Pneumatic transport system and pneumatic transport method for grains

Abstract

The present invention provides an air transport system and method that can adjust the temperature of grains after air transport to a target temperature without excessively drying the surface of the grains. [Solution] A pneumatic transport system and pneumatic transport method for grains, comprising: a blower means for taking in outside air and generating an airflow for transporting grains; an indirect heating means for heating the outside air taken in by the blower means; a steam spraying means for spraying steam onto the outside air taken in by the blower means to heat and humidify it; a measuring means for measuring the state of the adjusted air heated and humidified by the indirect heating means and the steam spraying means; and a control means to which the measured value of the adjusted air state measured by the measuring means and a wet-bulb temperature setpoint are input, wherein the control means controls the output of the indirect heating means or the output of the steam spraying means based on the wet-bulb temperature measured value and wet-bulb temperature setpoint obtained from the input measured value of the adjusted air state.

Description

Technical Field

[0001] The present invention relates to a system for pneumatically transporting grains used as raw materials and a method for pneumatically transporting grains in the food industry including the brewing industry, and aims to adjust the temperature of the grains being pneumatically transported to a target temperature and then transport them.

Background Art

[0002] In the raw material processing step in the brewing industry, grains such as steamed rice that have been steamed by a steaming device and cooled to a set temperature by a cooling device may be transported by pneumatic transportation due to the positional relationship between the steaming device, the cooling device, and the koji-making device used in the next koji-making step.

[0003] For example, in sake production, the appropriate temperature of the steamed rice of sake-making rice at the start of the koji-making process is 32°C - 33°C for yeast koji and 31°C - 33°C for koji, and the state of the steamed rice used for koji-making has been considered good when it is "hard outside and soft inside" (relatively hard on the surface and soft inside).

[0004] Citation Document 1 describes a method of drying the surface layer of steamed rice by contacting the steamed rice after cooking with hot air for drying, then adjusting the temperature of the steamed rice with cold air, and again contacting the steamed rice with hot air for drying.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the method described in Reference 1, when the surface of the steamed rice discharged from the conveyor belt at controlled temperature comes into contact with dry hot air, the temperature of the steamed rice surface naturally drops below that of before air transport due to the latent heat of vaporization as the moisture on the surface of the steamed rice evaporates. However, because the target temperature for the product is not taken into consideration, the temperature of the steamed rice drops too low, making it difficult to adjust the temperature of the steamed rice after air transport to the target temperature. Furthermore, when steamed rice that has dropped too low is heated to the starting temperature for koji production in the next koji production process, condensation forms on the surface of the steamed rice due to the surrounding atmosphere, increasing the risk of bacterial contamination, and ultimately making it difficult to produce high-quality koji.

[0007] The present invention aims to solve the aforementioned conventional problems and to provide a pneumatic conveying system and method for conveying grains that can adjust the temperature of grains after pneumatic conveying to a target temperature. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides an air transport system for transporting grains while adjusting their temperature, comprising: a blowing means for taking in outside air and generating an airflow for transporting grains; an indirect heating means for heating the outside air taken in by the blowing means; a steam spraying means for spraying steam onto the outside air taken in by the blowing means to heat and humidify it; a measuring means for measuring the state of the adjusted air heated and humidified by the indirect heating means and the steam spraying means; and a control means to which the measured value of the state of the adjusted air and a wet-bulb temperature setpoint measured by the measuring means are input, wherein the control means controls the output of the indirect heating means or the steam spraying means based on the wet-bulb temperature measured value and the wet-bulb temperature setpoint obtained from the input measured value of the state of the adjusted air, thereby transporting grains pneumatically with the adjusted air in which the wet-bulb temperature measured value of the adjusted air is adjusted to the wet-bulb temperature setpoint.

