JPH0571212B2 - - 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).
1974-7P191), 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 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, in such a combustion furnace, the temperature of the upper layer of carbon fuel is still low at the beginning of combustion, so for a while after combustion starts,
The combustion furnace emits low-temperature combustion gas containing a large amount of carbon monoxide. As a result, the air preheater installed downstream of the carbon dioxide generator cannot reach its full potential, creating a new problem in that it takes a long time for the temperature inside the combustion furnace to stabilize and stable combustion to occur. It has arisen.

The present invention provides a perishables storage device which has a simple configuration, makes full use of the capacity of the air preheater immediately after startup, and allows the combustion furnace to perform stable combustion in a short period of time.

Means for Solving the Problems Accordingly, the present invention energizes the heater and operates the circulation blower at the time of startup.

Effect The effect of this technical means is as follows.
The carbon dioxide generator is provided with a heater that heats carbon fuel, and when the heater is started, the heater is energized and a circulation blower is operated, whereby the heater is cooled by the air flow and the energization rate of the heater increases. For this reason, the amount of heat supplied into the combustion furnace increases,
Additionally, the blowing of air promotes heat conduction, and the temperature inside the combustion furnace stabilizes faster than when there is no wind. Therefore, when the carbon fuel reaches a temperature level where it can be combusted, there is not much difference in temperature between the upper and lower parts of the carbon fuel, and even if combustion starts, the combustion furnace will contain a large amount of carbon monoxide. No combustion gas is emitted. For this reason, the air preheater installed downstream of the carbon dioxide generator receives high-temperature combustion gas, which allows the air preheater to fully demonstrate its capacity, stabilizes the temperature inside the combustion furnace, and stabilizes combustion. The time required to do so can be significantly reduced.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a fire grate 9 is provided so as 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 at the same time the circulation blower 12 is operated to supply combustion air to the combustion furnace 8. When the temperature of the carbon fuel 10 rises to a point where it can be combusted, the carbon fuel 10 starts to burn. The amount of combustion at this time is determined by the surface area of the carbon fuel 10 and the amount of oxygen supplied to the carbon fuel 10.

Exhaust gas containing a large amount of carbon dioxide generated by the carbon dioxide generator 7 is purified by the purification catalyst 13. The purification catalyst 13 is provided with a heater (not shown), and when the temperature of the purification catalyst 13 is lower than the activation temperature, the purification catalyst 13 is heated by the heater. The exhaust gas purified by the purification catalyst 13 preheats combustion air in the air preheater 14, is cooled in the cooler 15, and 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.

When the carbon dioxide concentration in the refrigerator 17 reaches the set value, the scrubber 16 operates to adsorb and desorb excess carbon dioxide exceeding the set value, and adjusts the carbon dioxide concentration in the refrigerator 17 to the set value. ing.

When the oxygen concentration in the refrigerator 17 reaches the set value, the carbon dioxide generator 7 is 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.

Generally, the electric heater 11 is controlled by controlling the amount of current supplied depending on the temperature of the heater in order to prevent disconnection of the heater wire. On the other hand, the temperature of the heater is determined by the amount of current supplied to the heater and the amount of heat released. Therefore, if the temperature of the heater is controlled to be constant, the amount of current applied to the heater will vary greatly depending on the heat dissipation conditions of the heater.

When the circulation blower 12 is stopped at startup to preheat the carbon fuel 10, the heat dissipation of the electric heater 11 is due to radiation and natural convection of the atmosphere, so the temperature of the heater reaches the set value at a stage where the amount of electricity is relatively small. . The temperature of the carbon fuel 10 is mainly raised by the electric heater 1.
Since this is done by radiation from the carbon fuel 10, the lower layer of the carbon fuel 10 reaches a temperature at which it can be combusted. Heat transfer from the lower layer to the upper layer of the carbon fuel 10 is performed by thermal conduction, but if the air flowing inside the carbon fuel 10 is only due to natural convection due to heater heating,
It takes a very long time for the carbon fuel 10 in the upper part of the combustion furnace 8 to reach a combustible temperature. Therefore, when the temperature of the carbon fuel 10 at the lower part of the combustion furnace 8 reaches a combustible temperature, if combustion air is supplied to the combustion furnace 8 for combustion, the carbon fuel at the lower part of the combustion furnace 8 When the combustion gas 10 comes into contact with the carbon fuel 10 in the upper part of the low-temperature combustion furnace 8, the reaction in which monoxide carbon changes into carbon dioxide stops, and a large amount of carbon monoxide is generated. In particular, when high-temperature sintered carbon fuel is used as a fuel, the amount of carbon monoxide generated is considerably greater than that of unsintered carbon fuel, and the time required for the combustion furnace 8 to stabilize is also longer. .

