JPH11216498A - Multiple-disk drier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the heat efficiency and production efficiency utilizing waste-heat air, waste gas, etc., by senselessly lowering the heat-transfer coefficient with respect to the thickness. SOLUTION: A plurality of disks 8 rotating in a drying space 7 are solid and store the heat of the waste gas introduced into the drying space 7. Heat is exchanged between the raw liq. to be dried and the disk on the surface of the disk 8. The geometrical direction leading to a discharge port from a feed port is practically parallel to the revolving surface of each of the plurality of disks, and the hot air is strightened among many disks. A thicker disk is desirable unlike the conventional fin. The heat-exchange efficiency is increased by the thicker disk. The disk is preferably made of a titanium alloy from the standpoint of acid resistance and thermal conductivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-plate dryer, and more particularly, to a method for easily disposing liquid domestic waste containing a physiologically active substance and liquid sludge containing an organic substance, or as a fertilizer. The present invention relates to a multi-plate dryer for drying into a powder form for reuse.

[0002]

2. Description of the Related Art Liquid domestic waste containing a physiologically active substance, liquid sludge containing an organic substance, etc., are easily discarded or collected as a powder by drying for reuse as fertilizer. I have. In order to produce foods suitable for storage, liquids have been converted into powders.

[0003] As a dryer for such powdering,
It is known that a multilayer disc is used. The disk of such a dryer, which is the invention of the present inventor, supplies high-temperature steam from the pipe into a plurality of hollow disks coaxially arranged on a pipe-shaped shaft, and a liquid material is formed on the high-temperature surface of the disk. Is known as a heat exchanger in which the liquid material is dried by heat exchange between the liquid material and the disk, and the solid material adhering to the surface of the liquid material is scraped off with a scraper to be recovered in powder form.

In such a dryer, in order to increase the heat exchange rate of the heat exchanger, measures are taken to reduce the thickness affecting the thermal conductivity of the disk or to increase the flow rate of steam. . Such dryers requiring a steam generation source have recently been required to have extremely low cost, and their use has been reduced.

On the other hand, it is a recent tendency that a large amount of air containing waste heat is discarded from an incinerator or the like. A dryer for powdering using such waste heat is required.
Fins equivalent to the aforementioned disks are commonly used in steam heaters and the like to increase thermal efficiency. Heat supply to such fins is performed inside the fins. The heat exchange rate of the heat exchange between the disk or fin into which the waste heat utilizing air is supplied inside and the liquid contacting from the outside is extremely reduced, and when compared with a constant energy supply, the production efficiency (speed) Is also extremely reduced.

[0006] Despite these difficulties, the advantages of using disks or fins with a large area are not lost in principle. A dryer having high thermal efficiency and high production efficiency while maintaining such advantages is desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-plate dryer having high heat efficiency and high production efficiency.

Another object of the present invention is to provide a multi-plate dryer having high thermal efficiency and high production efficiency utilizing waste hot air, waste exhaust gas and the like.

It is another object of the present invention to provide a multi-plate dryer in which increasing thermal efficiency coincides with increasing production efficiency at the same time.

Another object of the present invention is to provide a multi-plate dryer having high heat efficiency and high production efficiency by utilizing waste heat air, waste gas, etc. by reducing the heat conduction coefficient of the fins contrary to common sense. Is to provide.

[0011]

A multi-plate dryer according to the present invention includes a dryer body. The dryer body forms a drying space inside. A plurality of disks rotatably supported coaxially and rotatably with respect to the dryer main body are arranged in the drying space. A gap is provided between the plurality of disks. The dryer main body is provided with a supply port for supplying a drying gas and a discharge port for discharging the drying gas from the dryer main body.

The number of disks is 3 or more (including 3). If the thickness of the material to be dried that adheres to the surface of the disk increases, the amount of heat of the drying gas that is discharged from the discharge port without being stored in the disk increases, so that the stored amount is increased and stabilized. , Designed to increase the number of disks. The higher the thermal conductivity of the disk, the faster the heat storage and the quicker the heat release. In order to increase the thermal conductivity of the disk, the disk is made of metal. Since the geometric direction from the supply port to the discharge port is substantially parallel to the rotating surface of each of the plurality of disks, the flow of the dry air is rectified, turbulence does not easily occur, and the thermal efficiency is high.

[0013] In order to increase the thickness of the disk so as to increase the total heat capacity of the disk in the limited dry space, it is preferable to form the disk in a solid state. In order to further increase the corrosion resistance and the thermal conductivity, the disk is formed at least on the outside of a titanium alloy. Titanium alloy also has high thermal conductivity.

