JP7116606B2 - Method and apparatus for treating organic waste - Google Patents

Description

The present invention relates to a method and apparatus for treating organic waste.

In the general treatment of organic waste, the organic waste is dehydrated using a dehydrator and disposed of as landfill or industrial waste. In recent years, it has been effectively used as a fuel resource after being dried or carbonized.

In the drying process, the dried matter and exhaust gas (heat medium gas or carrier gas) are discharged from the dryer in a mixed state. This mixture is separated into powder and separated gas using a solid-gas separator, and the separated gas is released into the atmosphere through a deodorizing process and a dust collecting process.

In the operation of a dehydrator or dryer, it is desirable to measure the moisture content of dehydrated or dried matter. By measuring the moisture content, it is possible to change the dehydration conditions and drying conditions, for example, and make the moisture content of the dehydrated and dried products constant. It should be noted that if the variation in moisture content is eliminated, it becomes easier to sell the dehydrated or dried product as a fuel resource. In addition, by measuring the moisture content, the operation can be optimized, the consumption of chemicals and electric power can be suppressed, and economical operation management becomes possible.

An apparatus and method for measuring the moisture content of dehydrated matter is disclosed in Patent Document 1 below. In the device according to Patent Document 1, a microwave moisture content meter is arranged in a dewatered cake discharge part of a continuous press-fit dehydrator, and a dehydrated cake is discharged between a pair of transmitting and receiving antennas provided facing the microwave moisture content meter. A portion of the compacted dehydrated cake in the chamber is continuously passed through to directly and continuously measure the moisture content of the dehydrated cake.

In addition, Patent Document 2 below discloses an apparatus and method for measuring the water content of a dehydrated product and performing control based on the measured value. In Patent Document 2, a moisture content meter is arranged at the cake discharge part of the screw press to measure the moisture content, and when the measured moisture content of the dehydrated cake deviates from the standard moisture content, the screw shaft of the screw press is rotated. It is an invention that changes the number and dosing rate.

Japanese Patent No. 4342478 Japanese Patent No. 4840380

The measurement devices according to Patent Documents 1 and 2 are intended to measure only the dehydrated cake that passes through a small space between a pair of transmitting and receiving antennas, and the moisture content of most of the dehydrated cake that does not pass through the space is unknown. be. There is a problem in terms of accuracy in estimating the moisture content measured in this way as the moisture content of the entire dehydrated cake.

In addition, when the dehydrated cake adheres and clogs between the pair of transmitting and receiving antennas, the clogged dehydrated cake is continuously measured, and there is a problem that the moisture content of the flowing dehydrated cake that should be measured is not known.

Accordingly, the main object of the present invention is to measure at least one of dehydrated and dried organic wastes as a measurement target and to measure the moisture content of the target with high accuracy. A secondary object of the present invention is to control at least one of the dehydration conditions and the drying conditions based on the measured value of the moisture content to achieve a uniform moisture content.

The present invention, which has solved the above problems, is as follows.
<First Aspect>
It is characterized by having a measurement process that continuously performs a series of operations of continuously collecting the dehydrated organic waste discharged from the discharge port of the dehydrator, compacting it, and then measuring the moisture content using microwaves. and organic waste disposal method.

(Effect)
In the present invention, the dehydrated matter is collected after being discharged from the dehydrator. The dewatered product tends to disperse as it exits the dehydrator. For example, when an in-machine centrifugal dehydrator is used as a dehydrator, when the dehydrated matter is discharged from the discharge port of the dehydrator, the gravity acceleration is 2000 to 3000 G from the dehydrator into the atmosphere (that is, an atmosphere of 1 G). Since it drips, dehydrated matter will be dispersed. By collecting the dehydrated matter in a dispersed state in this way, it is possible to obtain measurement results that are more objective than those of Patent Documents 1 and 2 described above. That is, in Patent Documents 1 and 2, since the dehydrated cake passing through a small space between a pair of transmitting and receiving antennas is measured, the measured value may not indicate the moisture content of the entire dehydrated product. In addition, when the dewatering machine is clogged with the dehydrated cake, a problem occurs in measuring the moisture content. If a problem occurs in measuring the moisture content, it becomes difficult to properly control the operation of the dehydrator. Furthermore, since the type of dehydrator is specified, a centrifugal dehydrator that can operate more efficiently cannot be used. In the present invention, the problems of Patent Documents 1 and 2 are resolved, and the moisture content can be measured with high accuracy. In addition, a centrifugal dehydrator can be employed for efficient operation.

In addition, when the moisture content of the dehydrated matter discharged from the outlet of the dehydrator changes by continuously performing a series of operations of "collecting the dehydrated matter, compacting it, and measuring it with microwaves", The change can be quickly detected. In other words, a method of periodically sampling the organic waste discharged from the dehydrator to measure the moisture content is conceivable, but in this case, changes in the moisture content cannot be detected while sampling is not being performed. Therefore, by performing continuous operation as in the present invention, such inconvenience can be eliminated.

<Second Aspect>
It is characterized by having a measurement process that continuously performs a series of operations, in which the dried organic waste discharged from the outlet of the dryer is continuously collected, compacted, and then the moisture content is measured by microwaves. and organic waste disposal method.

(Effect)
By continuously performing a series of operations of collecting the dried matter after being discharged from the dryer, collecting the dried matter, compacting it, and measuring it with microwaves, the same effects as in the first embodiment. can be obtained.

<Third Aspect>
The collection of the dehydrated matter is
The method for treating organic waste according to the first aspect, wherein the dehydrated matter is partly withdrawn while moving through a channel connected to the dehydrator.

(Effect)
For example, in a system that stores dehydrated matter in a storage tank, even if the dehydrated matter stored in the storage tank is sampled and the moisture content is measured, the dehydration effect of the dehydrator cannot be confirmed in real time. There's a problem. By collecting the moving dehydrated matter as in the present invention, there is an effect that the dehydration effect can be confirmed in real time.

<Fourth Aspect>
The collection of the dried matter is
The organic waste treatment method according to the second aspect, which is carried out by extracting part of the dried matter while it is moving through a channel connected to the dryer.

(Effect)
By extracting a portion of the dried matter moving in the channel, the same effect as (3) above can be obtained.

