JPS58104484A - Automatic drying controlling system of product such as laver - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an automatic drying control system for products such as seaweed.

Generally, the process of drying seaweed is carried out as follows. Seaweed taken from the sea is soaked in fresh water, cut into small pieces, mixed with water, then transferred to a mesh container called a misu, drained of water, and then passed through a drying oven to dry. do.

FIG. 1 is an explanatory diagram showing a seaweed drying process consisting of four processes. In the figure, 1a to 1d are drying ovens, respectively. As described above, the seaweed placed in the container called misu is first conveyed by a conveyor through the drying oven 1a, and then
The process is completed, and then the drying oven ib is transported to complete the second process, and the drying ovens 1c and ld
The third and fourth processes are completed.

Drying categories are determined for each process. In other words, if the first process is a step of drying to a temperature of θ1 (°C) and a moisture content of Wl (%), the second process is a step of drying at a temperature of θ2 (°C).
, the third process is the step of drying to moisture W2 (%), the third process is θ3 (C), W, (%), and the fi4 process is θヰ (℃)
, W4 (%). After completing all the steps, the dried seaweed is peeled off from the container that exits the drying oven 1d. A burner is installed in each drying oven to heat the air inside the oven.

Figure 2 is a graph showing the relationship between the time elapsed during the seaweed drying process and the dryness (moisture content) of the seaweed.
This has been determined from past experience and results of experiments. The preheating area, the constant rate drying area, and the decreasing rate drying area took about 2 hours in total, and the initial moisture content was reduced to 100%.
%, it can be seen that it dries to about 7 to 8%.

However, in the past, the drying process as described above was controlled by humans, relying only on their intuition, while monitoring the temperature and humidity of the burners in each furnace and taking into account the weather conditions that day. Ta. However, in the drying process, whether drying progresses too much or slows down too much, the final quality of the seaweed will be greatly affected. For example, if drying progresses too much, it will cause cracks, while if it is delayed, it will become cloudy (the luster will be lost). However, manual control required extreme caution, as failures could occur when peeling the seaweed from the container. Furthermore, although it is said that the temperature and humidity of the drying oven is controlled while monitoring, it is not a method that directly detects and controls the temperature and dryness (moisture content) of the seaweed itself, but rather it is controlled by monitoring the temperature and humidity inside the oven. Since it was an indirect method of control, it was greatly affected by outside air conditions, making it difficult to realize a completely automatic drying control system.

This invention was made in consideration of the most difficult circumstances, and therefore, the purpose of this invention is to provide a fully automated drying control system for products such as seaweed, which is independent of outside air conditions. Our goal is to provide the following.

The main point of the structure of this invention is that it uses an infrared temperature sensor and a microwave-based moisture sensor that can detect the temperature and dryness of the seaweed that is constantly moving inside the drying oven without contact. Second, the drying process control is fully automated.

Next, an embodiment of the present invention will be described with reference to the drawings. Referring again to FIG. 2, the drying process of seaweed will be explained in more detail in order to understand the present invention. Now, Figure 2 shows the drying curve of raw seaweed. As mentioned earlier, this has been obtained through conventional experience, experiments, etc. First, wet raw seaweed is allowed to reach a predetermined temperature during the material preheating period. In this case, there is almost no change in the moisture content of the seaweed. In the subsequent constant rate drying, water evaporation and drying time show a linear relationship, and this relationship continues until the moisture content reaches about 40%. At this stage, free water such as adhering water on the surface evaporates, and drying proceeds quickly at a relatively high temperature. In the next lapse rate drying, the surface moisture disappears and the dryer the surface becomes, the more difficult it becomes to dry, which is called drying of bound water, and the drying rate also decreases.

In the present invention, this drying curve and the temperature of the seaweed at that point are set in advance as data in the control device, the temperature sensor and the moisture sensor monitor the condition of the seaweed one by one, and these sensor signals are processed by the control device. The drying section performs arithmetic processing against preset data, and based on the results, predetermined drying conditions are established while performing shibana control, hot air flow rate control, and damper control.

FIG. 3 is a system configuration diagram showing an embodiment of the present invention. In the figure, 2 is a drying oven (1a to 1 in Figure 1).
1d),
It is assumed that seaweed is being conveyed by a conveyor (not shown) in a direction perpendicular to the plane of the paper. 3 is a non-contact moisture sensor,
4 is also a non-contact temperature sensor, 5 is an intake hole damper,
6 is an exhaust hole damper, 7 is a variable speed fan, 8 is a burner, 9
10 is an oil valve, 10 is a fan drive motor, 11 is a humidity setting device, 12 is a humidity setting device, 13 and 14 are comparators, and 15 is a control device.

Air heated by a burner 8 supplied with oil through an oil valve 9 is supplied to a variable speed fan 7 driven by a motor 10.
A large amount of air is blown and circulates in the furnace 2, thereby drying seaweed (not shown). The humidity of the air inside the furnace is high, even if it reaches 100%.
If this air has reached this point, this air is no longer useful for drying the seaweed, so the exhaust hole damper 6 must be opened to exhaust the air to the outside, and the intake hole damper 5 must also be opened to take in low-humidity air. There is. The temperature of the seaweed itself detected by the non-contact temperature sensor 4 is compared with the temperature set by the temperature setting device 11 in the comparator 13, and a signal representing the difference is input to the control device 15.

Similarly, the moisture contained in the seaweed itself detected by the non-contact type moisture sensor 3 is sent to the dryness setting device 12 in the comparator 14.
The water content is compared with the set water content, and a signal representing the difference is input to the control device 15. The control device 15 performs predetermined arithmetic processing on the input difference signal to generate a control output, and controls the oil valve 9 (controls the heating temperature) and the variable speed motor IO (controls the amount of hot air). It also controls the opening degree of the exhaust damper 6.

