JP6845048B2 - How to modify the granular activated carbon adsorption tower, collector and granular activated carbon adsorption tower - Google Patents

Description

The present invention relates to a granular activated carbon adsorption tower, a collector provided in the granular activated carbon adsorption tower, and a method for modifying the granular activated carbon adsorption tower, and more particularly to a moving bed type granular activated carbon adsorption tower in which granular activated carbon is extracted from the lower part and replenished from the upper part.

A granular activated carbon adsorption tower is known as a device for removing pigments and harmful substances from liquids such as sugar and wastewater (Patent Document 1). In particular, the moving bed type granular activated carbon adsorption tower in which the granular activated carbon is extracted from the lower part and replenished from the upper part has high utilization efficiency of the activated carbon, and it is easy to miniaturize the apparatus. The moving bed type granular activated carbon adsorption tower is provided with a filling container filled with granular activated carbon, a supply port for the liquid to be processed is provided at the lower part of the filling container, and a collection part for the processed liquid is provided at the upper part of the filling container. There is. The liquid rises in the filling container while in contact with the granular activated carbon, and the pigment and harmful substances are removed by the granular activated carbon. A collector, which is a liquid take-out part, is provided on the upper part of the filling container. The liquid is discharged to the outside of the filling container through a screen provided on the collector. The screen has a gap smaller than that of the granular activated carbon, so that the granular activated carbon is prevented from being mixed with the liquid and discharged. Since the granular activated carbon layer adsorbs more pigments and harmful substances toward the lower part, the saturated granular activated carbon can be sequentially replaced by extracting the granular activated carbon from below.

To replace the granular activated carbon, first stop the supply of liquid. Next, the granular activated carbon is extracted by gravity from the extraction pipe connected to the bottom of the filling container, and new granular activated carbon is supplied by gravity from the feed tank at the top of the filling container. Granular activated carbon is supplied in the form of a slurry mixed with water. When the granular activated carbon is replaced, pulverized coal is generated due to friction between the granular activated carbons. Since the pulverized coal passes through the screen and mixes with the liquid, after exchanging the granular activated carbon, the liquid is passed until the pulverized coal is no longer mixed with the liquid. After that, the processing of the liquid is started.

Japanese Unexamined Patent Publication No. 2011-16070

When replacing the granular activated carbon, it takes time until the pulverized coal is no longer mixed in the liquid, that is, it takes time for the turbidity to be removed from the liquid. This is because the ascending flow of the liquid supplied from below the filling container causes the pulverized coal to float in the upper part of the filling container, and the pulverized coal is discharged together with the liquid. This tendency becomes remarkable when the linear velocity (LV) of the liquid is high. On the other hand, by increasing the LV, the liquid processing capacity can be increased, which makes it possible to increase the processing amount per unit time or to reduce the size of the apparatus. However, at present, it is difficult to shorten the time until the turbidity disappears while increasing the processing capacity of the liquid by increasing the linear velocity.

An object of the present invention is to provide a granular activated carbon adsorption tower capable of shortening the time until the pulverized coal is no longer mixed in the liquid even when the LV of the liquid is high.

The granular activated carbon adsorption tower of the present invention is a filling container filled with granular activated carbon, and is connected to an upper portion forming an upper space in which the cross-sectional area decreases upward and a lower end of the upper space to form a central space. A filling container provided with a body portion, a liquid supply nozzle provided at the lower part of the filling container to supply a liquid to be treated with granular activated carbon, and a liquid supply nozzle penetrating the upper part and above the liquid supply nozzle. It has a collector for collecting the liquid treated with the granular activated carbon, a supply port for the granular activated carbon provided in the upper portion, and a discharge port for the granular activated carbon provided in the filling container. The collector is located inside the filling container, with a first filter that allows the liquid to pass through and blocks the passage of the granular activated carbon, and is located downstream of the first filter with respect to the flow of the liquid, penetrating the upper part and passing the liquid. It has a discharge pipe for discharging to the outside of the filling container, and the upper end of the first filter is below the upper portion.