[0009] Furthermore, the present invention relates to an air transport method for transporting grains while adjusting their temperature, and is characterized in that the air transport system comprises: a blowing means for taking in outside air and generating an airflow for transporting grains; an indirect heating means for heating the outside air taken in by the blowing means; a steam spraying means for spraying steam onto the outside air taken in by the blowing means to heat and humidify it; a measuring means for measuring the state of the adjusted air heated and humidified by the indirect heating means and the steam spraying means; and a control means to which the measured value of the state of the adjusted air and a wet-bulb temperature setpoint measured by the measuring means are input, wherein the control means controls the output of the indirect heating means or the steam spraying means based on the wet-bulb temperature measured value and the wet-bulb temperature setpoint obtained from the input measured value of the state of the adjusted air, thereby transporting grains pneumatically with the adjusted air in which the wet-bulb temperature measured value of the adjusted air has been adjusted to the wet-bulb temperature setpoint.

[0010] According to the pneumatic conveying system and method for grains of the present invention, by conveying grains with adjusted air whose wet-bulb temperature has been controlled, the surface of grains such as steamed rice is not excessively dried, and the temperature of the grains after pneumatic conveying does not fall below the wet-bulb temperature measurement value. Therefore, the temperature of the grains after pneumatic conveying can be easily adjusted to a target temperature.

[0011] In the aforementioned pneumatic conveying system and pneumatic conveying method for grains, it is preferable that the control means variably controls the output of the indirect heating means and the output of the steam spraying means. With this configuration, when producing adjusted air with a controlled wet-bulb temperature, the control means variably controls the output of the indirect heating means and the steam spraying means, thereby efficiently adjusting the dry-bulb temperature and relative humidity. This makes it easy to adjust the wet-bulb temperature measurement value of the adjusted air to the set wet-bulb temperature.

[0012] In the aforementioned pneumatic conveying system and pneumatic conveying method for grains, it is preferable that the output of the steam spraying means is set to a fixed value, and the control means variably controls the output of the indirect heating means. With this configuration, when producing adjusted air with a controlled wet-bulb temperature, by setting the output of the steam spraying means to a fixed value and the control means variably controlling the output of the indirect heating means, the wet-bulb temperature measurement value of the adjusted air can be easily adjusted to the wet-bulb temperature set value by adjusting the output of the indirect heating means while spraying steam at a constant flow rate. [Effects of the Invention]

[0013] According to the present invention, by transporting grains pneumatically with adjusted air whose wet-bulb temperature measurement value has been adjusted to a set wet-bulb temperature, the surface of the pneumatically transported grains is not excessively dried by the adjusted air, and the temperature of the grains after pneumatic transport can be easily adjusted to the target temperature. Furthermore, if used for transporting steamed rice to a koji-making apparatus, the temperature of the rice at the start of the koji-making process is stabilized, allowing for the stable production of high-quality koji. In addition, the pneumatic grain transport system and method of the present invention can be easily added to existing equipment. [Brief explanation of the drawing]

[0014] [Figure 1] This is a flow diagram of a pneumatic conveying system for grains according to one embodiment of the present invention. [Figure 2] This is a control flowchart diagram of a pneumatic conveying system for grains according to one embodiment of the present invention. [Modes for carrying out the invention]

[0015] The present invention relates to a pneumatic transport system and method for transporting grains, which use adjusted air with a controlled wet-bulb temperature for pneumatic transport. Hereinafter, as an embodiment of the present invention, the grains to be transported pneumatically will be described with reference to the drawings, using steamed rice for sake brewing. Furthermore, in this specification, "controllability" refers to the accuracy of control and the responsiveness of control. Therefore, "excellent controllability" means "accurate control" or "quick response."

[0016] Figure 1 is a flow diagram showing an embodiment of the pneumatic conveying system 1 for grains according to the present invention, and the pneumatic conveying system 1 mainly consists of a blower 11, an indirect heating 12, a steam spraying 13, a measuring 14, and a control 15.

