JP2005103405A - Apparatus for removing foreign matter in organic waste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for removing foreign matter in organic waste which can suppress the degradation of the dehydration capacity of a dehydrator and can be made inexpensive and small-sized. <P>SOLUTION: This apparatus is provided with: a foreign matter deposition part 6 which is formed at the lower part of a storage vessel 2 and on which the foreign matter deposits; a waste supply pipeline 20 which discharges liquid organic waste 1 and supplies it to a screw press 9; and a foreign matter removing pipeline 21 which discharges the foreign matter which has deposited on the foreign matter deposition part from the storage vessel 2 and supplies it to the screw press 9; a fixed displacement pump 24 which is provided in the waste supply pipeline 20; and 1st and 2nd valves 26a and 26b which are provided in series with a fixed interval therebetween in the foreign matter removing pipeline 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is installed in a methane fermentation-related facility that stores, solubilizes, and solubilizes organic waste, and relates to a removal device that removes impurities contained in the organic waste.

  Conventionally, as this type of removal device, for example, as shown in FIG. 5, a tempering tank 52 for storing organic waste 51 and an organic waste 51 discharged from the tempering tank 52 are mixed with heavy impurities. Separation tank 53 that separates into organic waste 51 containing and organic waste 51 containing lightweight impurities, and heavy impurities from organic waste 51 containing the above heavy impurities (shells, bones, gravel, etc.) Some are provided with a screw conveyor 54 for solid-liquid separation and a screw press 55 for solid-liquid separation of lightweight impurities from the organic waste 51 including the lightweight impurities (vinyl pieces, plastic pieces, etc.).

  Each of the screw conveyor 54 and the screw press 55 is provided with a rotatable screw 57 inside a cylindrical outer cylinder screen 56 in which a large number of moisture discharge holes (not shown) are formed. . The tempering tank 52 and the separation tank 53 are connected via a transfer pipe 58, and the separation tank 53 and the screw conveyor 54 are connected via a contaminant discharge pipe 59. 53 and the screw press 55 are connected via a supernatant liquid transport pipe 60. Furthermore, one each of the on-off valves 61 and 62 is provided in the said contaminant discharge pipe | tube 59 and the supernatant liquid conveyance pipe | tube 60 (for example, refer patent document 1).

  According to this, the liquid organic waste 51 stored in the tempering tank 52 is stirred and tempered, and then discharged to the separation tank 53. Heavy impurities precipitate at the bottom of the separation tank 53, and one of the on-off valves 61 is opened, whereby organic waste 51 mainly containing heavy impurities is supplied from the separation tank 53 to the screw conveyor 54, and screw It is dehydrated by the conveyor 54, and heavy impurities are separated and discharged. Further, by opening the other on-off valve 62, the supernatant liquid of the organic waste 51 in the separation tank 53 is supplied to the screw press 55, dehydrated by the screw press 55, and lightweight impurities are separated and discharged. .

However, in the above conventional type, since two dehydrators, the screw conveyor 54 and the screw press 55, are provided, there is a problem that the cost is increased or the size is increased. In addition, lightweight impurities adhere to the moisture discharge holes (not shown) formed in the outer cylinder screen 56 of the screw press 55, clog the moisture discharge holes, and the dewatering capacity of the screw press 55 is reduced. Therefore, it was necessary to clean the inside of the screw press 55 frequently. Further, when the on-off valves 61 and 62 are opened and the organic waste 51 is supplied from the separation tank 53 to the screw conveyor 54 or the screw press 55, the supply amount is likely to fluctuate. There was a problem that the dehydration capacity of 55 could not be maintained properly. Further, it is difficult to improve the removal efficiency of foreign substances only with the screw conveyor 54 and the screw press 55.
JP-A-11-300396

  The present invention can achieve cost reduction and downsizing, can suppress a decrease in the dewatering capacity of the dehydrator, can supply organic waste quantitatively from the storage tank to the dehydrator, An object of the present invention is to provide an organic waste contaminant removal apparatus capable of improving the removal efficiency of waste.