<Fifth Aspect>
An organic waste treatment apparatus having a measuring device for measuring the moisture content of dehydrated organic waste,
The measuring device is
a collection unit that continuously collects the dehydrated matter;
a consolidation unit for consolidating the collected dehydrated matter;
An organic waste treatment apparatus characterized by having a measuring unit for measuring the moisture content of the compacted dehydrated matter by microwaves.

(Effect)
The same effects as those of the first aspect are obtained.

<Sixth Aspect>
An organic waste treatment apparatus having a measuring device for measuring the moisture content of dried organic waste,
The measuring device is
a collection unit that continuously collects the dried matter;
a consolidation unit for consolidating the collected dried matter;
1. An organic waste treatment apparatus, comprising a measuring unit for measuring the moisture content of the compacted dried matter by microwaves.

(Effect)
The same effects as those of the second aspect are obtained.

<Seventh Aspect>
The organic waste treatment device has a pipe connected to the discharge part of the dehydrator,
the collecting part of the measuring device is inserted inside the tube,
The movement speed of the dehydrated matter moving inside the tube is in the range of 0.5 m / s to 150 m / s,
The organic waste treatment apparatus according to the fifth aspect, wherein the insertion area of the collection part is 0.05% to 5% of the cross-sectional area of the pipe.

(Effect)
When the moving speed of the dehydrated matter is within the general range of 0.5 m/s to 150 m/s, if the insertion area of the collection part is less than 0.05%, the amount of dehydrated matter collected is small and the predetermined amount Since the measurement cannot be started until the dehydrated matter is deposited, there is a problem that it is difficult to detect the moisture content of the dehydrated matter in real time. Further, if the insertion area of the collecting portion is larger than 5%, the amount of dehydrated matter collected increases, and there is a high possibility that the inside of the measuring device will be clogged with the dehydrated matter.

Therefore, in the present invention, by setting the moving speed of the dehydrated matter and the insertion area of the collecting portion within the above ranges, the amount of the dehydrated matter to be collected can be optimized, and the occurrence of the above problems can be prevented. .

<Eighth Aspect>
The organic waste treatment device has a pipe connected to the outlet of the dryer,
the collecting part of the measuring device is inserted inside the tube,
The moving speed of the dried matter moving inside the tube is in the range of 0.5 m / s to 150 m / s,
The organic waste treatment apparatus according to the sixth aspect, wherein the insertion area of the collection part is 0.05% to 5% of the cross-sectional area of the pipe.

(Effect)
With respect to drying, the same effects as those of the seventh aspect are obtained.

INDUSTRIAL APPLICABILITY According to the present invention, at least one of dehydrated matter and dried matter of organic waste is measured, and the moisture content of the object can be measured with high accuracy. Moreover, based on the measured value of the moisture content, at least one of the dehydration conditions and the drying conditions can be controlled, and the uniformity of the moisture content can be achieved.

1 is a flowchart of an organic waste disposal method according to the present invention; FIG. FIG. 2 is a plan cross-sectional view of a tube and measuring device; 4 is a perspective view of a collection part; FIG.

Preferred embodiments of the present invention are described below with reference to the drawings. The following description and drawings merely show one embodiment of the present invention, and should not be construed as limiting the content of the present invention to this embodiment.

FIG. 1 is a flowchart of a method for treating organic waste W, which is an example of the present invention. A treatment apparatus 1 for organic waste W includes a dehydrator 3, a hot air generator 4, a continuous hot air dryer 5, a solid-gas separator 6, and the like. The configuration and processing flow of the processing apparatus 1 will be described in detail below.

(Organic waste W)
The treatment device 1 treats organic waste W. As shown in FIG. Examples of this organic waste include sewage sludge (including surplus sludge, initial settling sludge, mixed raw sludge, mixed sludge, digested sludge, sludge mixed and digested with biomass, etc.), wastewater treatment sludge, paper sludge, activated sludge. , building pit sludge, agricultural settlement effluent sludge, and other organic sludge. Among these sludges, it is particularly suitable for treatment of sewage sludge. In addition, the organic waste W includes those mixed with inorganic substances.
The organic waste W is stored in the organic waste storage tank 2 and supplied to the dehydrator 3 by the supply pump 21 .

(Dehydrator 3)
The treatment apparatus 1 has a dehydrator 3 for dehydrating the organic waste W. As shown in FIG. In the embodiment of FIG. 1, the organic waste W is dehydrated by the dehydrator 3 and then sent to the continuous hot air dryer 5 .

Examples of the dehydrator 3 include a centrifugal dehydrator, a belt press dehydrator, a screw press dehydrator (including a multi-plate dehydrator), a rotary press dehydrator, a rotary pressure dehydrator, and a multi-disc dehydrator. can be mentioned. Among these dehydrators, a centrifugal dehydrator is particularly suitable.

The centrifugal dehydrator 3 includes a dehydrator used for a two-liquid preparation method in which two types of coagulants are added to the organic waste W to adjust the properties of the organic waste W. This two-liquid conditioning centrifugal dehydrator can easily reduce the maximum particle size and average particle size of the dehydrated material. Two-liquid tempering centrifugal dehydrator is divided into in-machine two-liquid tempering centrifugal dehydrator and external two-liquid tempering centrifugal dehydrator. , and the other type is a polymer flocculant. The same applies hereinafter.) to the sludge inside the machine, and the latter is a dehydrator that supplies two kinds of flocculants to the sludge outside the machine. Either type may be used in the present invention.

The two-liquid refining type centrifugal dehydrator 3 is provided with a rotating bowl on the outside, and a screw conveyor is provided inside the rotating bowl. A supply port is provided at one end of the rotary bowl, and a discharge port is provided at the other end. The organic waste W supplied into the rotating bowl from the supply port is conveyed to the other end side while being agitated by the screw conveyor, and is discharged from the discharge port as dehydrated matter. The organic waste W is dehydrated by the centrifugal force generated by the rotation of the rotating bowl while moving from one end to the other end in the rotating bowl.

The in-machine two-liquid conditioning centrifugal dehydrator 3 adds the polymer flocculant HC and the inorganic flocculant IC to the organic waste W by injecting them into the rotating bowl. On the other hand, the external two-liquid tempering type centrifugal dehydrator 3 adds the polymer flocculant HC and the inorganic flocculant IC to the organic waste W before being supplied to the rotating bowl.