[0017] As shown in Figure 1, outside air is first taken in by the blower 11 and heated and humidified by the indirect heating 12 and the steam spraying 13. Subsequently, the measuring 14 measures the state of the heated and humidified adjusted air, and the measured value of the adjusted air state is input to the control 15. The control 15 controls the output of the indirect heating 12 and the steam spraying 13 based on the wet-bulb temperature measurement value obtained from the measurement value and the wet-bulb temperature set value that has been input to the control 15 in advance, thereby producing adjusted air with an adjusted wet-bulb temperature. This adjusted air is supplied to the intake rotary feeder 3.

[0018] In Figure 1, the steamed rice supplied to the koji-making apparatus 6 is supplied to the cooler 2, where it is cooled, and then supplied to the intake rotary feeder 3. The steamed rice discharged from the cooler 2 and the adjusted air, whose wet-bulb temperature has been controlled, are mixed in the intake rotary feeder 3, and the steamed rice, along with the adjusted air, is transported to the koji-making apparatus 6 via the air transport piping 5.

[0019] Next, the pneumatic conveying system and method for conveying grains according to this embodiment will be described in detail. First, outside air is taken in by the blowing means 11 to generate an airflow for conveying grains. In this invention, the blowing means can be appropriately selected from blowers, fans, etc., depending on the airflow and pressure required for conveying grains by air.

[0020] In the present invention, the outside air taken in by the air blowing means is taken in from indoors or outdoors and is not particularly limited.

[0021] In the present embodiment, the outside air taken in by the air blowing means 11 is first heated by the indirect heating means 12. The indirect heating means 12 in the present embodiment is specifically an electric heater. In the present invention, the indirect heating means is used to adjust the dry bulb temperature of the conditioned air without changing the absolute humidity in the taken-in outside air. Examples of the indirect heating means in the present invention include, but are not limited to, plate heat exchangers.

[0022] In the present embodiment, the outside air heated by the indirect heating means 12 is heated and humidified by spraying steam from the steam spraying means 13. In the present invention, the steam spraying means is mainly used to adjust the humidity of the conditioned air. The steam spraying means in the present invention is specifically composed of a nozzle, a flow rate adjusting valve, and the like. In the present embodiment, the humidity of the conditioned air is mainly the relative humidity, but in another embodiment, it may be the absolute humidity of the conditioned air.

[0023] The flow rate of the steam sprayed from the steam spraying means 13 can be adjusted by the opening degree of the flow rate adjustment valve or the pressure of the steam supplied to the flow rate adjustment valve. When adjusting the flow rate of the steam, it is preferable to keep the pressure of the steam supplied to the flow rate adjustment valve constant and adjust the opening degree of the flow rate adjustment valve, so that the flow rate of the steam can be easily adjusted. In the present invention, the steam sprayed by the steam spraying means may be sprayed while adjusting its flow rate, or may be sprayed at a constant flow rate. For example, as in the present embodiment, by adjusting the opening degree of the flow rate adjustment valve which is the steam spraying means 13, while variably controlling the output of the steam spraying means 13, and by variably controlling the output of the indirect heating means 12, the wet bulb temperature of the adjusted air can be easily adjusted. Also in the present invention, by variably controlling the output of the steam spraying means while fixing the output of the indirect heating means, the wet bulb temperature of the adjusted air can be adjusted. As yet another embodiment, when spraying steam at a constant flow rate, the wet bulb temperature of the adjusted air can be adjusted by variably controlling the output of the indirect heating means 12, so the control is easy. Preferably, while variably controlling the output of the steam spraying means 13 to adjust the humidity and variably controlling the output of the indirect heating means 12 to adjust the dry bulb temperature, it is easier to adjust the wet bulb temperature and the controllability is excellent to adjust the measured value of the wet bulb temperature of the adjusted air to the wet bulb temperature set value.