When replacing the granular activated carbon, the amount of extraction in a unit time is generally larger than the amount of supply in a unit time, so that the liquid stays in the upper part of the adsorption tower. When the liquid is passed through the liquid at a high LV in this state, the granular activated carbon on the upper part of the filling container becomes easy to move, and as a result, the pulverized coal floats in the liquid. The movement of the pulverized coal is more likely to be activated as the LV of the liquid is higher, and it takes a long time for the movement of the pulverized coal to subside. In particular, in the upper space where the cross-sectional area decreases upward, the flow velocity of the liquid increases toward the upper side, so that the movement of the pulverized coal becomes active. According to the present invention, the upper end of the first filter of the collector is below the upper portion. That is, the first filter is arranged so as to avoid the upper space where the movement of the pulverized coal tends to be activated for a long time. Therefore, according to the present invention, it is possible to provide a granular activated carbon adsorption tower capable of shortening the time until the pulverized coal is no longer mixed in the liquid even when the LV of the liquid is high.

It is the whole block diagram of the granular activated carbon adsorption system. It is a schematic block diagram of a granular activated carbon adsorption tower. It is an enlarged view of the part A of FIG. It is a partially enlarged view of the 1st filter. It is a figure which shows the behavior of pulverized coal schematically. It is a conceptual diagram of the 2nd filter.

Hereinafter, embodiments of the granular activated carbon adsorption tower of the present invention will be described with reference to the drawings. The granular activated carbon adsorption tower according to the present embodiment is applied to a process of removing a pigment from a sugar to make the sugar colorless. However, the granular activated carbon adsorption tower of the present invention is not limited to this, and can be applied to, for example, removal of chromaticity and COD in wastewater, chromaticity component of a feed solution, and removal of odor and organic components.

First, with reference to FIG. 1, the overall configuration of the granular activated carbon adsorption system including the granular activated carbon adsorption tower of the present invention will be described. The granular activated carbon adsorption system 1 includes a granular activated carbon adsorption tower 2 for removing pigment components from liquid sugar, a pulse receiving tank 3, a scrubber 4, a regeneration furnace 5, a quenching tank 6, and an activated carbon feed tank 7. ,have. Each of these devices is connected by a pipe, and the granular activated carbon taken out from the granular activated carbon adsorption tower 2 is regenerated and returned to the granular activated carbon adsorption tower 2 again.

Specifically, when sugar is passed through the granular activated carbon adsorption tower 2 for a certain period of time, the granular activated carbon filled in the lower part of the granular activated carbon adsorption tower 2 is saturated. Therefore, this granular activated carbon is taken out from the granular activated carbon adsorption tower 2. Reproduce. The operation for that purpose is called a pulse operation, and the details will be described later. The granular activated carbon taken out from the granular activated carbon adsorption tower 2 by gravity is discharged to the pulse receiving tank 3, sent to the washing tower 4, and washed with washing water. The washed granular activated carbon is sent to a regeneration furnace 5 equipped with a burner. The granular activated carbon is heated in the regeneration furnace 5 to remove the pigment component adhering to the granular activated carbon. After that, the granular activated carbon is cooled in the quenching tank 6 and sent to the feed tank 7. The feed tank 7 is installed directly above the granular activated carbon adsorption tower 2, and the regenerated granular activated carbon is supplied to the granular activated carbon adsorption tower 2 from the top of the granular activated carbon adsorption tower 2 by gravity. The granular activated carbon is supplied to the granular activated carbon adsorption tower 2 in the form of a slurry which is a mixture with water. In this way, the granular activated carbon adsorption system can process the liquid while efficiently recovering and regenerating the granular activated carbon.

