JP2009095809A - Removing method and apparatus for deposited sludge in storage tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove sludge by preventing leakage of odor and vapor in a storage tank and low-boiling temperature components in sludge to the outside of the tank by removing the sludge in a sealed system in a cleaning process of deposited sludge in the storage tank. <P>SOLUTION: Cleaning pipes 4 having spray nozzles 6 near the tips are fixed at existing manholes 3 in a top plate 2 of the storage tank 1 in such a manner as to be sealed and turnable in the peripheral direction of the cleaning pipes. A storage liquid and/or a cleaning liquid 14 are/is jetted from the spray nozzles 6, the deposited sludge 13 in the storage tank 1 is suspended in the storage liquid and/or the cleaning liquid 14 to be extracted from the storage tank 1, and the extracted storage liquid and/or the cleaning liquid 14 is returned to the cleaning pipes 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for removing sludge accumulated in a storage tank for storing coal tar, crude oil, heavy oil and the like.

Of the hazardous material storage tanks, those exceeding 1000 kiloliters are required to be inspected once every 10 years under the Fire Service Act.
During open inspection, it is necessary to clean the accumulated sludge in the tank to inspect up to the tank bottom plate. The sediment sludge in the tank is a sediment in which heavy matter, pitch, and coal / coke powder contained in the heavy oil settle to the bottom of the tank.

  Conventionally, in the cleaning of sludge in the tank, after draining the liquid in the tank, the side plate manhole in the lower part of the tank is opened, and the accumulated sludge is discharged manually from the tank. Also, if the height of the accumulated sludge is higher than the side plate manhole, and it is hardened by consolidation, the steam sludge is crushed with the pressure and heat of the steam, and suspended in the solvent. The height of the accumulated sludge was lowered to the position where the side plate manhole could be opened.

  However, since these methods are implemented in an open system, there is a problem that odors and vapor in the tank leak outside the tank. In addition, the working environment in the tank was filled with odors and vapors, and the temperature and humidity in the tank were high in summer, making it difficult to discharge sludge for a long time. As a method of treating accumulated sludge in tanks instead of human power, a method of suspending and removing sludge by circulating cleaning liquid such as storage liquid and cleaning oil in the tank is performed. There is a problem that the position to circulate is limited to one place, and only the deposited sludge in a limited range is processed.

In addition, as a more aggressive method for removing the accumulated sludge, in Patent Document 1, the common liquid or the cleaning liquid in the tank is spouted from the vicinity toward the accumulated sludge by a cleaning pipe installed on the side wall of the tank so as to freely advance and retreat at predetermined intervals. Thus, it is proposed to stir, disperse and dissolve the deposited sludge and extract it out of the tank.
In this method, it is necessary to provide multiple holes on the side wall of the tank used to install cleaning pipes. However, it is safe to make a hole in the side wall while using a tank that stores hazardous materials. In addition, it is difficult under the Fire Service Law. In addition, since the accumulated sludge in the tank is also accumulated on the inner side of the tank wall surface, it is practically difficult to make a hole in the side wall of the portion lower than the height of the accumulated sludge.

Even if the cleaning pipe is inserted with a hole, the cleaning pipe installation part is the liquid part in the tank, so there are safety problems such as leakage from the seal part. In addition, in order to inject the cleaning liquid to the entire height direction of the accumulated sludge, it is necessary to provide a plurality of cleaning tube installation holes in the height direction and circumferential direction of the tank. Get higher.
In addition, when the cleaning pipe is replaced with another hole, the tank may be an open system, and there is a problem that liquid, odor in the tank or vapor leaks.
JP 2001-276765 A

  In the process of cleaning the sludge in the tank, the present invention removes sludge in a closed system, and prevents the odor in the tank and the leakage of low boiling point components in the vapor and sludge to the outside of the tank. An object is to provide a method and apparatus for removing sludge.