Preferably, the supply port is arranged at a position higher than the discharge port. A scraper is fixed to the main body of the dryer for stripping off the dried matter that has dried and adhered to the rotating surface of the disk. Immediate scraping of the dried material can increase the overall heat conduction.

On a section perpendicular to the rotation center axis of the disk, a line perpendicular to the rotation center axis and vertically upward is defined as Y
When an XY orthogonal coordinate system having an origin as an axis and a rotation center axis is set, the supply port is located substantially in the first quadrant in the rectangular coordinate system, and the discharge port is located substantially in the third quadrant in the coordinate system. The receiving port for receiving the powdery dried material scraped by the scraper is designed to be located in the fourth quadrant in the coordinate system,
The apparatus has a circulation system for the stock solution to be dried. The circulation system includes a stock solution tank, a circulation pump, and a discharge port for discharging the stock solution toward the disk. The discharge port is arranged in a coordinate system generally in a third quadrant, and the stock solution tank is generally formed in a coordinate system. Preferably, it is located below the origin.

Since the disk does not have a heat source inside, it is not necessary to reduce the thickness of the disk so that heat is easily conducted from the inside to the outside, and it is preferable to increase the thickness because the heat capacity increases. It is particularly preferred that the disc is solid.

[0017]

FIG. 1 shows an embodiment of a multi-plate type dryer according to the present invention. Four columns 2 stand on the base 1. A bearing 3 is fixed and supported on a beam extending between the tops of the columns 2. Bearing 3 on both sides
In addition, a rotating shaft 4 is supported rotatably. An outer wall that is the dryer main body 5 is fixed to and supported by a support so as to cover the rotation shaft. The dryer main body 5 is formed so as to include a cylindrical portion. The rotating shaft 4 is driven to rotate by a low-speed output drive motor 6.

The interior of the dryer main body 5 is formed in a drying space 7. Many disks 8 of the same diameter coaxially with the rotation shaft 4
Has been fixed. The disks 8 are all arranged in the drying space 7. It is preferable that all of the plurality of disks 8 have the same thickness. It is preferable that the distance width between the adjacent disks 8 is all the same. It is particularly preferable that the disk 8 is not hollow but solid, that is, solid, as described later. Preferably, the material is a titanium alloy that has high corrosion resistance and therefore high surface thermal conductivity. The disk 8 can be multi-layered and a titanium alloy can be used only for the surface layer.

FIG. 2 shows the arrangement of the components. In order to express this arrangement relationship, a coordinate system is set. The origin O is set on the rotation center axis of the rotation shaft 4. A line passing vertically upward through the origin O is the Y axis, and a line passing horizontally through the origin O is X
An orthogonal coordinate system XY for the axis is set. Dryer body 5
Has a cylindrical part 9.

[0020] The cylindrical portion 9 generally belongs to the third quadrant. The dryer main body 5 is provided with a supply port forming supply section 12 having a first connection section 11 that is connected to the cylindrical section 9 continuously and smoothly in the horizontal direction. The supply port forming supply portion 12 is a duct for supplying waste gas to the drying space 7.

The cross section of the supply port forming supply portion 12 in a vertical plane is substantially rectangular. Supply Port Forming Supply Portion 12
Generally belongs to the first quadrant. The dryer body 5 further includes a discharge port forming discharge portion 14 including a second connection portion 13 that is continuously and smoothly connected to the cylindrical portion 9 in an obliquely upward direction.

The discharge port forming discharge portion 14 is a duct for discharging waste gas from the drying space 7 to the outside. The waste gas discharged from the discharge port forming discharge part 14 may be returned to the supply port forming supply part 12. The cross section of the discharge port forming discharge portion 14 orthogonal to the obliquely upward direction is substantially rectangular.

The discharge port forming discharge portion 14 generally faces obliquely forward and downward, and generally belongs to the third quadrant. The dryer main body 5 further includes an extraction portion 16 for forming a powder outlet, which includes a third connection portion 15 that continuously bends and connects to the supply portion 12 for forming the supply port.

The outlet 16 for forming the powder outlet faces downward and rearward. A scraper 17 is fixedly provided on the inclined wall facing downward and rearward of the extraction portion 16 for forming a powder outlet. The scraper 17 extends in the radial direction. The dryer main body 5 further includes a stock solution tank 18 located below the origin.

FIG. 3 shows the positioning of the scraper 17 and the adjacent disk 8. A pedestal is mounted on the ramp described above. The scraper 17 fixed to the pedestal has a concavely opened elastic portion 19 on both sides. The elastic portions 19 on both sides are respectively in contact with opposing surfaces on both sides of the adjacent disk 8.

