JP4689871B2 - Superheated steam drying method and superheated steam dryer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention includes ingredients (egg eggs, potatoes, fruit, etc.), packaging materials (retort packs, dairy products such as milk, paper packs such as drinking water, bottles and bottle caps for drinking water, packaging bags such as sprouts Etc.), containers (such as side dishes and bento containers), food transport containers (containers for carrying bread, noodles, etc.), industrial parts (machine parts after washing, precision parts such as IC substrates, casting products, etc.) ) And the like, and in particular, a novel drying method and drying apparatus in which a superheated steam of 100 ° C. or higher is brought into contact with these objects to be dried. It is related to.
BACKGROUND OF THE INVENTION
[0002]
  For example, food, containers, packaging materials, etc. have water drops (droplets) adhering to the surface of the object to be treated such as food after washing. Therefore, the object to be processed after washing is usually subjected to a process for removing the surface moisture.
  As such a water removal treatment method, an appropriate method according to the properties of the object to be treated, such as supply of hot / cold air for drying, centrifugal dehydration, natural standing for a certain period of time, and wiping, is appropriately selected. In particular, wind drying, which blows warm air or cold air, is often applied to drying foods and the like. Specifically, the air is compressed with a large-capacity blower and sprayed onto the food or the like with a nozzle, and the surface moisture is blown away, or dry air heated with an electric heater or the like is sprayed onto the food or the like. In addition, such a drying process has a bactericidal effect which kills the miscellaneous bacteria which adhere to the surfaces, such as a foodstuff, and are not easy to dry. The food from which the moisture on the surface has been removed is subjected to, for example, the next package operation, etc., and proceeds to a processing step into a product form.
[0003]
  By the way, also in such drying and processing (package processing, etc.), mass production, that is, efficiency of drying work (shortening of drying time) and speeding up of food processing are being promoted due to market prices. . However, in the conventional wind drying in which mainly hot and cold air is blown, it is difficult to follow the previous stage of drying at a higher processing speed. For example, in the case of chicken eggs, the conventional processing amount was about 30,000 eggs per hour, but in recent years, a processing amount of about 120,000 eggs per hour is required, and the packing operation itself is almost the same. Although it was possible to cope with it, the previous drying operation could not catch up, and in some cases, the occurrence of mold and the propagation of various bacteria could be caused due to poor drying. Such a situation is a similar problem in foods, containers and packaging materials other than eggs.
[0004]
  Of course, in the drying method of blowing warm air to the ingredients, for example, if the temperature of the supply air is increased and the amount of the air is increased, the drying process can be performed in a short time, but particularly when the object to be treated is an ingredient. However, there is a case where the food material is thermally denatured by hot hot air, and there is a limit to the method of increasing the hot air temperature and the air volume.
  In addition, it is possible to increase the amount of drying processing (absolute amount) by adding only a drying device to the packing processing device, but conventionally, a series of operations from drying to packing is the same transport. It was difficult to adopt at the factory where the line was used. Furthermore, the form of increasing only the drying device requires a larger installation space and unavoidably increases the equipment cost, so an increase in cost is inevitable and it cannot be said that it is a fundamental solution that can achieve the efficiency of drying. It was.
[0005]
  For this reason, it is conceivable to introduce an ultraviolet sterilizer as a drying device. However, there is a drawback that the equipment cost is greatly increased, and it has not been a form that can be introduced in any factory.
  Recently, the problem of food poisoning of heat-resistant bacteria (bacteria that require a temperature of about 130 ° C for sterilization) has been widely taken up, and there is a need for a drying method that not only shortens the drying time but also enables effective sterilization. It was done.
[0006]
[Technical issues for which development was attempted]
  The present invention has been made in view of such a background, and in the conventional technical common sense, it is not linked to the drying action, but rather focuses on the steam used for the humidifying action. It is an attempt to develop a novel drying method that allows efficient drying by using it as a high-temperature overheated state of 100 ° C. or higher.
[0007]
[Means for Solving the Problems]
  That is, the superheated steam drying method according to claim 1 comprises:
  A superheated steam in a high temperature state of 100 ° C. or higher is brought into contact with the entire surface of the object to be processed, and at least the liquid component on the surface of the object to be processed is removed by evaporation.A drying method,
  The object to be processed is sequentially conveyed to a substantial processing unit to which superheated steam is supplied,  In addition, when performing a normal drying operation in the processing unit, the superheated steam is supplied only to the target object located in the normal ejection zone,
  If the workpiece is unexpectedly irregularly stopped during work,
  After normal injection for an appropriate time in the normal ejection zone is completed, superheated steam is jetted for a certain period of time to the untreated object located in the preliminary ejection zone immediately before the regular ejection zone.It is characterized by that.
  According to the present invention, the superheated steam of 100 ° C. or more is sprayed onto the object to be dried, so that the processing amount can be significantly increased as compared with the wind drying performed by blowing warm / cold air. Further, along with drying, the surface of the object to be treated can be sterilized, and particularly heat-resistant bacteria can be effectively killed.
  AlsoIn the case where the conveyance of the object to be processed is irregularly stopped, after the supply of superheated steam in the regular ejection zone is finished, the next process (regular injection) was supposed to be performed. Since superheated steam is supplied to the object to be processed positioned in the preliminary ejection zone, the object to be processed positioned in the normal ejection zone is not overheated even when the transport device stops suddenly. Such pre-injection is particularly effective in the case where some time (inertial time) is required for the superheated steam to reach the specified state when the irregular stop is released and the line is restarted. It becomes a method.