Next, the configuration of the granular activated carbon adsorption tower 2 will be described. FIG. 2 shows a schematic configuration diagram of the granular activated carbon adsorption tower 2. FIG. 3 shows an enlarged view of part A of FIG. The granular activated carbon adsorption tower 2 has a filling container 11 filled with granular activated carbon for removing pigment from sugar, and a skirt 12 for supporting the filling container 11. Hereinafter, the layer of granular activated carbon filled in the filling container 11 may be referred to as activated carbon layer C. The filling container 11 has a cylindrical body portion 14, a truncated cone-shaped upper portion (conical) 13 connected to the top of the body portion 14, and a lower portion 15 connected to the bottom portion of the body portion 14. ing. The upper portion 13 forms an upper space 16 whose cross-sectional area is reduced upward. A supply port 17 for granular activated carbon is provided at the top of the upper portion 13. The supply port 17 is connected to the feed tank 7 by a granular activated carbon supply pipe 18. The inclination angle of the upper portion 13 is set to an angle that enhances the filling efficiency of the granular activated carbon. The lower portion 15 has a conical shape that facilitates the discharge of granular activated carbon, and forms a lower space 21 whose cross-sectional area is reduced downward. A sampling port 19 for extracting granular activated carbon is provided at the bottom of the filling container 11. The extraction port 19 is connected to the pulse receiving tank 3 by a granular activated carbon extraction pipe 20.

Examples of the granular activated carbon filled in the granular activated carbon adsorption tower 2 include coal-based and coconut shell-based granular activated carbon. Coal-based granular activated carbon has shapes such as crushed, spherical, and pellet-shaped, and has developed pores of about 2 to 5 nm, and is excellent in removal performance of polymer-based pigment components. Depending on the application, coconut shell-based granular activated carbon can also be used. The coconut shell-based granular activated carbon has developed pores of about 1.2 to 3 nm, and is excellent in the ability to remove small molecules such as odor components.

A liquid supply nozzle 22 is provided in the lower part of the filling container 11, more specifically, in the lower part 15. The liquid supply nozzle 22 is connected to the liquid supply pipe 23, and the liquid to be treated with the granular activated carbon is supplied. A plurality of liquid supply nozzles 22 are provided on the side wall of the lower portion 15 at equal intervals in the circumferential direction, but the installation position and number thereof are not limited.

A collector 24 for collecting the liquid treated with granular activated carbon is provided in the upper part of the filling container 11, more specifically, the upper part 13. The collector 24 is connected to the liquid discharge pipe 25, and the liquid treated with the granular activated carbon is discharged. A plurality of collectors 24 are provided on the side wall of the upper portion 13 at equal intervals in the circumferential direction, but the number thereof is not limited. The detailed configuration and installation position of the collector 24 will be described later.

An atmospheric communication pipe 26 penetrates the upper portion 13. The air communication pipe 26 is above the collector 24 and penetrates the upper portion 13. The air communication pipe 26 is provided to protect the filling container 11 and improve the filling effect. When the granular activated carbon is replaced, the filling container 11 temporarily becomes negative pressure because the amount of the granular activated carbon extracted in the unit time is larger than that in the granular activated carbon supplied in the unit time. Therefore, by introducing air into the filling container 11 from the air communication pipe 26 released to the atmosphere, it is possible to prevent damage to the filling container 11 due to excessive negative pressure.

Referring to FIG. 3, the collector 24 has a tubular shape extending in the vertical direction as a whole. More specifically, the collector 24 penetrates the first filter 27 provided inside the filling container 11 and above the liquid supply nozzle 22 and the upper portion 13, and the processed liquid is discharged to the outside of the filling container 11. It has a discharge pipe 28 for discharging. A flange 29 provided at the upper end of the discharge pipe 28 is sandwiched between the flange 31 of the nozzle 30 of the upper portion 13 and the flange 32 of the liquid discharge pipe 25, and is fixed by bolts and nuts (not shown). The first filter 27 is a tubular screen that is supported by the discharge pipe 28 and covers a part of the side surface of the discharge pipe 28. The first filter 27 and the discharge pipe 28 have a cylindrical shape having the same central axis, and the first filter 27 is outside the discharge pipe 28. Therefore, the discharge pipe 28 is located downstream of the first filter 27 in the liquid flow direction. The first filter 27 allows the liquid to pass while blocking the inflow of granular activated carbon. As shown in the partially enlarged view of the first filter 27 in FIG. 4 (enlarged view of part B in FIG. 3), the first filter 27 has annular wedge wires 33 arranged at intervals in the vertical direction. The interval d is determined so that the liquid can pass through but the granular activated carbon does not pass through. The first filter 27 may be a net-like body such as a wire mesh.

