JP2003106768A - Vacuum dryer and processing tank thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum dryer 1 capable of automatically stopping when the drying degree reaches a prescribed value. SOLUTION: The temperature of a steam discharge tube 15 disposed between a processing tank 8 and a condensation means 11 rises after the drying process is started to the steady condition, and after that, the temperature begins to lower as the drying degree of a processed object W is lowered, that is, as the quantity of the discharged steam is reduced. Accordingly, if the relational expression between the temperature of the steam discharge tube 15 and the drying degree of the processed object W is previously found, the drying of the processed object W can be finished with a required value of the drying degree by automatically stopping the operation of the vacuum dryer 1 based on the value detected by a temperature sensor 16 mounted on the steam discharge tube 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum dryer for drying a water-containing treated material such as raw garbage to reduce its volume and volume, and a treatment tank therefor.

[0002]

2. Description of the Related Art A conventional vacuum dryer 1'includes a processing tank 8 ', a heating means 9, a stirring means 10, a condensing means 11, a drainage tank 12, a decompression means 13 and a deodorizing tank 14 as shown in FIG. The heating means 9 heats the water-containing treated material W (hereinafter referred to as treated material W) in the treatment tank 8 ', and
The vapor evaporated from the processed material W is rapidly cooled by the condensing means 11 to be separated into gas and condensed water, which are discharged through the drainage tank 12 and the deodorizing tank 14, respectively. The decompression means 1
3 is installed for sucking vapor or gas from the processing tank 8 ′ or the like.

This type of vacuum dryer 1'is provided with a control means (not shown) such as a microcomputer, and automatically stops its operation when a predetermined drying process is performed. For example, as the control means conventionally used in the vacuum dryer 1 ′, the water removal amount of the processed material W in the processing tank 8 ′, that is, the weight reduction rate or the discharge rate of the processed material W in the processing tank 8 ′, is used. There is a system in which the operation of each component such as the heating means 9 is stopped based on the amount of water increase in the water tank 12.

However, when the processed products W having different degrees of dryness are dried based on the water removal amount of the processed products W, there is a problem that the dryness of the processed products W after the drying process is different every time. For example, when the treated material W is raw garbage, which is a mixture of various raw materials, the purpose of the drying treatment is not only to reduce the volume and amount of the raw garbage but also to effectively use resources such as conversion to organic fertilizer. Depending on the purpose of the drying process,
It is desirable to be able to control the degree of dryness after the drying treatment. In other words, if you simply reduce the volume and weight, it is sufficient to perform the drying process to the extent that the garbage is burnt (approximately 5% dryness), but when converting to organic fertilizer, an appropriate dryness (approximately 10% It should be ~).

On the other hand, as a means for automatically stopping the vacuum dryer 1'when the dryness of the processed material W reaches a desired value, a contact type humidity sensor or vapor pressure sensor is provided in the processing tank 8 '. It is also conceivable to dispose them and perform control based on these detected values.

However, in the case of the humidity sensor, it is difficult to accurately measure the dryness of the whole food waste because the kinds of food waste are various. Moreover, when the drying process is performed while stirring the processed material W in the processing tank 8 ', the humidity sensor comes into contact with a wide variety of objects, so that it is difficult to determine the measured value. Further, the humidity sensor is expensive, and it is not economical because a plurality of installations are required to detect the dryness of the whole food waste more accurately.

Further, in the case of the vapor pressure sensor, the detected value gradually decreases toward a predetermined rated negative pressure (for example, 600 mmHg) until a predetermined dryness (for example, 30 to 50%) is reached, The predetermined dryness (for example, 30 to 50)
%) Or less, the detected value did not decrease from the predetermined rated negative pressure, and the dryness of the processed material W could not be calculated.

[0008]

As described above, in the conventional vacuum dryer, it is difficult to set the desired dryness and carry out the dry treatment when processing the processed products having different dryness. It was

The present invention has been made in view of the above problems, and an object thereof is to provide a vacuum dryer which can be automatically stopped when a predetermined dryness is reached.