  In order to achieve the above object, according to the first aspect of the present invention, a removal device for removing impurities contained in the solubilized liquid organic waste, the storage tank storing the organic waste, A filtration type dehydrator for dehydrating organic waste discharged from the storage tank, and the dehydrator includes a filtration screen having a plurality of moisture discharge openings, and the storage tank In the lower part of the inside, there is formed a dust depositing portion for depositing deposited dust, discharging the organic waste in the storage tank and supplying it to the dehydrator, and the dust depositing portion described above A contaminant removal conduit that discharges the contaminants accumulated in the reservoir together with the organic waste from the storage tank and supplies it to the dehydrator is provided.

  According to this, among the impurities contained in the organic waste stored in the storage tank, mainly heavy impurities having a large specific gravity are accumulated in the contaminant accumulation part. For this reason, the organic waste supplied to the dehydrator from the debris removal pipeline is more heavy than the organic waste supplied to the dehydrator from the waste supply pipeline. Contains.

  Usually, the organic waste in the storage tank is supplied from the storage tank to the dehydrator through the waste supply pipe, and dehydrated by the dehydrator. As a result, the organic waste is separated into filtrate and contaminants. At this time, the contaminants in the organic waste supplied to the dehydrator from the waste supply pipeline are compared with the contaminants in the organic waste supplied to the dehydrator from the contaminant removal pipeline. Many of these were mainly lightweight, and this lightweight contaminant adhered to the screen of the dehydrator, and the water discharge opening was easily clogged.

  On the other hand, the supply of organic waste from the waste supply pipe to the dehydrator is periodically stopped, and the foreign matter accumulated in the foreign matter accumulation part is removed from the storage tank together with the organic waste. It is supplied to the dehydrator through the contaminant removal pipeline and dehydrated by the dehydrator. At this time, the foreign matter accumulated in the foreign matter accumulation part is mainly heavy and hard compared to the foreign matter in the organic waste supplied to the dehydrator from the waste supply pipe, The heavy contaminants collide with the lightweight contaminants adhering to the moisture discharge opening, and the lightweight contaminants are peeled off from the screen of the dehydrator. In this way, by periodically switching the nature of the contaminants in the organic waste supplied to the dehydrator from light to heavy, the screen is cleaned and the clogging of the water discharge opening is reduced. For this reason, the fall of the dewatering capability of a dehydrator can be suppressed and the frequency | count of cleaning inside a dehydrator can be reduced.

In the second aspect of the invention, a constant displacement pump is provided in the waste supply pipe, and a plurality of switching devices for opening and closing the pipe are provided in series in the contaminant removal pipe.
According to this, organic waste in the storage tank is quantitatively transferred from the waste supply line to the dehydrator by driving the constant displacement pump with the contaminant removal pipe closed by the switchgear. Can be supplied to. Thereby, there is no fluctuation | variation of the supply amount of organic waste, and the dehydrating capability of a dehydrator is maintained appropriately.

  In addition, by stopping the constant displacement pump and stopping the supply of organic waste from the waste supply line to the dehydrator, the switchgear is opened and closed temporarily by opening and closing each switchgear. Contaminants are collected in the meantime, and then the contaminants collected between the switchgear are supplied to the dehydrator. As a result, since a certain amount of contaminants accumulated between the switchgears can be supplied to the dehydrator, there is no fluctuation in the supply amount, and the organic waste in the storage tank is removed from the contaminant removal conduit. Can be supplied quantitatively. Therefore, the dehydrating ability of the dehydrator is maintained properly.

In the third aspect of the invention, a sedimentation separation device for sedimentation and separation of the filtrate discharged from the dehydrator is provided.
According to this, the organic waste is dehydrated by a dehydrator and separated into a filtrate and impurities, and then the filtrate is further settled and separated by a sedimentation separator. Thereby, since the contaminants remaining in the filtrate can be settled and removed, the efficiency of removing the contaminants is greatly improved.