Therefore, in the present invention, at the time of starting, the electric heater 11 is energized and the circulation blower 12 is operated. As a result, by forcing air to flow through the electric heater 11 from the time of preheating, the electric heater 1
Since the temperature of 1 is lowered, the amount of electricity is increased compared to when there is no wind. The amount of heat is supplied to the carbon fuel 10 by radiation from the electric heater 11 and from the electric heater 1.
Since this is carried out by heat conduction of the high temperature circulating air heated by 1, a larger amount of the heat conduction of the high temperature circulating air is supplied to the carbon fuel 10 than when there is no wind. For this reason, the temperature of the carbon fuel 10 rises much faster than when there is no wind. Then, when the carbon fuel 10 reaches a combustible temperature, combustion starts. Furthermore, since high-temperature air heated by the heater flows through the carbon fuel 10, heat conduction to the carbon fuel 10 in the upper part of the combustion furnace 8 is promoted, unlike when there is only natural convection when there is no wind.

In addition, since the temperature of the electric heater 11 is low immediately after starting, the electric heater 11 is provided with a temperature detection section 19 that detects the temperature of the electric heater 11.
Circulating blower 1 is installed so that the output value of 9 is constant.
If the operation is performed so as to increase the amount of air blown in step 2, the amount of radiation from the electric heater 11 will always be constant, so
More effective heating can be achieved.

In addition, when there is no wind, the air preheater 14 has almost no effect during preheating, but in the present invention, even before starting combustion, the air that has flowed through the carbon fuel 10 is heat exchanged with the air preheater 14. Since the carbon fuel 10 is fed back to the combustion furnace 8 again, the carbon fuel 10 can be heated very efficiently.

On the other hand, by operating the circulation blower 12 from the time of startup, air is also circulated to the purification catalyst 13, so that the energization rate of the heater of the purification catalyst 13 can also be increased. As a result, the temperature of the purification catalyst 13 can be raised much faster than the conventional windless preheating, and the catalytic performance of the purification catalyst 13 can be fully exhibited. Further, since the heat added by the purification catalyst 13 is also exchanged with the air preheater 14 and fed back to the combustion furnace 8, the carbon fuel 10 can be heated very efficiently.

As a result of the above, the carbon fuel 1 in the upper part of the combustion furnace 8
0 rises in temperature relatively quickly and significantly reduces the amount of carbon monoxide generated when the combustion gas of the carbon fuel 10 in the lower part of the combustion furnace 8 touches the carbon fuel 10 in the upper part of the combustion furnace 8 after combustion starts. I can do it. For this reason, high-temperature combustion gas is supplied to the air preheater 14 in a short time, so the air preheater 14 can fully demonstrate its capacity, the temperature inside the combustion furnace 8 is stabilized, and combustion is stabilized. can be significantly shortened.

Effects of the Invention The present invention provides a carbon dioxide generator with a heater that heats carbon fuel, energizes the heater at the time of startup, and operates a circulation blower.
The air preheater can fully demonstrate its capacity, the temperature inside the combustion furnace is stabilized, and the time required for combustion to become stable can be significantly shortened.

[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, 8... Combustion furnace, 1
1... Electric heater, 12... Circulation blower, 14
...Air preheater.

Claims (1)

[Claims] 1. A refrigerator, a carbon dioxide generating device that supplies carbon dioxide generated by burning carbon fuel provided inside a combustion section to the refrigerator, and generates the carbon dioxide by circulating air in the refrigerator as combustion air. a circulation blower that supplies the device; a purification catalyst provided downstream of the carbon dioxide generator;
an air preheater that preheats combustion air by exchanging heat with the exhaust gas of the carbon dioxide generator provided downstream of the purification catalyst; and a heater that heats the carbon fuel in the carbon dioxide generator. . A fresh produce storage device, characterized in that the heater is energized at startup, and the circulation blower is operated before the carbon fuel reaches an ignition temperature.