JP2001165572A - Screw conveyor system of drier for waste containing water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw conveyor type of drier which can perform drying efficiently and can effectively prevent the diffusion of stenchy matter, etc., in one which dries half solid or solid matter containing water such as excrementitious matter, strained lees, etc., while carrying it. SOLUTION: A gas combustion chamber 3 in the shape of a dual cylinder is arranged to cover the periphery of a carrying barrel 2, and it is arranged so that the exhaust gas from this may pass the hollow axis 11 with a large diameter of a screw shaft and that it may pass the jacket 36 of a spare reservoir tank 25. Moreover, the mixed gas 2:1 in volume ratio between hydrogen and oxygen is used as combustion gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw conveyor type drying apparatus for drying semi-solid or solid hydrates such as manure and squeeze while conveying them. In particular, the present invention relates to a heating-type screw-conveyor-type drying device in which a screw-conveyor-type transport cylinder is covered with a heating jacket.

[0002]

2. Description of the Related Art A screw conveyor or a screw feeder is usually composed of a screw body in which a helical (helical) wound curved blade is wound around a single shaft, a cylindrical shape or a gutter shape. And transports powdery, granular, or semi-solid bodies.

[0003] The screw conveyor-type drying apparatus performs drying by heating or the like during transportation by such a screw conveyor.

For example, Japanese Patent Application Laid-Open No. 10-170151 discloses that
There is disclosed an apparatus that promotes drying by performing heating from an electric heater covering a transfer cylinder (barrel) and reducing the pressure by a vacuum pump. Further, Japanese Patent Application Laid-Open No. 5-116734 discloses a drying apparatus of a type in which dry air or hot air is blown into a transport cylinder (barrel).

[0005] In these screw conveyor type drying apparatuses, the water content of the object to be treated is not so high, and
This is very effective when pollutants such as malodorous substances are not emitted from the object to be treated.

However, it is not suitable for drying water-containing waste containing a large amount of water such as livestock manure and sludge and having a problem such as offensive odor.

[0007] In the case of livestock manure, such as a pig farm, the solid content is typically only around 5%, since it contains urine and some washing water. It is quite difficult to dry such livestock excrement containing a large amount of water into a solid that can be easily handled.

It would not be a problem if a microorganism treatment tank of a sufficient size could be provided in the vicinity of the livestock facilities, but it would be difficult in some cases to provide such equipment due to location conditions. In areas such as the Ryukyu Islands where water storage dams are extremely small and large amounts of water for treatment tanks cannot be secured, manure disposal has been a major problem.

[0009]

The screw conveyor type drying apparatus has excellent characteristics in that it requires a small installation space and is easy to collect and treat odorous substances. , Due to low thermal efficiency during drying,
The efficiency of the drying treatment was extremely low for hydrated waste containing a large amount of water.

In order to improve the drying efficiency, when the dry air is blown in, the heat is diffused together with the blown dry air to lower the heat efficiency, and it is extremely difficult to recover the odorous substances. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to efficiently dry semi-solid or solid hydrates such as manure and scum, especially waste containing a large amount of water. And a screw conveyor type drying apparatus capable of effectively preventing the diffusion of malodorous substances and the like.

[0012]

According to the first aspect of the present invention, there is provided a screw conveyor type drying apparatus for drying a semi-solid or solid hydrate such as manure and scum while conveying the same. A heating means or a heating medium path is provided inside the screw body composed of the screw shaft and the blade, while being covered by the heating jacket.

With the above-described structure, it is possible to efficiently dry water-containing substances, particularly wastes containing a large amount of water, and to effectively prevent the diffusion of malodorous substances and the like.

According to a second aspect of the present invention, in the screw conveyor type drying apparatus, the heating jacket is a double cylindrical combustion chamber that guides a combustion flame in a screw axial direction from a combustion gas inlet to a smoke exhaust port. A heating medium path is provided inside the screw body, using a flue gas from the smoke outlet as a heating medium.

With this configuration, the combustion heat of the fuel gas can be used efficiently.

In the screw conveyor type drying apparatus according to the third aspect of the present invention, the screw main body may be provided in a preliminary storage tank or hopper for temporarily storing the hydrated product before being guided to the screw conveyor type transfer tube. A heat exchange means for exchanging heat with the exhaust gas discharged through the passage and preheating the hydrated material is provided.

With such a configuration, the heat of combustion of the fuel gas can be more efficiently used to promote the drying.

