REMAINING AMOUNT DETECTION APPARATUS AND CARBON DIOXIDE GAS SUPPLY APPARATUS

Abstract

A remaining amount detection apparatus detects a remaining amount of a beverage in a beverage barrel connected to a beverage server. The remaining amount detection apparatus includes a pressure sensor configured to detect a pressure in a channel for supplying a carbon dioxide gas to the beverage barrel, and a controller configured to obtain the remaining amount of the beverage based on a change of a detected pressure that is the pressure detected by the pressure sensor. The controller obtains the remaining amount based on a time ti between a first time tt1 at which a decrease amount of the detected pressure is larger than a first reference value R1 and a second time tt2 at which after the first time tt1, an increase amount from a minimum value Pmin after the detected pressure takes the minimum value Pmin is larger than a second reference value R2.

Description

TECHNICAL FIELD

The present invention relates to a remaining amount detection apparatus and a carbon dioxide gas supply apparatus.

BACKGROUND ART

PTL 1 describes a beverage dispenser that sends a gas from a gas supply source to an airtight beverage container, thereby pushing out a beverage in the beverage container to a pouring means and causing it to pour the beverage. This beverage dispenser includes a gas flow amount measuring means for measuring the flow amount of the gas sent from the gas supply source to the beverage container, a calculation means for calculating the remaining amount of the beverage in the beverage container or the cumulative amount of the beverage sent from the beverage container to the pouring means based on the cumulative flow amount of the gas measured by the gas flow amount measuring means, and a display means for displaying the remaining amount of the beverage in the beverage container or the cumulative amount of the beverage sent from the beverage container to the pouring means, which is calculated by the calculation means.

CITATION LIST

Patent Literature

• PTL 1: Japanese Patent Laid-Open No. 2007-45503

SUMMARY OF INVENTION

Technical Problem

The pressure in the path between the gas supply source and the beverage container can change during the pouring period of the beverage from a pouring tap. For example, the pressure may lower when pouring of the beverage is started and then rise. Hence, the cumulative flow amount of the gas measured by the gas flow amount measuring means may include a considerably large error derived from the change of the pressure, and the remaining amount of the beverage or the cumulative amount of the beverage sent from the beverage container to the pouring means, which is calculated from the cumulative flow amount, may also include an error.

The present invention has as its object to provide a technique advantageous in more correctly detecting the remaining amount of a beverage in a beverage barrel connected to a beverage server.

Solution to Problem

One aspect of the present invention is directed to a remaining amount detection apparatus that detects a remaining amount of a beverage in a beverage barrel connected to a beverage server, and the remaining amount detection apparatus comprises: a pressure sensor configured to detect a pressure in a channel for supplying a carbon dioxide gas to the beverage barrel; and a controller configured to obtain the remaining amount of the beverage based on a change of a detected pressure that is the pressure detected by the pressure sensor, wherein the controller obtains the remaining amount based on a time between a first time at which a decrease amount of the detected pressure is larger than a first reference value and a second time at which after the first time, an increase amount from a minimum value after the detected pressure takes the minimum value is larger than a second reference value.

Another aspect of the present invention is directed to a carbon dioxide gas supply apparatus that supplies a carbon dioxide gas to a beverage barrel connected to a beverage server, and the carbon dioxide gas supply apparatus comprises: a pressure adjuster including a primary-side port and a secondary-side port and configured to adjust a pressure of the carbon dioxide gas supplied from a carbon dioxide gas supply source to the primary-side port and send the carbon dioxide gas from the secondary-side port; a pressure sensor configured to detect a pressure in a first channel that connects the secondary-side port and the beverage barrel; and a controller configured to obtain a remaining amount of a beverage in the beverage barrel based on a change of a detected pressure that is the pressure detected by the pressure sensor, wherein the controller obtains the remaining amount based on a time between a first time at which a decrease amount of the detected pressure is larger than a first reference value and a second time at which after the first time, an increase amount from a minimum value after the detected pressure takes the minimum value is larger than a second reference value.