The seaweed being conveyed through the furnace 2 is constantly moving, and as explained earlier with reference to FIG. 1, it progresses from one furnace to the next as the drying conditions change over time. go. Therefore, if the entire process is divided into four steps and four furnaces are installed, a temperature sensor and a moisture sensor will be installed in each furnace, which are structurally shielded from each other, and each will be an independent drying device with burner control and hot air flow control. By controlling the damper, it is possible to realize a fully automated drying control system throughout the entire process.

FIG. 4 is a block diagram showing another embodiment of the invention. In the embodiment shown in the figure, for example, if there are four furnaces, the sensor and control means for the operation terminal are provided individually, or only one control device is provided in common for the four furnaces. , this is an embodiment in which this one control device controls one of six furnaces on a 10% basis. In FIG. The moisture sensor 3b and temperature sensor 4b are sensors provided for the second furnace, and similarly, the moisture sensor 3c and temperature sensor 4c are sensors provided for the third furnace. In the furnace, a moisture sensor 3d and a temperature sensor 4d are installed.
are respectively provided for the fourth furnace. Further, the control means 20a of the operation terminal (which controls the drive motors of the fan drive motor 10, oil valve 9, exhaust damper 6, etc. in FIG. 3) is connected to the first furnace, hereinafter referred to as the control means 20b.

20e and 20d are the second. Third. This is provided for the fourth six furnaces. The control device 15 is provided commonly to all the furnaces. This control device 15 scans the sensors and control means of the six furnaces and performs time-sharing control. In this way, it is possible to reduce the cost of the system (by using a common control device). In FIG. 4, 17 is a display section, and 18 is a setting section.

FIG. 5 is an explanatory diagram showing the configuration of an infrared temperature sensor used in the present invention. In the figure, numeral 21 is seaweed, which is the object to be measured. The infrared temperature sensor 22 includes a lens L, a detection amplifier A1, a linearizer Z1, a display unit, a power source P, and the like. Then, the infrared rays emitted from the seaweed are collected by the lens L, converted into an electrical signal, amplified by the amplifier A, linearized by the linearizer 2, and then output (0 to 10 volts DC). do. This sensor has the characteristic of being able to measure relatively low temperatures without touching the object.

FIG. 6 is an explanatory diagram showing the configuration of a microwave moisture sensor used in the present invention. In the figure, the moisture sensor includes a microwave oscillator O, a transmitting antenna S, a receiving antenna R, and a detector D1. It consists of D2, environment correction means E, differential amplifier B, etc. Transmission antenna S
The attenuation rate of the microwaves passing through the seaweed varies depending on the moisture content of the seaweed 21 placed between the seaweed and the receiving antenna R, so by determining this attenuation rate, the water content of the seaweed 21 can be determined. be able to. The environment correction means E is for correcting errors that occur in measured values due to environmental temperature, humidity, etc. This sensor has the feature of being able to measure the moisture content of an object without touching it.

As explained above, according to the present invention, the temperature and dryness (moisture content) of seaweed can be directly monitored by employing non-contact sensors such as infrared temperature sensors and microwave moisture sensors. As a result, it is possible to accurately grasp the condition of the seaweed, and as a result, the drying process can be controlled without being affected by outside air conditions, resulting in fully automated control and a high quality seaweed finish. It has become possible.

By applying the principles of the present invention, the present invention can be applied to drying processes for secondary industrial products such as ``tobacco drying'' and shiitake mushroom drying, in addition to the seaweed drying described above.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the seaweed drying process, which consists of four processes. Figure 2 is a graph showing the relationship between time elapsed in the drying process and degree of dryness. Figure 3 is a system showing an embodiment of the present invention. 4 is a block diagram showing another embodiment of this invention, FIG. 5 is an explanatory diagram showing the structure of an infrared temperature sensor used in this invention, and FIG. 6 is a diagram showing a microwave moisture sensor also used in this invention. This is an explanatory diagram showing the configuration of the sensor. 〇 Symbol explanation la to 1d...Drying oven, 2...Drying oven, 3...Moisture sensor, 4...Temperature sensor, 5...Intake hole damper , 6... Exhaust hole damper, 7... Fan, 8... Burner, 9... Oil valve, 10... Fan drive motor, 11... Temperature setting device, 12... Dryness Setting device, 1
3.14... Comparator, 15... Control device, 1
7...Display section, 18...Setting section, 20...Control means, 21...Seaweed, 22...Infrared temperature sensor agent Patent attorney Difference Akio Ki Patent attorney Kiyoshi Matsuzaki Figure 1 Figure 2 30 tθ ta0 12(:
In5in□斡林硕内 fig.3

Claims (1)

[Claims] ■) A temperature sensor that non-contactly measures the temperature of a product such as seaweed being conveyed in a drying oven, a moisture sensor that also non-contactly measures the moisture content, and the temperature and humidity inside the drying oven. and a control section, the control section compares the product temperature detected by the temperature sensor with the set temperature, and the comparison result between the product moisture detected by the moisture sensor and the set dryness. An automatic drying control system for products such as seaweed, characterized in that the dryness of the product is controlled by controlling the adjusting means based on the comparison result. 2. The automatic drying control system according to claim 1, wherein the temperature sensor is an infrared temperature sensor and the moisture sensor is a microwave moisture sensor. Automatic drying control system. 3) In the automatic drying control system according to claim 1 or 2, the sensor and the adjustment means are provided in each of the plurality of steps, and a common control section controls them in a time-divisional manner. Automatic drying control system for products such as seaweed, characterized by