System for drying objects to be dried

A far infrared radiation heater 33 is disposed on the back of a ceiling of a drying chamber 11. The inside of the drying chamber 11 is evenly heated by the heat emitted from the far infrared radiation heater 33. The drying chamber 11 is provided with air charge means 16 and air exhaust means 17 each communicating with the inside thereof. Outside air is introduced into the drying chamber 11 by means of the air charge means 16. On the other hand, the air exhaust means 17 continuously maintains the inside of the drying chamber 11 in a state of reduced pressure. Thus, objects to be dried which are placed in the drying chamber are dried by heating under reduced pressure while continuously introducing fresh air. Therefore, the present invention provides a system for drying objects to be dried whereby not only can dried products be produced within a short period of time but also the flavor is satisfactorily retained in the dried products.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a system for drying objects to be dried. 
More particularly, the present invention is concerned with a system for 
drying objects to be dried by which, for example, the objects such as 
marine and agricultural products, flowers, woods and lumbers can be 
efficiently dried. 
2. Description of the Prior Art 
Dried fishes or stockfishes which not only can be stored for a prolonged 
period of time but also possess peculiar flavors are produced from fish of 
family Scombroidea and Carangidae and other various marine products and 
are supplied to the market. 
In the conventional drying system for obtaining such dried products, as 
shown in FIG. 12, heating means 3 such as a boiler is disposed beside a 
drying chamber 2 in which objects to be dried 1 are housed. While hot air 
or blast generated from the heating means 3 is fed into the drying chamber 
2, the air inside the drying chamber 2 is transferred into a cooling 
chamber 4. In this cooling chamber 4, the air led from the drying chamber 
2 is cooled and dehumidified. The dehumidified air is recycled via the 
heating means 3 into the drying chamber 2, while part of the air 
dehumidified in the cooling chamber 4 is directly fed into the drying 
chamber 2. That is, in the conventional system, dried goods are produced 
by circulating air. 
However, in the above conventional system for drying objects to be dried, 
the temperature of the inner part of the drying chamber 2 is raised by hot 
air or blast fed from the heating means 3 and water evaporation from the 
surface of each of the objects to be dried 1 is conducted by the heat 
given by the hot air or blast, so that a great many days have been taken 
during the period from the start of the drying to the output of the dried 
products. This has brought about a problem that, even if dried products 
are produced from fresh marine products, the objects to be dried are 
oxidized during the production of dried fishes or stockfishes, thereby 
losing their freshness. Further, a large quantity of energy is required 
for the heating, thereby causing the cost of the dried products to be 
unfavorably high. Still further, in the conventional drying system, not 
only is the regulation of the moisture content of the dried products 
difficult but also the moisture of the inner part of the objects to be 
dried cannot be evaporated to a desired degree, so that there has been a 
limit in the deliciousness in the eating of the dried products. Still 
further, the conventionally produced dried products contain some ordinary 
levels of various common bacteria or germs, so that the duration in which 
the relish of, for example, dried salmons is ensured is as short as about 
one month thereby necessitate a quick delivery from the distributive 
machinery to the table. 
This invention has been made to overcome the above problems of the prior 
art. Therefore, the objective of the present invention is to provide a 
system for drying objects to be dried by which dried products can be 
produced within a short period of time, the drying cost is low, the 
production of the dried products can be accomplished without detriment to 
fresh flavor and the amount of various common bacteria or germs contained 
in the dried products can be reduced to thereby extend the duration in 
which the relish of the dried products is ensured. 
SUMMARY OF THE INVENTION 
The system for drying objects to be dried according to the present 
invention comprises a drying chamber having walls including side walls and 
a ceiling in which objects to be dried are housed, a far infrared 
radiation heater disposed on at least a part of the walls to evenly heat 
the inside of the drying chamber with heat emitted from the far infrared 
radiation heater and air charge and air exhaust means both communicating 
with the inside of the drying chamber, the former introducing outside air 
into the drying chamber while the latter exhausting the air from the 
drying chamber to thereby continuously maintain the inside of the drying 
chamber in a state of reduced pressure, wherein the temperature of the 
inside of the drying chamber is detected with the use of a temperature 
sensor and output of the far infrared radiation heater regulated on the 
basis of the temperature detected by the temperature sensor and wherein 
the air charge and air exhaust means being separately controlled. 
In the system for drying objects to be dried according to the present 
invention, which has the construction as described above, circulatory 
blowing means may be provided at one of a pair of mutually opposite side 
wall surfaces inside the drying chamber, the circulatory blowing means 
being capable of generating a substantially horizontal air stream flowing 
to the opposite side wall surface, to thereby cause the circulatory 
blowing means to feed air so as to form a horizontal air stream flowing 
toward the object to be dried. 
In the system for drying objects to be dried according to the present 
invention, the inside of the drying chamber is uniformly heated by means 
of the far infrared radiation heater, the air stream inside the drying 
chamber is circulated to thereby promote the drying and further the inside 
of the drying chamber is maintained in a state of reduced pressure, so 
that moisture can be evaporated not only from the surface of each of the 
objects to be dried but also from the inner part thereof with the input of 
less energy within a short period of time. 
