JP2002333275A - Method and apparatus for superheated vapor drying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel method for drying which dries a material to be treated by spraying a vapor of a high-temperature superheated state at 100 deg.C or higher to the material to be treated such as a hen's egg. SOLUTION: The method for drying comprises the steps of further heating live vapor S generated by a vapor generator by a superheated vapor generator 3 to a superheated vapor S at 100 deg.C or higher, sequentially guiding the vapor S to a treating unit 4 in which the material W to be treated is sequentially conveyed, contacting the guided vapor S to substantially overall surface of the material W, and vapor removing surface liquid-like component of the material W. The method further comprises the step of ejecting the vapor S to an untreated material W disposed in a preliminary ejection zone ZB of immediately this die of a normal ejection zone ZA for a predetermined time after the normal ejection of a suitable time in the normal ejection zone ZA is finished when conveying of the material W is irregularly stopped during the drying work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to foodstuffs (potatoes such as chicken eggs and potatoes, fruits, etc.), packaging materials (retort packs, milk products such as milk, paper packs such as drinking water, bottles and bottles for drinking water, etc.). Caps, sprouts packaging bags, etc.), containers (side dishes and lunch boxes, etc.), food transport containers (containers for transporting bread, noodles, etc.), industrial parts (machined parts after washing, IC base, etc.) For precision parts, cast products, etc.), and in particular, the object to be processed is dried by bringing superheated steam of 100 ° C. or more into contact with the object to be processed. The present invention relates to a novel drying method and a drying apparatus.

BACKGROUND OF THE INVENTION

[0002] For example, foods, containers, packaging materials, etc., after washing, water droplets (droplets) adhere to the surface of the object to be treated, such as foods. Since the object to be processed is contaminated, the object to be processed after the cleaning is generally subjected to a treatment for removing the surface moisture. As such a water removal treatment method, an appropriate method depending on the properties of the object to be processed, such as supply of hot / cold air for drying, centrifugal dehydration, natural leaving for a certain time, wiping, etc., is appropriately selected. And especially for drying of foodstuffs, etc.
Wind drying that blows hot or cold air is often used. Specifically, a method of compressing air with a large-capacity blower and spraying it on a food or the like with a nozzle to blow off moisture on the surface, or blowing dry air heated by an electric heater or the like on the food or the like is used. In addition, such a drying treatment also has a bactericidal effect of killing various bacteria that are susceptible to drying and adhered to the surface of a food material or the like. The food or the like from which the moisture on the surface has been removed is processed, for example, in the next package, etc., and proceeds to a processing step into a product form.

[0003] By the way, in such drying and processing (package processing, etc.), mass production, that is, more efficient drying (shortening of drying time) and speeding up of food processing are being promoted in view of market prices and the like. Have been. However, in the conventional wind drying in which hot and cold air is mainly blown, it is difficult to make the preceding stage drying follow the faster processing speed. For example, in the case of chicken eggs, a processing amount of about 30,000 eggs per hour was conventionally used, but in recent years, a processing amount of about 120,000 eggs per hour has been required. Although we can handle it, the previous drying work can not catch up, and in some cases,
Poor drying may lead to the occurrence of mold and the propagation of various bacteria. Such a situation is a similar problem in foods, containers, and packaging materials other than chicken eggs.

[0004] Of course, in a drying method in which warm air is blown onto food, for example, if the temperature of the supplied air is increased and the amount of air is increased, drying can be performed in a short time. In some cases, inconvenience that foodstuffs are thermally denatured by high-temperature hot air may occur, and there is a limit to a method of increasing hot air temperature and air volume.
Although it is possible to increase the drying processing amount (absolute amount) by adding only a drying device to the packed packing device, a series of operations from drying to packing can be performed by the same transport. It was difficult to adopt it at a factory that operates on a line. Further, the form in which only the drying device is added requires a larger installation space and increases in equipment costs are inevitable, so that an increase in cost is unavoidable and cannot be said to be a fundamental solution method that can achieve more efficient drying. Was.

[0005] For this reason, it is conceivable to introduce an ultraviolet sterilizer as a drying apparatus. However, there is a drawback that the equipment cost is greatly increased, and it has not been possible to introduce it at any factory. Recently, heat-resistant bacteria (1 for sterilization)
The problem of food poisoning (bacteria requiring a temperature of about 30 ° C.) has also been taken up greatly, and there has been a demand for a drying method capable of not only shortening the drying time but also performing effective sterilization.

[0006]

[Technical Problems Attempted to Be Developed] The present invention has been made in view of such a background.
It is not tied to the drying action, but rather focuses on the steam used for the humidifying action, and uses it as a high-temperature superheated state of 100 ° C or higher to achieve efficient drying. It attempted to develop a new drying method.

[0007]

According to a first aspect of the present invention, there is provided a method for drying a superheated steam, wherein a superheated steam in a high-temperature state of 100 ° C. or more is brought into contact with substantially the entire surface of the object to be processed. It is characterized in that the surface liquid component is removed by evaporation. According to the present invention, since the drying is performed by injecting the superheated steam of 100 ° C. or more to the object, the processing amount can be significantly increased as compared with the wind drying performed by blowing hot and cold air. Further, with drying, the surface of the object to be treated can be sterilized, and in particular, heat-resistant bacteria can be effectively killed.

[0008] The superheated steam drying method according to claim 2 is characterized in that:
In addition to the requirement of claim 1, the object to be processed is sequentially transported to a substantial processing section to which superheated steam is supplied, and when performing a normal drying operation in the processing section, The superheated steam is supplied only to the object located in the normal ejection zone, and during the work, if the conveyance of the object is suddenly stopped irregularly, the regular injection in the normal ejection zone for an appropriate time is performed. After the completion, the superheated steam is injected for a certain period of time to an unprocessed object located in the preliminary ejection zone immediately before the normal ejection zone. According to this invention, when the transfer of the object to be processed is irregularly stopped unexpectedly, after the supply of the superheated steam in the normal ejection zone is finished, the process (normal injection) is performed next. To supply superheated steam to the workpiece located in the preliminary ejection zone, which should have been heated, excessively heat the workpiece located in the regular ejection zone even if the transport device suddenly stops. There is no. This kind of preliminary injection is particularly effective when the irregular stop is released and the line is restarted, and when it takes some time (inert time) for the superheated steam to reach the specified state, the drying is particularly effective. Method.