A plurality of openings 34 communicating with the internal flow path of the discharge pipe 28 are formed in a region facing the first filter 27 on the side surface of the discharge pipe 28 (hereinafter referred to as a filter facing region). A plurality of openings 34 are provided at the same height position at equal intervals and are provided in a staggered arrangement in the vertical direction, but the installation positions and the number thereof are not limited. Claw-shaped engaging portions 35 that engage with the upper and lower ends of the first filter 27 are provided at the upper and lower ends of the filter facing region of the discharge pipe 28. By removing both ends of the first filter 27 from the engaging portion 35, the first filter 27 can be removed from the discharge pipe 28. No openings 34 are provided above and below the filter facing region of the discharge pipe 28, and the lower end of the discharge pipe 28 is closed.

The liquid is introduced from the liquid supply nozzle 22 to the lower part of the activated carbon layer C of the filling container 11, and is filtered by the granular activated carbon while ascending the activated carbon layer C. The filtered liquid passes through the first filter 27, is then introduced into the internal flow path of the discharge pipe 28 through the opening 34 of the discharge pipe 28, and is discharged to the liquid discharge pipe 25.

Instead of the above-mentioned opening 34, a slit-shaped opening similar to that of the first filter 27 may be provided in the filter facing region on the side surface of the discharge pipe 28. In this case, the first filter 27 may be provided on the outside of the discharge pipe 28, but the distance between the openings on the side surface of the discharge pipe 28 is about the same as the distance d of the first filter 27, that is, the liquid can pass through but is granular. The first filter 27 may be omitted as long as the size does not allow the activated carbon to pass through.

Next, the pulse operation will be described with reference to FIG. To replace the granular activated carbon, first, the second valve 9 provided in the granular activated carbon supply pipe 18 is opened, and then the first valve 8 provided in the granular activated carbon extraction pipe 20 is opened. New granular activated carbon is supplied to the filling container 11 from the feed tank 7 through the granular activated carbon supply pipe 18. At the same time, the granular activated carbon is discharged by gravity through the granular activated carbon extraction pipe 20. In order to promote the filling of the granular activated carbon, the granular activated carbon is supplied in the form of a slurry mixed with water. As a result, new granular activated carbon is supplied, and the granular activated carbon is compactly packed in the filling container 11. When the supply of the granular activated carbon is completed, the first valve 8 and the second valve 9 are closed.

Next, the liquid is passed through the liquid supply pipe 23. The liquid becomes an upward flow, moves to the upper part of the filling container 11, and is discharged to the outside of the filling container 11 through the first filter 27 and the discharge pipe 28. During the pulse operation, the granular activated carbons come into contact with each other and rub against each other to generate pulverized carbon. In this process, the liquid takes up pulverized coal. The pulverized coal is also discharged to the outside of the granular activated carbon adsorption tower 2 through the first filter 27 and the discharge pipe 28, but the amount of pulverized coal contained in the liquid gradually decreases when the liquid is passed through the liquid at an LV of a predetermined value or less. To do. The pulverized coal may be confirmed, for example, with a sight glass (not shown) provided in the liquid discharge pipe 25, or a liquid is sampled from the liquid discharge pipe 25 and the pulverized coal is captured by a filter paper (not shown). You may observe. When it is determined that the amount of pulverized coal discharged is sufficiently reduced according to a predetermined standard, the treatment of the liquid can be started.