Further, the system for drying objects to be dried according to the present 
invention comprises a drying chamber in which a plurality of trucks each 
having a vast plurality of objects to be dried shelfwise housed therein 
can be linearly accommodated, a plurality of far infrared radiation 
heaters disposed at predetermined intervals at upper parts of the drying 
chamber to evenly heat the inside of the drying chamber with the heat 
emitted from the far infrared radiation heaters and air charge and air 
exhaust means both communicating with the inside of the drying chamber, 
the former introducing outside air into the drying chamber while the 
latter exhausting the air from the drying chamber to thereby continuously 
maintain the inside of the drying chamber in a state of reduced pressure, 
and 
wherein circulatory blowing means is provided at one of a pair of mutually 
opposite side wall surfaces inside the drying chamber, the circulatory 
blowing means being capable of generating a substantially horizontal air 
stream flowing the one side wall surface to the opposite side wall 
surface, to thereby cause the circulatory blowing means to feed air so as 
to form a horizontal air stream flowing toward the inner part of the 
trucks. 
In the above system for drying objects to be dried, with respect to the 
plurality of far infrared radiation heaters disposed at predetermined 
intervals, the air stream generated by the circulatory blowing means can 
be so set as to flow from the one side wall surface to the opposite side 
wall surface along the side of a first far infrared radiation heater, to 
flow from the opposite side wall surface to the one side wall surface 
along the side of a second far infrared radiation heater, to flow from the 
one side wall surface to the opposite side wall surface along the side of 
a third far infrared radiation heater, and thus to alternately flow in the 
same direction in the entirety of the drying chamber. 
Moreover, the air stream generated by the circulatory blowing means can be 
so set as to flow counter at predetermined time intervals. 
The system for drying objects to be dried according to the present 
invention forms the substantially horizontal flow of an air stream in the 
drying chamber by means of the circulatory blowing means, so that the 
surface of each of the objects to be dried housed in the trucks can be 
positively dried by this flow of the air stream to thereby remove moisture 
from the surface. 
Further, the setting of the air stream generated by the circulatory blowing 
means so as to flow in alternately opposite directions along the sides of 
a vast plurality of far infrared radiation heaters enable the air stream 
to evenly flow through the entirety of the drying chamber, so that a vast 
plurality of objects to be dried can be dried substantially uniformly. 
Still further, the setting of the air stream set to flow in alternately 
opposite directions so as to flow counter at predetermined time intervals 
can accomplish drying of a vast plurality of objects to be dried with 
further improved uniformity.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings, embodiments of the system for drying objects to 
be dried according to the present invention will be described below. 
FIG. 1 schematically shows a system for drying objects to be dried 
according to one embodiment of the present invention, and FIG. 2 is a 
schematic perspective view thereof. 
In this drying system 10, a second chamber 12 is constructed above a drying 
chamber 11 having its periphery surrounded with a thermal insulating 
material. The drying chamber 11 has a gate 13 through which entrance and 
exit can be made. 
A truck 14 is loaded with a vast plurality of objects to be dried 15 in 
multilayered form and placed in the drying chamber 11 to thereby have the 
objects to be dried housed in the drying chamber 11. 
The drying chamber 11 is provided with air charge means 16 and air exhaust 
means 17 which are separately disposed in communicating relationship with 
the inside of the drying chamber 11 at upper and lower parts of the drying 
chamber 11, respectively. 
The air charge means 16 introduces outdoor fresh air via a pipe 18 into the 
drying chamber 11 and circulates an air stream in the drying chamber 11. 
Outdoor air is suctioned by a fan 19 installed in the second chamber 12. 
The suctioned air is temporarily introduced via air filters 20, 21 into 
the second chamber 12 and then fed via an opening (not shown) formed 
through a ceiling 11a of the drying chamber 11 into the drying chamber 11. 
The air fed into the drying chamber 11 appropriately circulates between the 
drying chamber 11 and the second chamber 12 by means of the air charge 
means 16. Accordingly, circulation of an air stream is generated in the 
drying chamber 11. 
The air exhaust means 17 exhausts air humidified in the drying chamber 11 
outdoors via two pipes 23, 24 disposed beside the drying chamber 11 and is 
equipped with blowers 25, 26 driven by a single or separate motors. 
The pipe 18 of the air charge means 16 and the pipes 23, 24 of the air 
exhaust means 17 are respectively provided with valves 31, 32, 33, which 
are manually or automatically operated to thereby regulate the openness of 
each of the pipes. 
In the air charge means 16, the quantity of suctioned air is regulated by 
means of a regulator 27 of a control panel 60. The quantity of suctioned 
air is set by means of an air quantity setting device 28. 
On the other hand, in the air exhaust means 17, the quantity of exhausted 
air is regulated by means of a regulator 29. The quantity of exhausted air 
is set by means of an air quantity setting device 30. For example, the air 
exhaust capacity ranges from a maximum of 1500 m.sup.3 /h to a minimum of 
500 m.sup.3 /h. 
