JPH01179622A - Apparatus for preservation of perishable material - Google Patents

Abstract

PURPOSE:To adequately control CO2 concn. in a perishables storage chamber that the air is circulating between the chamber and a combustion furnace for making CO2, by providing a CO2 adsorption device in the passage of combustion gas from the furnace to the chamber for adsorbing excess CO2, and also providing change-over valves at the upper and down stream of the furnace for making a bypass from the chamber to the device, reliesing CO2 adsorbed in the device with air stream in this bypass, and feeding this CO2 into the chamber when CO2 concn. in the chamber become lower than a prescribed value. CONSTITUTION:The objective perishable material preservation apparatus is composed of a perishable material storage chamber 1, a combustion furnace 12, a blower 14 and carbon dioxide gas adsorption devices 22, 23 arrange din circular form. Change-over valves 41, 42 are attached to the upstream and the downstream of the combustion furnace 12. When the oxygen concentration in the gaseous atmosphere in the storage chamber 1 is lowered below a prescribed level and the carbon dioxide gas concentration is lower than a prescribed level, the change-over valves 41, 42 are connected with each other to desorb the carbon dioxide gas absorbed in the adsorption devices 22, 23 and to increase the carbon dioxide gas concentration in the storage chamber 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fresh produce storage device that allows fresh produce such as vegetables and fruits to be stored for a long period of time at the production site or at the distribution stage.

BACKGROUND OF THE INVENTION Refrigerated storage is a common means of storing perishables, but in addition to this, a longer term storage method involves changing the air composition within the storage room. It reduces the oxygen (02) a degree in the storage and releases carbon dioxide (Co□
) It is known that by increasing the concentration, it is possible to suppress the respiration of fresh foods and also to prevent chemical reactions such as alteration and decomposition by microorganisms and oxidation.

An example of the above-mentioned conventional fresh food storage device will be described below with reference to the drawings.

FIG. 4 shows a system diagram of a conventional fresh food storage device. Reference numeral 1' is a storage, and a cooling device 4' consisting of an evaporator 2' and a condensing unit 3' is provided. 5′
is heated in a propane gas cylinder and combusted using the carbon dioxide gas generator 6' using the air introduced from the storage 1' through the inlet pipe 7'.
The combustion exhaust gas generated by the +531 reaction, that is, carbon dioxide gas Co2, is discharged to the storage 1' through a discharge pipe 8'. Reference numeral 9' denotes a carbon dioxide adsorption device, which is introduced into the storage 1' through an inlet pipe 10', adsorbs excess carbon dioxide CQ2, and then returned to the storage 1' through a discharge pipe 11'. 12'
The gas monitor detects the degree of gas expansion in the storage area 1' and controls the carbon dioxide gas generator 6' and the carbon dioxide adsorption device 9' in a timely manner.

Problems to be Solved by the Invention However, with the above configuration, the components of the gas generated by the carbon dioxide gas generator 6 are carbonic acid i, <Co2
In addition, it contains large amounts of gases such as ethylene and globylene that are harmful to the storage of fruits and vegetables, and because these gases are directly released into the storage 1', they often have a negative effect on the stored products. was.

In view of the above-mentioned problems, the present invention provides a fresh food storage device that does not emit harmful gases into the storage.

Means for Solving the Problems In order to solve the above problems, the fresh produce storage device of the present invention has the following features:
A combustion furnace that burns carbon-containing fuel, a blower that circulates the air used for combustion, an absorber that contains adsorbent to adsorb excess carbon dioxide, and a gas atmosphere in the storage room that is detected to operate each part. The storage, combustion furnace, blower, and adsorber are arranged in an annular manner, and the flow path switching valves installed upstream and downstream of the combustion furnace are connected to convert the gas atmosphere in the storage to the set concentration. When the concentration of carbon dioxide reaches the set concentration, if the carbon dioxide concentration is below the set value, the flow path switching valve is switched so that the storage, blower, and adsorber are communicated, and the blower circulates the gas in the storage and adsorbs it to the adsorber. It desorbs carbon dioxide and increases the concentration of carbon dioxide in the storage.

Function: Since the present invention burns carbon-containing fuel with the above configuration, it can be stored in clean air without generating harmful gases. Furthermore, even if the carbon dioxide concentration in the storage is less than the set concentration, it is possible to easily bring the concentration to the set concentration and maintain the perishables in a stable gas atmosphere.

EXAMPLE Hereinafter, a fresh food storage apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a fresh produce storage device in one embodiment of the present invention.