Advantageous Effects of Invention

According to the present invention, there is provided a technique advantageous in more correctly detecting the remaining amount of a beverage in a beverage barrel connected to a beverage server.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view schematically showing the configuration of a carbon dioxide gas supply apparatus according to the embodiment;

FIG. 2 is an enlarged view of a relief valve in an example shown in FIG. 1;

FIG. 3 is a view schematically showing the operation of the carbon dioxide gas supply apparatus according to the embodiment;

FIG. 4 is an enlarged view of a portion A in FIG. 3;

FIG. 5 is an enlarged view of a portion B in FIG. 3;

FIG. 6 is a view for exemplarily explaining remaining amount detection in the carbon dioxide gas supply apparatus according to the embodiment; and

FIG. 7 is a view showing an example of the configuration of a remaining amount detection unit according to the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made to an invention that requires a combination of all features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.

FIG. 1 schematically shows the configuration of a carbon dioxide gas supply apparatus 100 according to the embodiment. The carbon dioxide gas supply apparatus 100 is configured to adjust a carbon dioxide gas supplied from a carbon dioxide gas supply source (for example, a carbon dioxide gas cylinder) 3 to a target pressure and supply it to a beverage barrel 1. The carbon dioxide gas supply apparatus 100 can also be understood as a beverage pouring system. The carbon dioxide gas supplied to the beverage barrel 1 pushes down the liquid surface of a sparkling beverage in the beverage barrel 1 by its pressure, and the sparkling beverage in the beverage barrel 1 is thus pushed out from the beverage barrel 1 and supplied to a beverage server 2. The sparkling beverage can be, for example, beer, low-malt beer, a beer-like beverage, sour, highball, or the like.

The carbon dioxide gas supply apparatus 100 includes a pressure adjuster 10, a relief valve 20, and a controller 30. The pressure adjuster 10 can include a primary-side port P1 and a secondary-side port P2. The pressure adjuster 10 can be configured to adjust the pressure of the carbon dioxide gas supplied from the carbon dioxide gas supply source 3 to the primary-side port P1 and send it from the secondary-side port P2. The secondary-side port P2 of the pressure adjuster 10 is connected to the beverage barrel 1 via a first channel PH1. The relief valve 20 can be connected to the first channel PH1.

The controller 30 can be configured to control the pressure adjuster 10 and the relief valve 20. Based on the output of a temperature sensor 81 that detects the temperature of the sparkling beverage sent from the beverage barrel 1 to the beverage server 2, the controller 30 can control the relief valve 20 such that the pressure in the first channel PH1 is reduced (or the first channel PH1 is temporarily opened to the atmosphere). Control of the relief valve 20 by the controller 30 may be performed by the controller 30 supplying an electrical signal to the relief valve 20, or may be performed indirectly by the controller 30 controlling another constituent element (for example, a three-way valve V4), as will be described later. Such other constituent element may be regarded as a constituent element of the relief valve 20.

The temperature sensor 81 can be arranged in or connected to a channel that connects the beverage barrel 1 and the beverage server 2. The temperature sensor 81 may be understood as a constituent element of the carbon dioxide gas supply apparatus 100 or, or may be understood not as a constituent element of the carbon dioxide gas supply apparatus 100. The temperature sensor 81 may be provided in the beverage server 2. Alternatively, the temperature sensor 81 may be attached to the beverage barrel 1.

The carbon dioxide gas supply apparatus 100 can further include a second channel PH2 that supplies the carbon dioxide gas supplied from the carbon dioxide gas supply source 3 to the relief valve 20 to supply, to the relief valve 20, a force for maintaining the relief valve 20 in a closed state. The carbon dioxide gas supply apparatus 100 can further include a regulator 40 that reduces the pressure of the carbon dioxide gas supplied from the carbon dioxide gas supply source 3 to a predetermined pressure. The carbon dioxide gas supply apparatus 100 can further include a third channel PH3 that supplies, to the pressure adjuster 10, the carbon dioxide gas whose pressure is reduced to the predetermined pressure by the regulator 40. The second channel PH2 can be arranged to supply, to the relief valve 20, the carbon dioxide gas whose pressure is reduced to the predetermined pressure by the regulator 40.