[0008]
  Further claims2The superheated steam drying method according to claim1In addition to the requirements listed,
  Even when the preliminary injection for an appropriate time in the preliminary ejection zone, which is performed at the time of the irregular stop, is terminated, if the irregular stop state continues, the supply of superheated steam to the processing unit is shut off, It is characterized in that superheated steam is discharged outside the processing section.
  According to the present invention, when the irregularly stopped state continues even after the injection of the superheated steam in the preliminary ejection zone is completed, the superheated steam is released to the outside (outside of the processing unit). Can be effectively prevented.
[0009]
  And claims3The superheated steam drying method according to claim1 or 2In addition to the requirements listed,
  The processing section 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 sealed state or an open state.
  According to the present invention, since the processing unit can adopt either a closed system or an open system, various forms can be adopted depending on the properties of the object to be processed.
[0010]
  And claims4The superheated steam drying method according to claim1, 2 or 3In addition to the requirements listed,
  When the processing unit is formed in a hermetically sealed state, the processing unit has a processing chamber with a substantially sealed atmosphere, and the superheated steam is supplied to the object to be processed in the processing chamber. Is.
  According to this invention, since the object to be processed is dried in a substantially sealed processing space, it is easy to form an atmospheric temperature suitable for drying. Moreover, in this invention, superheated steam is injected and it drys, and scattering of the overheated steam to the exterior can be prevented almost completely.
[0011]
  And claims5The superheated steam drying method according to claim4In addition to the requirements listed,
  The processing chamber formed in the substantially hermetically sealed state is provided with a blower, and circulates warm air using the residual heat of the superheated steam in the treatment chamber, and the hot air blown from the blower is referred to as superheated steam. It is characterized by spraying on the object to be processed after contact.
  According to this invention, since the warm air is circulated in the closed processing space using the residual heat of the superheated steam, the drying action by the superheated steam is promoted, and drying at a higher speed can be performed. In particular, since the warm air blown from the blower is applied to the processed object, the water adhering to and remaining on the processed object can be effectively removed. In addition, since the air in the processing space is appropriately stirred, a local temperature rise in the processing space can be effectively prevented.
[0012]
  And claims6The superheated steam dryer described is
  A steam generator for generating water vapor;
  Further heating the generated steam to a high temperature state of 100 ° C or higher;
  Introducing the superheated steam generated in the superheated steam generation section, comprising a processing section for bringing the superheated steam into contact with almost the entire surface of the workpiece,
  At least the liquid component on the surface of the workpiece was removed by evaporationA drying device,
  The processing section includes a transport device that sequentially transports the object to be processed,
  A regular injection port for blowing superheated steam only to the object to be processed located in the regular ejection zone on the transport device;
  A pre-injection port that blows superheated steam only to the object to be processed located immediately in front of the normal ejection zone,
  In a normal drying operation, superheated steam is injected from the normal injection port so that only the target object located in the normal injection zone is processed.
  If the transport of the workpiece suddenly stops during the drying operation, after the regular injection for an appropriate period of time is completed, superheated steam is injected from the preliminary injection port and immediately before the normal injection zone. Processed the object to be positionedIt is characterized by this.
  According to the present invention, the superheated steam at 100 ° C. or higher is brought into contact with the object to be dried, so that high-speed drying is possible compared with conventional wind drying by hot / cold air blowing, and the processing amount is markedly increased. Can be increased. For example, in the case of chicken eggs, the processing amount of about 30,000 eggs / hour in the conventional wind drying can be processed at about 120,000 eggs / hour in the superheated steam drying of the present invention. In addition, it is possible to sterilize the object to be treated as it is dried, and heat-resistant bacteria that have been difficult to kill, especially in the case of wind drying, can be effectively killed by this drying technique using superheated steam.
  AlsoIf the transport of the object to be processed suddenly stops irregularly, after the injection of superheated steam for a certain period of time in the regular ejection zone ends, the superheated steam enters the preliminary ejection zone immediately before the regular ejection zone in the transportation direction. Therefore, when the transport device is stopped, the object to be processed positioned in the normal ejection zone is not heated too much. Note that 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 superheated steam is insufficiently sprayed for a while.
[0013]
  And claims7The superheated steam drying apparatus according to claim6In addition to the requirements listed,
  The processing unit has a drying path for supplying superheated steam to the substantial processing space from the superheated steam generating unit, and a discharge path for releasing superheated steam from the superheated steam generating unit to the outside of the processing space,
  Even if the preliminary injection to the object to be processed located in the preliminary ejection zone is completed, if the irregular stopped state continues, the superheated steam path is switched from the drying path to the discharge path, and the superheated steam is discharged. It is characterized by being discharged to the outside of the processing space.
  According to the present invention, when the irregular heating continues even after the injection of the superheated steam in the preliminary jetting zone is completed, the superheated steam is discharged from the drying path to the discharge path. While preventing the rise effectively, thermal denaturation of the object to be treated can be avoided. If the irregular stop is prolonged, the superheated steam supply path is shut off with a solenoid valve, etc., and the voltage and current of the superheated steam generator are reduced to the standby mode. Can be applied at once.
[0014]
  And claims8The superheated steam drying apparatus according to claim6 or 7In addition to the requirements listed,
  The substantial processing space in the processing unit is a substantially sealed processing chamber, and the superheated steam is contacted and supplied to the object to be processed in the processing chamber.
  According to the present invention, since the object to be processed is dried in a processing chamber formed in a substantially sealed state, it is easy to form an atmospheric temperature (warm state) suitable for drying. Moreover, in this invention, superheated steam is sprayed on a to-be-processed object, and it dries, and scattering of the superheated steam to the exterior can be prevented almost completely by a processing chamber.