In Fig. 1, 1 is a storage unit such as a refrigerator for storing all perishables, a compressor 2, a condenser 3, an evaporator 4.
A cooling device 7 consisting of blowers 5 and 6 is mounted entirely on top. Connected to the storage 1 are a carbon dioxide gas generating device 8 for completely filling the interior of the storage with carbon dioxide gas Co2, and a carbon dioxide adsorption device 9 for adsorbing and removing excess carbon dioxide gas C02 in the combustion gas. The carbon dioxide gas generator 8 is configured between an introduction pipe 1o that introduces air in the storage 1 and a connecting pipe 11 that leads the combustion gas generated here to the carbon dioxide adsorption device 9, and is connected to a combustion furnace 12 and a combustion chamber 12. It consists of a gas cooler 13. A blower 14 is installed in the connecting pipe 11 between the cooler 13 and the carbon dioxide adsorption device 9, and guides the air in the storage tank 1 through the introduction pipe 1o to the combustion furnace 12. After cooling in the combustion gas total cooler 13, the connecting pipe 1
1 is led to a carbon dioxide adsorption device 9. The combustion furnace 12 includes an inner casing 16 having a heat insulating pipe 16 on its inner surface, and an air passage 1 between the inner casing 16 and the inner casing 16 for supplying secondary combustion air.
7, a grate 2° on which the solid fuel 19 is placed within the heat insulating pipe 16, and an ignition heater 21 for completely heating the combustion air and combusting the solid fuel 19. There is.

The solid fuel 19 is a high purity carbon combustion type C+
By the reaction of 020N2→co2+N2, the combustion gas becomes carbon dioxide gas CO2 and nitrogen (N2).

On the other hand, the carbon dioxide adsorption device 9 is for adsorbing excess carbon dioxide CO2 in the combustion gas and discharging it outside the storage 1. For the two adsorbers 22 and 23, the inlet pipes 24 and 25 and the discharge pipes 26 and 2 are connected so that the combustion gas alternately circulates.
7. It is composed of switching valves 28 and 29. The absorbers 22 and 23 are filled with adsorbents 30 and 31, and carbon dioxide gas C02? When the adsorption capacity decreases, the blower 32 switches the outside air to the switching valve 33. Discharge pipe 26.
Air is blown to the adsorber 22 or 23 through the inlet pipe 34 or 36 connected to the inlet pipe 27 to desorb carbon dioxide, and the discharge pipe 36 or 37 is connected to the inlet pipe 24 or 25.
, and is configured to be exhausted to the atmosphere through an exhaust pipe 39 through a switching valve 38.

For example, when the adsorber 22 is in the stratification mode and the adsorber 23 is in the desorption mode, the switching valves 28 and 29 are set in the direction in which the combustion gas flows through the inlet pipe 24, adsorber 22, and discharge pipe 26. Open and again.

The switching valves 33 and 38 are connected to the outside air by the conveyor 32,
It passes through the inlet pipe 35, adsorber 23, and discharge pipe 37, opens in the flow direction, and is exhausted to the atmosphere through the exhaust pipe 39. The exhaust pipe 40 is connected to the switching valve 29 and the storage deposit box. 4
Air path switching valves 1 and 42 are provided between the storage 1 and the combustion furnace 12, and between the cooler 13 and the blower 14, respectively.

44 is a controller that controls the air volume of the blower 14, and a gas monitor 46 that detects the gas concentration in the storage 1.
The air volume is determined by the signal. 46 is a chamber, a container provided in the introduction pipe 10 between the storage 1 and the switching valve 410, and a sampling tube 47 of the gas monitor 45 is connected thereto. 49 is an air passage switching valve that introduces the atmosphere into the combustion furnace 8. 48 is a means for operating each part depending on the gas atmosphere of the storage.

Regarding the fresh food storage device configured as described above, the first
The operation will be explained using FIG.