Both of these air charge means 16 and air exhaust means 17 are operated by 
a 100-V power source 22. 
A far infrared radiation heater 38 shown in FIG. 3 is disposed on the 
ceiling 11a of the drying chamber 11. 
In this far infrared radiation heater 38, a ceramic spray deposit layer 35 
is provided on a base material 34 forming the ceiling 11a. Heating means 
36 is arranged on the back of the base material 34, and its outside is 
covered with a casing 37. 
The above base material 34 is, for example, an Al plate of 2 mm in 
thickness, and the thickness of the ceramic spray deposit layer 35 is 
about 20 .mu.m. The member composing the base material 34 is not 
particularly limited as long as it is a material suitable for use as a 
base of thermal ceramic spraying. The base material 34 may be composed of 
stainless steel or other materials. A porous plate such as a punching 
plate may also be used, in which the pores may be used as a passage for 
air. 
It is not necessary to compose the above ceramic of a single type of raw 
material, and a composition of various raw materials mixed together may be 
used to compose the ceramic. Although the raw material to be employed is 
not particularly limited, for example, zirconia, magnetite, alumina, 
zircon, iron, chrome, mangan and other compound oxides may be mentioned as 
raw materials for composing ceramics capable of emitting far infrared 
radiation in greater intensities. 
The thermal spraying of ceramic is generally conducted with the use of a 
plasma spraying gun. This plasma spraying gun produces an ultrahigh 
temperature plasma arc flame of at least ten thousand .degree.C., into 
which pulverized raw material is fed. The raw material is melted in a 
high-speed jet of 1-2 in Mach number and caused to strike the surface of 
the target base material to thereby form a ceramic layer. 
The far infrared radiation heater 38 for use in this embodiment is 
constructed as described above over the substantially entire surface of 
the ceiling 11a of the drying chamber 11 and driven by a 200 V power 
source 43 as shown in FIG. 1. 
The drying chamber 11 has a temperature sensor 42 disposed therein and is 
provide with an inverter 44 as shown in FIG. 1. The output of the above 
far infrared radiation heater 38 can be continuously regulated. 
When the above far infrared radiation heater 38 is used, the temperature at 
2.5 m above the floor surface reaches predetermined 37.degree. C. about 10 
min after the start of the driving of the far infrared radiation heater 38 
as indicated by full line 47 in FIG. 4. The temperature at the vicinity of 
the floor is about 41.degree. C., which is higher than the above-mentioned 
temperature as indicated by full line 48 in FIG. 4. Therefore, the objects 
to be dried is placed at the vicinity of the floor can also be effectively 
dried in the drying chamber 11. The use of the above far infrared 
radiation heater 38 leads to releasing of moisture not only from the 
surface of each of the objects to be dried but also from the center 
thereof with less energy input because of high far infrared radiation 
efficiency. Experimental results demonstrated the release of moisture from 
the inner part in an amount of twice that attained by the drying performed 
with the use of the conventional heating means. 
The construction of the system 10 for drying objects to be dried according 
to this embodiment is as described above. The function of the system will 
now be described below. 
At this time, a vast plurality of objects to be dried 15 are housed in 
layered form in the truck 14 and accommodated in the drying chamber 11. 
The air charge means 16, air exhaust means 17 and far infrared radiation 
heater 38 are regulated by the control panel 60 and are individually 
driven. 
Outside fresh air is fed via the second chamber 12 into the drying chamber 
11 by the air charge means 16. In the drying chamber 11, convection 
current occurs and an air stream is circulated. The air is exhausted from 
the drying chamber 11 to the outside by the air exhaust means 17. In the 
drying chamber 11, air exhaust is conducted so that the pressure is held 
at, for example, 3 mb or more, preferably 10 mb or more below atmospheric 
pressure. 
Further, in the drying chamber 11, far infrared radiation which is easily 
absorbed by the objects to be dried 15 is emitted from the ceiling 11a by 
the drive of the far infrared radiation heater 38. 
Therefore, in this drying chamber 11, the inner parts thereof are heated 
substantially uniformly, the air stream is circulated and the pressure is 
reduced, so that moisture evaporation is promoted. With respect to the 
objects to be dried 15 housed in the truck 14, moisture evaporation occurs 
not only from the surface but also the center thereof. Thus, moisture 
evaporation can be effected rapidly in this drying chamber 11, so that the 
drying time can be cut down. Upon completion of the above requisite 
drying, the drive of the far infrared radiation heater 38 is stopped, 
preferably followed by putting the dried objects in rest for cure in the 
drying chamber 11 for a given period of time. 
Examples of the objects to be dried in the drying chamber 11 include horse 
mackerel or saurel, mackerel or scombroid, salmon, anchovy, sardine paper, 
flatfish or plaice and other fishes and octopus, scallop, amanori or 
laver, sea tangle, kind of carpenter's tellin, trepang or sea slug and 
other marine products. 
