JPH0348774B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention improves respiration and microorganisms by adjusting the air composition of the atmosphere in which fresh food is placed.
It is used in the field of fresh food storage as a storage device that suppresses enzyme activity.

Conventional technology Conventional storage devices are used, for example, in Kaoru Kato's ``About a new resource-based CA storage system'' (air conditioning and refrigeration).
1674-7 P191), the structure was as shown in Figure 2.

That is, fuel supplied from a cylinder or the like is mixed with air 3 supplied from the refrigerator 2 by the circulation blower 1, and the mixture is combusted in the carbon dioxide generator 4 to generate carbon dioxide. Since the carbon dioxide generated by the carbon dioxide generator 4 is supplied to the refrigerator 2, oxygen in the refrigerator 2 is decreased and carbon dioxide is increased. When the carbon dioxide concentration reaches the set value, the scrubber 5 is operated to adsorb excess carbon dioxide. Next, when the oxygen concentration reaches the set value, the carbon dioxide generator 4 is stopped and the oxygen supply blower 6 is operated to maintain a constant air composition in the atmosphere in which the perishables are placed. It is used to store things.

Problems to be Solved by the Invention However, when a petroleum-based gas fuel is used as fuel for a perishables storage device having such a structure, the exhaust gas contains a large amount of water vapor, so it takes a very long time to condense this water vapor. The problem was that a large condenser was required.

Therefore, if carbon fuel is used as fuel, the problem of water vapor generation can be avoided. However, when re-igniting the refrigerator from a state where the oxygen concentration is low, the amount of circulating air becomes extremely large if you try to perform combustion with the same amount of combustion as when the oxygen concentration is normal. Therefore, even if the carbon fuel is heated to a combustible temperature through preheating, a problem has arisen in that the carbon fuel is cooled by the circulating air and cannot start combustion.

The present invention provides a fresh food storage device that has a simple configuration and can re-ignite even if the oxygen concentration inside the refrigerator is low.

Means for Solving the Problems Therefore, the present invention connects a refrigerator and a carbon dioxide generator, and installs a purification catalyst, an air preheater, a cooler, a circulating blower, and a scrubber in the order downstream of the carbon dioxide generator. Place and connect the scrubber and refrigerator,
An inlet is provided in the path between the refrigerator and the carbon dioxide generator, an outlet is provided between the circulation blower and the scrubber, and an oxygen concentration detector is installed inside the refrigerator.If the oxygen concentration in the refrigerator is below a predetermined value, At startup, the opening/closing part installed in the path between the refrigerator and the carbon dioxide generator and the opening/closing part installed in the path between the refrigerator and the scrubber are closed, and the intake and exhaust ports are opened to perform combustion.
When the temperature of the combustion section reaches a predetermined temperature, the inlet and outlet are closed and the two opening/closing sections are opened.

Effect The effect of this technical means is as follows.

When operating a perishables storage device in a state where the oxygen concentration inside the refrigerator is low, a signal from an oxygen concentration detector installed inside the refrigerator is used to open and close the path between the refrigerator and the carbon dioxide generator at the time of startup. Close the opening and closing section provided in the path between the refrigerator scrubber and the refrigerator scrubber, and open the inlet and outlet to perform combustion. At this time, the air used for combustion has a concentration of oxygen in the atmosphere.
21%, combustion begins as soon as the combustion air is preheated and contacts the hot carbon fuel. After the temperature inside the combustion furnace and the temperature of the fuel have risen sufficiently, the intake port and the exhaust port are closed and the two opening/closing portions are opened, thereby supplying air with a low oxygen concentration inside the refrigerator to the combustion furnace. Here, the temperature of the combustion furnace and the carbon fuel are sufficiently high due to combustion with an oxygen concentration of 21%, so it is possible to minimize the temperature drop of the carbon fuel due to the combustion air, and it is possible to prevent the temperature of the carbon fuel from decreasing due to combustion air. It can be re-ignited.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings.

In FIG. 1, a fire grate 9 is provided to partition a combustion furnace 8 of a carbon dioxide generator 7, and a carbon fuel 10 is supplied onto the fire grate 9. Further, an electric heater 11 is provided below the grate 9. At the time of startup, the electric heater 11 is energized, and when the carbon fuel 10 is heated to a temperature sufficient for combustion, the circulation blower 12 is operated to supply combustion air to the combustion furnace 8. Since the carbon fuel 10 is already sufficiently heated, combustion begins as soon as air contacts the carbon fuel 10. The amount of combustion at this time is the surface area of carbon fuel 10,
It is determined by the amount of oxygen supplied to the carbon fuel 10.