The elastic portions 19 are respectively provided on the disks 8
In the direction opposite to the rotation direction a. Elastic part 1
9 is urged in the opening direction and can contact the rotating surface of the disk 8 by its own opening force. This opening force acts to peel off solid matter adhering to the rotating surface.

FIG. 2 shows a stock solution circulation system. The stock solution circulating system includes a stock solution tank 18, a circulating pump 21, and a discharge port 22 for discharging the circulating solution to the rotating surface of the disk 8. The semi-dry liquid flowing down the rotating surface of the disk 8 returns to the stock solution tank 18.

The circulation pump 21 supplies the reflux liquid in the stock solution tank 18 to the discharge port 22. The stock solution tank 18 is connected to a stock solution tank 24 for supply via a supply pump 23. The undiluted solution is supplied from the undiluted supply tank 24 to the undiluted solution tank 18 by an amount corresponding to the reduced amount of the liquid in the undiluted solution tank 18.

From the supply port forming supply portion 12 to the drying space 7
The hot air blown into the disk 8 is substantially counter to the rotating direction of the disk 8. In FIG. 2, most of the flow of hot air from the supply port forming supply portion 12 to the discharge port forming discharge portion 14 is as follows.
In the drawing, the disk 8 rotates in a counterclockwise direction (clockwise direction). If the flow velocity is constant, the hot air of the flow velocity contacts the rotating surface of the disk with a larger area during the passage. The average velocity of the hot air is V and the linear velocity of the average radius of the disk 8 is-
Expressed as v, the hot air contacts the disk 8 having an effective radius width r and the area of t (V−v) r during the unit time t.

The hot air is subjected to a rectifying action through a plurality of divided drying spaces between the multiple disks 8. The temperature of the hot air is made uniform in the plurality of divided spaces. The object to be dried on the surfaces of the plurality of disks 8 receives uniform heat and is dried uniformly, so that there is no separation into a part that is too dry and a part that is not sufficiently dried, and the thermal efficiency is higher. high.

The circulating stock solution ejected from the discharge port 22 flows down on the vertical surface of the disk 8, and the thin stock solution layer formed on the surface rotates upward by about the same as the disk 8 and rises by about 4
A thin dry layer is formed which dries and solidifies during 3/3 turns. The object to be dried, which receives heat from the disk 8, exchanges heat with hot air, evaporates the liquid containing water as a main component, and is discharged from the discharge port forming discharge portion 14.

Unlike conventional fins used for heat exchange, the thicker the disk 8 according to the present invention, the better the thermal efficiency.
The total heat transfer coefficient K of the hollow disk is represented by the following equation.

K = 1 / {(1 / ht) + (d / λt) + (D / λ)} ht; heat transfer coefficient between the disc and the drying gas as a heating medium d; the disc Λt; thermal conductivity of the disk λ; thermal conductivity of the layer to be dried D: thickness of the layer to be dried In the case of a hollow disk, the thinner the thickness d of the disk, the smaller the heat transfer coefficient K high. The disk 8 of the present invention is supplied with heat not from inside but from outside. When the internal temperature of the disk 8 is equilibrated, the amount of heat given to the object to be dried by the disk 8 depends on the amount of heat received by the surface layer of the disk 8 from hot air. When the amount of heat received by the disk 8 from the hot air fluctuates, the thicker disk 8 can store a large amount of heat therein. The inner portion of the inner layer is replenished by the reduced amount of the surface layer portion of the disk 8 which is reduced in order to apply heat to the material to be dried. The higher the replenishing speed, the better the thermal conductivity λt of the disk 8 is. On the other hand, since high corrosion resistance is required, a titanium alloy is appropriate in view of the balance. Since heat exchange is performed via the surface layer, a titanium alloy having good corrosion resistance even if it has lower thermal conductivity than cast iron is preferable. Thermal conductivity is 100 ° C, industrial titanium 0.041 (cal / sec /
cm * cm / ° C / cm), 0.017 for 6Al-6V-2Sn. It is naturally preferable that the outer layer is made of titanium and the inner layer is made of copper, and the heat conduction 高 め to the inside is increased and the highly corrosion-resistant surface layer is made of a titanium alloy. Even though it has lower thermal conductivity than standard stainless steel,
In the present invention in which heat exchange is performed in the surface layer, the use of Hastelloy or a titanium alloy with a higher priority on corrosion resistance practically results in higher thermal conductivity.