As the polymer flocculant HC, for example, polyacrylamide-based or polyacrylic ester-based ones can be used. Examples of inorganic flocculants IC include ferric sulfate (especially polyferric sulfate (polyiron)), ferrous sulfate, ferric chloride, aluminum sulfate and polyaluminum chloride (PAC), ferric chloride etc. can be used. By using these two types of flocculants, the maximum particle size and average particle size of the dehydrated product can be reduced. Additionally, the water content of the dehydrated product can also be reduced.

The injection rate of the inorganic flocculant IC is preferably 5% or more with respect to the amount of solids in the sludge supplied to the dehydrator 3 . For example, when the amount of solid matter in the sludge supplied to the dehydrator 3 is 4 m ³ /h, it is preferable to inject 0.2 m ³ /h or more of the inorganic flocculant IC. By injecting 5% or more of the inorganic flocculant IC, the properties of the dehydrated matter become suitable for drying in the continuous hot air dryer 5, and the dehydrated matter adheres to the continuous hot air dryer 5 and accumulates. can prevent you from doing it.

As described above, the more the injection rate of the inorganic flocculant IC is increased from 5%, the more difficult it is for the dehydrated matter to adhere and accumulate in the continuous hot air dryer 5 .
However, increasing the amount of inorganic flocculant IC increases the chemical cost. In addition, depending on the type of inorganic coagulant IC, sulfur or hydrogen chloride volatilizes from the inorganic coagulant IC to lower the acid dew point, and sulfuric acid or hydrochloric acid contained in the inorganic coagulant IC dissolves, causing the continuous hot air dryer 5 to corrodes the inside of the Considering these demerits, it is preferable to set the injection rate of the inorganic flocculant IC to 30% or less.

By injecting the inorganic flocculant IC, the water content of the dehydrated product can also be lowered. For example, when the injection rate of the inorganic flocculant IC is 5% to 30%, the moisture content of the dehydrated product can be about 75% to 79%.

In addition to the inorganic coagulant IC, the polymer coagulant HC is injected into the two-liquid conditioning centrifugal dehydrator 3 . Like the inorganic flocculant IC, the polymer flocculant HC has the function of flocculating sludge. Therefore, it is preferable to change the injection rate of the polymer coagulant HC according to the injection rate of the inorganic coagulant IC. For example, when the injection rate of the inorganic flocculant IC is 5% to 30%, the injection rate of the polymer flocculant HC is about 0.1% to 5% with respect to the solid amount of the sludge supplied to the dehydrator 3. It is preferable to

As the in-flight two-liquid tempering type centrifugal dehydrator, for example, "Technical Information and Research" on the website of the Japan Sewage Works Agency dated April 20, 2015, "No. 133 2012/12/13 Technical information <Technology Introduction > "In-machine two-liquid conditioning type centrifugal dehydrator" - Realization of dehydrated sludge with low moisture content" can be used.

In the case of using the in-machine two-liquid tempering type centrifugal dehydrator 3, when discharged from the discharge port of the dehydrator 3, from the dehydrator 3 with a gravitational acceleration of 2000 to 3000 G into the atmosphere, that is, 1 G atmosphere, the dehydrated matter is dispersed. Therefore, it becomes easier to evenly collect the dehydrated matter discharged from the in-machine two-liquid conditioning type centrifugal dehydrator 3 . Along with this, the properties of the dehydrated matter suitable for drying in the continuous hot air dryer 5, particularly the particle size of the dehydrated matter, can be easily controlled within the desired range.

In addition, a one-liquid tempering type centrifugal dehydrator 3 may be used, and in that case, either type of the in-machine one-liquid tempering type centrifugal dehydrator 3 or the external one-liquid tempering type centrifugal dehydrator 3 may be used. good. When using the one-liquid refining type centrifugal dehydrator 3, only the inorganic coagulant IC is injected without injecting the polymer coagulant HC. The injection rate of the polymer flocculant HC is the same as in the case of the two-liquid conditioning centrifugal dehydrator 3 . Specifically, it is preferable to set the injection rate of the inorganic flocculant IC to 5% or more, more preferably 30% or less, based on the amount of solids in the sludge supplied to the dehydrator 3 .

(Dehydrated material conveying machine 7)
Sludge (dehydrated material) discharged from the dehydrator 3 is supplied to the dehydrated material conveying machine 7 . The moisture content of the dehydrated product is preferably 81% or less, more preferably 78% or less. If the water content is higher than 81%, the dehydrated matter tends to adhere to the inside of the continuous hot air dryer 5, and there is a risk that the dehydrated matter will clog the inside. In the configuration of FIG. 1, the dewatering machine 3 and the dehydrated material conveying machine 7 are connected by a pipe 30, and the dehydrated material moves to the dehydrated material conveying machine 7 through the inside of the pipe 30. In FIG.

As the dehydrated matter conveying machine 7, a screw conveyer, a belt conveyer, or the like, which conveys the dehydrated matter by mechanical power, can be used. In FIG. 1, a screw conveyor is used as the dehydrated matter conveying machine 7 . Further, a supply port is provided in a longitudinally intermediate portion (near the center) of the screw conveyor 7 in FIG.

(Method of supplying dehydrated matter)
When the dehydrated matter is supplied to the continuous hot air dryer 5, the supply amount (kg-ds/min) of the dehydrated matter to the continuous hot air dryer 5 is X, and the amount of dehydrated matter held in the continuous hot air dryer When (kg-ds) is Y, the continuous hot air drying is performed so that the average residence time T for the dehydrated matter to stay in the continuous dryer as defined by the following formula 1 is within the range of 0.05 to 10 minutes. It is preferred to feed the machine 5.
T=Y/X Expression 1
The residence time T is preferably in the range of 0.1 to 7 minutes, more preferably in the range of 0.2 to 5 minutes.
By setting the supply amount of the dehydrated matter to the continuous hot air dryer 5 within the above range, the retention time of the dehydrated matter in the continuous hot air dryer 5 becomes an appropriate value, and the final product emits a bad odor. can be suppressed.