  According to the first aspect of the present invention, clogging of the moisture discharge opening of the dehydrator is reduced, so that a decrease in the dewatering capacity of the dehydrator is suppressed, and the number of times of cleaning the dehydrator can be reduced. Further, the number of dehydrators can be reduced to one, and the cost can be reduced.

  According to the second aspect of the present invention, the organic waste in the storage tank is quantitatively supplied from the waste supply pipe to the dehydrator and is quantitatively supplied from the contaminant removal pipe to the dehydrator. It becomes possible. For this reason, the dewatering capability of the dehydrator is maintained properly.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
In a methane fermentation-related facility for treating organic waste with methane fermentation, as shown in FIG. 1, organic waste 1 such as crushed garbage is stirred in a storage tank 2 (also referred to as a solubilization tank) to be liquid. After removing impurities contained in the organic waste 1 that has become liquid (slurry or paste) and becomes liquid, the organic waste 1 is supplied to the methane fermentation tank.

The configuration of the removal device 3 will be described below.
At the bottom of the storage tank 2, a funnel-shaped foreign matter accumulation portion 6 is formed which has a smaller diameter as it goes downward. A conical plate 7 having a smaller diameter toward the upper side is provided inside the storage tank 2. One screw press 9 (an example of a filtration type dehydrator) that dehydrates the organic waste 1 discharged from the storage tank 2 is installed below the storage tank 2.

  As shown in FIGS. 1 and 2, the screw press 9 includes a cylindrical outer screen 11 for filtration in which a large number of moisture discharge holes 10 (an example of a moisture discharge opening) are formed, and organic waste. A supply port 12 for supplying the product 1 into the outer cylinder screen 11, a contaminant discharge port 13 for discharging impurities obtained by dehydrating the organic waste 1, and for discharging moisture from the inside of the outer cylinder screen 11. A filtrate discharge port 14 that collects and discharges the filtrate drained to the outside through the hole 10, and the organic waste 1 supplied from the supply port 12 into the outer cylinder screen 11 is pressed against the contaminant discharge port 13. It comprises a rotatable screw 15 that conveys and a presser device 16 that adjusts the moisture of the contaminants discharged from the contaminant discharge port 13.

  Between the storage tank 2 and the screw press 9, the organic waste 1 in the storage tank 2 is discharged and deposited on the waste supply pipe 20 that supplies the screw press 9 and the foreign matter accumulation section 6. A contaminant removal conduit 21 for discharging the contaminants together with the organic waste 1 from the storage tank 2 and supplying it to the screw press 9 is provided. The upper end of the waste supply pipe 20 penetrates the bottom of the storage tank 2 and enters the inside of the conical plate 7 from below. Further, the upper end portion of the contaminant removal conduit 21 is connected to the lower end of the bottom portion of the storage tank 2. Further, the lower end of the waste supply pipe 20 and the lower end of the contaminant removal pipe 21 are connected to the supply port 12 of the screw press 9.

  The waste supply pipe 20 is provided with a constant capacity pump 24 and a valve 25 which is an opening / closing device for opening and closing the pipe 20. The contaminant removal conduit 21 is provided with a first valve 26a (an example of an opening / closing device) and a second valve 26b (an example of an opening / closing device) for opening and closing the conduit 21 in series. Yes. The first valve 26a and the second valve 26b are separated by a fixed distance A and are connected via a short pipe 21a.