According to a fourth aspect of the present invention, in the screw conveyor type drying apparatus, an outer diameter of the screw shaft is equal to or more than の of an inner diameter of the screw conveyor type transfer cylinder, and the screw shaft is a hollow for guiding the exhaust gas. It is characterized by being a shaft.

With this configuration, the combustion heat of the fuel gas can be efficiently used, and the exhaust gas can be smoothly discharged even when the screw conveyor type drying apparatus is quite long.

According to a sixth aspect of the present invention, in the screw conveyor type drying apparatus, the combustion gas supplied to the heating jacket comprises a mixed gas of hydrogen and oxygen, and their volume mixing ratio is approximately 2: 1. It is characterized by.

With such a configuration, CO, CO ₂ ,
The release of environmentally harmful substances such as NOx and SOx is almost nil, and the exhaust gas is pollution-free. Further, since it is not necessary to feed primary and secondary combustion air, and the pressure at the time of introducing hydrogen gas is large, the jacket-like combustion chamber can be formed long, so that the heating and drying processes can be efficiently performed. Can do well.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.
5 will be described.

FIG. 1 schematically shows a longitudinal section of the screw conveyor type drying apparatus 10 in the longitudinal direction. FIG. 2 schematically shows a cross section of the inside of the transport cylinder (barrel) 2 in the transverse direction.

A hollow shaft 11 having a large diameter and a helical blade 12 around the hollow shaft 11 form a screw body 1. In the illustrated example, the shape of the blades 12 is standard in a screw conveyor or a screw feeder.

The screw body 1 disposed in the transporting cylinder (barrel) 2 is driven by a motor 15 from the driving end of the hollow shaft 11, and is filled with water-containing waste, for example, water-supplied waste from a charging hopper (preliminary storage tank) 25. Manure 5
It is transported to the discharge pipe 21.

The outer peripheral surface of the transfer tube 2 is covered by a jacket type gas combustion chamber 3 and is directly heated by combustion heat. On the charging hopper 25 side of the gas combustion chamber 3, craters (combustion gas introduction ports) 31 are arranged. On the other hand, the gas combustion chamber 3
The end on the discharge pipe 21 side is provided with a combustion chamber exhaust portion 32 arranged so as to cover the front end surface of the transfer cylinder 2, that is, the discharge end surface.
Connected to Therefore, the combustion gas flame 33 spreads from the crater 31 on the input hopper 25 side toward the tip end of the transfer cylinder 2, and the generated exhaust gas is discharged to the combustion chamber exhaust part 32.

In the exhaust portion 32 of the combustion chamber, the tip of the hollow shaft 11 is located. A plurality of exhaust gas inlets 13 for receiving exhaust gas from the exhaust portion 32 of the combustion chamber are provided at a tip portion of the hollow shaft 11. On the other hand, a portion near the drive end of the hollow shaft 11 is located in the exhaust gas introduction portion 37 of the exhaust gas pipe 35. A plurality of exhaust gas outlets 14 are provided in a portion near the drive end of the hollow shaft 11. Further, the exhaust gas pipe 35 is connected to a preheating jacket 36 that covers a lower peripheral surface of the charging hopper 25.

Therefore, the exhaust gas from the combustion chamber 3 is
From the exhaust portion 32 of the combustion chamber, the exhaust gas inlet 13, the exhaust gas path 34, and the exhaust gas outlet 14 in the hollow shaft 11
Through the exhaust gas pipe 35 and into the preheating jacket 36.

Since the screw conveyor type drying apparatus has such a configuration, the excrement 5 and the like charged into the charging hopper 25 are first heated to a certain extent by the preliminary heating jacket 36, 2
Is supplied as appropriate. Then, while being conveyed in the conveying cylinder 2, the heating is performed from the conveying cylinder 2 side and the screw body 1 side, that is, from inside and outside, so that the whole is heated substantially uniformly and efficiently. Therefore, moisture removal through the appropriately provided vent 4 can be performed very efficiently. Due to such a heating method, the heat utilization efficiency can be improved by at least 50% or more as compared with the conventional apparatus.

In particular, as shown in FIG. 2, the hollow shaft 11 whose inner cavity forms the exhaust gas path 34 is provided with a large diameter, so that the exhaust gas in the hollow shaft 11 and the excrement 5 and the like to be conveyed are formed. Heat exchange is performed smoothly. In the specific example shown in FIG. 2, the outer diameter d of the hollow shaft 11 is 0.6 to 0.65 times the inner diameter D of the transport cylinder 2. In general,
Preferably, d ≧ D / 2.