FIG. 5 schematically shows the behavior of pulverized coal when a liquid is passed through after filling with granular activated carbon. The upper part of the activated carbon layer C is filled with liquid. The round arrow schematically shows the movement of the pulverized coal, and the larger the arrow, the higher the speed of the pulverized coal, which means that the pulverized coal is actively moving. In the lower part of the activated carbon layer C, the granular activated carbon is in a strong compaction state due to the pressing force of the granular activated carbon above it, so that the movement of the pulverized carbon is small. On the other hand, in the upper part of the activated carbon layer C, the pulverized coal is agitated by the upward flow F of the liquid. In particular, since the pressure density of the uppermost portion of the activated carbon layer C is low, the granular activated carbon is largely moved by the liquid. As a result, the pulverized coal existing between the granular activated carbons is blown up and mixed with the liquid above. Further, since the cross-sectional area of the upper portion 13 decreases toward the upper part, the flow velocity of the liquid also increases toward the upper part, and the movement of the pulverized coal becomes active accordingly.

FIG. 5A shows the configuration of the present embodiment together with FIG. 3, and the upper end of the first filter 27 is below the upper portion 13. The position of the upper end of the first filter 27 is not limited as long as this condition is satisfied, but it is preferably in the vicinity of the upper portion 13 in order to maximize the filtration capacity of the activated carbon layer C. It is desirable that the upper end of the first filter 27 is in a range h of about 0 to 30 cm downward from the connecting portion 35 between the upper portion 13 and the body portion 14 (see FIG. 3). On the other hand, when the filtration capacity of the activated carbon layer C is fully utilized, at least a part of the first filter 27 is connected to the connecting portion 35 between the upper portion 13 and the body portion 14 as shown in FIG. 5 (b). Although it is desirable to be above, since the liquid is sucked from the top of the activated carbon layer C or the liquid above it, the liquid containing the pulverized carbon exceeding the allowable value is sucked in for a long time until the movement of the pulverized carbon stops. Become.

Further, the LV of the liquid is generally set to about 2 to 3 m / h in the case of a highly viscous liquid such as sugar, but when the LV is increased (for example, about 5 to 10 m / h), the unit time is increased. It has the advantage of increasing processing power. This also leads to a reduction in the size of the filling container 11 if the processing amount per unit time is the same. However, when the LV is raised, the movement of the pulverized coal is activated, the mixing of the pulverized coal into the liquid does not stop easily, and it takes a long time to start the processing of the liquid.

On the other hand, in the embodiment shown in FIGS. 3 and 5A, the first filter 27 can suck the liquid while avoiding the region where the pulverized coal actively moves. This is because the first filter 27 is installed in the region of the activated carbon layer C, which has a large inner diameter of the filling container 11 and is in a state of consolidation to some extent. In such a region, the movement of the pulverized coal existing between the grains of the granular activated carbon is small, and the movement of the pulverized coal converges in a short time, so that it is easy to suppress the mixing of the pulverized coal into the liquid. Therefore, the above-mentioned predetermined criteria can be satisfied in a shorter time.

When the liquid is introduced into the granular activated carbon adsorption tower 2 from below, the upper part of the filling container 11 is an air layer at an initial stage. This air layer is pushed up by the liquid and discharged from the air communication pipe 26. In this process, pulverized coal may enter the atmospheric communication pipe 26 and clog the atmospheric communication pipe 26. Clogged air communication pipe 26 leads to deterioration of filling performance of granular activated carbon. This is especially noticeable when the LV is high. A second filter 36 is provided in the air communication pipe 26 in order to suppress clogging of the air communication pipe 26. Referring to FIG. 6, a bucket-shaped screen is attached to the side wall of the air communication pipe 26 as the second filter 36. Although the second filter 36 is provided in all the atmospheric communication pipes 26, it may be attached only to a part of the atmospheric communication pipes 26. It is also desirable to have piping that can clean the screen on a regular basis.

The present invention can also be applied to the modification of the existing granular activated carbon adsorption tower 2. For example, when the first filter 27 is provided directly below the upper portion 13 as shown in FIG. 5 (b), the discharge pipe 28 is cut at a position directly above the first filter 27, and the discharge pipe 28 is cut. Insert a short tube between the cut ends on both sides. As a result, the same configuration as in FIG. 5A can be obtained.