[0015]
  And claims9The superheated steam drying apparatus according to claim8In addition to the requirements listed,
  The sealed processing chamber includes a blower that circulates warm air using the residual heat of the superheated steam in the processing chamber.
  According to this invention, since the warm air using the residual heat of the superheated steam circulates in the process chamber by the blower installed in the process chamber, the drying action by the superheated steam is promoted, and a more efficient drying process is performed. Yes. In particular, when warm air blown from the blower is applied to the object to be processed, moisture, water vapor, and the like attached and remaining on the object can be effectively evaporated. Further, a local temperature rise in the processing space can be prevented due to the circulation of warm air.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention will be described below based on 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 explaining the operation mode of the apparatus. The drying method of the present invention is a state in which steam, which has been used exclusively as a humidifying action, is jetted onto a target object W such as food in a high temperature overheated state of 100 ° C. or higher, and the surface is still wet after cleaning. The object W to be processed is mainly dried. For this reason, as shown in FIGS. 1 and 2 as an example, the superheated steam drying apparatus 1 includes a steam generating unit 2 that generates water vapor, a superheated steam generating unit 3 that reheats the generated water vapor to generate superheated steam, And a processing unit 4 that dries the object to be processed W after cleaning with superheated steam.
[0017]
  What can be dried according to the present invention includes ingredients (egg eggs, potatoes and other fruits, fruits), packaging materials (retort packs, milk products such as milk, paper packs such as drinking water, drinking water bottles, etc. Bottle caps, packaging bags such as bean sprouts), containers (containers for side dishes and lunch boxes), food transport containers (containers for carrying bread, noodles, etc.), industrial parts (washing machines for machined parts, IC bases) In this embodiment, as shown by way of example in FIG. 1 to FIG. 1, a case where a chicken egg is used as a workpiece W is shown. In FIG. 2, the one installed in the front stage of the superheated steam drying apparatus 1 according to the present invention is the egg washing apparatus A. In the illustrated embodiment, the egg is conveyed while rotating on a roller conveyor. Yes (about 120 mm is required as the transport distance for one rotation of the egg), and an egg-washing brush B is attached along the way. Here, the same conveying device C (here, a roller conveyor) is applied from washing to drying, but it is not always necessary to adopt the same conveying mode.
  Hereinafter, each component of the superheated steam dryer 1 will be described.
[0018]
  First, the steam generation unit 2 will be described. This is a part that generates water vapor by evaporating water, and generally obtains steam at an appropriate temperature and pressure by a steam generator (boiler) that can generate water vapor efficiently at low cost. Is possible. However, the steam generation unit 2 is not necessarily limited to the generation method using a boiler. For example, water can be obtained by heating water by electromagnetic induction, a Joule heating device, or the like. Moreover, by making the heating part of these various steam generation parts 2 into a negative pressure, water vapor can be generated more efficiently. Note that the temperature or the like of the generated steam can be controlled by the controller 10 connected to the steam generation unit 2.
[0019]
  Next, the superheated steam production | generation part 3 is demonstrated. This has the ability to further heat the steam generated by the steam generating section 2 (this is used as live steam) and convert the live steam into superheated steam in a high temperature state of about 100 ° C. to 1000 ° C. Here, as an example, superheated steam having a desired temperature is obtained by electromagnetic induction heating. For this reason, the superheated steam generator 3 includes a non-metallic hollow pipe member 12, a metal electromagnetic induction heating body 13 having a honeycomb structure and the like housed in the pipe member 12, and the pipe member 12. And a coil 14 wound around the outer periphery of the coil. Here, the mechanism for generating superheated steam will be schematically described. First, a high-frequency current is passed through the coil 14 to generate a magnetic field (line of magnetic force). When this line of magnetic force passes through the electromagnetic induction heating body 13, an eddy current is generated. . And this eddy current generates heat by friction with the metal atom of the electromagnetic induction heating body 13, and heats the gas, liquid, or live steam passing through the pipe member 12 to a higher temperature range.
  Note that the temperature of the superheated steam and the like can be controlled by the controller 15 connected to the coil 14.
[0020]
  Although the method of generating superheated steam by electromagnetic induction heating has been described here, for example, Joule heat is used or LPG or heavy oil is burned in consideration of the processing amount, processing speed, processing temperature, running cost, etc. The live steam can be reheated by the burner. Specifically, with respect to a technique using Joule heat, a metal having high electrical resistance is energized and heated, and live steam is brought into contact with the metal body to generate superheated steam. In the method using a burner in which LPG, heavy oil, or the like is burned, for example, a pipe 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 or the like of the superheated steam is controlled by the controller 15 connected to the reheating device.
  Further, in this specification, the raw steam before reheating, the superheated steam after reheating, the steam that has been dried to some extent and has become a somewhat low temperature, etc. are collectively referred to as S. Is.
[0021]
  Next, the processing unit 4 will be described. This is a substantial work site for introducing the superheated steam S and drying the processed object W after cleaning. In this embodiment, as an example, the processed object W just before the drying process is performed. The apparatus includes a temperature sensor 17 that measures the product temperature, a transfer device 18 that transfers the workpiece W to the processing unit 4, and a processing chamber 19 that is substantially sealed. At this time, instead of always introducing the superheated steam S into the processing chamber 19, when the transfer device 18 is irregularly stopped (for example, the workpiece W is caught in the middle of transfer, or the components of the device are damaged). In consideration of the case where the conveyance of the workpiece W is irregularly stopped), a bypass path is configured that can release the superheated steam S to the outside (outside the processing unit 4). Specifically, a route for supplying the superheated steam S from the superheated steam generation unit 3 to the processing chamber 19 is a drying route 20, and a route for allowing the superheated steam generation unit 3 to be discharged to the outside is a discharge route 21. A valve such as an electromagnetic valve responsible for switching 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.