Further, the superheated steam drying method according to a third aspect is in addition to the requirement according to the second aspect, even if the preliminary injection for an appropriate time in the preliminary injection zone, which is performed during the irregular stop, ends. When the irregular stop state is continued, the supply of the superheated steam to the processing section is shut off, and the superheated steam is discharged to the outside of the processing section. According to this invention, even if the injection of the superheated steam in the preliminary ejection zone ends, if the irregular stop state continues, the superheated steam is discharged to the outside (outside the processing unit). Can be effectively prevented from being thermally denatured.

A superheated steam drying method according to claim 4 is characterized in that:
In addition to the requirement of the above-mentioned claim 2, the processing unit for drying the object to be processed by applying superheated steam to the object to be processed is appropriately selected and formed in a substantially closed state or an open state. It consists of According to the invention,
Since the processing section can have either a closed system or an open system structure, it can take various forms depending on the properties of the object to be processed.

A superheated steam drying method according to claim 5 is
In addition to the requirement according to claim 2, when the processing section is formed in a closed state, the processing section has a processing chamber having a substantially closed atmosphere, and the processing object is formed in the processing chamber. The contact supply of superheated steam is performed. According to the present invention, since the object to be processed is dried in a substantially closed processing space, it is easy to form an atmosphere temperature suitable for drying. Further, in the present invention, drying is performed by injecting superheated steam, and scattering of the superheated steam to the outside can be almost completely prevented.

A superheated steam drying method according to claim 6 is characterized in that:
In addition to the requirement according to claim 5, the processing chamber formed in the substantially closed state is provided with a blower, and circulates hot air utilizing the residual heat of the superheated steam in the processing chamber, from the blower. The blown hot air is blown to the object to be processed after coming into contact with the superheated steam. According to the present invention, since the warm air is circulated in the closed processing space by using the residual heat of the superheated steam, the drying action by the superheated steam is promoted, and the drying can be performed at a higher speed. In particular, the warm air blown out from the blower is applied to the object to be processed after the treatment, so that the moisture and the like adhering to and remaining on the object to be processed can be effectively removed. In addition, since the air in the processing space is appropriately stirred, it is possible to effectively prevent a local temperature increase in the processing space.

A superheated steam dryer according to claim 7 is
A steam generating section for generating steam, a superheated steam generating section for further heating the generated steam to a high temperature state of 100 ° C. or higher, and a superheated steam generated in the superheated steam generating section are introduced to cover the superheated steam. And a treatment section for contacting substantially the entire surface of the treatment object, wherein at least the surface liquid component of the treatment object is evaporated and removed.
According to the present invention, since the drying process is performed by bringing the superheated steam of 100 ° C. or more into contact with the object to be processed, high-speed drying can be performed as compared with the conventional wind drying by blowing hot / cold air,
The amount of processing can be significantly increased. For example, in the case of a chicken egg, the processing amount of about 30,000 eggs / hour in the conventional wind drying can be performed, but the processing of about 120,000 eggs / hour can be performed in the superheated steam drying of the present invention. In addition, the object to be processed can be sterilized with the drying, and heat-resistant bacteria, which were difficult to kill particularly in the case of wind-drying, can be effectively killed by the present drying method using superheated steam.

The superheated steam drying apparatus according to claim 8 is
In addition to the requirement of the claim 7, the processing unit is a transport device that sequentially transports the workpiece, a regular injection port that blows overheated steam only to the workpiece located in the normal ejection zone on the transport device, It has a preliminary injection port that blows superheated steam only to the object to be processed located immediately before the regular ejection zone.In normal drying work, superheated steam is ejected from the regular ejection port and located in the regular ejection zone. If the transport of the workpiece suddenly stops irregularly during the drying operation, the regular injection for an appropriate time is terminated, and then the superheated steam is injected from the preliminary injection port. To process the object to be processed located immediately before the normal ejection zone. According to the present invention, when the transfer of the object to be processed suddenly and irregularly stops, after the injection of the superheated steam for a certain period of time in the normal ejection zone is terminated, the auxiliary which is immediately in front of the normal ejection zone in the transfer direction is provided. Since the superheated steam is supplied to the ejection zone, when the transfer device is stopped, the object to be processed located in the regular ejection zone is not overheated. Such preliminary injection is a particularly effective drying method when the irregular stop is canceled and the conveying device is started up, and when the spray of the superheated steam is insufficient for a while.

A superheated steam dryer according to claim 9 is
In addition to the requirement according to claim 8, the processing unit discharges superheated steam from the superheated steam generation unit to the outside of the processing space, and a drying path that supplies superheated steam from the superheated steam generation unit to the substantial processing space. Discharge path, even if the pre-injection to the processing object located in the preliminary ejection zone is terminated, if the irregular stop state continues, the path of the superheated steam from the drying path The method is characterized by switching to a discharge path and discharging superheated steam to the outside of the processing space. According to the present invention, if the irregular stop is continued even after the injection of the superheated steam in the preliminary ejection zone ends, the drying path is switched to the discharge path to discharge the superheated steam to the outside. The rise can be effectively prevented, and thermal denaturation of the object can be avoided. If the irregular stop is prolonged, the supply path of the superheated steam is shut off by a solenoid valve or the like, and the voltage and current of the superheated steam generator are reduced to the standby mode, so that energy saving measures and safety measures can be taken. Can be applied all at once.

According to a tenth aspect of the present invention, in addition to the requirement of the seventh, eighth or ninth aspect, a substantial processing space in the processing unit is a substantially closed processing chamber. The method is characterized in that a contact supply of superheated steam to an object to be processed is performed in a processing chamber. According to the present invention, since the object to be processed is dried in the processing chamber formed in a substantially closed state, it is easy to form an atmosphere temperature (warm state) suitable for drying. Further, in the present invention, drying is performed by injecting the superheated steam to the object to be processed, and scattering of the superheated steam to the outside can be almost completely prevented by the processing chamber.