  On the downstream side of the screw press 9, a sand settling tank 29 (an example of a settling / separation device) is installed for settling and separating the filtrate discharged from the filtrate discharge port 14. As shown in FIGS. 3 and 4, the sand settling tank 29 is provided with a plurality of sand settling containers 31 inside the tank body 30. An inlet 32 communicating with the filtrate outlet 14 is formed in the front wall 30a of the tank body 30, and an overflow plate 33 is provided between the left and right side walls 30b of the tank body 30, and the overflow plate 33 and the tank A pit 34 is formed between the main body 30 and the rear wall 30c. Each of the sand sinking containers 31 has a rectangular box shape with an open upper surface, and is arranged between the front wall 30a and the overflow plate 33 so that it can be lifted upward. The filtrate supplied from the screw press 9 to the sand settling tank 29 is settled and separated, and then supplied from the pit 34 to the methane fermentation tank by the pump 35.

Hereinafter, the operation of the above configuration will be described.
Among the impurities contained in the organic waste 1 stored in the storage tank 2, mainly heavy impurities (shells, bones, gravel, etc.) having a large specific gravity are accumulated in the impurity accumulation part 6. Further, since the upper end portion of the waste supply pipe 20 has entered the inside of the conical plate 7 from below, the heavy contaminants that settle in the storage tank 2 are blocked by the conical plate 7 and discarded. It is impossible to enter the upper end portion of the article supply conduit 20. Thereby, the organic waste 1 supplied from the contaminant removal conduit 21 to the screw press 9 is more compared to the organic waste 1 supplied from the waste supply conduit 20 to the screw press 9. Contains a lot of heavy impurities.

  Usually, both the first and second valves 26a and 26b are closed, the valve 25 is opened, and the constant displacement pump 24 is driven. 20 is quantitatively supplied from the supply port 12 to the screw press 9 and dehydrated. That is, as shown in FIG. 2, the organic waste 1 supplied to the screw press 9 is transported from the supply port 12 side to the contaminant discharge port 13 side through the outer cylinder screen 11 by the rotation of the screw 15. The organic waste 1 is separated into filtrate and contaminants, the contaminants are discharged from the contaminant discharge port 13, and the filtrate is collected through the moisture discharge hole 10 of the outer cylinder screen 11 and collected into the filtrate discharge port 14. Discharged from.

  Thereafter, the filtrate discharged from the filtrate discharge port 14 flows into the tank body 30 of the sand settling tank 29 from the inlet 32, passes through the overflow plate 33 through each sand settling container 31, and flows into the pit 34. As a result, the impurities remaining in the filtrate settle and separate in each of the sand settling vessels 31, and the filtrate accumulated in the pit 34 is fed into the methane fermentation tank by the pump 35.

  As described above, since the organic waste 1 in the storage tank 2 can be quantitatively supplied to the screw press 9 by the constant displacement pump 24, there is no fluctuation in the supply amount, and the dewatering capacity of the screw press 9 Can be maintained appropriately, and the amount of input from the sand settling tank 29 to the methane fermentation tank can be controlled almost quantitatively. Moreover, since the impurities remaining in the filtrate are further settled and separated in the sand settling tank 29, the efficiency of removing the impurities is greatly improved.

  At this time, the contaminants in the organic waste 1 supplied from the waste supply pipe 20 to the screw press 9 are contained in the organic waste 1 supplied from the contaminant removal pipe 21 to the screw press 9. In many cases, the lightweight impurities were attached to the outer cylinder screen 11 of the screw press 9 and the moisture discharge hole 10 was easily clogged.

  In contrast, the constant displacement pump 24 is periodically stopped to close the valve 25, and the first valve 26a is opened while the second valve 26b is closed. As a result, the supply of the organic waste 1 from the waste supply pipe 20 to the screw press 9 is stopped, and the foreign matter accumulated in the foreign matter depositing section 6 is transferred from the storage tank 2 to the foreign matter removal pipe. 21 flows into the short tube 21a. Next, by closing the first valve 26a and opening the second valve 26b, a certain amount of contaminants accumulated in the short pipe 21a passes through the contaminant removal conduit 21 and passes through the supply port 12. It is quantitatively supplied to the screw press 9 and dehydrated.

  As described above, since a certain amount of contaminants stored in the short pipe 21a between the valves 26a and 26b can be supplied to the screw press 9, there is no fluctuation in the supply amount, and the dewatering capacity of the screw press 9 Is maintained properly.