[0010]

A vacuum dryer according to the present invention comprises a treatment tank for containing a hydrous treated product, a heating means for heating the hydrous treated product, and a liquefied vapor discharged from the treatment tank. A condensing means, a decompressing means for decompressing the inside of the processing tank, a temperature sensor installed in a vapor discharge pipe from the processing tank to the condensing means, and automatic operation control based on a detection value of the temperature sensor. And a control means.

According to the above configuration of the present invention, when the drying process progresses and the dryness of the processed product decreases, the temperature of the steam discharge pipe decreases as the amount of steam discharged from the processing tank decreases. Since the temperature gradually decreases, the progress of the drying process, that is, the dryness of the processed product can be determined based on the detection value of the temperature sensor installed in the steam discharge pipe, and the desired dryness is obtained. At this point, the operation of the vacuum dryer can be automatically stopped and controlled.

Further, in the processing tank, an upper opening charging port is formed in a part or all of the upper surface portion, and a projecting portion is formed by gradually reducing the diameter from the upper edge portion of the side surface portion or in the vicinity thereof. The steam discharge port is formed in the protrusion.

That is, the processing tank of the conventional vacuum dryer is
In many cases, the inlet and steam outlet are formed on the upper surface, making it difficult to evenly load the processed material into the processing tank. In addition, the amount of steam in the processing tank is the amount that the inlet is formed. The air collection function to the outlet was low. However, since the vacuum dryer of the present invention performs automatic operation control based on the detection value of the temperature sensor installed in the steam discharge pipe between the processing tank and the condensing means, the steam is smoothly discharged from the processing tank. It is therefore desirable to be able to quickly transfer the heat energy to the steam discharge pipe. Therefore, if the treatment tank is configured as described above, the function of collecting air to the steam discharge pipe in the treatment tank is improved, so that the temperature change of the steam discharge pipe becomes more remarkable, and the automatic operation control of the vacuum dryer is performed. The accuracy of can be improved.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a vacuum dryer according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a vacuum dryer 1 according to an embodiment of the present invention, in which FIG. 2 shows a casing of the vacuum dryer 1. On the upper surface of the casing 2,
A lid 3 is attached so as to be openable and closable, and a control panel 4 is installed on its side. Further, a panel 6 having a large number of ventilation holes 5 is detachably attached to a side surface portion on the left side of the casing 2 in the drawing, and a take-out port 7 for the processed material W is attached to the side surface portion on the right side of the drawing [see FIG. ) Reference] is provided.

2A and 2B are sectional views taken along the lines AA and BB of FIG. 1, respectively. As shown in FIGS. 2A and 2B, inside the casing 2, Treatment tank 8, heating means 9,
Stirring unit 10, condensing unit 11, drainage tank 12, decompression unit 1
3 and a deodorizing tank 14 are installed. In the figure, 15 is a steam discharge pipe, 16 is a temperature sensor, and 17 is a control means. 2A and 2B, wirings between the control means 17 and each component are not shown.

As shown in FIG. 3, for example, the processing tank 8 is formed in a substantially kamaboko shape which is rectangular when viewed from the front and from the top, and horseshoe-shaped when viewed from the side, and the entire upper part has an upper opening. It has a mouth 8a. In addition, a protruding portion 8b having a trapezoidal cross section is formed by gradually reducing the diameter in the horizontal direction from the vicinity of the upper edge portion of the protruding curved surface portion of the side surface portion, and the steam discharge port 8c is formed at the center of the tip end surface of the protruding portion 8b. ing. Further, a door member 8d for opening and closing the discharge port for the processed material W is provided on the side surface portion of the processing tank 8 on the left side of the drawing. And the processing tank 8 is, as shown in FIG.
The upper edge portion is installed so as to project from the upper surface portion of the casing 2,
The inlet 8 a of the processing tank 8 can be opened and closed by the lid 3.

As shown in FIG. 2 (A), the heating means 9 may be, for example, a rubber heater mounted on the outer peripheral surface of the processing tank 8 as long as the object W in the processing tank 8 can be heated. Good. If the heating means 9 is configured to blow hot air or the like into the treatment tank 8, a blower port (not shown) may be formed in the treatment tank 8 correspondingly.