[0022]
  The temperature sensor 17 is preferably one that can measure the product temperature of the object to be processed W in a non-contact state using, for example, thermal radiation of an object so as not to contaminate the object to be processed W after cleaning. The measured product temperature of the workpiece 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 conveyance speed of the workpiece W, the temperature in the processing chamber 19, and the like, and these data are taken into a control device such as the controller 10 or 15. The temperature of the superheated steam S is determined (for example, around 170 ° C. when the throughput is 30,000 eggs / hour, and around 230 ° C. when the throughput is 30,000 eggs / hour).
  The transport device 18 transports the workpiece W from the cleaning device A to the processing chamber 19. In the present embodiment, the transport device 18 is substantially the same as the transport device C (here, a roller conveyor) in the preceding cleaning step. Are the same.
[0023]
  The processing chamber 19 is a substantial processing space for injecting the superheated steam S onto the object to be processed W on the transfer device 18 and performing drying. In this embodiment, the processing chamber 19 and the transfer port 23 of the object to be processed W are transported. Although the outlet 24 is opened, it is formed in a substantially hermetically closed state. Further, the processing chamber 19 includes an injection port 25 that blows the superheated steam S introduced from the drying path 20 to the workpiece W, and a blower 26 that circulates the air, steam S, and the like in the processing chamber 19. It is.
[0024]
  In the present embodiment, the ejection tip 25 is formed in a wide-angle shape so that the superheated steam S can be brought into contact with almost the entire surface of the workpiece W. That is, the egg as the object to be processed W is conveyed while being rotated. As described above, the egg is rotated once at about 120 mm, so that the tip of the injection port 25 has at least the rotation length. The superheated steam S can be injected over a length of about 120 mm.
[0025]
  Further, in the present embodiment, two injection ports 25 are provided continuously in the front-rear direction with respect to the conveyance direction of the workpiece W, and the latter one is a normal one that injects the superheated steam S during normal operation. The front side in the transport direction is a preliminary one that injects superheated steam S onto unprocessed eggs and the like when the transport device 18 of the workpiece W unexpectedly stops irregularly. That is, when the conveying device 18 is irregularly stopped, the preliminary injection of the superheated steam S is performed on the workpiece W, which should have been processed (normal injection) immediately after the normal injection. Is what you do.
[0026]
  Here, the normal injection port that operates during normal operation is distinguished from the normal injection port by 25A, and the preliminary injection port that operates during irregular stop is labeled 25B, and the zone (section) in which the superheated steam S is ejected by the normal injection port 25A. Is a normal ejection zone ZA, and a zone (section) in which superheated steam S is ejected by the preliminary ejection port 25B is defined as a preliminary ejection zone ZB. Further, a valve such as an electromagnetic valve for switching the superheated steam S to the regular injection port 25A or the preliminary injection port 25B is used as a switching valve 27 (see FIG. 3).
[0027]
  In this way, even when the conveying device 18 is irregularly stopped by supplying the superheated steam S to the unprocessed workpiece W immediately after the regular ejection zone ZA during the irregular stop, The steam S does not continue to act on the workpiece W to which S has been injected, and thermal denaturation of the workpiece W can be prevented. In addition, when the irregularly stopped state is released and the conveying device 18 is restarted, the drying process can be performed in consideration of the time (inertial time) required for the superheated steam S to rise up as specified. The operation mode of the apparatus at the irregular stop will be described in detail later.
  Incidentally, a temperature sensor is provided at the injection port 25 to sequentially detect the temperature of the superheated steam S acting on the workpiece W, thereby constantly controlling the voltage and frequency of the superheated steam generation unit 3, It is preferable to set the desired temperature.
[0028]
  The blower 26 circulates warm air using the remaining heat of the superheated steam S in the processing chamber 19, thereby promoting drying performed in the processing chamber 19. In particular, in the present embodiment, since the blower 26 is installed so that the wind blown from the blower 26 acts on the workpiece W immediately after being exposed to the superheated steam S, the blower 26 is installed on the surface of the workpiece W. Adhering and remaining water, water vapor and the like are effectively evaporated.
[0029]
  Here, in order to circulate the air or the like in the processing chamber 19 more effectively, it is preferable to provide guide bodies 28 at the upper and lower portions in the processing chamber 19 as shown in FIG. The air blown from the blower 26 is guided to the bottom of the processing chamber 19 by the body 28, and the air or the like located in the upper portion of the processing chamber 19 is guided to the suction port of the blower 26. It is. Further, as shown in the figure, the guide body 28 is provided above the ejection port 25 and below the workpiece W, so that the main processing portion such as the ejection port 25 and the workpiece W on which the superheated steam S acts, It is also responsible for shielding from the hot air circulation path. That is, the guide body 28 promotes the warm air circulation in the processing chamber 19, but on the other hand, substantially isolates the substantial main processing portion, and has the effect of appropriately increasing the temperature of the main processing portion. Yes.
[0030]
  In this embodiment, the processing unit 4 is a sealed system in which the processing chamber 19 that is a substantial processing space is formed in a substantially sealed state, that is, a sealed system. Depending on the above, it is possible to make an open system without any particular boundary with the outside. Specifically, when the object to be processed W is, for example, a metal member after cleaning, it is not necessary to worry so much about the adverse effect exerted on the object to be processed W by heat, and the post-treatment of the superheated steam S is not necessary. Therefore, it is not particularly 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 workpiece W is an unfilled paper pack or an empty container that is not filled with a beverage or the like, the drying processing section (processing chamber 19) does not have to be a closed system.
