Continuous-processing type hot-water sterilizer and food cooker

Continuous-processing type sterilizer and cooker for providing packaged foods completely sterilized with a small heat-energy consumption and retaining the color, fragrance, taste, texture and quality similar to unprepared foods by taking the steps of immersing a product cage, wherein contains the packaged foods, in pressurized hot-water in a sterilization tank, moving the cage within the hot water by means of a drive means for a given period of time, transferring it through a transfer tank from the hot water to a pressurized cooling water in a cooling tank, and moving it within the cooling water by means of a drive means for a given period of time. Both the sterilization tank and the cooling tank are connected to the transfer tank at their one end, the sterilization tank having a preparatory chamber at its other end and the cooling tank having an off-loading chamber at its other end. The chamber is provided with an elevator, lowering or raising within the connecting portion between the chamber and the tank, and separating the chamber from the tank in a manner that the rim of the elevator is bound to the flange of the lower end of the chamber thereby forming an airtight system.

BACKGROUND OF THE INVENTION 
This invention relates to heat-treatment for foods. More particularly, the 
invention is directed to a continuous-processing type hot-water sterilizer 
and cooker for insuring sterilization and cooking of packaged foods in a 
manner such that the foods may retain the color, fragrance, taste, texture 
and quality similar to unprepared food. 
Conventional sterilizers, having both a hot-water tank and a sterilization 
tank, require an installation of powerful hot-water pumps, large diameter 
pipes and large-size control valve because they must rapidly circulate hot 
water between these two tanks. It takes a considerable amount of time for 
sterilization tank to be filled to a given level with hot water. 
This time increases when larger sterilizers are used to accomodate a 
greater volume of foods to be sterilized. Under this sterilization method, 
time needed to attain a given high temperature for sterilizing and the 
time needed to cool the sterilized foods to a given low temperature are 
considerable and consequently there is an impact on the quality of the 
foods. Namely, when hot water is placed in the sterilization tank, the 
foods on the bottom begin to cook immediately, those on the top later. 
Likewise, when the tank is emptied, the foods on the top lose temperature 
first, those on the bottom later. Therefore, there is a difference in 
cooking time between foods placed in the top and bottom of the product 
cage. Moreover the sterilization tank and its pipe arrangement are heated 
or cooled alternatively with hot water or cooling water, so that a large 
amount of heat energy is lost. 
SUMMARY OF THE INVENTION 
The sterilizer and cooker of this invention which overcome the above 
discussed and numerous other disadvantages and deficiencies of the prior 
art relate to a hot-water sterilizer of a continuous-processing type for 
packaged foods comprising: 
(1) a sterilization tank containing hot water therein under a given 
pressure and having a preparatory chamber at its one end; 
(2) a cooling tank containing cooling water therein under a given pressure 
and having an off-loading chamber at its one end; and 
(3) a transfer tank connected to the other end of the sterilization tank at 
its one end and the other end of the cooling tank at its other end. 
The preparatory chamber has a pipe arrangement for injecting and 
discharging a pressurized gas and an elevator on which a product cage 
containing packaged foods therein is placed. The elevator lowers or raises 
within the connecting portion between the chamber and the sterilization 
tank. The elevator also separates the chamber from the tank in a manner 
that the rim of the elevator is bound to the flange of the lower end of 
the chamber by means of a packing material thereby forming an airtight 
system. 
The transfer tank has one transport means for moving the product cage from 
the other end of the sterilization tank to its one end thereby removing 
the product cage from the hot water in the sterilization tank, another 
transport means for moving the product cage from the one end of the 
transfer tank to the other end of the transfer tank, and yet another 
transport means for moving the product cage from the other end of the 
transfer tank to the other end of the cooling tank thereby immersing the 
product cage in the cooling water in the cooling tank. 
The off-loading chamber has a pipe arrangement for injecting and 
discharging a pressurized gas and an elevator on which the product cage is 
placed. The elevator lowers or raises within the connecting portion 
between the chamber and the cooling tank. The elevator also separates the 
chamber from the cooling tank in a manner that the rim of the elevator is 
bound to a flange of the lower end of the chamber by means of a packing 
material thereby forming an airtight system. 