Further, the objects to be dried include woods and agricultural products, 
for example, cereals such as rice, fruits such as persimmon, and 
vegetables such as green pepper, carrot, cabbage, tuber (potato) or corm 
(sweet potato), bamboo shoot and mushroom. Still further, flowers (to give 
dry flowers) and animal bones can be dried. In particular, the drying of 
animal bones leads to sterilization of meat pieces and their adherence to 
the bones, thereby supplying the market with delicious products 
appreciated as pet foods of fine quality. 
Naturally, the system is applicable to drying of the washing and of 
industrial products after washing, such as IC chips after washing. 
In other fields of application, this system can be appreciated when drying 
fossils containing water in a large quantity. For example, although the 
drying of sand containing shell fossils has heretofore been effected by 
heating a large quantity of sand at about 1000.degree. C., the whole sand 
can be uniformly dried at temperatures as low as about 50.degree. C. with 
the use of this system. Thus, shell fossils can be recovered from the sand 
in a state of fine quality and stored. 
The drying for producing, for example, sardine paper as a marine product 
has heretofore been carried out in the sun, so that the production of the 
dried fish is influenced by the weather. However, the sardine paper can be 
produced with no care of the weather by the use of the above drying system 
10 according to this embodiment of the present invention. Therefore, the 
production of dried fish or stockfish can be performed in accordance with 
the plan set. In the production of sardine paper, excessive drying makes 
sardine constituting the paper separated one by one. 
However, the degree of dryness can be appropriately regulated by 
controlling the temperature of the drying chamber, the drying time and the 
pressure from the control panel 60 of the above drying system 10. Thus, a 
desirable sardine paper production can be accomplished. 
This embodiment does not cool humidified air but expels it outside, thereby 
saving the conventionally required energy for cooling. Further, the drying 
can be achieved within a short period of time by the use of far infrared 
radiation, so that the production cost can be reduced. The short drying 
time avoids oxidation of the objects to be dried. Thus, dried goods with 
high freshness can be produced, which is delicious when eaten. 
The conditions for treating objects to be dried such as fishes and 
shellfishes with the use of the above system to thereby produce dried 
goods ensuring favorable taste will be described below. 
When fishes or shellfishes are brought to death, the meat quality changes 
with the lapse of time. That is, ATP (adenosine triphosphate) occurring in 
the muscle decomposes as follows: 
ATP.fwdarw.ADP (adenosine diphosphate).fwdarw.AMP (adenylic 
acid).fwdarw.IMP (inosinic acid).fwdarw.HxR (inosine).fwdarw.Hx 
(hypoxanthine). 
It has been shown by experiments that the rate of the above decomposition 
highly depends on the type of fish or shellfish. There is a close 
relationship between the amount of inosinic acid and the deliciousness, 
and it is known that, generally, the greater the content of inosinic acid, 
the better the taste. 
In the fish meat, the content of ATP (adenosine triphosphate) is rapidly 
reduced after death, and instead the content of IMP (inosinic acid) is 
increased. For example, FIG. 5 shows changes in the contents of 
ATP-associated compounds occurring in the muscle of a cod subjected to 
euthanasia ("marine useful materials", page 199 of New Complete Edition of 
Science of Fisheries, edited by Junsaku Nonaka). As apparent from this 
figure, the content of IMP is increased with the decrease of the content 
of ATP and reaches the maximum 2 to 3 days after death. When the drying of 
the object to be dried is terminated at the maximum content of IMP, the 
dried product is delicious. 
In the system of the present invention, not only is the drying time 
extremely short as compared with that of the conventional means but also 
the temperature and pressure during the drying can be freely regulated by 
the use of the far infrared radiation heater, air charge and air exhaust 
means. Therefore, the system can be regulated so as to terminate the 
drying when the content of inosinic acid is at the maximum. Consequently, 
dried products whose inosinic acid content is at the maximum can be 
obtained without exception no matter what types of objects are to be 
dried. In the drying of, for example, raw fish with the use of this 
system, the drying temperature, for example, ranges from 0.degree. to 
50.degree. C., preferably from 10.degree. to 40.degree. C., and 
appropriate temperature regulation comprising, for example, initial drying 
at 30.degree. C. for 20 hr followed by drying at 10.degree. C. for 30 hr 
followed by heating at 38.degree. C. can be effected so as to obtain a 
dried product whose inosinic acid content is at the maximum. 
Further, the drying of, for example, raw fish by the conventional drying 
method denatures the protein because of the heat, thereby deteriorating 
the flavor of the fish meat protein. In contrast, the present invention 
achieves uniform heating of the whole at low temperatures, e.g. about 
38.degree. C., so that denaturation of the protein can be avoided to 
thereby produce a dried product which is delicious when eaten. 
Still further, when fishes or shellfishes die and the amount of ATP is 
reduced to a certain level, they generally undergo cadaveric rigidity. 