  At this time, the foreign matter (shells, bones, gravel, etc.) accumulated in the foreign matter accumulation part 6 is contaminated in the organic waste 1 supplied to the screw press 9 through the waste supply pipe 20. Compared to the above, there are many heavy and hard things, such heavy impurities collide with the lightweight impurities adhering to the moisture discharge hole 10 of the screw press 9, and the lightweight impurities are screw-pressed. 9 is peeled from the outer cylinder screen 11. Thus, by periodically switching the property of the impurities in the organic waste 1 supplied to the screw press 9 from the light weight to the heavy, the outer screen 11 is cleaned, and the moisture discharge hole 10 Therefore, the decrease in the dewatering ability of the screw press 9 can be suppressed, and the number of cleanings inside the screw press 9 can be reduced.

  In addition, since the screw press 9 is shared by switching the waste supply conduit 20 and the contaminant removal conduit 21, the number of screw presses 9 can be reduced to one, and cost reduction and downsizing can be achieved. be able to.

  In the sand settling tank 29, mainly heavy impurities (heavy items such as shells, bones, and gravel) are gradually accumulated from the sand settling container 31 close to the inlet 32 side. When a predetermined amount of foreign matter is accumulated in each sedimentation container 31, as shown by the phantom line in FIG. 3, each sedimentation container 31 is lifted above the tank body 30, and the dust in each sedimentation container 31. After removing the object, each emptied sand sinking container 31 is inserted into the tank body 30.

In the above embodiment, the first valve 26a and the second valve 26b are provided in series in the contaminant removal conduit 21, but three or more valves may be provided in series.
In the above embodiment, as an example of a dehydrator provided with a filtration screen having a large number of moisture discharge openings, an outer cylinder screen 11 having a plurality of moisture discharge holes 10 as shown in FIG. Although the screw press 9 provided is mentioned, the present invention is not limited to the screw press 9. For example, an inclined screen in which a water discharge opening is formed between a plurality of bar screens, or a mesh with a predetermined opening (for water discharge). A vibration sieve made of a wire mesh or the like having an opening) may be used as the dehydrator.

It is a figure which shows the structure of the removal apparatus in embodiment of this invention. It is a schematic diagram which shows the structure of the screw press of a removal apparatus similarly. It is the figure which made the side surface of the sand settling tank of a removal apparatus into the cross section similarly. It is a top view of the sand settling tank of a removal apparatus same as the above. It is a figure which shows the structure of the conventional removal apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Organic waste 2 Storage tank 3 Removal apparatus 6 Contamination deposit part 9 Screw press (dehydrator)
10 Moisture drain hole (moisture drain opening)
11 Outer cylinder screen 20 Waste supply line 21 Contaminant removal line 24 Constant displacement pumps 26a and 26b Valves (switching devices)
29 Sedimentation tank (sedimentation separator)

Claims (3)

A removal device for removing impurities contained in a solubilized liquid organic waste, the storage tank storing the organic waste, and the organic waste discharged from the storage tank being dehydrated A filtration type dehydrator, the dehydrator is provided with a filtration screen having a plurality of moisture discharge openings, and deposits of deposited impurities are deposited in the lower part of the storage tank. A waste supply pipe that discharges organic waste in the storage tank and supplies it to the dehydrator, and a storage tank that stores the contaminants accumulated in the foreign matter storage section together with the organic waste. An organic waste contaminant removal apparatus, comprising: a contaminant removal conduit that is discharged from the wastewater and supplied to a dehydrator. The waste supply pipe is provided with a constant displacement pump, and the contaminant removal pipe is provided with a plurality of switching devices for opening and closing the pipe in series. Organic waste contaminant removal equipment. The organic waste contaminant removal device according to claim 1 or 2, further comprising a sedimentation separation device that sediments and separates the filtrate discharged from the dehydrator.

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