[0031]
  An 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 substantially described while describing the operation mode of the apparatus. In the description, a case where a chicken egg is applied as the workpiece W will be described.
(1) Cleaning the workpiece
  First, prior to substantial drying, a general object to be processed W is cleaned. Here, as shown in FIG. 2, the egg that is the object to be processed W is cleaned by the cleaning device A. Here, the eggs are cleaned with the attached brush B while being fed by a conveying device C such as a roller conveyor. Moreover, 6 rows (a processing amount of 30,000 to 35,000 eggs per hour) or 12 rows (a processing amount of 60,000 to 120,000 eggs per hour) were placed on one transport device C. It is often conveyed in a state. Here, the transport device C of the cleaning device A is substantially the same as the transport device 18 of the subsequent superheat treatment drying device 1, but a separate device may be applied.
[0032]
(2) Preparation for superheated steam supply
  Along with such a cleaning operation, the superheated steam drying apparatus 1 prepares the superheated steam S to be sprayed on the workpiece W. Specifically, the steam generation unit 2 generates a raw steam S (water vapor) of about 100 ° C., and the superheated steam generation unit 3 reheats it to obtain a superheated steam S of 100 ° C. or higher. Further, here, the switching valve 22 is set so as to introduce the superheated steam S from the superheated steam generation unit 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 ( (See FIG. 3 (a)). Note that such a preparatory work for the superheated steam S may be performed at least before the eggs (after completion of the temperature detection) are sent to the normal ejection zone ZA of the processing unit 4, and may be performed, for example, prior to the cleaning process. .
[0033]
(3) Chicken egg temperature measurement
  As shown in FIG. 2, the washed eggs are transported to the processing unit 4 after the product temperature is measured by the temperature sensor 17 in the vicinity of the entrance 23 of the drying apparatus. In addition, it is desirable to measure the temperature of the egg in a non-contact state so as not to allow dirt to adhere to the cleaned egg.
[0034]
(4) Superheated steam ejection during normal operation (regular injection)
  When the egg being transported enters the regular ejection zone ZA, the superheated steam S is ejected from the regular ejection port 25A toward the egg. That is, the egg that is the object to be processed W comes into contact with the jetted superheated steam S while passing through the lower portion of the regular jet 25A, and the surface is dried and sterilized. The eggs are transported while rotating on the transport device 18, and the injection port 25 continues to spout the superheated steam S for at least one turn of the eggs so that the superheated steam S acts on almost the entire surface of the eggs. Is.
[0035]
  Incidentally, the time for one egg to 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 about 60,000 eggs / hour. It is about 0.75 seconds. The set temperature of the superheated steam S is a parameter such as the product temperature detected immediately before the processing, the conveyance speed or the temperature in the processing chamber 19, and is about 170 ° C. for a processing amount of 30,000 eggs / hour, 6 In the case of a throughput of 10,000 eggs / hour, the temperature is set to about 230 ° C.
  Further, during the drying operation, it is preferable to constantly detect, for example, the temperature of the injection port 25 and the temperature inside the processing chamber 19 to maintain the dry sterilization conditions constant.
[0036]
(5) Hot air circulation in the processing chamber
  Note that while the superheated steam S is supplied to the processing chamber 19 and the eggs are being dried, the air blower 26 installed in the processing chamber 19 is always operated, and warm air using the remaining heat of the superheated steam S is operated. Is circulated in the processing chamber 19. This hot air circulation effectively prevents a local temperature rise inside the processing chamber 19, prevents thermal denaturation of the eggs, shortens the drying time of the eggs with the superheated steam S, and further increases the efficiency of drying. It pushes forward. In particular, in the present embodiment, as shown in FIG. 3A, the air blower 26 warms the egg immediately after contacting the superheated steam S in the vicinity of the outlet 24 that is the outlet of the processing chamber 19. In this way, the water droplets and water vapor remaining on the eggs are evaporated almost completely. Incidentally, the drying promotion effect of hot air circulation will be described in detail later together with the applicant's test data.
[0037]
  In order to circulate the warm air more effectively, in this embodiment, as shown in FIGS. 2 and 3, for example, guide bodies 28 are provided at the upper and lower portions of the processing chamber 19. As a result, the hot air discharged from the blower 26 is directed from the upper part of the carry-out port 24 to the lower side of the egg being processed and from here to the upper side of the injection port 25 by bypassing the carry-in port 23 of the process chamber 19. Circulated and guided from here to the suction port of the blower 26. In addition, the guide body 28 is provided in an enclosed state as if it shields the main processing parts such as the eggs and the injection nozzles 25 to which the superheated steam S is sprayed. For this reason, the main processing portion has a tendency that the temperature is somewhat higher than the surrounding hot air circulation portion, but this can further promote the drying of the workpiece W. Of course, since the inside of the processing chamber 19 circulates warm air as described above, the main processing portion described above does not become excessively hot.
  And the egg which finished drying of almost all surfaces is sent out from the carry-out port 24 of the processing chamber 19, and an appropriate product form such as packing is applied.
[0038]
  The drying mode during normal operation takes the form as described above. Hereinafter, the drying mode when an unexpected irregular stop occurs due to a catastrophic failure or the like will be described. In additionThe present inventionThen, when the conveying device 18 is irregularly stopped, the normal injection of the superheated steam S is performed for a while and then switched to the preliminary injection. Further, at this point, if the irregular stop is still continuing, the superheated steam S is discharged to the outside, and will be described below in each stage.