[0024] In the present embodiment, the steam sprayed from the steam spraying means 13 is not particularly limited as long as it is purified. For example, steam supplied through the steaming device 4 can be mentioned. Also, the pressure of the sprayed steam can be controlled by the set pressure of the steaming device 4. The set pressure of the steaming device in the present invention can be, for example, 0.005 MPa to 0.060 MPa.

[0025] In this embodiment, the measuring means 14 measures the dry-bulb temperature and relative humidity, which are measured values ​​of the adjusted air state after heating and humidifying by the indirect heating means 12 and the steam spraying means 13. The measuring means 14 in this embodiment employs a dry-bulb temperature sensor 141 and a relative humidity sensor 142. The measuring means in this invention also includes a wet-bulb temperature sensor. The measuring means in this invention is not particularly limited and can measure the wet-bulb temperature directly or indirectly, or it can be used by a control means to obtain a measured value for calculating the wet-bulb temperature. The wet-bulb temperature may be calculated from the dry-bulb temperature and absolute humidity. When a combination of a dry-bulb temperature sensor 141 and a relative humidity sensor 142 is used as the measuring means 14, as in this embodiment, the dry-bulb temperature of the adjusted air can be adjusted to below the heat resistance temperature of each piece of equipment based on the measured value of the dry-bulb temperature sensor 141, which is more preferable in that it can prevent damage to each piece of equipment due to overheating.

[0026] Furthermore, in the present invention, a dry-bulb temperature sensor may be added downstream of the indirect heating means to measure the dry-bulb temperature, and the output of the indirect heating means may be adjusted independently to set the dry-bulb temperature to a constant value without output control by the control means. In this case, the control means will control the output of the steam spraying means based on the wet-bulb temperature measurement value and the wet-bulb temperature set value obtained from the measured value of the adjusted air condition.

[0027] Furthermore, in the present invention, the steam pressure may be kept constant and a fixed amount of steam may be supplied by fixing the output of the steam atomizing means using an orifice or nozzle. In this case, the control means will control the output of the indirect heating means based on the wet-bulb temperature measurement value and the wet-bulb temperature set value obtained from the measured value of the adjusted air state.

[0028] In this embodiment, the measured values ​​of the heated and humidified adjusted air state, measured by the measuring means 14, are input to the control means 15. The control means 15 calculates the wet-bulb temperature measurement value obtained from the measurements taken by the dry-bulb temperature sensor 141 and the relative humidity sensor 142. Based on the calculated wet-bulb temperature measurement value and the wet-bulb temperature set value that has been pre-inputted to the control means 15, the control means 15 controls the output of the indirect heating means 12 or the steam spraying means 13.

[0029] In this embodiment, controlling the output of the indirect heating means 12 by the control means 15 means that, when a dry-bulb temperature setting value is established with the dry-bulb temperature of the adjusted air as a fixed value, the output of the indirect heating means 12 is variably controlled based on the dry-bulb temperature, which is a measured value of the state of the adjusted air, or the output of the indirect heating means 12 is variably controlled based on the wet-bulb temperature obtained from the measured value of the state of the adjusted air.

[0030] In this embodiment, controlling the output of the steam atomizing means 13 by the control means 15 means variably controlling the output of the steam atomizing means 13 based on the wet-bulb temperature obtained from the measured values ​​of the adjusted air state, or variably controlling the output of the steam atomizing means 13 by adjusting the opening degree of the flow control valve, which is the steam atomizing means 13, based on the relative humidity, which is the measured value of the adjusted air state. In the present invention, controlling the output of the steam atomizing means may also be done by adjusting the pressure of the steam supplied to the flow control valve.