1 Granular activated carbon adsorption system 2 Granular activated carbon adsorption tower 3 Pulse receiving tank 7 Activated carbon feed tank 8 First valve 9 Second valve 11 Filling container 13 Upper part 14 Body part 15 Lower part 16 Upper space 17 Granular activated carbon supply port 18 Granular Activated carbon supply pipe 19 Granular activated carbon extraction port 20 Granular activated carbon extraction pipe 21 Lower space 24 Collector 25 Liquid discharge pipe 26 Atmospheric communication pipe 27 First filter 28 Liquid discharge pipe 33 Wedge wire 34 Opening 35 Connection 36 Second filter C Activated carbon layer

Claims (6)

A filling container filled with granular activated carbon, comprising an upper portion forming an upper space in which the cross-sectional area decreases upward, and a body portion connected to the lower end of the upper space and forming a central space. Filling container and
A liquid supply nozzle provided at the bottom of the filling container and supplying a liquid to be treated with the granular activated carbon,
A collector that penetrates the upper portion and is provided above the liquid supply nozzle to collect the liquid treated with the granular activated carbon.
With the granular activated carbon supply port provided in the upper portion,
It has a discharge port for the granular activated carbon provided in the filling container, and has.
The collector is located inside the filling container and is located downstream of the first filter with respect to the flow of the liquid and the upper portion of the first filter which allows the liquid to pass through and blocks the passage of the granular activated carbon. A granular activated carbon adsorption tower having a discharge pipe that penetrates a portion and discharges the liquid to the outside of the filling container, and the upper end of the first filter is below the upper portion. The granular activated carbon adsorption tower according to claim 1, wherein the first filter is a tubular screen that is supported by the discharge pipe and covers a part of the side surface of the discharge pipe. The granular activated carbon adsorption tower according to claim 1 or 2, which has an atmospheric communication pipe penetrating the upper portion, and the atmospheric communication pipe has a second filter inside the filling container. The granular activated carbon adsorption tower according to claim 3, wherein the atmospheric communication pipe is above the collector and penetrates the upper portion. A collector that is attached to a filling container filled with granular activated carbon and collects liquids treated with granular activated carbon.
The filling container forms an upper space in which the cross-sectional area decreases upward, and is connected to an upper portion provided with a supply port for the granular activated carbon at the top and a central space connected to the lower end of the upper space and having a constant cross-sectional area. A liquid supply nozzle for supplying the liquid to be treated with the granular activated carbon is provided below the filling container and below the collector, and the granular activated carbon is supplied to the top of the upper portion. A port is provided, and a discharge port for the granular activated carbon is provided at the bottom of the filling container.
The collector is located inside the filling container and is located downstream of the first filter with respect to the flow of the liquid and the upper portion of the first filter that allows the liquid to pass through and blocks the passage of the granular activated carbon. A collector having a discharge pipe that penetrates the portion and discharges the liquid to the outside of the filling container, wherein the upper end of the first filter is below the upper portion. A filling container filled with granular activated carbon, the upper portion forming an upper space in which the cross-sectional area decreases upward, and the body portion connected to the lower end of the upper space to form a central space having a constant cross-sectional area. A filling container provided with the above, a liquid supply nozzle provided below the filling container and supplying a liquid to be treated with the granular activated carbon, and a liquid supply nozzle penetrating the upper portion and above the liquid supply nozzle. A collector for collecting the liquid treated with the granular activated carbon, a supply port for the granular activated carbon provided at the top of the upper portion, and a discharge port for the granular activated carbon provided at the bottom of the filling container. It is a method of remodeling the granular activated carbon adsorption tower that it has.
The collector
A first filter located inside the filling container that allows the liquid to pass through and blocks the passage of the granular activated carbon.
It has a discharge pipe located downstream of the first filter with respect to the flow of the liquid, supporting the first filter, penetrating the upper portion, and discharging the liquid to the outside of the filling container. ,
As the upper end of said first filter is positioned lower than the upper portion, inserting a conduit between said upper end of said first filter and the through portion of the upper portion of the discharge pipe A method of modifying a granular activated carbon adsorption tower.

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