[1] Injection in regular ejection zone
  When the conveying device 18 unexpectedly stops irregularly, normal injection from the normal injection port 25A is continued for an appropriate time. That is, after the superheated steam S sufficient for drying is injected from the normal injection port 25A to the eggs that have been stopped in the normal injection zone ZA, the injection from the normal injection port 25A is stopped.
[0039]
[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 that has been 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 that have been stopped in the preliminary ejection zone ZB come into contact with the superheated steam S, and the surface is dried. In addition, such preliminary injection is stopped after being performed for an appropriate period of time (the degree that does not cause heat denaturation of eggs while sufficiently drying the surface of the eggs located in the preliminary injection zone ZB), as in the case of the regular injection. It is what
  In addition, when the irregular stop is performed, the egg located in the preliminary ejection zone ZB immediately before the regular ejection zone ZA is dried when the irregular suspension is canceled and the transport line is resumed. This is because the time to stand up (inert time) is taken into account.
[0040]
[3] External release of superheated steam
  When the irregular injection continues at the stage where the preliminary injection of the superheated steam S is completed, the superheated steam S is switched to the discharge path 21 by the switching valve 22 and released to the outside (FIG. 3C). reference). In this way, when irregularly stopped, the superheated steam S is discharged to the outside through the bypass line, thereby preventing the temperature inside the processing chamber 19 from rising and effectively preventing the heat denaturation of the eggs.
  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 switched to the standby mode to save energy. And safety measures can be taken at the same time.
[0041]
[4] Canceling irregular stop (restart)
  When releasing the irregular stop and returning the transfer line, the superheated steam S is supplied from the regular injection port 25 </ b> A as the transfer device 18 is restarted. Specifically, the setting of the switching valve 22 is switched to introduce the superheated steam S from the superheated steam generation unit 3 into the processing chamber 19, and the setting of the switching valve 27 is switched (switching is performed when preliminary injection is completed). If necessary, the superheated steam S is injected from the 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 requires some time (inertial time) to rise as specified. That is, even if the line is restored, the superheated steam S may not be sufficiently injected.The present inventionThen, the drying process of the egg located in the preliminary ejection zone ZB is performed at the time of irregular stop.
[0042]
  In addition, the normal injection after the restart is performed after the egg located immediately before the preliminary ejection zone ZB at the irregular stop reaches the normal ejection zone ZA (as an example, the position of P1 in FIG. 3A). The object W to be processed is transferred to the position P2). Of course, if the egg located before the preliminary ejection zone ZB at the irregular stop is transported to the regular ejection zone ZA during the inertia time, the superheated steam S that has risen as prescribed after the inertia time will be used as it is. Regular drying can be performed if it is made to act. However, since the conveyance speed actually varies depending on the processing amount of the egg, etc., at least the egg located before the preliminary ejection zone ZB when being irregularly stopped is overheated while being transported to the regular ejection zone ZA. The steam S is set to rise sufficiently (the initial time is kept below the required conveyance time), and the superheated steam S that has risen sufficiently is supplied from the regular injection port 25A at an appropriate timing.
[0043]
  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, hot air drying 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., about 170 It shows about the drying which carried out the warm air blowing with the superheated steam of about ° C, and compares the case where about 30,000 eggs are processed per hour.
[0044]
  First, what is shown in FIG. 7 is comparison data of drying effects, and raw eggs that have been pre-cooled to a product temperature of about 10 ° C. that often produces insufficient drying results in conventional wind drying (chicken eggs before being processed) And the raw material egg with an average product temperature of about 25 ° C. was used, and the drying results of both were also compared.
  From this result, it is clear that the drying effect when heated with hot air in addition to drying with superheated steam, especially with superheated steam, is much better. It became clear that the drying effect was worse than wind drying. This is probably because there is not enough heat to evaporate the moisture on the surface of the eggs.
[0045]
  Further, what is shown in FIG. 8 is comparison data of the bactericidal effect, and shows the result of wiping inspection using raw eggs having an average product temperature of about 25 ° C. From this result, it was confirmed that the bactericidal effect was excellent when drying with superheated steam was performed (regardless of the combination of warm air blowing). Specifically, it can be seen that drying with superheated steam can reduce the number of general bacteria to about 1/100 compared to conventional wind drying. Especially in E. coli, the value is 0, so E. coli is almost completely killed. It has been found that it can be made.
[0046]
  Furthermore, what is shown in FIG. 9 is comparison data of the freshness keeping effect, and shows whether or not the eggs have undergone a decrease in freshness after using a raw egg having an average product temperature of about 25 ° C. It is a thing. In addition, the how unit in a table | surface shows the swell value of the egg white (white) which is a substitute characteristic of a chicken egg freshness, and has shown that the freshness is so good that this value is high. From this result, it was found that there was no decrease in the freshness of eggs by overheated steam, that is, no heat denaturation.
  From the above results, it was found that the drying method in which superheated steam is sprayed on chicken eggs hardly causes thermal denaturation of chicken eggs, and is excellent in sterilizing effect with drying. Furthermore, in addition to superheated steam injection, it has been found that when accompanied by warm air blowing, the drying effect is particularly excellent, and eggs can be dried almost completely in a short time.
[0047]
[Other embodiments]
  The present invention is based on the embodiment described above as one basic technical idea, but the following modifications can be considered. First, the embodiment shown in FIGS. 1 to 3 is a mode in which the superheated steam S is jetted onto the workpiece W only from above. This is because the egg that is the object to be treated W is conveyed while rotating, and it can be taken because the superheated steam S can be brought into contact with almost the entire surface of the object to be treated W even if it is sprayed only from above. It is a form. Therefore, various injection forms can be adopted according to the shape of the object to be processed W, the conveying form, and the like. For example, when the object to be processed W is packed in a retort pack, it is placed in a flat state. Since it is mainly transported on a flat surface, it is preferable to take a form in which superheated steam S is injected from both the upper and lower sides of the workpiece W as an example, as shown in FIG. Moreover, in the case of what is washed and dried in an inverted posture such as a paper pack (so-called milk pack) or the like, as an example, as shown in FIG.