(Maximum particle size)
It is preferable to provide the dehydrated material conveying machine 7 with measuring means for measuring the particle size of the sludge (dehydrated material). As a result of measuring the particle size of the dehydrated material, if the maximum particle size of the dehydrated material is higher than the standard value, the dehydrated material is sent to the digestion tank 20, and if it is equal to or less than the standard value, the dehydrated material is sent to the continuous hot air dryer 5. send to The reference value can be arbitrarily determined, but when the maximum particle size of the dehydrated matter is larger than 60 mm, it is sent to the digesting tank 20, and on the contrary, when the maximum particle size of the dehydrated matter is 60 mm or less, it is sent to the dryer 5. It is preferable to

If the dehydrated matter with a maximum particle size larger than 60 mm is supplied to the continuous hot air dryer 5, there is a high possibility that the dehydrated matter will adhere or accumulate inside the dryer 5. When the deposit amount exceeds a certain amount, it becomes necessary to temporarily stop the operation of the dryer 5 and manually discharge the deposit. In the present invention, long-term continuous operation of the dryer 5 is realized by preventing the supply of dehydrated matter having a maximum particle size larger than 60 mm.

The maximum particle size of the sludge is measured by the method described in JIS M 8801 coal test method, using a sieve with a sieve mesh size of 45 mm, sieving, and using a vernier caliper. Visually measure the sludge, and take the maximum diameter of the measured value as the maximum particle size.

When the two-liquid refining type centrifugal dehydrator 3 is used, the dehydrated product tends to be homogeneously granular (particulate matter), and the maximum particle size and average particle size can be easily measured. Therefore, the two-liquid refining centrifugal dehydrator 3 is more suitable than the one-liquid refining centrifugal dehydrator 3 .

In some cases, the dehydrated product is not homogeneously granular, that is, the dehydrated product is clumped with moisture or the like. Even if there is a lump of dehydrated matter (lump) in this way, it can be supplied to the dryer.

When the two-liquid conditioning centrifugal dehydrator 3 is used and the injection ratio of the inorganic flocculant IC is set to 5% or more, the dehydrated product tends to be more granular. By granulating the dehydrated matter, it becomes easier to stably supply the dehydrated matter to the continuous hot air dryer 5 . Further, when the dehydrated matter is granular, the resistance to the hot air flowing through the continuous hot air dryer 5 is reduced, and there is an advantage that the chances of contact between the hot air and the dehydrated matter can be increased.

(Average particle size)
The average particle size is measured by the following method. If the particle size of the dehydrated product is 500 microns or more, sieving is performed according to the method described in JIS M 8801 Coal Testing Methods. is defined as the average particle size. When the particle size of the dehydrated product is less than 500 microns, the particle size distribution is measured using a particle size distribution measuring device 8 (for example, a laser diffraction type particle size distribution measuring device, trade name SALD-3100, manufactured by Shimadzu Corporation), and the cumulative The particle size when the volume corresponds to 50% is determined as the average particle size.

The average particle size of the dehydrated matter may be measured, and if the average particle size is 1 mm to 30 mm, it may be sent to the dryer 5, and if it is outside that range, it may be sent to the digestion tank 20. If the average particle diameter is larger than 30 mm, the dehydrated matter is more likely to adhere or accumulate in the dryer 5, so such control is preferable. At the same time, if the average particle size is larger than 30 mm, there is a concern that the dried product, which is the final product, will be discharged without being sufficiently dried in the dryer 5, and the quality of the dried product, which is the final product, will be deteriorated.

(particle size distribution)
In order to stabilize the operation of the continuous hot air dryer 5, it is preferable to reduce fluctuations in the particle size distribution of the sewage sludge supplied per unit time. This is because a large change in the particle size distribution causes a problem. Specifically, when the particle size distribution value of the sludge increases, the moisture content of the dried matter discharged from the dryer 5 tends to become uneven, and when the particle size distribution value decreases, the moisture content of the dried matter tends to become uniform. .

(Hot air generator 4)
The dehydrated material discharged from the dehydrator 3 is sent to the continuous hot air dryer 5, and is dried in contact with the hot air in the dryer 5. - 特許庁The hot air used in this dryer 5 is generated by a hot air generator 4 . Specifically, the burner 4A supplied with the fuel F (LPG or the like) from a fuel tank (not shown) heats the compressed air sent from the storage tank 18 that stores the compressed air generated by the air compressor 17, Generates hot air. When the organic waste W is sludge, digestion gas generated when the sludge is digested may be used as the fuel F. The hot-air generator 4 is controlled by measuring the outlet temperature of the hot-air generator 4 and controlling the amounts of fuel F and air A supplied to the hot-air generator 4 so as to achieve a target temperature.

The temperature of the hot air is not particularly limited, but 5% or more of the inorganic flocculant IC is injected with respect to the solid amount of the organic waste W supplied to the dehydrator 3 to dehydrate, and the dehydrated matter is dried in the dryer 5. In this case, it is preferable to set the hot air temperature to 250°C to 500°C. By using hot air in this range, the moisture content of the dried organic waste becomes as low as about 10% to 50%, which increases the product value.

The hot air temperature is more preferably 350°C to 450°C, still more preferably 390°C to 410°C, and most preferably 400°C. When the hot air temperature is low, the dehydrated material cannot be sufficiently dried, and the moisture content of the dried material increases. On the other hand, when the temperature of the hot air is high, the fuel cost of the hot air generator 4 increases, resulting in poor economy. Therefore, a temperature of around 400° C. is the most suitable, considering the economic balance between the moisture content of the dried material and the fuel cost.

(Continuous hot air dryer 5)
The continuous hot air dryer 5 brings the dehydrated matter from the dehydrator 3 into contact with the hot air from the hot air generator 4, and dries the dehydrated matter into granules.

As the continuous hot air dryer 5, (1) a form in which dehydrated matter is dispersed in hot air and dried, such as a spray dryer, a flash dryer, a fluidized bed dryer, a rotary dryer, etc., (2) ) The dehydrated matter is transferred in a stationary state, such as aeration band dryers, tunnel dryers (parallel flow band dryers), and jet flow dryers, and hot air is brought into contact with the dehydrated matter during the transfer process. Examples include those in the form of drying, and (3) in the form of mechanically stirring the dehydrated matter, such as a stirring dryer, and bringing the dehydrated matter into contact with hot air to dry it. The "continuous type" of the continuous hot air dryer 5 means that it can be operated continuously.