When ATP is consumed up, the cadaveric rigidity is completed. When fish 
before the cadaveric rigidity is frozen, no significant change occurs in 
the fish during the freezing period but at the thawing it is likely that 
the fish body undergoes cadaveric rigidity, the meat pieces shrink and 
simultaneously a large amount of drip flows out. The use of the system of 
the present invention in drying previously frozen fish or shellfish 
permits the regulation of the temperature and pressure so that the 
inosinic acid content of the dried product is maximized as in the drying 
of fish after the occurrence of cadaveric rigidity subsequent to death. 
If the changes such as the vanishment of ATP and the stiffening of the 
muscle which usually occur gradually after death are advanced within a 
short period of time, the degree of shrinkage of the muscle is generally 
high. However, when the drying is conducted with the use of the drying 
system of the present invention, it has been confirmed that the meat of 
the fish or shellfish has less propensity for shrinkage or cracking, 
thereby producing a dried product whose size is close to that before the 
drying. 
In the above embodiment, the far infrared radiation heater is disposed on 
the ceiling. However, the part where the far infrared radiation heater can 
be disposed is not limited to the ceiling and includes, for example, right 
and left walls or four walls. Although the air charge means is disposed at 
an upper part and the air exhaust means at a lower part in the above 
embodiment, this may be reversed, that is, the air charge means may be 
disposed at a lower part and the air exhaust means at an upper part. 
Further, for example, the number of air intake ports of the air charge 
means and the number of air exhaust ports of the air exhaust means are by 
no way limited to those of the above embodiment. This system can be 
practiced in various different sizes from large to small ones. 
A second system for drying objects to be dried according to another 
embodiment of the present invention will be described below with reference 
to FIGS. 6 to 8. 
FIG. 6 schematically shows a system for drying objects to be dried 
according to another embodiment of the present invention, and FIG. 7 is a 
schematic perspective view thereof. 
This drying system 50 is constructed in a large box frame with thermal 
insulating structure whose size is approximately 7 m in length, 2.4 m in 
width and 2.6 m in height. The box frame can be installed outdoors. In the 
drying system 50, a second chamber 52 is constructed above a drying 
chamber 51 having its periphery surrounded with a thermal insulating 
material. The drying chamber 51 has a gate 53 through which entrance and 
exit can be made. 
Trucks 54 each of which is loaded with a vast plurality of objects to be 
dried 55 in multilayered form are placed in the drying chamber 51 to 
thereby have the objects to be dried 55 housed in the drying chamber 51. 
The drying chamber 51 is provided with air charge means 56 and air exhaust 
means 57 which are separately disposed in communicating relationship with 
the inside of the drying chamber 51. An air charge port 56a of the air 
charge means 56 and an air exhaust port 57a of the air exhaust means 57 
are disposed at upper and lower parts of the drying chamber 51, 
respectively. 
The air charge means 56 introduces outdoor fresh air via a pipe 58 into the 
drying chamber 51 and circulates an air stream in the drying chamber 51. 
Outdoor air is suctioned by a fan 59 as indicated by arrows in FIGS. 6 and 
7. The suctioned air is temporarily introduced via air filters (not shown) 
into the second chamber 52 and then fed via an opening (not shown) formed 
through a ceiling 51a of the drying chamber 51 into the drying chamber 51. 
On the other hand, the air exhaust means 57 exhausts air humidified in the 
drying chamber 51 outdoors via a pipe 63 and is equipped with a blower. 
The respective pipes 58 and 63 of the air charge means 56 and the air 
exhaust means 57 are respectively provided with valves, which are manually 
or automatically operated to thereby regulate the openness of each of the 
pipes. 
The air charge means 56 regulates the quantity of suctioned air by means of 
a regulator 87 of a control panel 70. The quantity of suctioned air is set 
by means of an air quantity setting device 88. 
On the other hand, the air exhaust means 57 regulates the quantity of 
exhausted air by means of a regulator 89. The quantity of exhausted air is 
set by means of an air quantity setting device 90. For example, the air 
exhaust capacity ranges from a maximum of 1500 m.sup.3 /h to a minimum of 
500 m.sup.3 /h. 
Both of these air charge means 56 and air exhaust means 57 are operated by 
a 100-V power source 62. 
Four far infrared radiation heaters 73 shown in FIGS. 7 and 8 are 
substantially linearly disposed on the ceiling 51a of the drying chamber 
51. 
The structure of each of the far infrared radiation heaters 73 is the same 
as that of the far infrared radiation heater 38 shown in FIG. 3. 
The use of the above far infrared radiation heaters 73 leads to free 
regulation of the drying temperature and to releasing of moisture not only 
from the surface of each of the objects to be dried but also from the 
center thereof with less energy input because of high far infrared 
radiation efficiency. Therefore, the objects to be dried can effectively 
be dried up to the inner parts thereof at a lowered cost. 