The configuration of the relief valve 20 is not limited to a specific configuration. FIG. 2 is an enlarged view of the relief valve 20 in the example shown in FIG. 1. In an example, the relief valve 20 can include a cylinder 21, a piston 22, a valve body 23, and a spring 24. The cylinder 21 can include, for example, a first opening OP1 provided with a seat 29, and a second opening OP2 communicating with the atmosphere. The piston 22 can separate the internal space of the cylinder 21 to a first space S1 and a second space S2. The valve body 23 can be arranged in the second space S2 and supported by the piston 22 to face the seat 29. The spring 24 can be arranged to press the valve body 23 to form a gap 28 between the seat 29 and the valve body 23.

The carbon dioxide gas supplied to the first space S1 via the second channel PH2 is introduced into the first space S1 and can give a force in a direction of pressing the valve body 23 against the seat 29 to the piston 22. The first opening OP1 communicates with the first channel PH1. The second opening OP2 makes the second space S2 communicate with the atmosphere.

The carbon dioxide gas supply apparatus 100 can further include the three-way valve V4 arranged in the second channel PH2. The three-way valve V4 can be controlled by the controller 30 to a first state in which the second channel PH2 and the first space S1 of the relief valve 20 are connected or a second state in which the first space S1 of the relief valve 20 communicates with the atmosphere. The carbon dioxide gas supply apparatus 100 can further include a check valve 60 arranged in the second channel PH2 to supply the carbon dioxide gas from the regulator 40 to the three-way valve V4. The check valve 60 can function to prevent the pressure of the carbon dioxide gas to be supplied to the three-way valve V4 or the first space S1 of the relief valve 20 from lowering when the pressure of the carbon dioxide gas supplied from the carbon dioxide gas supply source 3 lowers due to the decrease of the amount of the carbon dioxide gas in the carbon dioxide gas supply source 3.

The carbon dioxide gas supply apparatus 100 can further include a safety valve V3 connected to a position between the pressure adjuster 10 and the connecting portion of the relief valve 20 in the first channel PH1. The safety valve V3 functions to prevent the pressure in the first channel PH1 from being a predetermined pressure or more.

The configuration of the pressure adjuster 10 is not limited to a specific configuration. In an example, the pressure adjuster 10 can include a pressure intensifying valve V1 configured to increase the pressure in the first channel PH1, and a pressure reducing valve V2 configured to reduce the pressure in the first channel PH1. The internal space of the pressure adjuster 10 can include a first space S3, a second space S4, and a third space S5. The first space S3 and the second space S4 are partitioned by a diaphragm 13. A spring 14 can be connected to the diaphragm 13. Also, a valve body 11 can be coupled with the diaphragm 13, and a spring 12 can be connected to the valve body 11. The position of the valve body 11 is decided by the restoring force of the springs 12 and 14 and the diaphragm 13 and the pressure difference between the first space S3 and the second space S4, and the gap between the valve body 11 and the seat facing this is thus decided.

If the pressure intensifying valve V1 is opened, the carbon dioxide gas is introduced from the third channel PH3 to the first space S3 via the third space S5, and the pressure in the first space S3 increases. Thus, the carbon dioxide gas passing through a valve formed by the valve body 11 and a seal facing this increases, and the pressure of the carbon dioxide gas in the second space S4 increases. The pressure in the first space S3 increases until the restoring force of the springs 12 and 14 and the diaphragm 13 and the pressure difference between the first space S3 and the second space S4 balance, and the pressure in the second space S4, that is, the first channel PH1 also increases.

If the pressure reducing valve V2 is opened, the carbon dioxide gas is discharged to the first space S3, and the pressure in the first space S3 decreases. Thus, the carbon dioxide gas passing through the valve formed by the valve body 11 and the seal facing this decreases, and the pressure of the carbon dioxide gas in the second space S4 decreases. The pressure in the first space S3 decreases until the restoring force of the springs 12 and 14 and the diaphragm 13 and the pressure difference between the first space S3 and the second space S4 balance, and the pressure in the second space S4, that is, the first channel PH1 also decreases.