[0031] In this embodiment, by variably controlling the output of the indirect heating means 12 and the steam spraying means 13, it is possible to produce adjusted air in which the wet-bulb temperature measurement value is adjusted to the wet-bulb temperature setpoint. In another embodiment, the output of the steam spraying means is set to a fixed value, and the control means 15 variably controls the output of the indirect heating means 12 based on the calculated wet-bulb temperature measurement value and the wet-bulb temperature setpoint that has been input to the control means 15 in advance, thereby producing adjusted air in which the wet-bulb temperature measurement value is adjusted to the wet-bulb temperature setpoint.

[0032] In this invention, when the output of the indirect heating means is controlled by a control means based on the wet-bulb temperature obtained from the measured value of the adjusted air state, it is also possible to spray steam from the steam spraying means without output control by the control means. In this case, the output of the steam spraying means can be adjusted, for example, by calculating the amount of heat required by spraying steam according to a conventional method based on external air conditions such as temperature and humidity and the wet-bulb temperature setpoint, and by manually operating the opening of the flow control valve while keeping the pressure of the steam supplied to the flow control valve constant. This makes it possible to produce adjusted air in which the measured wet-bulb temperature of the adjusted air is adjusted to the wet-bulb temperature setpoint.

[0033] In this invention, when the output of the vapor atomizing means is controlled by a control means based on the wet-bulb temperature obtained from the measured value of the adjusted air state, the outside air can also be heated by an indirect heating means without output control by the control means. In this case, the output of the indirect heating means can be determined by calculating the required amount of heat from the sensible heat of the electric heater, which is the indirect heating means, according to a conventional method based on the outside air conditions such as temperature and humidity and the wet-bulb temperature setpoint, and then determining the output from the capacity of the electric heater. This makes it possible to produce adjusted air in which the measured wet-bulb temperature of the adjusted air is adjusted to the wet-bulb temperature setpoint.

[0034] In the present invention, when the output of the indirect heating means is variably controlled, and a dry-bulb temperature setpoint is provided for the adjusted air, the upper limit of the dry-bulb temperature setpoint is a temperature below the heat resistance temperature of each piece of equipment, and the lower limit is the wet-bulb temperature setpoint. As long as the dry-bulb temperature is maintained within the range of these upper and lower limits, the dry-bulb temperature setpoint when variably controlling the output of the indirect heating means is not particularly limited. Therefore, in the present invention, the combination of the dry-bulb temperature setpoint and relative humidity for producing adjusted air with a wet-bulb temperature adjusted to the wet-bulb temperature setpoint is not particularly limited as long as it is within the aforementioned range.

[0035] The control means in the present invention is not particularly limited as long as it can calculate a wet-bulb temperature measurement value based on a measurement value of the adjusted air state input from the measuring means, and control the output of the steam spraying means by adjusting the output of the indirect heating means, or the opening degree of the flow control valve which is a steam spraying means, or by adjusting the pressure of the steam supplied to the flow control valve, based on the calculated wet-bulb temperature measurement value and a wet-bulb temperature set value that has been input to the control means in advance. Examples include a PLC.

[0036] In this embodiment, the steamed rice discharged from the cooler 2 is mixed with adjusted air, whose wet-bulb temperature measurement value has been adjusted to the wet-bulb temperature setpoint, in the intake rotary feeder 3 and then air-conveyed to the koji-making apparatus 6. During the air-conveying stage, koji mold spores are inoculated into the steamed rice, for example, by a seeding machine (not shown). In this invention, the distance over which the grains are air-conveyed is not particularly limited as long as the grains can be air-conveyed, for example, 1m to 50m. In this invention, when the steamed rice is air-conveyed within the aforementioned distance range, the temperature of the steamed rice after air-conveying can be easily adjusted to the target temperature.

[0037] The grains used in this invention are not limited to rice as described above, but include barley, wheat, buckwheat, miscellaneous grains, corn, and the like. The state of the grains is not particularly limited, but examples include grains that have been steamed under no pressure or under pressure and then cooled.