The atmosphere inside storage 1 was initially N279% and N0221%.
When the carbon dioxide gas generator 8 is operated, the air inside the refrigerator is passed through the introduction pipe 10 and into the chamber 4 by the blower 14.
6. The solid fuel 19 is introduced into the combustion furnace 12 through the air path switching valve 41, heated by the ignition heater 21, and used for combustion of the solid fuel 19. Due to the reaction of C+02+N2→C02+N2, the combustion gas becomes carbon dioxide gas C○2 and nitrogen N2, and the cooler 13
After cooling with
, the blower 14 , and further passes through the switching valve 28 and the introduction pipe 24 to enter the adsorber 22 . Here, carbon dioxide gas Co
2 is adsorbed by the adsorbent 30, and only nitrogen N2 passes through the exhaust pipe 26 and the switching valve 29, through the exhaust pipe 4°, and circulates to the storage 1. After a certain period of time has passed, the adsorber through which the combustion gas circulates is switched from 22 to 23.
The switching valve 28 and 29 are switched, and the switching valve 28
, passes through the introduction pipe 25 and enters the adsorber 23. Here, carbon dioxide gas Co2 is again adsorbed by the adsorbent 31 and nitrogen N
2 passes through the exhaust pipe 27° switching valve 29 and circulates to the storage 1 through the exhaust pipe 4o. After a certain period of time has elapsed again, the adsorbers 22 and 23 are switched, and the combustion gas is alternately circulated.

During this time, the adsorbent 30 filled in the adsorber 22, 23
．． 31 reaches the limit of adsorption capacity for carbon dioxide CO2, and the carbon dioxide C02 in the combustion gas cannot be adsorbed completely, and is exhausted into the storage 1 through the exhaust pipe 40, and the carbon dioxide C○2 in the storage 1 is exhausted. The concentration begins to gradually increase. This is the state of the storage 1, which has a size of 75 mm, and has been in operation for about 2 hours since the start of operation. During this time, the oxygen o2 concentration in the storage 1 continues to decrease by 21% at first. The gas concentration in storage 1 was changed to oxygen (02
); 5%, carbonic acid/'/su (C02) = 5%, nitrogen (N
2) Assuming that 90% is the predetermined value, when the gas monitor 46 detects by sampling the gas in the chamber 46 that the carbon dioxide in the storage chamber 1 has increased to 6%, the carbon dioxide The blower 32 for desorption of the adsorption device 9 is operated, and regeneration of the adsorbent in the adsorption device is started. For example, when the adsorber 22 is adsorbing carbon dioxide gas CO2 through circulation of combustion gas, the adsorber 23 receives outside air by the blower 32 through the switching valve 33, the inlet pipe 36, and the exhaust pipe 27.
The carbon dioxide gas CO2 is desorbed and regenerated by being blown onto the adsorbent 31. Since this is performed alternately at regular intervals, the concentration of carbon dioxide C02 in the storage 1 is maintained at a predetermined 6%. On the other hand, the oxygen O2 concentration continues to decrease because it is being used for combustion during that time, and reaches the predetermined 5% after 10 hours, which is detected by the gas monitor 46, and the carbon dioxide gas generator 8 and carbon dioxide adsorption device Stop 9. Now, the inside of storage 1 is at the predetermined gas concentration oxygen (02
) = s%, carbon dioxide gas (C○) = 5%, nitrogen (N2) =
When it reaches 90%, storage begins.

Next, the set concentration is oxygen (O2) = 10%, carbon dioxide (C
The operation will be explained using FIGS. 1 and 3 in the case where O2)=10% and nitrogen (N2)=90%.

The atmosphere inside the storage 1 is initially 279% N and 0221%, and when the carbon dioxide generator 8 is operated, the air inside the storage is passed through the introduction pipe 10 by the blower 14 to the chamber 46.
, introduced into the combustion furnace 12 through the air path switching valve 41,
It is heated by the ignition heater 21 and used for combustion of the solid fuel 19. Due to the reaction of C+020N2→CO2+N2, the combustion gas becomes carbon dioxide gas CO2 and nitrogen N2, and after being cooled by the cooler 13, the air passage switching valve 42,
It passes through the blower 14, and further passes through the switching valve 28 and the introduction pipe 24.
and enters the adsorber 22. Here, carbon dioxide gas Co2 is adsorbed by the adsorbent 3o, and only nitrogen N2 is left in the exhaust pipe 2.
6. The oxygen passes through the switching valve 29 and is circulated to the storage 1 through the exhaust pipe 40 to reduce the oxygen concentration in the storage 1. During this time, the adsorbent 3o filled in the adsorber 22 reaches the limit of its adsorption capacity for carbon dioxide CO2, and the carbon dioxide CO2 in the combustion gas cannot be adsorbed completely and is passed through the exhaust pipe 4o to the storage. 1, and the concentration of carbon dioxide gas Co2 in the storage 1 begins to gradually increase. During this time, the oxygen concentration in the storage 1 initially decreases by 21% and then reaches the set concentration of 10%. However, the carbon dioxide concentration at that time was 9%, which is still below the set concentration. This decreases due to the adsorption of the adsorbent 3o. At that time, when the gas monitor 46 detects that the oxygen concentration in the storage 1 is below the set concentration and the carbon dioxide concentration is below the set concentration, the means 48 for operating each part is activated, and the air passage switching valves 41 and 42 are switched to the inlet pipe 10. The connecting pipe 43 and the connecting pipe 11 are switched to communicate with each other, and the storage 1, blower 14, and adsorber 22 communicate with each other. Then, the blower 14 operates at a low air volume to circulate the gas in the storage 1.