As shown in FIGS. 2 (A) and 2 (B), the stirring means 10 may have a structure capable of stirring the processed material W in the processing tank 8. For example, the structure can be freely rotated in the processing tank 8. It may be composed of an agitating member 10a attached to the agitator, a driving motor 10b for the agitating member 10a, and a winding transmission mechanism 10c for transmitting the driving force of the motor 10b to the agitating member 10a.

The condensation means 11 is for rapidly cooling the steam discharged from the processing tank 8 to separate it into condensed water and gas, and may be, for example, an air-cooled condenser having a condenser body 11a and a cooling fan 11b. The condensing means 11 is not limited to the air cooling type, and may be a water cooling type or the like.

The drain tank 12 is installed on the downstream side of the condensing means 11, and a drain pipe 18 is arranged between the condensing means 11 and the drain tank 12. The condensed water separated by the condensing means 11 is drained from the condensing means 11 via the drain pipe 18 to the drain tank 12
Sent to and stored.

The decompression means 13 is, for example, a vacuum pump, and an exhaust pipe 19 is provided between the decompression means 13 and the condensing means 11.
Vapor or gas is sucked out from the processing tank 8 and the condensing means 11. Further, a deodorizing tank 14 is installed on the downstream side of the pressure reducing means 13 so that the odor of the gas discharged from the vacuum dryer 1 can be removed.

The steam discharge pipe 15 extends horizontally from the steam discharge port 8c of the processing tank 8 and is bent downward above the condensing means 11 and downstream thereof (condensing means 11).
The temperature sensor 16 is installed on the outer peripheral surface near the end of the (side). The temperature sensor 16 is for measuring the temperature of the steam discharge pipe 15, and the detected value is transmitted to the control means 17.

The control means 17 includes a CPU, ROM, RA
A microcomputer including M, I / O ports, etc. may be used, and the I / O ports include the temperature sensor 16 and
Signal lines are wired between the control panel 4, the heating means 9, the motor 10b of the stirring means 10, the cooling fan 11b of the condensing means 11 and the pressure reducing means 13, and the detected value of the temperature sensor 16 is dried by the control panel 4. The operation of the heating means 9 and the like is stopped when the value reaches the value corresponding to the set value of the degree.

As described above, the vacuum dryer 1 according to the present embodiment is mounted on the outer peripheral surface of the processing tank 8 for containing the water-containing processed material W (hereinafter referred to as the processed material W) and the processing tank 8. And heating means 9 for heating the processed material W in the processing tank 8
A stirring means 10 for stirring the water, a condensing means 11 for separating the vapor discharged from the treatment tank 8 into condensed water and a gas, and a vapor or gas from the treatment tank 8 and the condensing means 11 installed on the downstream side of the condensing means 11. Decompression means 13 for sucking out, a temperature sensor 16 installed on the outer peripheral surface of the vapor discharge pipe 15 from the processing tank 8 to the condensing means 11, CPU, ROM, RAM, I / O.
And a control means 17 having a port and the like.
7 is configured to automatically stop the operation based on the detection value of the temperature sensor 16.

That is, in the step of drying the processed material W,
The amount of evaporation (m ³ / s) from the processed material W per unit time is
It gradually increases along with the heat treatment, reaches a steady state when the amount of evaporation reaches a predetermined amount corresponding to the output of the heating means 9, and decreases when the water content (dryness) of the processed material W falls below a predetermined value. Tends to do. On the other hand, the temperature of the steam discharge pipe 15 begins to rise gradually as heat energy is transferred from the steam when the steam starts to be discharged from the processing tank 8, and becomes a steady state when the flow rate of the steam is sufficiently increased. It tends to begin to fall as the steam flow rate decreases. Therefore, if the relational expression between the temperature of the steam discharge pipe 15 and the dryness of the processed material W is experimentally calculated in advance, the dryness of the processed material W can be easily calculated from the detected value of the temperature sensor 16. You can In addition,
This relational expression is the vacuum drying of the volume of the processing tank 8, the output of the heating means 9, the rotation speed of the stirring means 10, the output of the pressure reducing means 13, the length / shape / inner diameter / thickness / material of the steam discharge pipe 15, etc. The characteristics of the aircraft 1 should be indexed.