Of the continuous hot-air dryers 5, it is preferable to use the flash dryer 5F. This is because it is inexpensive and excellent in maintainability.

There are various types of the flash dryer 5F, but if the organic waste W is dried using the indirect heating dryer 3, the adhesion of the indirectly dried matter can be weakened, so the indirectly dried matter can be A flash dryer 5F, which does not have a crusher for crushing, can be used.

An example of the flash dryer 5F is shown in FIG. This air stream dryer 5F is a circular tube air stream dryer 5CF in which pipes through which hot air flows (hereinafter also referred to as "pipes") are arranged in an annular shape. The illustrated circular tube air current dryer 5CF includes a pipe 5a to which the hot air sent from the hot air generator 4 reaches first, a pipe 5b extending upward from the pipe 5a, and a pipe 5b extending upward from the pipe 5b. It consists of a horizontally extending pipe 5c and a pipe 5d extending downward from the pipe 5c. Between adjacent pipes (for example, between pipe 5a and pipe 5b), a pipe curved in an R shape is positioned. The lower end of the pipe 5d is joined to the left end of the pipe 5a, and the insides of the pipes are connected to each other at this joint. An intermediate portion of the pipe 5a is provided with a supply port 5X for the indirectly dried matter, and an intermediate portion of the pipe 5d is provided with an outlet port 5Y for the dried matter.

The hot air generated by the hot air generator 4 is supplied to the pipe 5a. At the same time, the indirectly dried material conveyed by the conveying means 7 falls from the supply port 5X into the hot air (hot air current) of the pipe 5a. The indirectly dried material that has fallen is dispersed in the form of powder in the hot air. Then, the granules are instantaneously dried while being sent in parallel with the hot air current (while being air-conveyed by the hot air). Specifically, the hot air accompanied by powder flows through the pipes 5a, 5b, 5c, and 5d in this order, and part of it is exhausted from the outlet 5Y. On the other hand, the indirectly dried material not discharged from the discharge port 5Y joins with the hot air newly sent from the hot air generator 4, flows again through the pipes 5a, 5b, 5c, and 5d, and part of it is discharged. It is exhausted to the outside from the outlet 5Y. As described above, part of the hot air is discharged from the outlet 5Y, and the rest of the hot air circulates through the pipes 5a to 5d. In this way, the indirectly dried matter newly charged and the indirectly dried matter circulating in the pipe are mixed in the pipe, thereby adjusting the adhesion and water content. That is, in the tubular flash dryer 5CF, the indirectly dried material is dried by absorbing the heat in the hot air. Therefore, this circular tube airflow dryer 5CF has a fundamentally different structure from indirect heating dryers and the like that dry by contacting heated pipes with the indirectly dried material.

The indirectly dried material immediately after being supplied to the circular tube-type airflow dryer 5CF often flows along the outer peripheral sides of the pipes 5a to 5d under the influence of centrifugal force. Then, as the drying of the indirectly dried matter progresses, the aggregated state of the indirectly dried matter is released and the average particle size becomes smaller, so that it flows along the inner peripheral side of each pipe 5a to 5d, and the exhaust provided inside the pipe 5d. It is discharged from the outlet 5Y.

In the operation of the circular tube air current dryer 5CF, it is preferable to set the wind speed of the hot air in each pipe 5a to 5d to 10 m/s or more. More preferably, it should be 15 m/s or more in order to smoothly convey the indirectly dried material with hot air. More preferably, the indirectly dried matter supplied from the supply port 5X collides with the circulating hot air at high speed, so that the indirectly dried matter can be dispersed in the hot air.

In FIG. 1, a tubular flash dryer 5CF having pipes 5a to 5d arranged in an annular shape is shown. However, the continuous hot air dryer 5 is not limited to the annular air current dryer 5F, and may be a straight pipe air current dryer 5LF in which all pipes are arranged linearly or substantially linearly. The circular tube type flash dryer 5CF is superior to the straight tube type flash dryer 5LF in that the installation space is smaller. However, even in the case of the straight pipe air current dryer 5LF, it is possible to reduce the installation space if the pipes are extended in the height direction.

Incidentally, even if the size of the cylindrical flash dryer 5CF is increased or decreased, there is almost no change in the retention time of the indirectly dried material in the dryer 5CF.

A stirring heat transfer dryer may be used instead of the continuous hot air dryer 5, or a flash dryer with a crusher may be used as the continuous hot air dryer 5. An indirect heating dryer (steam tube dryer) may be provided instead of the continuous hot air dryer 5, but the initial cost is overwhelmingly low, the grounding area of the equipment is not required, and the delivery time is shortened. Continuous hot air dryer 5 (in particular, circular tube air stream dryer 5CF or straight tube air stream dryer 5LF) is preferable.

The continuous hot air dryer 5 of the present invention has a heat capacity coefficient determined from the size of the continuous hot air dryer ⁵ and the temperature and amount of the supplied hot air gas. A dryer 5 is preferably used. The higher the heat capacity coefficient, the more heat energy can be transferred to the sludge, and the energy can be used to evaporate the water content of the sludge. Since the circular tube airflow dryer 5CF has a very high heat capacity coefficient compared to an indirect heating dryer such as an inclined disk dryer, sufficient drying can be performed with a short residence time.

(Solid-gas separator 6)
The hot air whose humidity is increased by drying the powder is exhausted from the continuous hot air dryer 5 as exhaust gas and sent to the solid-gas separator 6 . Since this exhaust gas contains particulate matter, it is separated into particulate matter and separated gas (gas separated from particulate matter) using a solid-gas separator 6 .

As the solid-gas separator 6, for example, a cyclone that collects dust by centrifugal force, a gravity sedimentation chamber that collects dust by gravity, a mist separator that collects dust by inertia, a bag filter that collects dust by filter cloth, a filling A moving particle bed air filter that collects dust with a layer, an electric dust collector that collects dust with electricity, or the like can be used.