Then, the circulating gas from the storage 1 causes the adsorbent 3o in the adsorber 22 to desorb the carbon dioxide adsorbed and discharge it into the storage 1, raising the carbon dioxide concentration in the storage 1 to the set concentration, and the blower 14 Stop and start storage.

As described above, according to this embodiment, there is a combustion furnace 12 that burns fuel containing carbon, a blower 14 that circulates air used for combustion, and adsorbers 22 and 23 that contain an adsorbent to remove excess carbon dioxide gas. and a means 48 for detecting the gas atmosphere in the storage 1 and operating each part, the storage 1, the combustion furnace 12,
A combustion furnace 1 is constructed by arranging a blower 14 and adsorbers 22 and 23 in an annular manner.
Connect flow path switching valves 41 and 42 upstream and downstream of 2, and when converting the gas atmosphere in storage 1 to the set concentration, if the carbon dioxide concentration is below the set level when the oxygen concentration reaches the set concentration, the flow path will be switched. Valves 41 and 42 are connected to storage 1 and blower 14.
, by switching to communicate with the adsorber 22 and circulating the gas in the storage 1 with the blower 14 to desorb the carbon dioxide adsorbed in the adsorber 22 and bring the carbon dioxide concentration in the storage 1 to the set concentration. Therefore, it can be stored in clean gas,
Furthermore, even if the set concentration of carbon dioxide gas in the storage 1 is high, it can be easily adjusted to the set concentration, so that perishables can be stored in a stable state.

Effects of the Invention As described above, the present invention includes a combustion furnace that burns fuel containing carbon, a blower that circulates air used for combustion, an adsorber containing an adsorbent to adsorb excess carbon dioxide, and It is equipped with a means to detect the gas atmosphere in the storage and operate each part, and the storage, combustion furnace, blower, and adsorber are arranged in a ring, and flow path switching valves installed upstream and downstream of the combustion furnace are connected.
When converting the gas atmosphere in the storage to the set concentration, when the oxygen concentration reaches the set concentration, and if the carbon dioxide concentration is below the setting, switch the flow path switching valve so that the storage, blower, and adsorber are in communication with each other. This method circulates the gas in the storage chamber and desorbs the carbon dioxide adsorbed in the adsorber to bring the concentration of carbon dioxide in the storage chamber to the set concentration.The carbon-containing fuel is combusted and the oxygen in the gas in the storage chamber is converted into carbonic acid. Since it is converted to gas, there is no generation of gas harmful to fresh produce, and raw vinegar can be stored in clean gas. Furthermore, even if the set concentration of carbon dioxide gas is high, it can be easily adjusted to the set concentration, so perishables can be stored in a stable state.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a fresh food storage device according to an embodiment of the present invention, Figs. 2 and 3 are diagrams showing changes in gas components in the refrigerator according to the same device, and Fig. 4 is a diagram of a conventional fresh food storage device. It is a system diagram. 1...Storage, 12...Combustion furnace, 14
...Blower, 22.23...Adsorption device,
41.42... Air path switching valve, 48...
...Means for operating each part. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 (%) (Time Figure 4)

Claims (1)

[Claims] a storage for storing perishables; a combustion furnace for burning carbon-containing fuel to introduce carbon dioxide gas into the storage;
A blower that circulates air from the storage to be used for combustion of the fuel in the combustion furnace, an absorber containing an adsorbent to adsorb excess carbon dioxide gas generated from the combustion furnace, and a gas atmosphere in the storage. the storage, the combustion furnace, the blower, and the adsorber are arranged in a ring, and flow path switching valves provided upstream and downstream of the combustion furnace are connected. When converting the gas atmosphere in the storage to a set concentration, if the oxygen concentration reaches the set concentration and the carbon dioxide concentration is below the set concentration, the flow path switching valve is connected to the storage, the blower, and the adsorber. The perishables storage apparatus is characterized in that the blower is used to circulate gas in the storage to desorb carbon dioxide adsorbed by the adsorber, thereby increasing the concentration of carbon dioxide in the storage.