High-temperature exhaust gas containing a large amount of carbon dioxide generated by the carbon dioxide generator 7 is purified by a purification catalyst 13 and supplied to an air preheater 14 . In this air preheater 14, the exhaust gas is heat exchanged with the combustion air, and after preheating the combustion air, the exhaust gas is heated in the cooler 15.
supplied to The exhaust gas cooled by the cooler 15 is supplied to the refrigerator 17 through the scrubber 16. Then, the air whose oxygen concentration has decreased due to this is supplied to the combustion furnace 8 again by the circulation blower 12. This cycle continues until the carbon dioxide concentration within the refrigerator 17 reaches the set value.

The scrubber 16 has, for example, a carbon dioxide adsorption layer filled with activated carbon or the like, a regenerator for desorbing the adsorbed carbon dioxide, and a bypass path. When it is detected by a signal from a gas sensor (not shown) provided in the refrigerator 17 that the carbon dioxide concentration in the refrigerator 17 has reached the set value, the scrubber 16 is operated to maintain the set value. Continues to adsorb excess carbon dioxide.
When it is detected by the signal from the oxygen concentration detector 21 in the refrigerator 17 that the oxygen concentration in the refrigerator 17 has reached a set value, the carbon dioxide generator 7, circulation blower 12, and scrubber 16 are stopped. Thereafter, the oxygen consumed by the stored perishables when they breathe is supplied from the oxygen supply blower 18 to the refrigerator 17, and the carbon dioxide generated when the perishables breathe is removed by the scrubber 16. By adsorption, the air composition within the refrigerator 17 is maintained at the set value.

The specific operational relationship of the embodiment of the present invention having such a configuration will be described below.

In combustion of carbon fuel, when oxygen comes into contact with the surface of the carbon fuel, a reaction occurs where carbon atoms combine with oxygen atoms to generate carbon monoxide. Next, near the surface of the carbon fuel, a reaction occurs in the gas phase in which carbon monoxide and oxygen atoms combine to generate carbon dioxide. Therefore, the combustion of carbon fuel largely depends on the surface area and oxygen concentration of the carbon fuel. For this reason refrigerator 17
When the air inside the refrigerator 17 is circulated for combustion, the oxygen concentration inside the refrigerator 17 decreases as the combustion progresses, so the amount of fuel consumed decreases as the combustion progresses.

Therefore, the method described below is used to prevent a decrease in fuel consumption. That is, if the amount of air supplied to the carbon fuel 10 is increased in accordance with the decrease in the oxygen concentration in the refrigerator 17, the amount of oxygen supplied to the carbon fuel 10 will increase, and the amount of oxygen that can be used for combustion will increase. Therefore, fuel consumption increases.

When the oxygen concentration inside the refrigerator 17 is not very small, there is no problem because the increased amount of air is not so large, but when the oxygen concentration inside the refrigerator 17 becomes small, the increased amount of air becomes very large. Therefore, when re-igniting the combustion furnace 8 and operating the perishables storage device from a state where the oxygen concentration inside the refrigerator 17 is low, it is necessary to raise the temperature of the carbon fuel 10 to a temperature at which it can be combusted during preheating. However, since the amount of air flowing into the combustion furnace 8 at the time of startup is large, the temperature of the carbon fuel 10 decreases with the start of air blowing, so there is a possibility that combustion will not start.

Therefore, in the present invention, the refrigerator 17 and the carbon dioxide generator 7 are connected, and the purification catalyst 13, the air preheater 14, and the cooler 1 are downstream of the carbon dioxide generator 7.
5. Arrange the circulation blower 12 and the scrubber 16 in this order, connect the scrubber 16 and the refrigerator 17, and install the inlet 1 in the path between the refrigerator 17 and the carbon dioxide generator 7.
9, a discharge port 20 is provided between the circulation blower 12 and the scrubber 16, and an oxygen concentration detector 21 is provided in the refrigerator 17, so that if the oxygen concentration in the refrigerator 17 is below the set value, the refrigerator 17 and An opening/closing part 22 provided in the path between the carbon dioxide generators 7;
The opening/closing part 23 provided in the path between the refrigerator 17 and the scrubber 16 is closed, the inlet 19 and the outlet 20 are opened to perform combustion, and when the temperature of the combustion furnace 8 reaches a predetermined temperature, the inlet 19 and the outlet 20 are opened. The discharge port 20 is closed and the two opening/closing parts 22 and 23 are opened.

Therefore, when operating the perishables storage device in a state where the oxygen concentration inside the refrigerator 17 is low, the signal from the oxygen concentration detector 21 provided inside the refrigerator 17 is used to detect whether the refrigerator 17 and carbon dioxide are being generated at the time of startup. The opening/closing part 22 provided in the path between the devices 7 and the opening/closing part 23 provided in the path between the refrigerator and the scrubber are closed, and the suction valve 25 provided in the suction port 19 and the discharge valve 24 provided in the discharge port 20 are opened. As a result, the circulation blower 12 takes in normal air from the atmosphere through the intake port 19 and supplies it to the carbon dioxide generator 7, and discharges the combustion gas generated in the combustion furnace 8 to the atmosphere through the exhaust port 20. At this time, since the air used for combustion has an atmospheric oxygen concentration of 21%, combustion starts as soon as the combustion air is preheated and comes into contact with the high-temperature carbon fuel 10. In addition, since the refrigerator 17 is isolated from the circulation path by closing the two opening/closing parts 22 and 23, normal air with an oxygen concentration of 21% does not enter the refrigerator 17 from the atmosphere, reducing the oxygen concentration. Combustion can be performed using normal atmospheric air without changing the air composition inside the refrigerator 17.