In a conventional screw conveyor, a hollow shaft may be used for reasons of weight reduction or other reasons. However, the ratio of the outer diameter d of the hollow shaft 11 to the inner diameter D of the transfer cylinder 2 is generally about 0.4 to 0.4. Less than that.

FIG. 3 shows the connection structure of the screw conveyor type drying device. Screw conveyor type dryer 10
Are connected in the vertical direction. That is, the excrement 5 and the like discharged from the first screw-conveyor-type drying device 10-1 are supplied from the inlet of the second screw-conveyor-type drying device 10-2 through the discharge pipe 21. 4th screw conveyor type dryer 1
After passing through 0-3 and 10-4, it is discharged to the dry solid storage tank 51 as a powdery solid.

As shown in FIG. 3, the combustion gas is supplied from the combustion gas source pipe 38 to each of the screw drying devices 10-1 to 10-4.
Is supplied to each of the combustion chambers 3 through a gas flow meter 37 and a fuel gas valve 35. In addition, water and odorous substances that have come out of the excrement 5 and the like are collected from each vent 41 into one vent pipe 4, and are collected by the water recovery device 45 and the deodorizing device
6 collects and removes. Thus, diffusion of pollutants such as malodorous substances to the surroundings is suppressed as much as possible.

Here, as shown in the figure, the screw-type drying devices 10-1 to 10-3 are arranged slightly inclined so as to rise as they are conveyed. This is to prevent a portion that moves without receiving a sufficient drying treatment from being generated when the input excrement 5 or the like has a very large amount of water and a high fluidity.

The combustion gas used in the embodiment is a mixed gas of hydrogen and oxygen, and has a volume mixing ratio of about 2: 1. This mixed gas is hereinafter referred to as “aqua gas”.

As described above, by using the aqua gas, it is not necessary to provide an air supply port for supplying primary and secondary combustion air in the combustion chamber 3, and it is not necessary to provide an air supply pipe.

Moreover, the product of combustion from the aqua gas is only water, and NOx is not generated because almost no nitrogen is mixed into the combustion chamber. Therefore, the emission of environmentally problematic substances such as CO, CO ₂ , NOx, and SOx is almost nil, and the exhaust gas is pollution-free.

Also, the aqua gas is supplied to the crater 31 at a high pressure, and the combustion flame tends to spread and spread, so that the jacket-like combustion chamber 3 and the transport cylinder 2 are considerably long. Can be formed. Therefore, the heating and drying processes can be performed efficiently.

FIG. 4 shows an aqua gas (hydrogen / oxygen 2: 1)
2 schematically shows a layout related to operation control of a device for generating a mixed gas).

The water introduced from the automatic water supply tank 64 is
It is electrolyzed in the electrolytic cell 61 to generate aqua gas. The generated aqua gas is stored in the lower tank 62 and the upper tank 63, and then supplied to the combustion gas storage tank (Bach tank) 73 through the moisture removal gas 68.
At this time, the generated aqua gas is supplied to the cooling fins 66 and 6
7 to be cooled appropriately.

As the water supplied to the automatic water supply tank 64, at least a portion of water generated by combustion of aqua gas recovered as distilled water can be used.

FIG. 5 schematically shows a layout of a mixing apparatus for mixing a small amount of petroleum-based gas for coloring a combustion flame into aqua gas. In the combustion of hydrogen gas, it is difficult to confirm whether or not ignition has occurred in the combustion of aqua gas because the combustion flame is colorless. Therefore, ordinary liquefied propane gas (LPG) or normal hexane, etc. A small amount of petroleum-based gas is mixed. About 0.1 to 0.01% by volume ratio is sufficient. Aqua gas is mixed in a proportional injection valve 71 from a Bach (buffer) tank 73 and a tank 72 such as an LPG through pressure regulators 74-1 and 74-2, and the mixed gas is mixed with flow meters 75-1 and 75- After 2, it is further mixed with aqua gas and adjusted to the above ratio. Then, the above-described combustion gas is supplied to the main pipe 38.

In the above embodiment, the description has been made on the assumption that aqua gas (a mixed gas of hydrogen and oxygen 2: 1) is used. However, even if an appropriate fuel gas such as natural gas or naphtha is used,
It goes without saying that effects other than those described in relation to aqua gas can be obtained. In some cases, an electric heater can be used for part or all of the heating means. For example, it is also possible to arrange an electric heater in the blade 12 in the same configuration as the above embodiment.