[0048]
  Further, when the superheated steam S is sprayed on an empty container (packaging material), that is, an unfilled container or the like that has not yet been filled with a beverage or the like, and the interior thereof is dried, for example, FIG. The form shown in (b) can be taken. First, FIG. 5A shows a case where the inside of an unfilled paper pack is dried, and FIG. 5B shows the inside of an unfilled bottle of drinking water (so-called PET bottle). Is the case. In such a case, the supply of the superheated steam S to the workpiece W may be unidirectional injection from the opening side. Specifically, when the workpiece W is conveyed in an inverted posture as illustrated, the superheated steam S may be injected only from above. However, in this case, in order to dry the container bottom more reliably, for example, the superheated steam S is injected while inserting the injection port 25 from the opening of the container to the vicinity of the bottom, or while reciprocating the injection port 25 several times. It is preferable to make it. The mode in which the injection port 25 can reciprocate inside the container (in the case of FIGS. 5A and 5B) can be moved in this manner, particularly in the case of a container having a narrow diameter and a deep bottom. It is an effective form. Of course, when 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 container bottom), and the superheated steam S is mainly applied to the bottom of the container. It is possible to inject.
[0049]
  Further, FIG. 5C shows a case where the superheated steam S is applied to a bottle cap such as a plastic bottle to dry the inside thereof. Here, the inside of the bottle cap is a general term for a portion that can be in direct contact with a filled beverage and a portion that is screwed into the neck of a plastic bottle or the like. In this case, as shown in the figure, since the bottle cap is often in a mode of rolling down on the inclined transfer path with the opening substantially upright, the superheated steam S is supplied to the inside (opening of the bottle cap). ) In one direction (in the figure, the injection is from the side facing the opening of the bottle cap). In the case of this bottle cap, as in the case of chicken eggs, the injection length of the injection port 25 (regular injection port 25A, preliminary injection port 25B) should be at least longer than the length of one rotation of the bottle cap. Is preferred.
[0050]
  In the embodiment shown in FIGS. 1 to 3, separate injection ports 25 (regular injection ports 25A, preliminary injection ports) are applied to the workpieces W located in the normal injection zone ZA and the preliminary injection zone ZB. Although the superheated steam S is contacted by applying 25B), it is not always necessary to form the injection ports 25 separately, and it is possible to make them common. Specifically, for example, as shown in FIG. 6A, when the injection port 25 is formed into a bendable nozzle shape and the normal injection zone ZA is switched to the preliminary injection zone ZB, the nozzle angle is mechanically changed. Is possible. Further, as shown in FIG. 6 (b), when a diverter plate 29 that can freely set the discharge direction of the superheated steam S is formed at the tip of the injection port 25, the normal injection zone ZA is switched to the preliminary injection zone ZB. Can mechanically change the direction of the deflecting plate 29.
[0051]
【The invention's effect】
  Claim 1 or6According to the described invention, a novel drying method using superheated steam S of 100 ° C. or higher is made concrete, and the amount of drying treatment per unit time is greatly increased as compared with conventional wind drying using hot and cold air. (For example, in the case of hen's egg, the conventional wind-drying processing amount is about 30,000 eggs / hour, but superheated steam drying can process about 120,000 eggs / hour). Moreover, the to-be-processed object W can also be sterilized with drying, and especially the heat-resistant microbes strong against heat can be effectively sterilized.
  Further, when the transport device 18 of the workpiece W unexpectedly stops irregularly, the superheated steam S is switched to the injection to the preliminary ejection zone ZB after the injection to the regular ejection zone ZA. The to-be-processed object W stopped on the regular ejection zone ZA is not excessively exposed to the superheated steam S, and the heat denaturation of the to-be-processed object W can be prevented. Further, since the preliminary ejection to the preliminary ejection zone ZB is performed, even if the superheated steam S does not rise as prescribed when the line is restored, the dry-processed object W is not generated. That is, it is possible to supply a sufficient amount of superheated steam S until the workpiece W that has stopped immediately before the preliminary ejection zone ZB reaches the normal ejection zone ZA when returning to the line. Thus, it is possible to prevent the generation of the object to be processed W that is not sufficiently dried.
[0052]
  Further claims2 or 7According to the described invention, even when the superheated steam S is ejected in the preliminary ejection zone ZB for a certain period of time, when the irregular stop continues, the switching valve 22 changes the drying path 20 to the discharge path 21. Thus, since the superheated steam S is released to the outside of the processing unit 4, thermal denaturation of the workpiece W can be effectively avoided. In addition, when 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 turned off to the standby mode, so that energy saving measures and safety measures can be taken at once. Can be applied.
[0053]
  And claims3According to the described invention, the processing unit 4 can appropriately adopt a configuration of a closed system that forms the processing chamber 19 in a substantially closed state and an open system that does not form a boundary with the outside. Various forms can be adopted depending on the properties and whether post-treatment of the superheated steam S is necessary or not.
[0054]
  And claims4 or 8According to the described invention, the object to be processed W is dried in the substantially sealed processing chamber 19, so that an atmospheric temperature suitable for drying can be relatively easily generated. Further, since the processing chamber 19 is a substantially closed space, the residual heat of the superheated steam S can be used to evaporate the water adhering to and remaining on the workpiece W almost completely.