The controller 30 can be configured to, when reducing the pressure in the first channel PH1 to reduce the pressure in the beverage barrel 1, open the relief valve 20 in accordance with a target pressure, that is, make the first channel PH1 communicate with the atmosphere via the second opening OP2 in a state in which the pressure reducing valve V2 is closed. According to the configuration that discharges the carbon dioxide gas in the beverage barrel 1 via the relief valve 20 when reducing the pressure in the beverage barrel 1, it is possible to prevent the carbon dioxide gas containing a beverage mist (for example, a beer mist) in the beverage barrel 1 from flowing into the pressure adjuster 10. This suppresses sticking of the constituent elements of the pressure adjuster 10 due to the beverage mist.

The carbon dioxide gas supply apparatus 100 can also include a pressure sensor 82 that detects the pressure in the first channel PH1. The controller 30 can control the pressure intensifying valve V1, the pressure reducing valve V2, and the relief valve 20 based on the output of the pressure sensor 82. Note that in an example, the controller 30 controls the three-way valve V4, thereby controlling the relief valve 20. The carbon dioxide gas supply apparatus 100 may further include a pressure sensor 83 that detects the pressure in the third channel PH3. The controller 30 can detect shortage of the carbon dioxide gas in the carbon dioxide gas supply source 3 based on the output of the pressure sensor 83.

Note that the pressure intensifying valve V1, the pressure reducing valve V2, and the three-way valve V4, and the temperature sensor 81, the pressure sensor 82, and the pressure sensor 83 are not connected to the controller 30 in FIG. 1, but these are connected to the controller 30 by wire or wirelessly.

FIG. 3 schematically shows the operation of the carbon dioxide gas supply apparatus 100. FIG. 4 is an enlarged view of a portion A in FIG. 3, and FIG. 5 is an enlarged view of a portion B in FIG. 3. The ordinate represents the pressure detected by the pressure sensor 82. The pressure may be the output value itself of the pressure sensor 82, or may be a value obtained by converting the output value (for example, an analog value or digital value represented by a relative measure) into a value of another measure (typically, a temperature). The abscissa represents time.

The example shown in FIG. 3 starts from a point of time when the beverage barrel 1 is brought from the outside (for example, 35° C.) into a room (for example, 25° C.), the first channel PH1 is connected to the beverage barrel 1, and the beverage server 2 is also connected. By the pressure of the carbon dioxide gas in the beverage barrel 1, the pressure in the first channel PH1 increases. At time t1, the beverage server 2 is operated to pour the beverage. The pressure in the beverage barrel 1 and the first channel PH1 thus lowers a little. When the beverage is poured, the temperature indicated by the output of the temperature sensor 81 rises.

In response to the rise of the temperature indicated by the output of the temperature sensor 81, the controller 30 changes the target pressure in the beverage barrel 1 (and the first channel PH1) to a pressure according to the temperature. According to the change of the target pressure, the controller 30 controls the pressure intensifying valve V1, the pressure reducing valve V2, and the relief valve 20 (the pressure intensifying valve V1, the pressure reducing valve V2, and the three-way valve V4) based on the target pressure after the change. More specifically, in this example, the controller 30 can control the pressure intensifying valve V1, the pressure reducing valve V2, and the three-way valve V4 such that the temperature indicated by the output of the pressure sensor 82 matches the target pressure. In an example, the controller 30 can intermittently open the pressure intensifying valve V1, as exemplarily shown in FIG. 4.

In the example shown in FIG. 3, at time t3, the beverage server 2 is further operated to pour the sparkling beverage, and at time t4, the beverage server 2 is further operated to pour the sparkling beverage. Also, in the example shown in FIG. 3, after that, the time further elapses, and at time t5 after the temperature of the sparkling beverage in the beverage barrel 1 approaches the room temperature, the beverage server 2 is further operated to pour the beverage. When the sparkling beverage is poured, the temperature indicated by the output of the temperature sensor 81 lowers.