[0017] According to an eleventh aspect of the present invention, in addition to the requirement of the tenth aspect, the processing chamber in the closed state circulates a hot air utilizing the residual heat of the superheated steam in the processing chamber. It is characterized by comprising. According to the present invention, since the hot air utilizing the residual heat of the superheated steam circulates in the processing chamber by the blower installed in the processing chamber, the drying action by the superheated steam is promoted, and a more efficient drying process is performed. I can do it. In particular, when the warm air blown out from the blower is applied to the object to be processed after the treatment, it is possible to effectively evaporate the moisture, water vapor, and the like attached to and remaining on the object to be processed. Further, due to the circulation of the warm air, a local temperature increase in the processing space can be prevented.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In the description, first, the superheated steam drying apparatus 1 according to the present invention will be described, and then the superheated steam drying method of the present invention will be described while describing the operation mode of this apparatus. In the drying method of the present invention, steam that has been conventionally used exclusively as a humidifying action is sprayed onto an object to be processed W such as foodstuff in a high-temperature superheated state of 100 ° C. or higher, and the surface is still wet after cleaning. The drying of the object W is mainly performed. For this reason, the superheated steam drying device 1 includes, as an example, as shown in FIGS. 1 and 2, a steam generator 2 that generates steam, a superheated steam generator 3 that reheats the generated steam to generate superheated steam, And a processing unit 4 for drying the object W after cleaning with superheated steam.

Here, what can be dried by the present invention are foodstuffs (potatoes such as chicken eggs and potatoes, fruits and the like), packaging materials (retort packs, dairy products such as milk, paper packs such as drinking water, drinking water, etc.). Bottles, bottle caps, sprouts and other packaging bags), containers (side dishes and lunch boxes, etc.),
Various types of food transport containers (such as containers for transporting bread and noodles, etc.), industrial parts (such as washing machines for machined parts, precision parts such as IC boards, and cast products) can be cited. In the embodiment, as an example, as shown in FIGS. In FIG. 2, a device installed before the superheated steam drying device 1 according to the present invention is a washing device A for eggs, and in the illustrated embodiment, the eggs are transported while rotating on a roller conveyor. Yes (about 120 mm is required as the transport distance for one turn of the egg), and an egg washing brush B is attached along the way. Here, the same transport device C (here, a roller conveyor) is used from washing to drying.
Is applied, but it is not always necessary to adopt the same transport mode. Hereinafter, each component of the superheated steam dryer 1 will be described.

First, the steam generator 2 will be described. This is the part that evaporates water to produce water vapor,
Generally, it is possible to obtain steam at an appropriate temperature and pressure by a steam generator (boiler) which can generate steam efficiently at low cost. However, the steam generation unit 2 is not necessarily limited to a boiler generation method. For example, it is possible to obtain water vapor by heating water by electromagnetic induction, a Joule heating device, or the like. In addition, by setting the heating section of each of the various steam generating sections 2 to a negative pressure, steam can be generated more efficiently. The temperature and the like of the generated steam can be controlled by the controller 10 connected to the steam generator 2.

Next, the superheated steam generator 3 will be described.
This further heats the steam generated by the steam generating section 2 (this is referred to as live steam) and reduces the live steam by 100%.
This is a portion having a capability of producing superheated steam in a high temperature state of not less than ° C and about 1000 ° C. Here, as an example, a superheated steam of a desired temperature is obtained by electromagnetic induction heating. For this reason, the superheated steam generation unit 3 includes a non-metallic hollow pipe member 12 and a metal electromagnetic induction heater 1 having a honeycomb structure and the like housed inside the pipe member 12.
3 and a coil 14 wound around the outer periphery of the pipe member 12. Here, the mechanism of generating the superheated steam will be briefly described.
When a high-frequency current is passed through the magnetic field, a magnetic field (lines of magnetic force) is generated. And this eddy current is the electromagnetic induction heater 1
3 generates heat due to friction with metal atoms, and the pipe member 1
The gas, liquid, live steam, or the like passing through 2 is heated to a higher temperature range. The temperature of the superheated steam, etc.
It can be controlled by a controller 15 connected to the coil 14.

Here, the method of generating superheated steam by electromagnetic induction heating has been described. However, taking into account the processing amount, processing speed, processing temperature, running cost, etc., for example, use of Joule heat, LPG or heavy oil It is possible to reheat live steam by a burner that burns the steam.
Specifically, in the method using Joule heat, a metal having a high electric resistance is energized and heated, and live steam is brought into contact with the metal body to generate superheated steam. Also LP
In the method using a burner in which G, heavy oil, or the like is burned, for example, a tube through which live steam passes is heated by the burner to generate superheated steam. Of course, even when these reheating methods are applied, the control method is different, but the temperature and the like of the superheated steam are controlled by the controller 15 connected to the reheating device. Further, in the present specification, the term “S” is used to collectively refer to the raw steam before reheating, the superheated steam after reheating, and the steam that has been dried to a certain low temperature after the object to be processed W has been dried. Things.

Next, the processing section 4 will be described. This is a substantial work site for introducing the superheated steam S and drying the object W after cleaning. In the present embodiment, as an example, the object W to be processed immediately before the drying process is performed is performed. It comprises a temperature sensor 17 for measuring the product temperature, a transfer device 18 for transferring the workpiece W to the processing section 4, and a processing chamber 19 formed in a substantially sealed state. At this time, the superheated steam S is not always introduced into the processing chamber 19, but the transfer device 18 is stopped irregularly (for example, the workpiece W is caught in the middle of the transfer, or a component member of the device is damaged. Therefore, a bypass path that can discharge the superheated steam S to the outside (outside of the processing unit 4) is configured in consideration of the case where the conveyance of the workpiece W is stopped irregularly. Specifically, a path for supplying the superheated steam S from the superheated steam generator 3 to the processing chamber 19 is a drying path 20, and a path for discharging the superheated steam S to the outside from the superheated steam generator 3 is a discharge path 21. A valve, such as an electromagnetic valve, which performs a switching operation at these branch points is referred to as a switching valve 22 (see FIG. 3). Hereinafter, each component of the processing unit 4 will be described in more detail.