(exhaust treatment)
The separated gas separated from the particulate matter by the solid-gas separator 6 is dust-removed by a venturi scrubber 11 that collects dust by washing, and then is sucked by an exhaust fan 12 and conveyed to a mist separator 13 . Then, after being further dust-removed by the mist separator 13, it is deodorized by the plasma deodorizer 14 and diffused into the atmosphere E. The method for treating the separated gas discharged from the solid-gas separator 6 is not limited to the above contents, and each facility may be changed as appropriate.

(Storage of Granules)
Granular material is discharged from the lower end of the solid-gas separator 6 and supplied to the granular material upstream conveying machine 9 through the pipe 31 . When granular material with a high moisture content accumulates at the lower end of the solid-gas separator 6, the granular material adheres to the valve and may not be discharged well. Therefore, it is preferable to provide a rotary valve 19 for scraping by a rotating blade.

As the granular material upstream conveying device 9, a screw conveyer, a belt conveyer, or the like, which conveys by mechanical power, can be used. The screw conveyor 9 has a powder supply port at an intermediate portion in the longitudinal direction of the screw conveyor 9, and a powder discharge port at one end (right side in the drawing) and the other in the longitudinal direction of the screw conveyor 9. It is provided at the end side end (left side in the drawing). The granules supplied from the supply port are conveyed to one end by forward rotation of the screw conveyor 9 and discharged from the discharge port at the one end. Conversely, when the screw conveyor 9 rotates in the reverse direction, the granular material is carried to the other end and discharged from the discharge port at the other end. The temperature of the granular material supplied to the screw conveyor 9 is as high as about 65.degree. C. to 90.degree.

Granules discharged from the discharge ports (one end side discharge port and the other end side discharge port) of the screw conveyor 9 are supplied to separate screw conveyors 10 through pipes 32 . By rotating the screw conveyor 10 forward or backward, the particles are distributed to one end side and the other end side of the screw conveyor 10 . Then, the granular material discharged from one end side discharge port or the other end side discharge port passes through the pipe 33 and is stored in each container 15 (four containers in the illustrated embodiment).

(Measuring device N)

Measuring devices N can be provided at positions N4 and N5 downstream of the dehydrator 3 and positions N1 and N2 downstream of the dryer 5 .

In addition, the measuring device N is provided downstream of the dehydrator 3 and downstream of the dryer 5, and the measuring device N is provided at the position of N6 inside the dehydrator 3 and the position of N3 inside the dryer 5. Also good.

Further, the measuring device N may be provided downstream of the dehydrator 3 or downstream of the dryer 5, and the measuring device N may be provided at the position N7 upstream of the dehydrator 3 or the position N4 upstream of the dryer 5. .

In addition, since the reference numerals N1 to N7 in FIG. 1 exemplify the positions where the measuring device N is provided, it is not necessary to provide the measuring device N at all the positions N1 to N7, and the positions other than N1 to N7 may be provided with the measuring device N. For example, in order to measure the moisture content of the dried material discharged from the dryer 5, a measuring device N may be provided in the pipe 32 between the granular material upstream conveying machine 9 and the granular material downstream conveying machine 10. , the measuring device N may be provided in the pipe 33 between the powder downstream carrier 10 and the container 15 .

However, it is important to measure the moisture content of at least one of the dehydrated matter discharged from the dehydrator 3 and the dried matter discharged from the dryer 5 . Therefore, it is desirable to install the measuring device N on at least one of the downstream side of the dehydrator 3 and the downstream side of the dryer 5 with reference to the organic waste treatment process.

In addition, when measuring the moisture content of the dehydrated matter discharged from the dehydrator 3, it is preferable to provide it at the position of N5. Moreover, when measuring the moisture content of the dried material discharged from the dryer 5, it is preferably provided at the position of N1. This is because the most representative portion of the sludge flowing in the process can be collected at positions N5 and N1.

In addition, although not shown, the dehydrated matter supplied from the supply port of the dehydrated matter conveying machine 7 drops and first lands inside the dehydrated matter conveying machine 7, or a measuring device N is provided in the vicinity thereof. can be

In FIG. 1, portions N7, N4 and N2 are also constructed of pipes, like the portion N5.

An example of the measuring device N is shown in FIG. This measuring device N is inserted into the inside of the tube 30 through a hole provided at an arbitrary location in the peripheral wall of the tube 30, and includes a sampling section 40 for sampling dehydrated matter and dried matter passing through the inside of the tube 30; A conveying unit 41 arranged outside and conveying the dehydrated matter and the dried matter collected by the collecting unit 40 outward, and the dehydrated matter conveyed by the conveying unit 41 arranged outside the conveying unit 41 is the dried matter. and a measurement unit 44 arranged outside the consolidation unit 43 for measuring the moisture content of the dehydrated matter and the dried matter consolidated by the consolidation unit 43 . The direction toward the center of the tube 30 is called the center side, and the direction radially outward from the center of the tube 30 is called the outside. The collecting section 40, the conveying section 41, the compacting section 43, and the measuring section 44 are adjacent to each other in this order from the central portion toward the outside, and the dehydrated matter and the dried matter collected by the collecting section 40 are conveyed outward. . In the illustrated embodiment, the collecting part 40 and the conveying part 41 are tubular, and a screw as a conveying device 42 is arranged inside them. It has a form to move the dried matter to the outside. Since the collecting section 40 also has a conveying means 42 inside, the collecting section 40 also plays a role similar to that of the conveying section 41 . The conveying device 42 may use known means such as a piston instead of the screw. It is preferable that the conveying speed at which the dehydrated matter and the dried matter are conveyed by the conveying device 42 is set to an arbitrary speed at least to the extent that the dehydrated matter and the dried matter do not accumulate excessively inside the collection unit 40 . The measurement unit 44 is configured to measure the moisture content of the organic waste W using microwaves. The organic waste W after measurement is returned to the inside of the pipe 30 through a return section (not shown).

Conventionally, the time required for one measurement (time from sampling to obtaining measurement results) was long. Therefore, there is a problem that the feedback control and the like cannot be performed in real time. In other words, it often takes about half a day to one day to obtain the measurement result after collecting the organic waste W. Therefore, the content of the control was suitable for the operating condition one hour ago, and was not suitable for the operating condition of the device 35 at the present time. Moreover, even with a general moisture meter (infrared type or halogen type), it takes about 30 minutes to 1 hour to obtain measurement results.