Further, the temperature change of the steam discharge pipe 15 gradually starts to rise from the end portion on the upstream side (processing tank 8 side) from room temperature to the steady state, while it starts to drop from the steady state on the downstream side end. From the department. That is, when the temperature drops from the steady state, the thermal energy received from the steam by the steam discharge pipe 15 gradually decreases as the distance from the processing tank 8 increases, so that the temperature starts to drop from the downstream end.
Therefore, it is desirable that the temperature sensor 16 is installed at the downstream end of the steam discharge pipe 15 or in the vicinity thereof. When the steam discharge pipe 15 is sufficiently long, a plurality of temperature sensors 16 may be installed at predetermined intervals in order to grasp the temperature distribution more accurately. Also,
Since the detection value of the temperature sensor 16 may differ depending on the regional temperature difference, it is desirable to cover the steam discharge pipe 15 and the temperature sensor 16 with a heat insulating material.

[0028]

EXAMPLES In the vacuum dryer 1 constructed as described above, the standard processing weight per batch is 20 kg, and the processing tank 8 is used.
The volume of each is 83 liters, and the power consumption of each component is
The heating means 9 is 3.0 kW, and the decompression means 13 is 0.55 k.
w, the motor 10b was 0.4 kw, the cooling fan 11b was 0.05 kw, and an experiment was conducted under the conditions that the diameter of the steam discharge pipe 15 was 17 mm, and the following results were obtained.

It has been found that when the weight of the processed material W is 10, 20 and 30 kg, the dryness of each of them becomes about 10% when the detection value of the temperature sensor 16 reaches 51 ° C. When the detection value of the temperature sensor 16 reached 53 ° C, the dryness was about 25%.

When the weight of the processed material W is 20 kg,
The time required for the drying treatment was 6 hours, and when the weight of the processed product W was 40 kg, the time required for the drying treatment was 9 hours.

From the above, in addition to the specifications of the vacuum dryer 1, for example, the drying capacity, the diameter and length of the steam discharge pipe 15,
Since the relational expression between the detection value of the temperature sensor 16 and the dryness of the processing object W can be empirically derived depending on the shape and material, the installation location of the temperature sensor 16, etc., the processing is performed from the detection value of the temperature sensor 16. The dryness of the object W can be calculated. Then, when the operation of the vacuum dryer 1 is stopped when the temperature reaches a predetermined temperature, the processed product W having the desired dryness is obtained.

The vacuum dryer 1 of the present invention is configured as described above, and the drying process is automatically performed based on the detection value of the temperature sensor 16 installed in the vapor discharge pipe 15 between the processing tank 8 and the condensing means 11. Since the processing is completed, the dryness of the processed material W can be finished to a desired value. In addition, the temperature sensor 16
Since it can be installed on the outer peripheral surface of the steam discharge pipe 15, it has better durability and is easier to maintain than other sensors that must be installed inside the processing tank 8 as mentioned in the conventional example. Can be done.

Further, in the vacuum dryer 1 of the present invention, it is necessary to accurately grasp the temperature change of the steam discharge pipe 15, and therefore, it is desirable to configure the processing tank 8 so that the steam can be discharged smoothly. On the other hand, in most of the processing tanks 8 ′ of the conventional vacuum dryer 1 ′, as shown in FIG. 4, the inlet 8a ′ and the vapor outlet 8c ′ are both formed on the upper surface of the processing tank 8 ′. Both could not be formed sufficiently large. That is, if the inlet 8a 'is formed to be large, the air collecting property to the vapor outlet 8c' is reduced accordingly,
While the steam cannot be discharged smoothly, if the connection area with the steam discharge pipe 15 is increased in order to improve the air collecting property to the steam discharge port 8c ', the processed material W is evenly charged into the processing tank 8'. There was a problem that it would be difficult. In view of this, in the present invention, the charging port 8a is provided in a part or all of the upper surface of the processing tank 8, and the protruding portion 8b having a gradually reduced diameter is formed at the upper edge portion of the side surface of the processing tank 8, and the protruding portion 8b is formed. Is provided with a steam discharge port 8c. That is, if the steam outlet 8c is formed on a surface different from the surface on which the charging port 8a is formed, the charging port 8a can be formed with a sufficiently large opening area, and it becomes easier to uniformly load the processed material W into the processing tank 8 and further the steam discharging can be performed. Since the formation area of the protruding portion 8b for enhancing the air collecting property to the outlet 8c can be formed sufficiently large, the exhausting property from the processing tank 8 to the steam discharge pipe 15 is improved, that is, the processing efficiency of the vacuum dryer 1 is improved, and The temperature change of the steam discharge pipe 15 can be made remarkable.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, the shape of the processing tank 8 is an inverted kamaboko shape. The shape is not limited, and may be a vertically long cylindrical shape or a vertically long polygonal cylindrical shape, or may have a projecting curved surface portion protruding downward such as a hemispherical shape, a semielliptic spherical shape, or a mortar shape. Further, the protruding portion 8b may be formed so as to be gradually reduced in diameter from the upper edge portion of the side surface portion or in the vicinity thereof, and the cross-sectional shape may be a semicircular shape other than the trapezoidal shape or may be formed at a plurality of positions. May be. In addition, the side surface portion of the processing tank 8 includes not only a flat surface but also a curved surface. For example, in the treatment tank 8 of FIG. 3, it may be formed at two locations in the side surface portion near the upper edge portion on the front surface side and the back surface side of the projecting curved surface portion, or on the left side surface portion and / or the right side surface portion. You may form.