The temperature sensor 17 can measure the temperature of the object W in a non-contact state using, for example, heat radiation of the object so as not to stain the object W after cleaning. Preferably, the measured temperature of the object W is used as one parameter for determining the set temperature of the superheated steam S. Incidentally, other parameters for determining the set temperature of the superheated steam S include the transport speed of the workpiece W, the temperature in the processing chamber 19, and the like.
The temperature of the superheated steam S is determined by the control devices such as 0 and 15 (for example, when the processing amount is 30,000 eggs / hour, the processing amount is around 170 ° C., and the processing amount is 30,000 eggs / hour. Around 230 ° C in some cases). The transport device 18 transports the workpiece W from the cleaning device A to the processing chamber 19, and in the present embodiment, is substantially the same as the transport device C (here, a roller conveyor) in the preceding cleaning process. They are the same.

The processing chamber 19 is a substantial processing space in which the superheated steam S is sprayed onto the workpiece W on the transfer device 18 to perform drying. In this embodiment, the loading port of the workpiece W is provided. The opening 23 and the carry-out port 24 are formed in a substantially closed state while being opened. Further, the processing chamber 19 converts the superheated steam S introduced from the drying path 20 into the workpiece W.
And a blower 26 that circulates air, steam S, and the like in the processing chamber 19.

In the present embodiment, the injection port 25 is formed so as to have a wide-angle operation front end so that the superheated steam S can be brought into contact with substantially the entire surface of the workpiece W. That is, the egg, which is the object to be processed W, is transported while rotating, and as described above, the egg rotates once at about 120 mm, so that the tip of the injection port 25 has at least this rotation length. (The superheated steam S can be injected over a length of about 120 mm).

In this embodiment, the object W to be processed is
The two orifices 25 are provided continuously in front and back with respect to the transport direction, the latter one is a regular one that injects the superheated steam S during normal operation, and the one at the near side in the transport direction is This is a spare device for injecting superheated steam S to untreated eggs or the like when the conveying device 18 of the processing target W has an unexpected irregular stop. That is, when the transport device 18 has been stopped irregularly, the preliminary injection of the superheated steam S to the workpiece W is to be performed immediately after the regular injection. Is what you do.

Here, the normal injection port acting during normal operation is 25A, and the preliminary injection port acting during irregular stop is 2A.
5B, the zone (section) in which the superheated steam S is ejected by the regular injection port 25A is referred to as the normal ejection zone ZA, and the zone (section) in which the superheated steam S is ejected by the preliminary injection port 25B. This is a preliminary ejection zone ZB.
Further, the superheated steam S is supplied to the regular injection port 25A or the preliminary injection port 2A.
A valve such as a solenoid valve that switches to 5B is referred to as a switching valve 27 (see FIG. 3).

By supplying the superheated steam S to the unprocessed workpiece W immediately after the normal ejection zone ZA during the irregular stop, even if the transfer device 18 is irregularly stopped, the normal operation is performed. In this case, the steam S is not continuously applied to the workpiece W to which the superheated steam S has been injected, and the thermal deformation of the workpiece W can be prevented. When the irregular stop state is released and the transport device 18 is restarted, the drying process can be performed in consideration of the time (inert time) required for the superheated steam S to rise as specified. The operation mode of the device at the time of irregular stop will be described later in detail. Incidentally, a temperature sensor is provided at the injection port 25, and the temperature of the superheated steam S acting on the workpiece W is sequentially detected, whereby the voltage and frequency of the superheated steam generator 3 are constantly controlled. It is preferable to set a desired temperature.

The blower 26 circulates warm air utilizing the residual heat of the superheated steam S in the processing chamber 19, thereby promoting drying performed in the processing chamber 19. Particularly in the present embodiment, the blower 2
The air blower 26 is installed so that the wind blown out from the workpiece 6 acts on the workpiece W immediately after being exposed to the superheated steam S. , Which effectively evaporates.

Here, in order to circulate the air and the like in the processing chamber 19 more effectively, it is preferable to provide the guide members 28 in the upper and lower parts in the processing chamber 19 as shown in FIG. The guide body 28 guides the air blown from the blower 26 to the bottom of the processing chamber 19, and guides the air or the like located in the upper part of the processing chamber 19 to the suction port of the blower 26. Is what is done. The guide body 28 is located above the injection port 25 as shown in FIG.
Since it is provided below the processing target W, it also has a function of shielding a main processing portion such as the injection port 25 on which the superheated steam S acts and the processing target W from the circulation path of the warm air. That is, while the guide body 28 promotes the circulation of the warm air in the processing chamber 19, on the other hand, it substantially isolates the substantial main processing portion, and plays a role of appropriately increasing the temperature of the main processing portion. I have.

In this embodiment, the processing section 4 is a closed system in which the processing chamber 19, which is a substantial processing space, is formed in a substantially closed state. However, the processing section 4 is not necessarily required. It is possible to provide an open system in which a boundary with the outside is not particularly provided depending on the properties of W and the like. Specifically, when the object to be processed W is, for example, a metal member after cleaning, there is no need to worry so much about the adverse effect of the heat on the object to be processed W, and post-treatment of the superheated steam S is not required. For this reason, it is not necessary to isolate the processing unit 4 from the outside, and the processing unit 4 is often formed in an open state. Further, even when the object to be processed W is an unfilled paper pack or an empty container or the like which is not filled with a beverage or the like, the drying processing section (processing chamber 19) does not need to be particularly closed.

