step S9). The eruption end time data stored here is used to calculate the elapsed time in step S4.

【0028】

The time from the start of ejection to the end of ejection may be counted inside the control device 20 as shown in FIG. 2, or the ejection time data is sent to the ejection valve control device 6 and counted on the ejection valve control device 6 side. You may try to do it. Alternatively, a dedicated timer 22 (Fig. 5) may be used.

【0029】

[Effect of the invention]

In the present invention, the carbon dioxide gas ejection time is adjusted in consideration of these parameters by detecting various fluctuation conditions with a sensor or the like or measuring the ejection time interval. Therefore, a desired amount of dry ice can always be produced regardless of fluctuations in the outside air temperature, the pressure of the raw material carbon dioxide gas, and the like. This enables vending at stores and the like.

[Simple explanation of drawings]

[Figure 1]

The block diagram of one Embodiment of this invention.

[Figure 2]

The flowchart of the process performed by the control device of the dry ice generator of an embodiment.

[Fig. 3]

Gas pressure 26kg / cm to produce 150g of dry ice²The graph which shows the relationship between the ambient temperature and the ejection interval in the state of.

[Fig. 4]

A graph showing the relationship between the gas pressure and the ejection interval at an ambient temperature of 30 ° C to produce 150 g of dry ice.

[Fig. 5]

The front view of the dry ice generator of an Example.

[Fig. 6]

The right side view of the dry ice generator of an Example.

[Explanation of symbols]

10 body 11 Supply room 12 doors 13 handle 14 Door switch 15 horn 16 nozzles 17 Solenoid valve 18 Gas supply pipe 19 Temperature sensor 20 Control unit 21 Main switch 22 timer 23 Gas pressure sensor 24 coin identification device 25 supply button