Further, in the above-described embodiment, the description has been made assuming that exhaust gas passes only through the hollow shaft 11 in the screw main body 1. However, an exhaust gas pipe can also be provided in the blade 12. Further, the hollow shaft 11 may be a double cylinder, and the exhaust gas may be passed only through the inner cavity of the outer cylinder, that is, only between the outer cylinder and the inner cylinder.

In the above embodiment, the standard type blade 1
2, that is, a helical type having the same pitch, but various types such as a ribbon type can be appropriately selected depending on the properties of the processing object.

In the above embodiment, the preheating jacket 36
Although the above description has been made on the assumption that the preliminary storage tank provided with is also a charging hopper, it is needless to say that various configurations are possible.

In the above description, the object to be subjected to the drying treatment is described as a very watery filth such as manure 5, but it can be used for various hydrated wastes and other drying treatments. For example, (1) sake lees (kas), (2) tea leaves of Japanese tea sold as plastic bottled beverages, (3)
Plum dried scum and (4) Chinese medicine extracted scum.

In the description of the above embodiment, an example in which four screw-conveyor-type dryers are connected and used has been described. However, if sufficient installation space can be obtained,
One long one can be used. It is also possible in some cases to combine with another drying device.

[0049]

According to the present invention, it is possible to efficiently dry water-containing substances, particularly wastes containing a large amount of water, and to effectively prevent the diffusion of malodorous substances and the like.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view in the longitudinal direction of a screw conveyor type drying apparatus according to an embodiment.

FIG. 2 is a cross-sectional view of the inside of a transport cylinder (barrel) according to the screw conveyor type drying device of the embodiment.

FIG. 3 is a layout diagram showing a connection configuration of a screw conveyor type drying apparatus according to the embodiment.

FIG. 4 is a schematic layout diagram for explaining a hydrogen / oxygen mixed gas (aqua gas) generation device.

FIG. 5 is a layout diagram for explaining a configuration for mixing a coloring gas with a hydrogen / oxygen mixed gas.

[Explanation of symbols]

 Reference Signs List 1 screw body 11 screw hollow shaft 12 screw blade 13 hollow shaft exhaust gas introduction port 14 hollow shaft exhaust gas exhaust port 15 motor driving hollow shaft 2 transport cylinder (barrel) 21 discharge pipe from transport cylinder 25 input hopper ( (Preliminary storage tank) 26 Input valve 3 Combustion chamber 31 Crater (combustion gas inlet) 32 Combustion chamber exhaust 33 Hydrogen flame (combustion flame) 34 Exhaust gas path in hollow shaft 35 Exhaust gas pipe from hollow shaft 36 Preheating jacket 4 Vent piping 41 Vent from transfer tube

Claims (7)

[Claims] 1. A screw conveyor type drying apparatus for drying while conveying semi-solid or solid hydrates such as manure and squeeze waste, wherein the screw conveyor type transfer cylinder is covered with a heating jacket, and a screw shaft and blades are provided. A heating device or a heating medium path is provided inside a screw main body made of a screw conveyor. 2. The heating jacket is a double cylindrical combustion chamber for guiding a combustion flame in a screw axial direction from a combustion gas introduction port to a smoke exhaust port side. 2. The screw conveyor type drying apparatus according to claim 1, wherein a heating medium path using exhaust gas from the chimney as a heating medium is provided. 3. A pre-storage tank or hopper for temporarily storing the hydrated product before being guided to the screw conveyor type transfer tube, exchanges heat with exhaust gas discharged through the inside of the screw body. 3. The screw conveyor type drying apparatus according to claim 2, further comprising a heat exchanging means for preheating the hydrated material. 4. An outer diameter of the screw shaft is at least の of an inner diameter of the screw conveyor type transfer cylinder,
The screw conveyor type drying device according to claim 2, wherein the screw shaft is a hollow shaft for guiding the exhaust gas. 5. The screw conveyor type drying apparatus according to claim 2, wherein a heat medium path for guiding smoke exhaust is provided inside said blade. 6. The combustion gas according to claim 2, wherein the combustion gas supplied to the heating jacket comprises a mixed gas of hydrogen and oxygen, and their volume mixing ratio is approximately 2: 1. Screw conveyor type drying equipment. 7. A recovery device for recovering water generated by combustion as distilled water, and an electrolyzer for generating the mixed gas again using at least a part of the recovered water. The screw conveyor type drying device according to claim 6.