One example of the superheated steam drying apparatus 1 according to the present invention is configured as described above. Hereinafter, the superheated steam drying method of the present invention will be described substantially while describing the operation mode of this apparatus. . In the description, a case where a chicken egg is applied as the object to be processed W will be described. (1) Cleaning of the Workpiece First, prior to substantial drying, the general workpiece W is to be washed. Here, as shown in FIG. Washed by A. Here, the eggs are washed by the attached brush B while the eggs are being sent by the transport device C such as a roller conveyor. In addition, the chicken eggs were placed on one carrier C in six rows (30,000 to 35,000 eggs / hour) or 12 rows (60,000 to 120,000 eggs / hour). It is often conveyed in a state. Note that here, the transport device C of the cleaning device A
Is substantially the same as the transfer device 18 of the post-heat treatment drying apparatus 1, but may be different.

(2) Preparation of supply of superheated steam With such a cleaning operation, the superheated steam drying apparatus 1
The superheated steam S to be sprayed on the workpiece W is prepared. More specifically, live steam S (steam) of about 100 ° C. is generated in the steam generating section 2, and the steam is reheated in the superheated steam generating section 3 to be superheated steam S of 100 ° C. or more.
Further, here, the switching valve 22 is set so as to introduce the superheated steam S from the superheated steam generator 3 into the processing chamber 19, and the switching valve 27 is set so that the superheated steam S is injected from the regular injection port 25A ( FIG. 3A). Note that such preparation work of the superheated steam S may be performed at least before the eggs (after the completion of the temperature detection) are sent to the regular ejection zone ZA of the processing unit 4, and may be performed, for example, prior to the cleaning step. .

(3) Temperature Measurement of Eggs As shown in FIG. 2, the washed eggs are transported to the processing section 4 after the temperature of the eggs have been measured by the temperature sensor 17 near the entrance 23 of the drying device. You. In addition, it is desirable that the temperature of the chicken eggs be measured in a non-contact state so as not to attach dirt to the washed eggs.

(4) Superheated Steam Injection during Normal Operation (Regular Injection) When the egg being transported enters the regular ejection zone ZA, superheated steam S is injected from the regular injection port 25A toward the egg.
That is, while passing through the lower part of the regular injection port 25A, the egg as the object to be processed W comes into contact with the jetted superheated steam S, and the surface is dried and sterilized. The eggs are transported while rotating on the transport device 18.
At least during the rotation of the egg, the superheated steam S is continuously ejected, and the superheated steam S acts on almost the entire surface of the egg.

By the way, the time during which one egg is in contact with the superheated steam S depends on the transport speed, but it is about 1.5 seconds for a throughput of 30,000 eggs / hour, and a throughput of 60,000 eggs / hour. Is about 0.75 seconds. The set temperature of the superheated steam S is determined by the temperature of the product measured immediately before the treatment, the conveying speed, the temperature in the processing chamber 19, and the like as parameters.
It is set at about 170 ° C. in the case of the throughput of time, and about 230 ° C. in the case of the throughput of 60,000 eggs / hour. Further, during the drying operation, for example, the temperature of the injection port 25 or the processing chamber 19
It is preferable to detect the internal temperature at all times and keep the dry sterilization conditions constant.

(5) Circulation of Hot Air in the Processing Chamber While the superheated steam S is supplied to the processing chamber 19 and the eggs are being dried, the blower 26 installed in the processing chamber 19 is always operated. The hot air utilizing the residual heat of the superheated steam S is circulated in the processing chamber 19. This hot air circulation effectively prevents local temperature rise inside the processing chamber 19, prevents heat denaturation of the eggs, and superheated steam S of the eggs.
The drying time is shortened, and efficient drying is further promoted. In particular, in the present embodiment, FIG.
As shown in (2), the air blower 26 is installed near the carry-out port 24, which is the outlet of the processing chamber 19, so as to blow warm air to the eggs immediately after the superheated steam S is brought into contact therewith. The water droplets and water vapor that evaporate are almost completely evaporated. Incidentally, the drying promotion effect of the warm air circulation will be described later in detail together with the test data of the present applicant.

In order to circulate the warm air more effectively, in the present embodiment, for example, as shown in FIGS. As a result, the warm air discharged from the blower 26 is directed from the upper portion of the carry-out port 24 to the lower side of the egg being processed and from there to bypass the carry-in port 23 of the processing chamber 19 and to the upper side of the injection port 25. , And from there, it is circulated and guided toward the suction port of the blower 26. In addition, the guide body 28 is provided in a so-called surrounding state as if it shields a main processing portion such as the egg and the injection port 25 to which the superheated steam S is sprayed. For this reason, the temperature of the main processing portion tends to be somewhat higher than that of the surrounding hot air circulation portion, and this can further promote the drying of the processing target W. Of course, since the inside of the processing chamber 19 circulates the warm air as described above, the temperature of the main processing portion does not become excessively high. Then, the chicken eggs, for which almost all surfaces have been dried, are sent out from the carry-out port 24 of the processing chamber 19, and are subjected to an appropriate product form such as packing.

The drying mode during the normal operation takes the above-described form. The following describes the drying mode when the egg transport device 18 unexpectedly stops due to a sudden failure or the like. I do. In the present embodiment, when the transfer device 18 has been stopped irregularly, the normal injection of the superheated steam S is performed for a while, and then the preliminary injection is switched to the preliminary injection. Further, at this time, if the irregular stop is still ongoing, the superheated steam S is released to the outside, and the steps will be described below. [1] Injection in the regular ejection zone When the conveying device 18 unexpectedly stops irregularly, the regular ejection from the regular ejection port 25A is performed for an appropriate time.
continue. That is, after the superheated steam S sufficient for drying is injected from the regular injection port 25A to the chicken eggs that have been stopped in the normal ejection zone ZA, the injection from the normal injection port 25A is stopped.