In response to the lowering of the temperature indicated by the output of the temperature sensor 81, the controller 30 changes the target pressure in the beverage barrel 1 (and the first channel PH1) to a pressure according to the temperature. According to the change of the target pressure, the controller 30 controls the pressure intensifying valve V1, the pressure reducing valve V2, and the relief valve 20 (the pressure intensifying valve V1, the pressure reducing valve V2, and the three-way valve V4) based on the target pressure after the change. More specifically, in this example, the controller 30 can control the pressure intensifying valve V1, the pressure reducing valve V2, and the three-way valve V4 such that the temperature indicated by the output of the pressure sensor 82 matches the target pressure. In an example, the controller 30 can intermittently open the three-way valve V4 in a state in which the pressure reducing valve V2 is continuously opened, as exemplarily shown in FIG. 5.

The carbon dioxide gas supply apparatus 100 can also function as a remaining amount detection apparatus that detects the remaining amount of the beverage in the beverage barrel 1 connected to the beverage server 2. The function as the remaining amount detection apparatus can be provided by a remaining amount detection unit 310 incorporated in the controller 30. The above-described pressure sensor 82 detects the pressure in the first channel PH1 that supplies the carbon dioxide gas to the beverage barrel 1. The controller 30 or the remaining amount detection unit 310 can be configured to obtain the remaining amount of the beverage in the beverage barrel 1 based on a change of the detected pressure that is the pressure detected by the pressure sensor 82.

Remaining amount detection in the carbon dioxide gas supply apparatus 100 according to the embodiment will be described with reference to FIG. 6. Here, FIG. 6 exemplarily shows a pressure (detected pressure) detected by the pressure sensor 82 in, for example, a period including time t3 in FIG. 3. The pressure may be the output value itself of the pressure sensor 82, or may be a value obtained by converting the output value (for example, an analog value or digital value represented by a relative measure) into a value of another measure (typically, a temperature). The abscissa represents time.

The controller 30 or the remaining amount detection unit 310 can be configured to detect, as time ti (pouring time), a time during which the beverage in the beverage barrel 1 is supplied to the beverage server 2 (that is, a time during which the beverage is poured from the beverage server 2). Here, the start point of the time ti is a first time tt1 at which the decrease amount of the detected pressure that is the pressure detected by the pressure sensor 82 is larger than a first reference value R1. Also, the end point of the time ti is a second time tt2 at which after the first time tt1, an increase amount from a minimum value Pmin after the detected pressure takes the minimum value Pmin is larger than a second reference value R2. The controller 30 or the remaining amount detection unit 310 can be configured to obtain the remaining amount of the beverage in the beverage barrel 1 based on the time ti. The first reference value R1 and the second reference value R2 may be identical to each other or may be different from each other.

The controller 30 or the remaining amount detection unit 310 can detect, as the first time tt1, a time at which, for example, the decrease amount of the detected pressure from a state in which the variation amount of the detected pressure falls within a predetermined amount for a predetermined time (for example, 1 sec) or more is larger than the first reference value R1. In addition, the controller 30 or the remaining amount detection unit 310 can update the minimum value of the detected pressure at any time, and if the increase amount from the latest minimum value is larger than a third reference value R3, decide the latest minimum value as the minimum value Pmin.

The controller 30 or the remaining amount detection unit 310 can be configured to obtain the consumption amount of the beverage by one continuous pouring of the beverage by the beverage server 1 by multiplying the time ti by a coefficient decided based on the detected pressure. The coefficient can be decided based on, for example, the detected pressure immediately before the decrease amount of the detected pressure becomes larger than the first reference value R1. Alternatively, the coefficient may be decided based on the detected pressure in at least a part of the period between the first time tt1 and the second time tt2. Alternatively, the coefficient may be decided based on the minimum value Pmin. The controller 30 or the remaining amount detection unit 310 can be configured to obtain the remaining amount of the beverage in the beverage barrel 1 by subtracting the integrated value of the consumption amount from the capacity (notarized capacity) of the beverage barrel 1.