[0038] In this invention, the preset wet-bulb temperature setting is the same as the target temperature of the grain after air transport. By setting the wet-bulb temperature setting of the adjusted air used for air transport to the same as the target temperature of the grain after air transport, the temperature of the grain after air transport can be made close to the wet-bulb temperature setting. For example, when using this invention for drawing in steamed rice in sake koji production, if the cooling temperature of the steamed rice is set slightly higher than the target drawing temperature, the temperature of the steamed rice after air transport will be close to the target temperature and will not fall below the target temperature, thus enabling high-quality koji production. The temperature of the grain after air transport is not particularly limited; for example, the temperature of steamed rice for sake brewing after air transport may be 33°C for sake starter koji and 32°C for kake koji.

[0039] Although one embodiment of the present invention has been described above, the above embodiment may be modified as appropriate. For example, in the flow diagram of the pneumatic conveying system for grains shown in Figure 1, the blowing means 11 may be located downstream of the indirect heating means 12. Furthermore, the positional relationship between the indirect heating means 12 and the steam spraying means 13 is not particularly limited, and the indirect heating means 12 may be provided downstream of the steam spraying means 13. Considering the ease with which the steam sprayed by the steam spraying means 13 dissolves into the air, it is preferable to provide the indirect heating means 12 upstream and the steam spraying means 13 downstream of the indirect heating means 12.

[0040] In addition to the indirect heating means and steam spraying means, a cooling means may be added. However, according to the pneumatic conveying system and pneumatic conveying method of the present invention, even if the outside air conditions are such that the temperature is 35.0°C and the relative humidity is 75%, as in summer, for example, a target wet-bulb temperature of 32.0°C can be produced, so a cooling means is not necessarily required. [Examples]

[0041] The present invention will be described in detail below with reference to Figures 1 and 2, using examples of the present invention. Figure 2 is a control flowchart of a pneumatic conveying system 1 for grains according to one embodiment of the present invention. In the following, the present invention will be applied in an environment where the ambient temperature is 18.0°C and the relative humidity is 60%, and the case in which steamed rice processed as a raw material for sake brewing is pneumatically conveyed to the koji-making apparatus 6 over a distance of 25m (Examples 1 and 2) or 40m (Example 3).

[0042] In the following embodiment, the target product temperature of the steamed rice after pneumatic transport was set to 32.0°C. Therefore, the wet-bulb temperature set value of the adjusted air used for pneumatic transport was set to 32.0°C. Outside air was taken in by a blower, which is the blowing means 11, to generate an airflow for transporting the steamed rice (step 100 in Figure 2). At this time, the airflow rate of the blower was 20 m³ 3 The pressure was set to / min, and the maximum static pressure was 39.8kPa. Furthermore, as mentioned above, the combination of dry-bulb temperature setting and relative humidity for producing adjusted air with a wet-bulb temperature set to match the wet-bulb temperature setting is not particularly limited as long as it is within the upper and lower limits. Since the heat resistance temperature of the air transport piping 5 was 50.0°C, the dry-bulb temperature setting was set to 45.0°C when variably controlling the output of the electric heater of the indirect heating means 12.

[0043] Next, the conditions of the outside air taken in by the blower 11 were measured by the dry-bulb temperature sensor 141 and the relative humidity sensor 142 of the measuring means 14 (step 101 in Figure 2), and the measured values ​​were a temperature of 29.8°C and a relative humidity of 29%. The measured values ​​were automatically input to the control means 15, which is a PLC (step 102 in Figure 2), and a wet-bulb temperature of 17.7°C was calculated from the measured values ​​(step 103 in Figure 2). Based on the wet-bulb temperature measured value and the wet-bulb temperature set value, the control means 15 variably controlled the output of the electric heater of the indirect heating means 12 with the dry-bulb temperature set value (45.0°C) as the set value to heat the outside air (steps 104 and 105 in Figure 2). To produce adjusted air with a dry-bulb temperature set to 45.0°C and a wet-bulb temperature set to 32.0°C, the relative humidity required is 40.5%. Therefore, steam was sprayed while variably controlling the output of the steam spraying means 13 with a target relative humidity of 40.5%, heating and humidifying the outside air heated by the electric heater (steps 104 and 106 in Figure 2). As a result, the adjusted air with the adjusted wet-bulb temperature had a dry-bulb temperature of 45.0°C, a relative humidity of 40.5%, and a wet-bulb temperature of 32.0°C (step 107 in Figure 2). In specific control, since the dry-bulb temperature rises due to steam spraying, adjustments are made using conventional control methods such as PID control to achieve the target dry-bulb temperature and relative humidity.