[2] Switching to Preliminary Injection The superheated steam S is switched to be supplied from the preliminary injection port 25B almost at the same time as the supply from the normal injection port 25A is stopped. Specifically, this operation is performed by setting the switching valve 27, and switches the path of the superheated steam S supplied from the superheated steam generator to the regular injection port 25A to the preliminary injection port 25B. (See FIG. 3B). By such an operation, the eggs remaining stopped in the preliminary ejection zone ZB come into contact with the superheated steam S, and the surface is dried. In addition, such a preliminary injection is performed for an appropriate time (while the surface of the egg located in the preliminary ejection zone ZB is sufficiently dried,
(This is a degree that does not cause heat denaturation in chicken eggs). In addition, at the time of irregular stop, drying the eggs located in the preliminary spout zone ZB immediately before the regular spout zone ZA is canceled by the irregular stop.
This is because the time (inert time) until the superheated steam S rises as prescribed when the transfer line is restarted is considered.

[3] External Release of Superheated Steam At the stage when the pre-injection of superheated steam S is completed, if the irregular stop is continued, the superheated steam S is supplied to the switching valve 22.
Is switched to the discharge path 21 and is discharged outside (see FIG. 3C). By releasing the superheated steam S to the outside at the time of irregular stop in this way, the temperature inside the processing chamber 19 is prevented from rising, and the heat denaturation of the eggs is effectively prevented. When the irregular stop is further continued, for example, the supply of the superheated steam S is shut off by the switching valve 22 and the power supply (voltage, current, etc.) of the superheated steam generation unit 3 is dropped to the standby mode, and energy saving measures are taken. And safety measures can be taken at the same time.

[4] Releasing Irregular Stop (Restart) When releasing the irregular stop and returning the transport line, the superheated steam S is supplied from the regular injection port 25A with the restart of the transport device 18. I do. Specifically, the switching valve 22
Is switched from the superheated steam generator 3 to the processing chamber 19, and the setting of the switching valve 27 is switched (this is unnecessary if the switching is performed at the stage when the preliminary injection is completed). Superheated steam S is supplied to regular injection port 25A
(See FIG. 3A). Even if the setting of the switching valves 22 and 27 is changed in this way, the superheated steam S still requires some time (inertia time) to rise as prescribed. That is, even if the line is returned, there is a possibility that the injection of the superheated steam S may be insufficient. Therefore, in this embodiment, the drying of the eggs located in the preliminary ejection zone ZB is performed at the time of irregular stop. is there.

After the restart, the regular injection is performed after the egg that was located immediately before the preliminary ejection zone ZB at the time of the irregular stop reaches the regular ejection zone ZA (for example, in FIG. 3A, The object to be processed W at the position of P1 becomes P
2). Of course, if the egg located before the preliminary ejection zone ZB at the time of irregular stop is transported to the regular ejection zone ZA during the above-mentioned inertial time, the superheated steam S that has risen as prescribed after the inertial time is converted into the egg as it is. If it works, regular drying can be performed. However, in actuality, the transport speed varies depending on the amount of processed eggs and the like. Therefore, here, at least the eggs located before the preliminary ejection zone ZB at the time of irregular stop are replaced with the regular ejection zones ZA.
Is set so that the superheated steam S rises sufficiently during the transfer (the inertia time is suppressed to the required transfer time or less), and at the appropriate timing, the sufficiently heated superheated steam S is supplied from the regular injection port 25A. Things.

Hereinafter, the effect of the superheated steam drying method of the present invention will be described in detail based on test data performed by the present applicant. In this test, drying with hot air at about 40 ° C (conventional method), drying with live steam (general steam) at about 95 ° C, drying with superheated steam (high-temperature steam) at about 170 ° C, It shows the drying in which hot air was blown together with superheated steam of about ° C, and each compares about the case of processing about 30,000 eggs per hour.

First, FIG. 7 shows comparison data of the drying effect. The raw egg pre-cooled to a temperature of about 10 ° C., which often causes insufficient drying results in the conventional wind drying (before the treatment is performed) Hen eggs) and a raw egg having an average product temperature of about 25 ° C. were used, and the drying results of both were also compared. The results clearly show that drying with superheated steam, especially drying with superheated steam, as well as the drying effect when hot air is blown, is even more excellent. However, it became clear that the drying effect was worse than that of wind drying. This is probably because the amount of heat for evaporating the water on the surface of the egg is insufficient.

FIG. 8 shows comparative data of the bactericidal effect, and shows the results of a wiping test using a raw egg having an average product temperature of about 25 ° C. From this result, it was confirmed that the sterilization effect was excellent when drying with superheated steam was performed (regardless of the combined use of hot air blowing). Specifically, it was found that drying with superheated steam can reduce the number of general bacteria to about 1/100 compared to conventional wind-drying. Especially, in the case of E. coli, the value is 0, so E. coli is almost completely killed. It turned out that it could be done.

Further, FIG. 9 shows comparison data of the freshness preserving effect, in which a raw egg having an average product temperature of about 25 ° C. was used, and after the drying treatment, whether or not the chicken egg had a decrease in freshness was determined. It is shown whether or not. The “how unit” in the table indicates a climax value of egg white (white body), which is a substitute characteristic of chicken egg freshness. The higher this value, the better the freshness. From this result, it was found that there was no decrease in freshness of chicken eggs due to superheated steam, that is, no heat denaturation was observed. From the above results, it was found that the drying method in which the superheated steam was sprayed on the chicken eggs hardly caused heat denaturation of the eggs, and also had an excellent sterilizing effect with the drying. Furthermore, it was found that when hot air blowing was added in addition to the superheated steam injection, the drying effect was particularly excellent, and the chicken eggs could be dried almost completely in a short time.

[0049]

[Other Embodiments] The present invention is based on the above-described embodiment as one basic technical idea, but the following modifications are conceivable. First, the embodiment shown in FIGS. 1 to 3 described above is a mode in which the superheated steam S is injected only from above into the workpiece W. This is due to the configuration in which the egg, which is the object to be processed W, is conveyed while rotating, and the superheated steam S can be brought into contact with almost the entire surface of the object to be processed W even when sprayed from only above. It is a form. Therefore, various injection modes can be adopted according to the shape of the workpiece W, the transport mode, and the like. For example, when the workpiece W packed in the retort pack is the workpiece W, the workpiece W is placed in a flat state. And is mainly conveyed on a flat surface, as an example in FIG.
It is preferable to adopt a mode in which the superheated steam S is injected from both the upper and lower sides of the workpiece W as shown in FIG. In the case of a paper pack (a so-called milk pack) that is washed and dried in an inverted posture, as an example, a form in which the superheated steam S is sprayed from the left and right as a whole can be adopted as shown in FIG.