Therefore, by using microwaves as in the present invention, the time from sampling to execution of control can be shortened (about 1 to 15 minutes), so the occurrence of the above-mentioned time lag can be prevented. can. Similarly, when measuring the moisture content of the dried product, it can be done in about 1 to 15 minutes.

Moreover, it is preferable to continuously perform a series of operations of collecting the organic waste W, compacting it, and measuring it. That is, the water content of the organic waste W can be determined by collecting the organic waste W continuously rather than intermittently, continuously compacting the collected organic waste W, and measuring the organic waste W continuously. You can see the changes in real time. As a result, the dehydration conditions and drying conditions of the dehydrator 3 and the dryer 5 can be quickly changed according to the change.

The measuring device N measures the moisture content based on the wave speed of microwaves (electromagnetic waves), and the transmission speed is greatly affected by the dielectric constant of air and objects. Therefore, before the microwave measurement, the organic waste W is compacted (pressed, etc.) so that the degree of influence by air is always maintained at the same level.

Regarding the collection of the organic waste W, it is possible to collect the stored organic waste W, but it is preferable to collect the organic waste W that is moving. For example, even if the moisture content of the organic waste W stored in the container 15 is measured, it is determined whether the dehydrator 3 or the dryer 5 is in an appropriate operating state, that is, is operated so as to achieve the desired moisture content. I don't know if Therefore, for example, by providing a measuring device N at the position of N1 or N4 in FIG. It is good to understand whether it is

Also, the sampling unit 40 of the measuring device N is inserted into tubes provided at, for example, N1, N2, N4, and N5. The moving speed of the dehydrated matter and the dried matter moving inside this tube is generally in the range of 0.5 m/s to 150 m/s. In addition, in FIG. 2, the sampling part 40 is inserted toward the center of the tube 30, but it may be inserted with a slight deviation from the center.

The insertion area D2 of the collection part 40 is preferably 0.05% to 5%, more preferably 1% to 5%, relative to the cross-sectional area D1 of the tube (meaning the cross-sectional area inside the tube; the same shall apply hereinafter). If the insertion area D2 of the sampling unit 40 is less than 0.05%, the amount of dehydrated matter or dried matter to be collected is small, and measurement cannot be started until a predetermined amount of dehydrated matter or dried matter is accumulated. There is a problem that it is difficult to detect the moisture content in real time. Further, if the insertion area of the collection unit 40 is more than 5%, the amount of dehydrated matter or dried matter collected increases, and there is a high possibility that the inside of the measuring device N will be clogged with the dehydrated matter or dried matter. .

As shown in FIG. 3, the sampling part 40 may be formed by horizontally extending a tube, cutting only the upper part of the tube horizontally, and providing an opening 45 opening upward. good. In FIG. 3, the opening 45 is hatched for convenience of explanation, but the hatched portion is normally hollow. With such a shape, dehydrated matter and dried matter falling from above due to gravity can be received in the collecting portion 40 through the opening 45 . Preferably, as shown in FIG. 3, the opening 45 is provided over the entire collecting portion 40 . In this case, the insertion area of the sampling part 40 indicates the total area of the opening 45 .

(delete)

In addition, the length L2 for inserting the extraction part 40 is preferably 60% or more, more preferably 80% or more, of the inner diameter L1 of the tube. If the insertion length L2 of the collection unit 40 is less than 60%, the amount of dehydrated matter or dried matter collected is small, and measurement cannot be started until a predetermined amount of dehydrated matter or dried matter is accumulated. Therefore, there is a problem that it is difficult to detect the moisture content of dehydrated matter and dried matter in real time. In addition, it is more preferable that the inner diameter L1 of the tube is 50 mm or more.

(Control details)
The reason for providing the measuring device N is to monitor the moisture content of dehydrated matter and dried matter. If the moisture content is not within the desired range, control may be performed to change the dehydration conditions or drying conditions. For example, a measuring device N may be provided at a downstream position (for example, N1) of the continuous hot air dryer 5, and the operation of the dryer 5 may be controlled based on the measurement results (feedback control). In this case, it is better to measure after the organic waste W is discharged from the solid-gas separator 6 rather than before it is supplied to the solid-gas separator 6 . This is because the organic waste W is moving at a high speed in a flow path (for example, a pipe) before being supplied to the solid-gas separator 6, making it difficult to collect the waste.

Of the continuous hot air dryers 5, the circular tube airflow dryer 5CF is suitable as the dryer 5 according to the present invention. This is because the tubular flash dryer 5CF has a short retention time of the organic waste W in the dryer 5CF, so the time required for one cycle of collection, consolidation, measurement, and control can be shortened. This is because the adjustment of the operation of the dryer 5CF can be quickly changed.

Although various control methods are conceivable for the continuous hot air dryer 5, temperature change of the hot air used for the continuous hot air dryer 5 can be exemplified. For example, the temperature of this hot air is changed to an arbitrary temperature in the range of about 250° C. to 500° C., and the organic waste W is dried to the target moisture content.

Further, a measuring device N may be provided downstream of the dehydrator 3 (for example, N4 or N5), and the operation of the dehydrator 3 may be controlled based on the measurement results. As for the control of the dehydrator 3, for example, in the case of the in-machine two-liquid tempering type centrifugal dehydrator 3, the injection amount of the polymer coagulant HC and the inorganic coagulant IC is changed, and the rotation speed of the rotating bowl is changed. can be mentioned. In addition, when the dehydrator 3 is a centrifugal dehydrator or a belt press dehydrator, the centrifugal force, the differential speed, the tension pressure of the filter cloth, the running speed of the filter cloth, the stirring rotation speed of the aggregation and mixing tank, etc. are changed. be able to.

As described above, according to the method and apparatus 1 for treating the organic waste W according to the present invention, the water content of the organic waste W discharged from the dehydrator 3 and the dryer 5 can be set to a value close to the target value. can be transitioned with As a result, the value of the organic waste W as a fuel resource or the like can be increased.