Further, by providing the discharge port 20 downstream from the cooler 15, the discharge valve 2 provided at the discharge port 20
4 does not require the use of heat-resistant materials, and a very inexpensive valve can be used. Furthermore, the discharge port 20
is located upstream of the scrubber 16, so water vapor generated by evaporation of moisture contained in the heat insulating material at the beginning of combustion is not sent to the scrubber 16 but is released into the atmosphere. For this reason, the activated carbon filled in the scrubber 16 is not poisoned by water, so the performance of the scrubber 16 will not be reduced even if it enters the circulation cycle operation mode.

In addition, by providing the suction port 19 upstream of the air preheater 14, the air preheater 14 can be prevented from running idle, and the life of the air preheater 14 can be improved.

After the temperature inside the combustion furnace 8 and the temperature of the carbon fuel 10 rise sufficiently, the intake valve 25 of the intake port 19
By closing the discharge valve 24 of the discharge port 20 and opening the two opening/closing parts 22 and 23 provided in the circulation path, the low oxygen concentration air in the refrigerator 17 is then supplied to the combustion furnace 8. Here, the temperatures of the combustion furnace 8 and the carbon fuel 10 are sufficiently high due to combustion using air with an atmospheric oxygen concentration of 21%, so that the temperature drop of the carbon fuel 10 due to the combustion air is minimized. It is possible to carry out re-ignition under low oxygen concentration.

The explanation so far has been that the circulation path is switched when the temperature of the combustion furnace 8 reaches a predetermined temperature, but the circulation path is switched after a predetermined period of time has elapsed, that is, the combustion in the combustion furnace 8 is started. The same effect can be obtained even if the treatment is performed after the time required for stabilization has elapsed.

Effects of the Invention The present invention connects a refrigerator and a carbon dioxide generator, and arranges a purification catalyst, an air preheater, a cooler, a circulation blower, and a scrubber downstream of the carbon dioxide generator in this order, and connects the scrubber and the refrigerator. An inlet is installed in the path between the refrigerator and the carbon dioxide generator, an outlet is installed between the circulation blower and the scrubber, and an oxygen concentration detector is installed inside the refrigerator to detect when the oxygen concentration in the refrigerator is below the set value. If there is, close the opening/closing part installed in the path between the refrigerator and the carbon dioxide generator and the opening/closing part installed in the path between the refrigerator and the scrubber at startup.
By opening the inlet and outlet to perform combustion, and when the temperature of the combustion part reaches a predetermined temperature, closing the inlet and outlet and opening the two opening/closing parts,
Even if the oxygen concentration inside the refrigerator is low, it can be re-ignited.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a fresh produce storage device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a conventional fresh produce storage device. 7... Carbon dioxide generator, 12... Circulating blower, 13... Purification catalyst, 14... Air preheater, 15... Cooler, 16... Scrubber, 17...
... Refrigerator, 19... Inlet, 20... Outlet, 2
1...Oxygen concentration detector.

Claims (1)

[Claims] 1. A refrigerator is connected to a carbon dioxide generator that supplies carbon dioxide to the refrigerator by burning carbon fuel in a combustion section provided inside, and a purification catalyst is provided downstream of the carbon dioxide generator, and the purification An air preheater for exchanging heat between exhaust gas from the carbon dioxide generating device and combustion air is provided downstream of the carbon dioxide generator, a cooler is provided downstream of the air preheater, and downstream of the cooler the air is heated as combustion air. A circulation blower is provided to circulate air in the refrigerator and supply it to the carbon dioxide generating device, and a scrubber is provided downstream of the circulation blower to keep the carbon dioxide concentration in the refrigerator at a set value, and the scrubber and the refrigerator are connected to each other. an inlet is provided in the path between the refrigerator and the carbon dioxide generator, an outlet is provided between the circulation blower and the scrubber, an oxygen concentration detector is provided in the refrigerator, and oxygen concentration in the refrigerator is If the concentration is below a predetermined value, at startup, the opening/closing part provided in the path between the refrigerator and the carbon dioxide generator and the opening/closing part provided in the path between the refrigerator and the scrubber are closed, and the opening/closing part provided in the path between the refrigerator and the scrubber is closed. The fresh food is characterized in that combustion is performed with an outlet open, and when the temperature of the combustion section reaches a predetermined temperature or after a predetermined time has elapsed, the intake port and the discharge port are closed, and the two opening/closing sections are opened. Object storage device.