When superheated steam S is injected into an empty container (packaging material), that is, an unfilled container or the like not yet filled with a beverage or the like to dry the inside thereof,
For example, the forms shown in FIGS. 5A and 5B can be adopted. First, FIG. 5A illustrates a case where the inside of an unfilled paper pack is dried, and FIG. 5B illustrates a case where the inside of a bottle of unfilled drinking water or the like (so-called PET bottle) is dried. Is the case. In such a case, the supply of the superheated steam S to the workpiece W may be performed by one-way injection from the opening side. Specifically, when the workpiece W is transported in an inverted posture as illustrated, the superheated steam S may be injected only from above. However, in this case, in order to more surely dry the container bottom, the superheated steam S is injected while the injection port 25 is inserted from the opening of the container to the vicinity of the bottom, or the injection port 25 is reciprocated several times. Preferably. In this manner, the injection port 25 is reciprocated inside the container (in the case of FIGS. 5A and 5B,
The form in which vertical movement is possible is a particularly effective form in the case of a container having a small diameter and a deep bottom. Of course, in reciprocating the injection port 25, the vertical movement is temporarily stopped at the position where the injection port 25 reaches the bottom dead center (the state closest to the bottom of the container), and the superheated steam S is mainly applied to the bottom of the container. It is possible to inject.

FIG. 5C shows a case where superheated steam S is applied to a bottle cap such as a PET bottle to dry the inside. Here, the inside of the bottle cap is a general term for a part that can directly contact the filled beverage and a part that is screwed into the neck of a plastic bottle or the like. In this case, the bottle cap is
In many cases, the roll is rolled down on the inclined transfer path with the opening almost upright, so that the supply of the superheated steam S can be injected from one direction toward the inside (opening) of the bottle cap (FIG. In the inside, it is sprayed from the side facing the opening of the bottle cap). Also in the case of this bottle cap, similarly to the case of chicken eggs, the injection length of the injection port 25 (regular injection port 25A, preliminary injection port 25B) is formed to be at least longer than the length of one rotation of the bottle cap. Is preferred.

In the embodiment shown in FIGS. 1 to 3, separate injection ports 25 (normal injection ports 25A, 25A) are provided for the workpiece W located in the normal ejection zone ZA and the preliminary ejection zone ZB. The superheated steam S is applied by applying the preliminary injection port 25B).
However, it is not always necessary to separately form the injection ports 25, and they can be shared. Specifically, for example, as shown in FIG. 6A, when the injection port 25 is formed in a bendable nozzle shape, and when switching from the normal ejection zone ZA to the preliminary ejection zone ZB, the nozzle angle is mechanically changed. It is possible to In addition, as shown in FIG. 6B, a diverting plate 29 capable of freely setting the discharge direction of the superheated steam S is formed at the tip end of the injection port 25 to switch from the normal ejection zone ZA to the preliminary ejection zone ZB. It is possible to mechanically change the direction of the deflection plate 29.

[0053]

According to the first or seventh aspect of the present invention, a novel drying method using superheated steam S of 100 ° C. or more is specified as a specific method, compared with a conventional method of wind drying using hot and cold air. It is possible to greatly increase the drying throughput per hour (for example, in the case of chicken eggs, the processing rate of about 30,000 eggs / hour in the conventional wind drying is about 120,000 eggs / hour in the superheated steam drying). Processing is possible). In addition, the object to be processed W can be sterilized together with the drying, and particularly, heat-resistant bacteria resistant to heat can be effectively sterilized.

According to the second or eighth aspect of the present invention, if the transfer device 18 for the object W is irregularly stopped unexpectedly, the superheated steam S is discharged to the normal ejection zone ZA. After the injection, the mode is switched to the injection to the preliminary ejection zone ZB. Therefore, the object W stopped in the normal ejection zone ZA is not continuously exposed to the superheated steam S, and the object W can be prevented from being thermally denatured. Further, since the pre-injection to the preliminary ejection zone ZB is performed, even if the superheated steam S does not rise as specified when the line is restored, the workpiece W having poor drying does not occur. That is, the workpiece W stopped immediately before the preliminary ejection zone ZB at the time of the irregular stop can supply a sufficient superheated steam S before reaching the normal ejection zone ZA at the time of returning to the line. This can prevent the object W from being insufficiently dried.

Furthermore, according to the third or ninth aspect of the present invention, even if the superheated steam S is jetted out of the preliminary jetting zone ZB for a predetermined time, if the irregular stop is continued, the switching valve 22 is used. By changing the drying path 20 to the discharge path 21, the superheated steam S is released to the outside of the processing unit 4, and thus, thermal denaturation of the processing target W can be effectively avoided. If the irregular stop is further prolonged, the supply path of the superheated steam S is shut off by the switching valve 22 and the power supply of the superheated steam generation unit 3 is dropped to the standby mode, so that energy saving measures and safety measures can be taken at once. Can be applied.

According to the fourth aspect of the present invention, the processing section 4 includes a closed system for forming the processing chamber 19 in a substantially closed state,
In particular, since a configuration with an open system that does not form a boundary with the outside can be appropriately adopted, various forms are adopted depending on the properties of the workpiece W and whether or not post-treatment of the superheated steam S is necessary. obtain.

According to the fifth or tenth aspect of the present invention, since the object to be processed W is dried in the substantially closed processing chamber 19, the ambient temperature suitable for drying can be relatively easily set. it can. Further, since the processing chamber 19 is a substantially closed space, the residual heat of the processing target W can be almost completely evaporated by using the residual heat of the superheated steam S.