[0044] The temperature of the steamed rice at the outlet of the cooler 2 was 34.0°C. The adjusted air, whose wet-bulb temperature had been adjusted to 32.0°C, was mixed with the steamed rice discharged from the cooler 2 in the intake rotary feeder 3, and air transport to the koji-making apparatus 6 was continued (steps 108 and 109 in Figure 2). The temperature of the steamed rice after air transport was 32.2°C. After the air transport of the steamed rice was completed, air transport was stopped, the operation of each apparatus was terminated, and the adjustment of the wet-bulb temperature of the adjusted air was completed (steps 110 and 111 in Figure 2). The temperature of the steamed rice after air transport was within the acceptable range based on the wet-bulb temperature setpoint, and the target temperature could be achieved. In addition, the surface of the steamed rice after air transport was not excessively dry and was in a suitable condition for starting koji production. [Examples]

[0045] Similar to Example 1, the target product temperature of the steamed rice after pneumatic transport was set to 32.0°C, and the wet-bulb temperature setpoint for the adjusted air used for pneumatic transport was set to 32.0°C. Since the heat resistance temperature of the pneumatic transport piping 5 was 50.0°C, the dry-bulb temperature setpoint for variably controlling the output of the electric heater of the indirect heating means 12 was set to 38.0°C, which is a margin beyond the upper limit of the dry-bulb temperature setpoint (50.0°C). Because the dry-bulb temperature setpoint was 38.0°C, the relative humidity required to produce adjusted air with a wet-bulb temperature setpoint (32.0°C) at the dry-bulb temperature setpoint was 65.7%. The control means 15 variably controlled the output of the indirect heating means 12 and the steam spraying means 13 with the dry-bulb temperature setpoint and relative humidity as target values ​​(steps 104-106 in Figure 2). As a result, the adjusted air, with its wet-bulb temperature controlled, had a dry-bulb temperature of 38.0°C, a relative humidity of 65.7%, and a wet-bulb temperature of 32.0°C (Step 107 in Figure 2). When steamed rice was transported by air using the adjusted air with a wet-bulb temperature of 32.0°C, the temperature of the steamed rice after air transport was 32.1°C, which was within the acceptable range based on the wet-bulb temperature set value (Steps 108-111 in Figure 2). By adopting this invention, it was possible to adjust the product temperature to the target level. [Examples]

[0046] The target product temperature of the steamed rice after air transport was set to 30.0°C, and the wet-bulb temperature set value for the adjusted air used for air transport was set to 30.0°C. The opening of the flow control valve, which is the steam spraying means 13, was fixed at 15.0%, and steam was sprayed at a constant flow rate of 20.0 kg / h to heat and humidify the outside air heated by the electric heater (steps 104-106 in Figure 2). The relative humidity measured by the measuring means 14 stabilized at around 75.0%, so the dry-bulb temperature required to produce adjusted air with a wet-bulb temperature set value of 30.0°C became 34.0°C. The control means 15 variably controlled the output of the electric heater, which is the indirect heating means 12, with a dry-bulb temperature of 34.0°C as the target value. After adjusting the wet-bulb temperature measurement to the wet-bulb temperature setpoint, the adjusted air had a dry-bulb temperature of 34.0°C, a relative humidity of 74.9%, and a wet-bulb temperature of 30.0°C (Step 107 in Figure 2). When steamed rice was transported by air using the adjusted air with a wet-bulb temperature of 30.0°C, the temperature of the steamed rice after air transport was 30.3°C, compared to 35.0°C before air transport, which was within the acceptable range based on the wet-bulb temperature setpoint (Steps 108-111 in Figure 2). The target temperature could be achieved in the same manner as in Examples 1 and 2.