  The present invention is a method for removing sludge accumulated in a storage tank, wherein a cleaning pipe having a jet nozzle near the tip is sealed in a circumferential direction of the cleaning pipe in an existing manhole on a tank top plate of the storage tank. The storage liquid and / or the cleaning liquid are ejected from the ejection nozzle, the sludge is suspended in the storage liquid and / or the cleaning liquid, and is extracted from the storage tank, and the extracted storage liquid and A method of removing accumulated sludge in a storage tank, wherein the cleaning liquid is returned to the cleaning pipe.

  Further, the present invention is a device for removing sludge accumulated in a storage tank, having a jet nozzle at the tip, and being fixed to an existing manhole on the tank top plate of the storage tank so as to be capable of rotating in a circumferential direction. A cleaning pipe, an extraction pipe connected to the vicinity of the bottom of the storage tank and extracting the storage liquid and / or cleaning liquid, a suction side connected to the extraction pipe, and a discharge side connected to a connection pipe and extracted. A circulating pump for returning the stored liquid and / or the cleaning liquid to the cleaning pipe, and the storage liquid and / or the cleaning liquid in the storage tank connected to the connection pipe on the discharge side of the circulating pump in a switchable manner. An apparatus for removing accumulated sludge in a storage tank, comprising: a discharge pipe that discharges outside the tank.

  According to the present invention, the storage liquid and / or the cleaning liquid can be ejected at high flow rate against the accumulated sludge in the tank safely and easily in a closed system, and the accumulated sludge can be pulverized, suspended, and extracted. It becomes.

An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a flow chart showing an example of a tank sludge removal apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing an enlarged view of part A in FIG.
In FIG. 1, a cleaning pipe 4 is erected in a manhole (existing) 3 provided on a tank top plate 2 of a storage tank 1. The cleaning tube 4 is installed through a swivel joint 5 at the connection with the manhole 3 and can be rotated 360 degrees.

The diameter of the cleaning tube 4 is not limited as long as it is equal to or smaller than the manhole diameter, but is easily handled at 100 to 200 mm. The number of cleaning pipes is determined by the size (diameter) of the tank and the amount of accumulated sludge, but it is preferable that two or three pipes are installed equally.
In the vicinity of the front end of the cleaning pipe 4 in the tank, an ejection nozzle 6 is installed to increase the ejection flow rate of the storage liquid and / or the cleaning liquid 14 and effectively pulverize and suspend the accumulated sludge. The ejection nozzle 6 is attached by welding, screwing or bolt fixing, and 3 to 4 nozzles are installed according to the height of the accumulated sludge as shown in FIG. The tip of the ejection nozzle 6 may be sealed with a cap, and the flow velocity of the ejection nozzle being used may be increased.

The size of the ejection nozzle 6 may be any size as long as it is smaller than the diameter of the cleaning tube 4, but is preferably 50 mm or less in order to further increase the ejection effect. The ejection angle is preferably about 90 degrees with respect to the length direction of the cleaning tube 4.
The cleaning pipe 4 is connected to the discharge side of the warmer 9 and the circulation pump 10 via a flexible hose 7 and a connection pipe 8. The suction side of the circulation pump 10 is connected to the existing extraction pipe 11 in the storage tank 1, and the discharge side is connected to the connection pipe 8 or the discharge pipe 15 via the switching valve 16. The storage liquid and / or the cleaning liquid 14 circulated by the above operation can be supplied to either the cleaning pipe 4 or the discharge pipe 15.

A heater 9 provided in the middle of the connecting pipe 8 uses steam 12 as a heating source, and heats the storage liquid and / or the cleaning liquid 14 so as to circulate at an optimum temperature for pulverization and suspension of the accumulated sludge 13. It is configured.
When processing the accumulated sludge 13 in the storage tank 1, the cleaning pipe 4 is loaded into the accumulated sludge 13 while being lowered into the storage tank 1 from the manhole 3 of the tank top plate 2 and is erected on the tank bottom plate.