According to the invention of claim 6 or 11, since the warm air utilizing the residual heat of the superheated steam S is circulated in the closed processing chamber 19, the drying action by the superheated steam S is promoted. High-speed drying can be performed. In particular, since the warm air blown out from the blower 26 is applied to the processed object W after the processing, it is possible to effectively evaporate moisture, water vapor, and the like attached to and remaining on the object W. Processing chamber 1
Since the air in the chamber 9 is appropriately circulated, a local temperature increase in the processing chamber 19 can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a superheated steam drying apparatus of the present invention.

FIG. 2 is a side view showing a state in which the superheated steam drying apparatus of the present invention is combined with a chicken egg washing apparatus.

FIG. 3 is an explanatory view showing stepwise an operation mode when the superheated steam drying apparatus of the present invention is irregularly stopped.

FIG. 4 is an explanatory diagram showing another supply form of superheated steam that can be taken in accordance with the shape of the object to be processed, the transfer form, and the like.

FIG. 5 is an explanatory diagram showing another supply form of superheated steam that can be taken in accordance with the shape of the object to be processed, the transfer form, and the like.

FIG. 6 is an explanatory diagram showing another embodiment in which supply of superheated steam is switched from a normal ejection zone to a preliminary ejection zone.

FIG. 7 is a table comparing superheated steam drying and mainly conventional wind drying for the drying effect.

FIG. 8 is a table comparing superheated steam drying and mainly conventional wind drying with respect to the bactericidal effect.

FIG. 9 is a table comparing superheated steam drying and mainly conventional wind drying with respect to freshness (thermal denaturation).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Superheated steam drying device 2 Steam generation part 3 Superheated steam generation part 4 Processing part 10 Controller 12 Pipe member 13 Electromagnetic induction superheater 14 Coil 15 Controller 17 Temperature sensor 18 Transfer device 19 Processing room 20 Drying path 21 Drainage path 22 Switching valve 23 Inlet 24 Outlet 25 Injection port 25A Regular injection port 25B Pre-injection port 26 Blower 27 Switching valve 28 Guide body 29 Deflector A Cleaning device B Brush C Transport device S Steam W Target object P1 Position of target object P2 Position of object to be processed ZA Regular ejection zone ZB Preliminary ejection zone

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // A23L 1/32 A23L 1/32 Z 3/40 3/40 B F term (reference) 3L113 AA02 AB01 AC05 AC31 AC45 AC46 AC48 AC67 BA39 CA04 CA05 CB08 DA06 DA10 4B022 LA05 LA06 LB09 LF04 LR01 LT05 4B042 AC10 AD40 AG07 AH09 AP02 AP17 AT05

Claims (11)

[Claims] 1. An overheating method in which superheated steam in a high temperature state of 100 ° C. or more is brought into almost contact with an object to be processed, and at least a surface liquid component of the object to be processed is evaporated and removed. Steam drying method. 2. The object to be processed is sequentially transported to a substantial processing section to which superheated steam is supplied. In performing a normal drying operation in the processing section,
Supply superheated steam only to the workpieces located in the regular ejection zone, and if the transport of the workpiece suddenly stops irregularly during the operation, the regular injection in the regular ejection zone at the appropriate time ends. 2. The superheated steam according to claim 1, wherein the superheated steam is jetted for a predetermined time to an unprocessed object positioned in a preliminary ejection zone immediately before the normal ejection zone. Drying method. 3. Even if the preliminary injection for an appropriate time in the preliminary injection zone, which is performed at the time of the irregular stop, is terminated, if the irregular stop state is continued, the superheated steam to the processing unit is provided. 3. The method according to claim 2, wherein the supply is shut off, and the superheated steam is discharged outside the processing section.
The superheated steam drying method described. 4. A processing section for drying a processing object by applying superheated steam to the processing object is selected and formed as appropriate in a substantially closed state or an open state. Superheated steam drying method. 5. When the processing section is formed in a closed state, the processing section has a processing chamber in a substantially closed atmosphere, and the contact supply of superheated steam to the object to be processed is performed in the processing chamber. The superheated steam drying method according to claim 2, 3 or 4, wherein: 6. A blower is provided in the processing chamber formed in a substantially closed state, and warm air using residual heat of superheated steam is circulated in the processing chamber, and hot air blown out from the blower is provided. 6. The method of drying a superheated steam according to claim 5, wherein the object is blown onto the object after contact with the superheated steam. 7. A steam generating section for generating steam, a superheated steam generating section for further heating the generated steam to a high temperature state of 100 ° C. or more, and introducing the superheated steam generated in the superheated steam generating section. A treatment unit for bringing superheated steam into contact with substantially the entire surface of the object to be processed, wherein at least a surface liquid component of the object to be processed is evaporated and removed. 8. A processing device, comprising: a transport device for sequentially transporting an object to be processed; a normal injection port for blowing superheated steam only to a target object located in a normal ejection zone on the transport device; It has a preliminary injection port that sprays superheated steam only to the target object located on the front side.In normal drying work, superheated steam is injected from the normal injection port, and only the target object located in the normal ejection zone is If the transport of the object to be processed suddenly stops irregularly during the drying operation, the regular injection for an appropriate time is terminated, then the superheated steam is injected from the preliminary injection port, and the normal injection is performed. 8. The superheated steam drying apparatus according to claim 7, wherein an object to be processed located immediately before the zone is processed. 9. The processing section has a drying path for supplying superheated steam from the superheated steam generation section to a substantial processing space, and a discharge path for discharging superheated steam from the superheated steam generation section to the outside of the processing space. Even if the pre-injection to the object located in the pre-injection zone is completed, if the irregular stop state is continued, the path of the superheated steam is switched from the drying path to the discharge path. The superheated steam drying apparatus according to claim 8, wherein the superheated steam is discharged to the outside of the processing space. 10. A processing chamber in the processing section is a substantially closed processing chamber, in which contact supply of superheated steam to a processing object is performed in the processing chamber. 10. The superheated steam dryer according to 8 or 9. 11. The superheated steam drying apparatus according to claim 10, wherein the closed processing chamber includes a blower for circulating hot air utilizing the residual heat of the superheated steam in the processing chamber.