[0047] By employing the pneumatic transport system of the present invention, it was possible to adjust the temperature of the steamed rice after pneumatic transport to the target temperature in a short time. In the koji-making process, the temperature at the start of the process was at the target temperature, and the degree of dryness of the steamed rice surface was appropriate. Furthermore, since the temperature of the steamed rice after pneumatic transport did not drop below the target, condensation on the surface of the steamed rice, which is seen when raising the temperature, did not occur. As a result, it was possible to produce koji of high quality in the end. [Explanation of symbols]

[0048] 1. Pneumatic conveying system 11. Blower 12 Indirect heating means 13. Steam atomization means 14 Measurement means 141 Dry-bulb temperature sensor 142 Relative Humidity Sensor 15 Control means 2 Cooler 3. Rotary feeder for incoming power 4 Steam regulator 5. Pneumatic conveying piping 6 Koji making equipment

Claims

1. An air transport system for transporting grains that have been steamed and then cooled, with the temperature adjusted accordingly. A means of blowing air to take in outside air and generate an airflow for transporting grain, An indirect heating means that heats the outside air taken in by the aforementioned blowing means, A steam spraying means that sprays steam into the outside air taken in by the aforementioned blowing means to heat and humidify it, A measuring means for measuring the state of the adjusted air heated and humidified by the indirect heating means and the steam atomizing means, The measurement means includes a control means to which a measured value of the adjusted air condition and a wet-bulb temperature set value set based on the target product temperature of the grain after air transport are input. The control means controls the output of the indirect heating means or the output of the steam atomizing means based on the wet-bulb temperature measurement value obtained from the input measured value of the adjusted air state and the wet-bulb temperature set value. A pneumatic transport system for grains that transports grains using adjusted air, the adjusted air whose wet-bulb temperature measurement value is adjusted to the wet-bulb temperature setpoint.

2. The pneumatic conveying system for grains according to claim 1, characterized in that the control means variably controls the output of the indirect heating means and the output of the steam spraying means.

3. The pneumatic conveying system for grains according to claim 1, characterized in that the output of the steam spraying means is set to a fixed value, and the control means variably controls the output of the indirect heating means.

4. A pneumatic transport method for transporting grains that have been steamed and then cooled, wherein the temperature of the grains is adjusted, A means of blowing air to take in outside air and generate an airflow for transporting grain, An indirect heating means that heats the outside air taken in by the aforementioned blowing means, A steam spraying means that sprays steam into the outside air taken in by the aforementioned blowing means to heat and humidify it, A measuring means for measuring the state of the adjusted air heated and humidified by the indirect heating means and the steam atomizing means, Using an air transport system comprising a control means to which the measured value of the adjusted air condition measured by the measuring means and a wet-bulb temperature set value set based on the target product temperature of the grain after air transport are input, The control means controls the output of the indirect heating means or the output of the steam spraying means based on the wet-bulb temperature measurement value obtained from the input measured value of the adjusted air state and the wet-bulb temperature set value, A method for transporting grains pneumatically using adjusted air, wherein the wet-bulb temperature measurement value of the adjusted air is adjusted to the wet-bulb temperature set value.

5. The pneumatic transport method for grains according to claim 4, characterized in that the control means variably controls the output of the indirect heating means and the output of the steam spraying means.

6. The pneumatic transport method for grains according to claim 4, characterized in that the output of the steam spraying means is set to a fixed value, and the control means variably controls the output of the indirect heating means.

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