In this embodiment, as shown in FIGS. 6 to 8, bulkhead platings 85, 86 are 
vertically disposed opposite to a pair of mutually opposite long side 
walls, respectively, to thereby define a partitioned narrow interstice in 
the vicinity of each of the long side walls. These interstices are 
partitioned by a plurality of diaphragms 95 into a set of spaces a, b, c 
and d, and a set of spaces a', b', c' and d', respectively. That is, each 
of the above interstices is partitioned into four small spaces each having 
a width nearly equal to the width of one of the far infrared radiation 
heaters 73. A vast plurality of openings 91, 92 are formed in the bulkhead 
platings 85, 86 along the direction of height as from positions slightly 
higher than the floor level. By virtue of the formation of such a vast 
plurality of openings 91, 92, for example, the air of the space a can be 
blown through the openings 91 in the substantially horizontal direction, 
and, contrarily, the space a' opposite thereto can suction the air blown 
from the openings 91 through the openings 92. Further, as shown in FIGS. 6 
to 8, sirocco fans 81 as circulatory blowing means capable of forcibly 
introducing air and circulating the air are disposed in alternate 
positions beside the linearly arranged far infrared radiation heaters 73. 
One sirocco fan 81 is provided for one far infrared radiation heater 73. 
The sirocco fans 81 are positioned at upper parts of the spaces a and c 
and upper parts of the spaces b' and d' as shown in FIG. 8. That is, as 
shown in the plan of FIG. 8, the sirocco fans 81 are disposed alternately 
right and left in a fashion such that a first one is put left as viewed 
from the gate 53, a second one right as viewed from the gate 53, a third 
one left as viewed from the gate 53 and so on. The above positioned 
sirocco fans 81 have respective blown air ports which are directed 
downward so as to blow air into the spaces a and c and the spaces b' and 
d'. 
The construction of the system 50 for drying objects to be dried according 
to this embodiment is as described above. The function of the system will 
now be described below. 
At this time, a vast plurality of objects to be dried 55 are housed in 
layered form in each of a plurality of, for example, four trucks 54 and 
accommodated in the drying chamber 51. The air charge means 56, air 
exhaust means 57 and far infrared radiation heaters 73 are regulated by 
the control panel 70 and are individually driven. Thus, the entirety of 
the system is air-conditioned. 
In this drying system 50, outside fresh air is fed via the second chamber 
52 into the drying chamber 51 by the air charge means 56. In the drying 
chamber 51, an air stream is circulated in the entirety thereof. The air 
is exhausted from the drying chamber 51 to the outside by the air exhaust 
means 57. In the drying chamber 51, air exhaust is conducted with greater 
power than that of air charge, so that the pressure is held at, for 
example, 3 mb or more, preferably 10 mb or more below atmospheric 
pressure. 
Further, in the drying chamber 51, far infrared radiation which is easily 
absorbed by the objects to be dried 55 is emitted from the ceiling 51a by 
the drive of the four far infrared radiation heaters 73. On the other 
hand, the air of the second chamber 52 is fed into the predetermined 
spaces a, c, b' and d' by the sirocco fans 81. Thus, the air is introduced 
into the left space below the first far infrared radiation heater 73 
positioned near the gate 53 and the introduced air is blown through the 
openings 91 in the substantially horizontal direction as indicated by the 
arrow A in FIG. 8. As a result, moisture evaporation is promoted from the 
objects to be dried 55 positioned in that vicinity especially by the 
effect of the air stream flowing in the direction of the arrow A. 
On the other hand, below the far infrared radiation heater 73 positioned 
second as viewed from the gate 53, the air is introduced into the right 
space b' because the sirocco fan 81 is positioned on the right side and 
the introduced air is blown through the openings 92 in the substantially 
horizontal direction as indicated by the arrow B in FIG. 8. 
Likewise, the introduced air is blown in the direction of the arrow A below 
the third far infrared radiation heater and in the direction of the arrow 
B below the fourth far infrared radiation heater. That is, in the drying 
chamber 51, the air is circulated in the entirety thereof and opposite 
horizontal air streams alternate below the far infrared radiation heaters 
73. 
As apparent from the above, in this embodiment, the inside of the drying 
chamber 51 is substantially uniformly heated by far infrared radiation, 
the inside of the chamber is continuously held in a state of reduced 
pressure by means of the air exhaust means 57, and a horizontal air stream 
flows in the vicinity of housed objects to be dried 15 to thereby 
circulate the air inside the chamber. Therefore, no matter where the 
objects to be dried are positioned, they can be dried rapidly and 
uniformly. 
Upon completion of the predetermined drying in the above manner, it is 
preferred that the driving of the far infrared radiation heaters 73 be 
terminated and, thereafter, one or more sirocco fans 81 be continuously 
driven to thereby cure the objects to be dried only by natural ventilation 
for a given period of time. 
In this embodiment, the dried products can be produced always throughout 
the year without the need of caring about the effects of rain or other 
outside weather conditions. Further, the number of days in which the 
production is to be effected can be reduced, so that the monthly treatment 
capacity can be markedly increased. For example, the drying of salmon in a 
drying chamber of 7 m in length can output dried salmon in an amount as 
large as 5 t per month. 
The objects to be dried in the drying chamber 51 are the same as those 
mentioned in the previous embodiment. 