The coefficient is given by a function having a value correlated with the detected pressure (for example, an evaluation value of the detected pressure) as a variable. Alternatively, the coefficient may be given by looking up a table based on the value correlated with the detected pressure. The evaluation value of the detected pressure can be, for example, a value indicating to which one of a plurality of classes the detected pressure belongs. The function or table for giving the coefficient can be decided based on an actually measured value. It was confirmed that the remaining amount of a beverage obtained by such a method is sufficiently correct to judge the exchange timing of the beverage barrel 1.

FIG. 7 shows an example of the configuration of the remaining amount detection unit 310. The remaining amount detection unit 310 can include, for example, a sampler 700, a filter 701, a pouring start detection unit 702, a pouring end detection unit 703, a coefficient decision unit 704, a time calculation unit 705, a pouring amount calculation unit 706, and a remaining amount calculation unit 707. The sampler 700 samples the pressure (information representing the pressure) detected by the pressure sensor 82 at a predetermined cycle. The filter 701 filters the pressure sampled by the sampler 700. This filtering can be, for example, processing of calculating the moving average of the pressure sampled by the sampler 700. The pouring start detection unit 702 detects the above-described first time tt1 based on the output of the filter 701. The pouring end detection unit 703 detects the above-described second time tt2 based on the output of the filter 701. The coefficient decision unit 704 decides the above-described coefficient based on the output of the filter 701. The time calculation unit 705 calculate the time between the first time tt1 and the second time tt2 as the time ti. Every time pouring is performed, the pouring amount calculation unit 706 calculate the consumption amount of the beverage in one pouring of the beverage by multiplying the time ti calculated by the time calculation unit 705 by the coefficient decided by the coefficient decision unit 704. The remaining amount calculation unit 707 calculates the remaining amount of the beverage in the beverage barrel 1 based on the integrated value of the consumption amount of the beverage and the capacity of the beverage barrel 1.

The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.

REFERENCE SIGNS LIST

1: beverage barrel, 2: beverage server, 3: carbon dioxide gas supply source, 10: pressure adjuster, 11: valve body, 12: spring, 13: diaphragm, 14: spring, S3: first space, S4: second space, S5: third space, 20: relief valve, 21: cylinder, 22: piston, 23: valve body, 24: spring, OP1: first opening, OP2: second opening, 29: seat, S1: first space, S2: second space, 30: controller, 40: regulator, 60: check valve, 81: temperature sensor, 82: pressure sensor, 83: pressure sensor, V1: pressure intensifying valve, V2: pressure reducing valve, V4: three-way valve, PH1: first channel, PH2: second channel, PH3: third channel, 100: carbon dioxide gas supply apparatus

Claims

1. A remaining amount detection apparatus that detects a remaining amount of a beverage in a beverage barrel connected to a beverage server, comprising: a pressure sensor configured to detect a pressure in a channel for supplying a carbon dioxide gas to the beverage barrel; anda controller configured to obtain the remaining amount of the beverage based on a change of a detected pressure that is the pressure detected by the pressure sensor,wherein the controller obtains the remaining amount based on a time between a first time at which a decrease amount of the detected pressure is larger than a first reference value and a second time at which after the first time, an increase amount from a minimum value after the detected pressure takes the minimum value is larger than a second reference value.

2. The remaining amount detection apparatus according to claim 1, wherein the controller obtains a consumption amount of the beverage by one continuous pouring of the beverage by the beverage server by multiplying the time by a coefficient decided based on the detected pressure.

3. The remaining amount detection apparatus according to claim 2, wherein the coefficient is decided based on the detected pressure immediately before the decrease amount of the detected pressure becomes larger than the first reference value.

4. The remaining amount detection apparatus according to claim 2, wherein the coefficient is decided based on the detected pressure in at least a part of a period between the first time and the second time.

5. The remaining amount detection apparatus according to claim 2, wherein the coefficient is decided based on the minimum value.

6. The remaining amount detection apparatus according to claim 2, wherein the controller obtains the remaining amount by subtracting an integrated value of the consumption amount from a capacity of the beverage barrel.