  Thereafter, the storage liquid and / or the cleaning liquid 14 is extracted from the storage tank 1 by the circulation pump 10, heated by the heater 9, and then stored at a high flow rate from the ejection nozzle 6 through the cleaning pipe 4. The cleaning liquid 14 is ejected toward the accumulated sludge 13, and the accumulated sludge 13 is pulverized and suspended. Next, the cleaning sludge 13 in the storage tank 1 can be uniformly pulverized and suspended by rotating the cleaning tube 4 and changing the angle to change the ejection direction of the ejection nozzle 6 at the tip. When this operation is repeated and the sludge concentration in the storage liquid and / or the cleaning liquid 14 becomes high, the storage liquid and / or the cleaning liquid 14 is discharged out of the storage tank 1 from the discharge pipe 15 by the operation of the switching valve 16. .

  In addition, when the cleaning pipes 4 are installed at a plurality of locations, a swirling flow is generated in the storage tank 1 by making the ejection direction of the ejection nozzle 6 constant, and the suspension of the accumulated sludge is more effectively promoted. You can also Further, when the cleaning pipe 4 cannot be charged into the sedimentation sludge 13 by its own weight, it is temporarily placed on the sedimentation sludge 13, and the swirling flow in the storage tank 1 generated by the ejection of the storage liquid and / or the cleaning liquid 14 is used. The accumulated sludge 13 can be lowered to the tank bottom plate by gradually pulverizing and suspending it.

Cleaning pipes 4 were installed in three of the existing manholes 3 on the tank top plate 2 of the coal tar storage tank 1 having an inner diameter of 21.2 m, a height of 9.8 m, and a capacity of 3000 kiloliters.
The storage liquid and / or cleaning liquid deposited in the storage tank 1 and heated to normal temperature to 100 ° C. by the heater 9 against the compacted coal tar sludge is discharged from the discharge nozzle 6 of the cleaning pipe 4 at a flow velocity of 10 to The coal tar sludge ejected at 30 m / S and accumulated was pulverized, suspended, and discharged out of the storage tank 1 by the circulation pump 10. As a result, the entire amount of sludge accumulated in the storage tank 1 could be removed.

It is a flowchart which shows an example of the removal apparatus of the accumulation sludge in a tank by this invention. It is explanatory drawing which expands and shows the A section of FIG.

Explanation of symbols

1 Storage tank 2 Tank top 3 Manhole (existing)
4 Washing pipe 5 Swivel joint 6 Jet nozzle 7 Flexible hose 8 Connection pipe 9 Heater
10 Circulation pump
11 Extraction pipe
12 steam
13 Sediment sludge
14 Stock solution and / or cleaning solution
15 discharge pipe
16 Switching valve

Claims (2)

  A method for removing sludge accumulated in a storage tank, wherein a cleaning pipe having a jet nozzle in the vicinity of the tip is sealed in an existing manhole on the tank top plate of the storage tank and is rotatable in the circumferential direction of the cleaning pipe The storage liquid and / or the cleaning liquid is ejected from the ejection nozzle, the sludge is suspended in the storage liquid and / or the cleaning liquid, and the storage liquid and / or the cleaning liquid extracted are discharged from the storage tank. Returning to the said washing | cleaning pipe | tube, The removal method of the accumulation sludge in a storage tank characterized by the above-mentioned.   A device for removing sludge accumulated in a storage tank, having a jet nozzle at the tip, and a washing tube fixed to an existing manhole on the tank top plate of the storage tank and rotatably pivoted in the circumferential direction, An extraction pipe connected to the vicinity of the bottom of the storage tank to extract the storage liquid and / or cleaning liquid, and a storage liquid extracted from the suction side connected to the extraction pipe and a discharge side connected to the connection pipe and / or A circulation pump that returns the cleaning liquid to the cleaning pipe, and a discharge that is switchably connected to the connection pipe on the discharge side of the circulation pump and discharges the storage liquid and / or the cleaning liquid in the storage tank to the outside of the storage tank. A device for removing accumulated sludge in a storage tank.

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