The heating means 9, the condensing means 11, the drainage tank 12, the decompression means 13, the deodorizing tank 14 and the like can be changed as appropriate, and the stirring means 10 and the drainage tank 12 shown in this embodiment are provided. It may not be necessary. Furthermore, the vacuum dryer 1 according to the present invention can be used together with the weight reduction rate of the processed material W in the processing tank 8, and in this case,
The weight measuring means (not shown) of the treatment tank 8 or the drain tank 12 may be provided with water level measuring means (not shown).

[0036]

As described above, the vacuum dryer of the present invention automatically terminates the drying process based on the detection value of the temperature sensor installed in the vapor discharge pipe from the processing tank to the condensing means. Therefore, the dryness of the processed product can be finished to a desired value.

Further, in the processing tank of the vacuum dryer of the present invention, as described above, it is possible to easily input the processed material and to improve the exhausting property from the processing tank to the steam discharge pipe. The processing efficiency can be improved, and the temperature change of the steam discharge pipe can be marked.

[Brief description of drawings]

FIG. 1 is a perspective view of a vacuum dryer according to the present invention.

2A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a sectional view taken along the line BB of FIG.

FIG. 3 is a perspective view of a processing tank of the vacuum dryer according to the present invention.

FIG. 4 is a schematic view showing a conventional vacuum dryer.

[Explanation of symbols]

1. Vacuum dryer 8. Processing tank 8a. Input port 8b. Protrusion 8c. Steam outlet 9. Heating means 10. Stirring means 11. Condensing means 12. Drainage tank 13. Decompression means 14. Deodorization tank 15. Steam exhaust pipe 16. Temperature sensor 17. Control means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F26B 9/06 B09B 3/00 303M 21/00 ZAB F term (reference) 3L113 AA07 AB05 AC01 AC21 AC24 AC46 AC58 AC67 AC75 BA01 CA08 CB01 CB13 CB16 CB29 DA07 DA24 4D004 AA03 AB01 AC01 CA42 CA48 CB28 CB32 CB36 CB50 DA01 DA02 DA06

Claims (2)

[Claims] 1. A treatment tank for containing a water-containing treated material, a heating means for heating the water-containing treated material in the treatment tank, a condensing means for liquefying the vapor discharged from the treatment tank, and the treatment tank. A pressure reducing means for reducing the pressure inside, a temperature sensor installed in a vapor discharge pipe extending from the processing tank to the condensing means, and a control means for performing automatic operation control based on a detection value of the temperature sensor. Vacuum dryer characterized by. 2. A treatment tank of a vacuum dryer for drying a water-containing treated material, wherein a charging opening of an upper opening is formed in a part or all of an upper surface portion and an upper edge portion of a side surface portion or A processing tank of a vacuum dryer, wherein a projection is formed by gradually reducing the diameter from the vicinity thereof, and a steam discharge port is formed in the projection.