Further, by controlling the amount of the organic waste W supplied to the dehydrator 3 and the amount of the coagulant used for dehydration, the moisture content of the dehydrated matter can be made uniform. If the moisture content of the dehydrated product becomes uniform, there is an advantage that the operation control in the subsequent steps (for example, the drying step) becomes easier. Further, when the dehydrator 3 has a surplus processing capacity, by increasing the supply amount of the organic waste W, the dehydration processing amount per unit time can be increased. Conversely, when the organic waste W exceeding the processing capacity of the dehydrator 3 is supplied, the load on the dehydrator 3 can be reduced by reducing the amount of organic waste W supplied. The product life of the machine 3 can be extended. Also, by optimizing the amount of flocculant used for dehydration, it is possible to prevent the addition of excess flocculant, thereby reducing running costs.

Furthermore, when the moisture content of the dried matter discharged from the dryer 5 is measured by the measuring device N, and the amount of hot air used in the dryer 5 and the temperature of the hot air are controlled based on the measured value, the amount of hot air By optimizing the air temperature and the hot air temperature, wasteful use of the auxiliary fuel used for the hot air generator 4 can be suppressed. In addition, by quickly changing the drying conditions based on the measured moisture content, it is possible to make the moisture content of the dried product uniform. can be done.

Although FIG. 1 illustrates the processing apparatus 1 including both the dehydrator 3 and the dryer 5, the present invention is not limited to such a form, and either the dehydrator 3 or the dryer 5 The processing device 1 may be provided with only one. In this case, it is preferable to install the measuring device N downstream of either the dehydrator 3 or the dryer 5 . Then, based on the moisture content measured by the measuring device N, either one of the dehydrator 3 and the dryer 5 may be controlled.

1: treatment device, 2: sludge storage tank, 3: dehydrator, 4: hot air generator, 5: continuous hot air dryer, 5a to 5d: pipe, 5F: flash dryer, 5CF: circular tubular flash dryer , 5X: supply port, 5Y: discharge port, 6: solid-gas separator, 7: dehydrated material conveying machine, 8: particle size distribution measuring device, 9: granular material upstream conveying machine, 10: granular material downstream conveying machine, 11: venturi scrubber, 12: exhaust fan, 13: mist separator, 14: plasma deodorizer, 15: container, 17: air compressor, 18: storage tank, 19: rotary valve, 20: digestion tank, 21: supply pump , 31 to 33: pipe, 40: collection unit, 41: transportation unit, 42: transportation equipment (screw, piston, etc.), 43: consolidation unit, 44: measurement unit, 45: opening, E: atmosphere, F: fuel , M: motor, N: (moisture content) measuring device, N1 to N7: example of installation location of measuring device, W: sludge

Claims (3)

A tubular flash dryer that dries organic waste,
A dried matter discharge pipe through which the dried matter discharged from the circular tube type flash dryer passes;
Having a dried matter measuring device for measuring the moisture content of the dried matter passing through the dried matter discharge pipe,
The device for measuring the dried matter is
a dried matter collection unit for continuously collecting the dried matter passing through the inside of the dried matter discharge pipe;
a dried matter conveying unit for conveying the dried matter collected by the dried matter collecting unit;
a dried matter consolidation unit for consolidating the dried matter conveyed by the dried matter conveying unit;
Having a dried matter measurement unit for measuring the moisture content of the dried matter in which the consolidation unit of the dried matter is compacted by microwaves,
With the dried matter measuring device attached to the dried matter discharge pipe,
The dried matter collection part is inserted inside the dried matter discharge pipe,
the dried matter conveying section, the dried matter consolidation section and the dried matter measuring section are located outside the dried matter discharge pipe;
The dried material collecting section, the dried material conveying section, the dried material compacting section, and the dried material measuring section are provided adjacent to each other in order from the center of the dried material discharge pipe toward the outside. A method of treating organic waste using an organic waste treatment apparatus, comprising:
A series of operations in which the dried organic waste discharged from the discharge port of the circular tubular flash dryer is continuously collected, transported, compacted, and then the moisture content is measured by microwaves. a measuring step performed by
and a control step of changing at least one of hot air volume and hot air temperature supplied to the circular tube air dryer based on the moisture content of the dried matter measured in the measuring step,
A method for treating organic waste, characterized in that the hot air temperature is changed in the range of 250 to 500°C. A two-liquid conditioning type dehydrator for dehydrating organic waste ,
A dehydrated matter discharge pipe through which the dehydrated matter discharged from the two-liquid conditioning type dehydrator passes;
Having a dehydrated matter measuring device for measuring the moisture content of the dehydrated matter passing through the dehydrated matter discharge pipe,
The dehydrated matter measuring device is
a dehydrated matter collection unit for continuously collecting the dehydrated matter passing through the inside of the dehydrated matter discharge pipe;
a dehydrated substance conveying unit for conveying the dehydrated substance collected by the dehydrated substance collecting unit;
a dehydrated matter consolidation unit for consolidating the dehydrated matter conveyed by the dehydrated matter conveying unit;
Having a dehydrated matter measurement unit that measures the moisture content of the dehydrated matter compacted by the dehydrated matter consolidation unit using microwaves,
With the dehydrated matter measuring device attached to the dehydrated matter discharge pipe,
The dehydrated matter collection unit is inserted inside the dehydrated matter discharge pipe,
the dehydrated matter conveying section, the dehydrated matter consolidation section and the dehydrated matter measuring section are located outside the dehydrated matter discharge pipe;
The dehydrated matter collecting section, the dehydrated matter conveying section, the dehydrated matter consolidation section, and the dehydrated matter measuring section are provided adjacent to each other in order from the center of the dehydrated matter discharge pipe toward the outside. A method of treating organic waste using an organic waste treatment apparatus, comprising:
A series of operations in which the dehydrated matter of the organic waste discharged from the discharge port of the two-liquid conditioning dehydrator is continuously collected, transported, compacted, and then the moisture content is measured by microwaves. a continuous measurement process;
Based on the water content of the dehydrated product measured in the measurement step, the amount of polymer flocculant supplied to the two-liquid refining type dehydrator, the amount of inorganic flocculant supplied to the two-liquid refining type dehydrator , and a control step of changing at least one selected from the group of the rotation speed of the rotating bowl of the two-liquid regenerating dehydrator;
The method for treating organic waste according to claim 1, comprising: 2. The method for treating organic waste according to claim 1, wherein the insertion area of said dried matter collecting portion is 0.05% to 5% of the cross-sectional area of said dried matter discharge pipe.

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