The functions and effects of this drying system 50 are the same as 
described in the previous embodiment, so that detailed description is 
omitted. 
The second embodiment of the present invention is as described above, which 
by no way limits the present invention. 
For example, opposite horizontal air stream flows alternate inside the 
drying chamber 51 in the above embodiment. Instead, for example, all 
sirocco fans 81 may be positioned on the same side to thereby cause all 
air streams to flow in the same horizontal direction. 
Further, the air streams flowing in alternately opposite directions can be 
so set as to flow counter at redetermined time intervals. This setting of 
the air streams so as to flow counter at predetermined time intervals can 
render the air circulation more uniform and can accomplish drying of a 
vast plurality of objects to be dried with improved uniformity. 
Still further, for example, pipes may replace the bulkhead platings 85, 86 
to thereby use the pipelines thereof for creating horizontal air streams. 
A further system for drying objects to be dried according to a third 
embodiment of the present invention will be described below with reference 
to FIGS. 9 to 11. 
FIG. 9 schematically shows a system for drying objects to be dried 
according to a third embodiment of the present invention, and FIG. 10 is a 
schematic perspective view thereof and FIG. 11 is a schematic plan view 
thereof. 
This drying system 100 is constructed in a large box frame with thermal 
insulating structure and can be installed outdoors. In the drying system 
100, two of second chambers 102 are constructed above a drying chamber 101 
having its periphery surrounded with a thermal insulating material. The 
drying chamber 101 has a gate 103 through which entrance and exit can be 
made. 
Truck 104 which is loaded with a vast plurality of objects to be dried 105 
in multilayered form are placed in the drying chamber 101 to thereby have 
the objects to be dried 105 housed in the drying chamber 101. 
The two second chambers 102 are arranged in a direction from the gate to 
the inside of the drying chamber, in each of which an infrared radiation 
heater 123 is provided. The structure of each of the far infrared 
radiation heaters 123 is the same as that of the far infrared radiation 
heater 38 shown in FIG. 3. 
The use of the above far infrared radiation heaters 103 leads to free 
regulation of the drying temperature and to releasing of moisture not only 
from the surface of each of the objects to be dried but also from the 
center thereof with less energy input because of high far infrared 
radiation efficiency. Therefore, the objects to be dried can effectively 
be dried up to the inner parts thereof at a lowered cost. 
Each of the second chambers 102 is provided with an fan 102a for 
circulating an air in the drying chamber 101. The fan 102a introduces air 
into the second chamber 102 from an opening 102b formed under the fan 
102a. The air introduced into the two second chambers 102 flows in a 
direction indicated by arrows C and D in FIGS. 9 and 11, and is returned 
to the drying chamber 101 from an opening 102c formed on a bottom wall of 
each of the second chambers 102, where the bottom wall composes a part of 
a ceiling of the drying chamber. 
Accordingly, the fan 102a generates a circulation of the air opposite to 
the arrow C or D under each of the second cambers 102. Further, as shown 
in FIG. 11, the arrows C and D are opposite to each other. 
The drying chamber 101 is provided with air charge means 106 and air 
exhaust means 107. An air charge port 106a of the air charge means 106 is 
connected with a first side chamber 101a disposed at a side portion of the 
drying chamber 101 and an exhaust port 107a of the exhaust means 107 is 
connected with a second side chamber 102b disposed at the other side of 
the drying chamber 101. 
The air charge means 106 comprises an air filter 109a, a pipe 108a, a 
blower 109 and a pipe 108b which are connected in this order. The air 
charge means 106 introduces outdoor fresh air via a pipes 108a and 108b 
into the drying chamber 101 by the blower 109 and circulates an air stream 
in the drying chamber 101. Namely, outdoor air is suctioned from the air 
filter 109a by the blower 109 disposed between the pipes 108a and 108b, as 
indicated by arrows in FIGS. 9-11. The suctioned air is temporarily 
introduced into the first side chamber 101a and then, as described below, 
fed via openings 141 formed through a bulkhead plating 135 of the first 
side chamber 101a into the drying chamber 101. 
On the other hand, the air exhaust means 107 comprises an air filter 110a, 
a pipe 113a, a blower 110 and a pipe 113b which are connected in this 
order. The air exhaust means 107 exhausts air humidified in the drying 
chamber 101 outdoors via openings 142 formed through a bulk head plate 136 
of the second side chamber 101b and pipes 108a and 108b. 
In this embodiment, as shown in FIGS. 9-11, bulkhead platings 135, 136 are 
vertically disposed opposite to a pair of mutually opposite side walls, 
respectively, to thereby define the narrow first and second side chambers 
101a and 101b in the vicinity of each of the side walls. A vast plurality 
of openings 141, 142 are formed in the bulkhead platings 135, 136 along 
the direction of height as from positions slightly higher than the floor 
level. By virtue of the formation of such a vast plurality of openings 
141, 142, for example, the air suctioned outdoors into the first side 
chamber 101a can be blown through the openings 141 in the substantially 
horizontal direction, and, contrarily, the second side chamber 101b 
opposite thereto can suction the air blown from the openings 141 through 
the openings 142. Further, the air suctioned from the drying chamber 101 
into the second side chamber 101b is exhausted outdoors. 