[0055]
  And claims5 or 9According to the described invention, since the warm air using the remaining heat of the superheated steam S is circulated in the closed processing chamber 19, the drying action by the superheated steam S is promoted, and drying at a higher speed can be performed. In particular, since the warm air blown from the blower 26 is applied to the processed object W after processing, moisture, water vapor, and the like attached and remaining on the processed object W can be effectively evaporated. Moreover, since the air in the processing chamber 19 is circulated appropriately, a local temperature rise 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 dryer according to the present invention.
FIG. 2 is a side view showing a state in which the superheated steam drying device of the present invention is combined with a chicken egg cleaning device.
FIG. 3 is an explanatory view showing stepwise operation modes when the superheated steam drying device of the present invention is irregularly stopped.
FIG. 4 is an explanatory view showing another supply form of superheated steam that can be taken corresponding to 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 corresponding to the shape of the object to be processed, the transfer form, and the like.
FIG. 6 is an explanatory view showing another embodiment for switching the supply of superheated steam from the normal ejection zone to the preliminary ejection zone.
FIG. 7 is a table comparing the drying effect between superheated steam drying and mainly conventional wind drying.
FIG. 8 is a table comparing superheated steam drying and mainly conventional wind drying in terms of sterilization effect.
FIG. 9 is a table comparing superheated steam drying and mainly conventional wind drying in terms of freshness (heat denaturation).
[Explanation of symbols]
  1 Superheated steam dryer
  2 Steam generator
  3 Superheated steam generator
  4 processing section
  10 Controller
  12 Pipe members
  13 Electromagnetic induction superheater
  14 coils
  15 Controller
  17 Temperature sensor
  18 Transport device
  19 treatment room
  20 Drying route
  21 Discharge route
  22 Switching valve
  23 Carriage entrance
  24 Unloading port
  25 injection port
  25A Regular injection port
  25B Preliminary injection port
  26 Blower
  27 Switching valve
  28 Guide body
  29 Turning plate
  A Cleaning device
  B Brush
  C Transport device
  S steam
  W Workpiece
  P1 Position of workpiece
  P2 Position of workpiece
  ZA regular ejection zone
  ZB preliminary ejection zone

Claims (9)

It is a drying method in which superheated steam at a high temperature of 100 ° C. or higher is brought into contact with the entire surface of the object to be processed, and at least the surface liquid component of the object to be processed is removed by evaporation ,
The object to be processed is sequentially transported to a substantial processing unit to which superheated steam is supplied, and when performing a normal drying operation in the processing unit, the object to be processed is located in a normal ejection zone. Only to supply superheated steam,
If the workpiece is unexpectedly irregularly stopped during work,
After regular injection for an appropriate time in the regular ejection zone has ended, superheated steam is ejected for a certain period of time to the untreated object located in the preliminary ejection zone immediately before the regular ejection zone . A superheated steam drying method. Even when the preliminary injection for an appropriate time in the preliminary ejection zone, which is performed at the time of the irregular stop, is terminated, if the irregular stop state continues, the supply of superheated steam to the processing unit is shut off, The superheated steam drying method according to claim 1 , wherein the superheated steam is discharged outside the processing section. 3. The superheated steam drying method according to claim 1 or 2, wherein the processing unit that applies superheated steam to the object to be processed to dry the object to be processed is appropriately selected to be substantially sealed or open. . When the processing unit is formed in a hermetically sealed state, the processing unit has a processing chamber having a substantially sealed atmosphere, and the superheated steam is supplied to the object to be processed in the processing chamber. The superheated steam drying method according to claim 1, 2 or 3 . The processing chamber formed in the substantially hermetically sealed state is provided with a blower, and circulates warm air using the residual heat of the superheated steam in the treatment chamber, and the hot air blown from the blower is referred to as superheated steam. The superheated steam drying method according to claim 4 , wherein spraying is performed on the object to be treated after contact. A steam generator for generating water vapor;
Further heating the generated steam to a high temperature state of 100 ° C or higher;
Introducing the superheated steam generated in the superheated steam generation section, comprising a processing section for bringing the superheated steam into contact with almost the entire surface of the workpiece,
A drying apparatus that evaporates and removes at least a surface liquid component of a target object ;
The processing section includes a transport device that sequentially transports the object to be processed,
A regular injection port for blowing superheated steam only to the object to be processed located in the regular ejection zone on the transport device;
A pre-injection port that blows superheated steam only to the object to be processed located immediately in front of the normal ejection zone,
In a normal drying operation, superheated steam is injected from the normal injection port so that only the target object located in the normal injection zone is processed.
If the transport of the workpiece suddenly stops during the drying operation, after the regular injection for an appropriate period of time is completed, superheated steam is injected from the preliminary injection port and immediately before the normal injection zone. A superheated steam drying apparatus characterized by processing a positioned object to be processed . The processing unit has a drying path for supplying superheated steam to the substantial processing space from the superheated steam generating unit, and a discharge path for releasing superheated steam from the superheated steam generating unit to the outside of the processing space,
Even if the preliminary injection to the object to be processed located in the preliminary ejection zone is completed, if the irregular stopped state continues, the superheated steam path is switched from the drying path to the discharge path, and the superheated steam is discharged. The superheated steam dryer according to claim 6, wherein the apparatus is discharged to the outside of the processing space. The superheated steam according to claim 6 or 7, wherein the substantial processing space in the processing section is a substantially sealed processing chamber, and the superheated steam is supplied to the object to be processed in the processing chamber. Drying equipment. 9. The superheated steam drying device according to claim 8, wherein the sealed processing chamber includes a blower that circulates warm air using residual heat of the superheated steam in the processing chamber.

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