The thickness of the material to be dried is preferably thin. It is better that the gap between the edge of the scraper and the rotating surface of the disk 8 is narrow. When designed to reach a specified degree of dryness during three-quarters of a turn, the gap is preferably zero.

The disk 8 is preferably made of a titanium alloy from the viewpoint of high corrosion resistance and high thermal conductivity. It is preferably solid, that is, solid so that the occupied space amount is small with a small volume, which is also advantageous in terms of manufacturing.

Waste gas from an incinerator or the like is used as the hot air. Examples of the stock solution include a solution in which a paint is dissolved in a thinner, a water-soluble organic substance, and a mixture of water and an organic substance. 14
The hot air at 0 ° C. can evaporate the thinner to solidify the paint components. Collect and reuse the thinner. If the temperature of the hot air is adjusted, separation by distillation can also be performed.

[0037]

As described above, the multi-plate type dryer according to the present invention has a high drying speed and high thermal efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a multi-plate type dryer according to the present invention.

FIG. 2 is a side sectional view of FIG. 1;

FIG. 3 is a sectional view showing a scraper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Rotating shaft 5 ... Dryer main body 7 ... Drying space 8 ... Disc 9 ... Cylindrical part 12 ... Supply part for supply port formation 14 ... Discharge part for discharge port formation 16 ... Extraction part for powder outlet formation 17 ... Scraper 18 ... stock solution tank 19 ... elastic part 21 ... circulation pump 22 ... discharge port

Claims (8)

[Claims] A dryer body forming a drying space therein; a plurality of disks rotatably supported coaxially with the dryer body and rotating within the drying space; and a plurality of disks between the plurality of disks. A space is provided, a supply port provided in the dryer main body for supplying a drying gas to the dryer main body, and a supply port provided in the dryer main body to discharge the drying gas from the dryer main body. The number of the discs is 3 or more, and the disc is formed of metal to increase the thermal conductivity of the disc, and the geometric direction from the supply port to the discharge port is A multi-plate dryer that is generally parallel to a rotating surface of each of the plurality of disks. 2. The disk according to claim 1, wherein the disk is formed to be thicker so as to increase the total heat capacity of the disk in a dry space having a limited volume. Plate dryer. 3. The multi-plate type dryer according to claim 1, wherein the outer side of the disk is made of a titanium alloy in order to further increase corrosion resistance and thermal conductivity. 4. The multi-plate type dryer according to claim 1, wherein the supply port is disposed at a higher position than the discharge port. 5. The multi-plate type dryer according to claim 1, wherein a scraper for removing a dried substance that dries and adheres to the rotating surface of the disk is fixed to the dryer main body. 6. The X-axis according to claim 5, wherein a line perpendicular to the rotation center axis and vertically upward on a cross section orthogonal to the rotation center axis of the disk is defined as a Y axis, and an origin is set on the rotation center axis. When the Y orthogonal coordinate system is set, the supply port is located substantially in the first quadrant in the orthogonal coordinate system,
The multi-plate type, wherein the discharge port is located substantially in the third quadrant in the coordinate system, and the receiving port for receiving the powdery dried material stripped by the scraper is located in the fourth quadrant in the coordinate system. Dryer. 7. The undiluted solution circulating system according to claim 6, further comprising a circulating system for the undiluted solution to be dried, wherein the circulating system includes a undiluted solution tank, a circulating pump, and a discharge port for discharging the undiluted solution toward the disk. Wherein the discharge port is disposed substantially in a third quadrant in the coordinate system, and the stock solution tank is disposed substantially below the origin in the coordinate system. 8. A dryer main body forming a drying space therein, a plurality of disks rotatably supported coaxially with respect to the dryer main body and rotating in the drying space, and a plurality of disks between the plurality of disks. A space is provided, a supply port provided in the dryer main body for supplying a drying gas to the dryer main body, and a supply port provided in the dryer main body to discharge the drying gas from the dryer main body. K = 1 / {(1 / ht) + (d / λt) + (D / λ)} ht; between the disk and the drying gas as a heating medium The heat transfer coefficient d: the thickness of the disk λt; the thermal conductivity of the disk λ; the thermal conductivity of the material layer to be dried D: the thickness of the material layer to be dried In order to reduce the thickness D of the layer to be dried, Is 3 or more (including 3), and the disk is formed of metal in order to increase the thermal conductivity λt of the disk so as to increase the overall heat transfer coefficient K. The geometric direction of the disk is generally parallel to the rotating surface of each of the plurality of disks, and the disks are solid to increase the heat capacity of the disks and reduce the thickness of the disks. Plate dryer.