The respective pipes 108a, 108b, 113a and 113b of the air charge means 106 
and the air exhaust means 107 are respectively provided with valves, which 
are manually or automatically operated to thereby regulate the openness of 
each of the pipes. 
The air charge means 106 and the air exhaust means 107 are each provided 
with a regulating system for regulating a quantity of the air flowing 
therethrough. The suctioning power of the air charge means 106 or the 
exhausting power of the air exhaust means 107 is suitably regulated by the 
regulating system for maintaining the inside of the drying chamber at a 
reduced pressure. In this connection, the pipe 108a of the charging means 
106 and the pipe 113a of the exhaust means 107 in this embodiment are 
connected with a connecting pipe 151 provided with a valve, as an 
assistant means for adjusting the air pressure in the drying chamber 101. 
Decrease in the quantity of air suctioned by the blower 109 can be coped 
with the regulation of the valve openness, as indicated by hatched arrows 
in FIGS. 9 and 11. Further, by such regulation, the heated air to be 
exhaust can be circulated. 
The construction of the system 100 for drying objects to be dried according 
to this embodiment is as described above. The function of the system will 
now be described below. 
At this time, a vast plurality of objects to be dried 105 are housed in 
layered form in the truck 104 and accommodated in the drying chamber 101. 
The air charge means 106, air exhaust means 107 and far infrared radiation 
heaters 123 are regulated by a control panel (not shown) as described in 
the second embodiment and are individually driven. Thus, the entirety of 
the system is air-conditioned. 
In this drying system 100, outside fresh air is fed via the first side 
chamber 101a into the drying chamber 101 by the air charge means 106 and, 
at this time, is blown through the openings 141 formed on the bulkhead 
plating 135 in the substantially horizontal direction. In the drying 
chamber 101, the blown air flows in the substantially horizontal 
direction, as indicated by arrows A shown in FIGS. 9 and 11. As a result, 
moisture evaporation is promoted from the objects to be dried 105 
positioned in that vicinity. 
The humidified air in the drying chamber 101 is suctioned via the vast 
plurality of the openings 142 formed on the bulkhead plating 136, 
introduced into the second side chamber 101b and then exhausted to the 
outside by the exhaust means 107. In the drying chamber 101, the pressure 
is held at, for example, 3 mb or more, preferably 10 mb or more below 
atmospheric pressure. 
Further, in the drying chamber 101, far infrared radiation which is easily 
absorbed by the objects to be dried 10is emitted from the ceiling by the 
drive of the far infrared radiation heaters 123. 
As apparent from the above, in this embodiment, the inside of the drying 
chamber 101 is substantially uniformly heated by far infrared radiation, 
the inside of the chamber is continuously held in a state of reduced 
pressure by means of the air exhaust means 107, and a horizontal air 
stream flows in the vicinity of housed objects to be dried 105. Therefore, 
no matter where the objects to be dried are positioned, they can be dried 
rapidly and uniformly. 
Moreover, in this embodiment, the fans 102a disposed in the second chambers 
102 generate a circulation of the air opposite to the arrow C or D under 
the second chambers 102, respectively. Further, as shown in FIG. 11, the 
arrows C and D are opposite to each other. As a result, the air in the 
chamber is evenly circulated. 
In this embodiment, the great amount of the dried products can be produced 
always throughout the year, as same as in the case of the first or second 
embodiment of the present invention. The objects 105 to be dried are the 
same as those mentioned in the previous embodiments and the same functions 
and effects as in the first and second embodiments can be expected. 
The third embodiment of the present invention is as described above, which 
by no way limits the present invention, and can be variously modified 
within the scope of the present invention. 
EFFECT OF THE INVENTION 
As described above, in the system for drying objects to be dried according 
to the present invention, outside air is introduced into the drying 
chamber by means of the air charge means. While the air stream is 
circulated inside the drying chamber by this air charge means, humidified 
air is exhausted by means of the air exhaust means. This air exhaust means 
exhausts air in quantity much greater than introduced by the air charge 
means to thereby maintain the inside of the drying chamber in a state of 
reduced pressure. The far infrared radiation heater uniformly heats the 
inside of the drying chamber. Therefore, the objects to be dried can be 
dried up to the inner parts thereof with less energy input within a short 
period of time. Moreover, inside the drying chamber, horizontal air stream 
is positively created by means of the circulatory blowing means, so that 
the drying of the objects to be dried can be promoted and simultaneously 
uniformized. Consequently, the drying can be effected at the optimum 
temperature within a short period of time, so that there is no waste of 
time and energy, and that there is no danger of temperature rise beyond 
necessity. 
In addition, cooling of humidified air is not needed, so that, in this 
respect as well, energy saving can be attained. Further, highly fresh 
dried products whose oxidation degree is low if any can be obtained. 
Also, dried products can be obtained without the influence of weather, so 
that planned production thereof can be effected.