Thus, the invention described herein makes possible the objectives as 
follows: 
(a) Foods are completely sterilized by a method which retains the proper 
color, fragrance, taste, texture and quality of the foods similar to that 
of foods under natural conditions; 
(b) Sterilization is performed under a temperature suitable for the raw 
materials, condiments and additives used to process foods for a very short 
time; 
(c) All foods placed in the product cage are immersed in hot water without 
any time difference between the top and bottom of the product cage thereby 
sterilizing all foods placed in the product cage uniformly, thus insuring 
an equal cooking time for all foods in the product cage; 
(d) All foods placed in the product cage are immersed in cooling water 
without any time difference between the top and bottom of the product cage 
thereby cooling all foods placed in the product cage uniformly, thus 
insuring an equal cooling time for all foods in the product cage; 
(e) The sterilizer is applicable to a variety of heating conditions, 
thereby treating some foods in large quantities and also diverse foods in 
small quantities; 
(f) The sterilizer consumes heat energy only to treat foods, thereby 
further prompting energy conservation; 
(g) The hot water in the sterilization tank is always maintained at a 
constant temperature because the product cages are driven in an 
intermittent manner within the hot water thereby creating a stirring 
operation, thus insuring that sufficiently hot water is in constant 
contact with the surface of the food containers or envelopes to enhance 
the efficiency of heat transmission; 
(h) The sterilizer has no heat transmission between the high temperature 
sterilization tank and the low temperature cooling tank because these two 
tanks are separated therefrom by the transfer tank, thereby raising the 
thermal efficiency of the overall equipment; and 
(i) The sterilizer always unifys the internal temperature of the cooling 
tank because product cages are driven in an intermittent manner within the 
cooling water thereby creating a stirring operation, thus insuring that 
sufficient cooling water is in constant contact with the surface of the 
food containers or envelopes thereby enhancing the cooling efficiency.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The hot-water sterilizer of this invention has a sterilization tank 1, a 
cooling tank 2 and a transfer tank 3, as shown in FIG. 1 and FIG. 2. The 
sterilization tank 1, which contains hot water H under a given pressure, 
has a preparatory chamber 11 at its one end portion 101. The cooling tank 
2, which contains cooling water C under a given pressure, has an 
off-loading chamber 21 at its one end portion 201. The transfer tank 3 is 
connected to both the other end portion 102 of the sterilization tank 1 at 
its one end portion 301 and the other end portion 202 of the cooling tank 
2 at its other end portion 302. 
The preparatory chamber 11 has an elevator 12 supporting a product cage 120 
thereon which contains packaged foods to be sterilized. The elevator 12 
lowers or raises within the connecting portion 111 between the preparatory 
chamber 11 and the sterilization tank 1 and is capable of separating the 
chamber 11 from the tank 1 in a manner that the rim of the elevator 12 is 
bound to the flange 110 of the lower end of the chamber 11 by means of a 
packing material 112 thereby forming an airtight system. The elevator 12 
may be driven by an air cylinder 15. The chamber 11 further has a pipe 
arrangement comprising a pressurized-gas injecting pipe 13 with a valve 
131 and a pressurized-gas discharging pipe 14 with a valve 141. 
The off-loading chamber 21 likewise has an elevator 22 supporting the 
product cage 120 thereon and lowering or raising within the connecting 
portion 211 between the chamber 21 and the tank 2. The elevator 22 is also 
capable of separating the chamber 21 from the tank 2 in a manner that the 
rim of the elevator 22 is bound to the flange 210 of the lower end of the 
chamber 21 by means of a packing material 212 thereby forming an airtight 
system. The elevator 22 may be driven by an air cylinder 25. The chamber 
21 further has a pipe arrangement, which comprises a pressurized-gas 
injecting pipe 23 with a valve 231 and a pressurized-gas discharging pipe 
24 with a valve 241. 
The sterilization tank 1 further has a drive means 150 for moving the 
product cage 120 within the hot water H from the one end portion 101 
thereof to the other end portion 102 thereof. The drive means 150 
comprises a transport means 151 reciprocatable and rotatable on guide 
rails (not shown in drawings) ranging from the one end to the other end of 
the sterilization tank 1. The guide rails may be extended to the end 201 
of the cooling tank 2. The drive means 150 also comprises air cylinders or 
hydraulic cylinders 152 and 153. The cylinder 152 is a cylinder for moving 
the transport means 151 in a reciprocating manner. The other cylinder 153 
is a cylinder for rotating the transport means 151. The transport means 
151 is provided with a locking means such as plural detents 154. The 
locking means also ensures a uniform spacing between contiguous product 
cages 120 on the transport means 151 during the transport of the product 
cage 120 in the sterilization tank 1. Upon rotating the transport means 
151 by the cylinder 153, the product cage 120 becomes free from the 
locking means. The sterilization tank 1 also has a pipe arrangement 155 
with a valve 156 for injecting a pressurized gas into the tank 1 and a 
circulation means 157 for circulating the hot water H. The circulation 
means 157 has a pump 158 and heating means 159 to maintain the hot water 
at a given temperature. 
The transfer tank 3 has transport means 31, 32 and 33. The first transport 
means 31 is an air cylinder for moving the product cage 120 from the 
transport means 151 at the end portion 102 of the sterilization tank 1 to 
the one end portion 301 of the transfer tank 3 thereby removing the 
product cage 120 from the hot water H in the sterilization tank 1. The 
second transport means 32 is an air cylinder for moving the product cage 
120 from the one end portion 301 of the transfer tank 3 to the other end 
portion 302 thereof. The third transport means 33 is an air cylinder for 
moving the product cage 120 from the other end portion 302 of the transfer 
tank 3 to the end portion 202 of the cooling tank 2 thereby immersing the 
product cage 120 in the cooling water C in the cooling tank 2. 