7. The remaining amount detection apparatus according to claim 2, wherein the coefficient is given by a function having the detected pressure as a variable.

8. The remaining amount detection apparatus according to claim 2, wherein the coefficient is given by looking up a table based on the detected pressure.

9. A carbon dioxide gas supply apparatus that supplies a carbon dioxide gas to a beverage barrel connected to a beverage server, comprising: a pressure adjuster including a primary-side port and a secondary-side port and configured to adjust a pressure of the carbon dioxide gas supplied from a carbon dioxide gas supply source to the primary-side port and send the carbon dioxide gas from the secondary-side port;a pressure sensor configured to detect a pressure in a first channel that connects the secondary-side port and the beverage barrel; anda controller configured to obtain a remaining amount of a beverage in the beverage barrel based on a change of a detected pressure that is the pressure detected by the pressure sensor,wherein the controller obtains the remaining amount based on a time between a first time at which a decrease amount of the detected pressure is larger than a first reference value and a second time at which after the first time, an increase amount from a minimum value after the detected pressure takes the minimum value is larger than a second reference value.

10. The carbon dioxide gas supply apparatus according to claim 9, wherein the controller obtains a consumption amount of the beverage by one continuous pouring of the beverage by the beverage server by multiplying the time by a coefficient decided based on the detected pressure.

11. The carbon dioxide gas supply apparatus according to claim 9, further comprising a relief valve connected to the first channel, wherein the controller controls the relief valve to reduce the pressure in the first channel in accordance with an output of a temperature sensor configured to detect a temperature of the beverage sent from the beverage barrel to the beverage server.

12. The carbon dioxide gas supply apparatus according to claim 11, further comprising a second channel configured to supply the carbon dioxide gas supplied from the carbon dioxide gas supply source to the relief valve to supply, to the relief valve, a force for maintaining the relief valve in a closed state.

13. The carbon dioxide gas supply apparatus according to claim 12, further comprising: a regulator configured to reduce a pressure of the carbon dioxide gas supplied from the carbon dioxide gas supply source to a predetermined pressure; anda third channel configured to supply, to the pressure adjuster, the carbon dioxide gas whose pressure is reduced to the predetermined pressure by the regulator,wherein the second channel supplies, to the relief valve, the carbon dioxide gas whose pressure is reduced to the predetermined pressure by the regulator.

14. The carbon dioxide gas supply apparatus according to claim 13, wherein the relief valve includes: a cylinder including a first opening provided with a seat, and a second opening communicating with atmosphere;a piston configured to separate an internal space of the cylinder to a first space and a second space;a valve body arranged in the second space and supported by the piston to face the seat; anda spring configured to press the valve body to form a gap between the seat and the valve body,the carbon dioxide gas supplied to the relief valve via the second channel is introduced into the first space and gives a force in a direction of pressing the valve body against the seat to the piston,the first opening communicates with the first channel, andthe second opening makes the second space communicate with the atmosphere.

15. The carbon dioxide gas supply apparatus according to claim 14, further comprising a three-way valve arranged in the second channel, wherein the three-way valve is controlled by the controller to one of a first state in which the second channel and the first space of the relief valve are connected and a second state in which the first space of the relief valve communicates with the atmosphere.

16. The carbon dioxide gas supply apparatus according to claim 15, further comprising a check valve arranged in the second channel to supply the carbon dioxide gas from the regulator to the three-way valve.

17. The carbon dioxide gas supply apparatus according to claim 11, further comprising a safety valve connected to a position between the pressure adjuster and a connecting portion of the relief valve in the first channel.

18. The carbon dioxide gas supply apparatus according to claim 11, wherein the pressure adjuster includes: a pressure intensifying valve configured to increase the pressure in the first channel; anda pressure reducing valve configured to reduce the pressure in the first channel.

19. The carbon dioxide gas supply apparatus according to claim 18, wherein when reducing the pressure in the first channel to reduce the pressure in the beverage barrel, the controller opens the relief valve in accordance with a target pressure in a state in which the pressure reducing valve is closed.