The cooling tank 2 has a drive means 250 for moving the product cage 120 
within the cooling water C from the one end portion 202 thereof to the 
other end portion 201 thereof. The drive means 250 comprises a transport 
means 251 reciprocatable and rotatable on guide rails (not shown) ranging 
from the end portion 202 to the other end portion 201 of the tank 2. The 
transport means 251 may be connected to the transport means 151 in the 
sterilization tank 1. The transport means 251 has a locking means such as 
plural detents 254 locking the product cage 120 therewith on the transport 
means 251 during the transport of the porduct cage 120 in the cooling tank 
2. This locking means also ensures a uniform spacing between contiguous 
product cages 120. The product cage 120 becomes free from the locking 
means by rotating the transport means 251 by the air cylinder 153. The 
cooling tank 2 also has a pipe arrangement 255 with a valve 256 for 
injecting a pressurized gas and a circulation means 257 for circulating 
the cooling water C. The circulation means 257 has a pump 258 and a 
heat-exchanger 259 to maintain the cooling water at a given temperature. 
The hot water H in the sterilization tank 1 usually is at a temperature 
ranging from about 105.degree. C. to about 140.degree. C. The cooling 
water C in the cooling tank 2 is usually at a temperature of around 
20.degree. C. The internal pressure of the tanks 1 and 2 is under about 
1.2 to 3.6 atmospheric pressure. The pressurized gas is usually selected 
from the group consisting of air, nitrogen and the inert gases. 
Using the abovementioned sterilizer of this invention, the packaged foods 
are sterilized and cooked, as shown in FIG. 3, through the steps 
comprising: 
(1) placing the product cage 120, containing the packaged foods, on the 
first elevator 12 in a preparatory chamber 11; the chamber 11 being 
connected to the one end of the sterilization tank 1 at its lower end 
containing hot water H, and the elevator 12 lowering and raising within 
the connecting portion 111 between the chamber 11 and the tank 1 and 
separating the chamber 11 from the tank 1 in a manner that the rim of the 
elevator 12 is bound to the flange of the lower end of the chamber 11 
through the packing material 112 thereby forming an airtight system, 
(2) closing the lid of the preparatory chamber 11 in an airtight manner, 
(3) injecting a pressurized gas into the preparatory chamber 11, thereby 
making the internal pressure of the chamber equivalent to a given pressure 
within the sterilization tank 1, 
(4) lowering the elevator 12 by means of the cylinder 15 and then moving 
the product cage 120 from the elevator 12 to the drive means 150 at the 
end 101 of the sterilization tank 1 through the connecting portion 111 by 
means of another cylinder 16, thereby quickly immersing the product cage 
120 in the hot water H of the sterilization tank 1, 
(5) locking the product cage 120 to the drive means 150 by means of the 
locking means, 
(6) moving the product cage 120 immersed in the hot water H, more 
preferably in an intermittent manner, by means of the drive means 150 from 
the one end of the sterilization tank to the other end of the 
sterilization tank over a given period of time, 
(7) transferring the product cage 120 from the sterilization tank 1 to the 
transfer tank 3, which is connected to the other end 102 of the 
sterilization tank 1, thereby removing the product cage 120 from the hot 
water H in the sterilization tank 1, 
(8) transferring the product cage 120 from the transfer tank 3 to the 
cooling tank 2 containing cooling water C under a given pressure, thereby 
quickly immersing the product cage 120 in the cooling water C; the 
transfer tank 3 passing through the one end 202 of the cooling tank 2, 
(9) moving the product cage 120 immersed in the cooling water C, more 
preferably in an intermittent manner, by means of the drive means 250 from 
the one end 202 of the cooling tank 2 to the other end 201 of the cooling 
tank 2 over a given period of time, 
(10) removing the product cage 120 from the drive means 250 by means of the 
cylinder 153, 
(11) moving the product cage 120 from the other end 201 of the cooling tank 
2 to the second elevator 22 through the connecting portion 211 by means of 
another cylinder 26, 
(12) raising the second elevator 22 to free the product cage 120 from the 
cooling water C and further to separate the off-loading chamber 21 from 
the cooling tank 2 in a manner that the rim of the elevator 22 is bound to 
the flange 210 of the lower end of the off-loading chamber 21 to form an 
airtight system; the off-loading chamber 21 being connected to the other 
end 201 of the cooling tank at its lower end and the off-loading opening 
of the off-loading chamber 21 being closed in advance with its lid to hold 
its internal pressure equivalent to that of the cooling tank 2, 
(13) opening the lid of the off-loading chamber 21 thereby making the 
internal pressure of the chamber equal to the atmospheric pressure, and 
(14) off-loading the product cage 120 from the second elevator 22. 
This system may be completely controlled by means of a computer 
incorporated therein.