JPS627074B2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The disclosed technology uses one drainage shaft and one drainage pump to drain precipitation from the floating roof and underground water collected under the bottom plate in a floating roof underground tank. This belongs to a technology that performs this through the activation and deactivation of .

<Summary of the gist> The present invention connects a roof drain pipe connected from the center of the floating roof of a floating roof underground tank to a drainage shaft through the tank body, and systemizes precipitation using a drainage pump installed at the bottom of the drainage shaft. This floating roof underground tank is designed to drain outside, and the groundwater from the water collection layer at the bottom of the tank frame is collected into a drainage shaft via a water collection pipe, and then drained out of the system using a drainage pump. This invention relates to a drainage device, and in particular, a drainage shaft is hung in the ground outside the tank body, and its bottom is lower than the water collection level of the water collection pipe, so that both the roof drainage pipe and the water collection pipe are connected to the drainage shaft. connected, and the drain pump start switch sensor is lower than the water collection level of the drain shaft, and
This invention relates to a drainage device for a floating roof underground tank, in which a stop switch sensor is provided at the bottom to form an adjustable capacity within the drainage shaft.

<Prior art> As is well known, there are various types of petroleum storage tanks, but recently floating roof underground tanks have been adopted due to restrictions such as pollution, disaster prevention, and environmental issues. As shown in Fig. 1, the structure is such that a continuous underground wall 2 is poured in a predetermined ground 1, a bottom plate 5 of the tank frame 4 is provided for an appropriate water collection layer 3 layered at a predetermined depth, and a side plate is installed. A floating roof 7, which slides through a pontoon (not shown) at 6, is movable up and down while following the liquid level, and petroleum 8 is stored inside and operated for receiving and discharging at a predetermined time.

Therefore, in this kind of water collection type floating roof type underground tank, consideration has been given to the reliable removal of precipitation from the floating roof 7 and the smooth removal of groundwater in the water collection layer 3. A roof drain pipe 11 is connected downward from the center of the floating roof 7 via a water collection basin 10 to the lower part of a drainage shaft 9 which also serves to prevent rotation of the floating roof 7, which is fixed to the bottom plate 5 and planted near the inner wall of the side panel 6. are connected to each other, and the water is drained out of the system via a drain pipe 13 by a drain pump 12 provided at the inner bottom of the drain pump 12,
On the other hand, in the latter case, a water collection pipe 14 whose inner end faces the water collection layer 3 and extends outward through the continuous underground wall 2 is connected to a drainage shaft 15 vertically installed in the ground 1 outside the tank body 4. Groundwater is collected and drained out of the system via a drain pipe 13 by a drain pump 12 provided at the bottom of the drain shaft 15.

<Problems to be Solved by the Invention> However, in this type of drainage system, firstly, a plurality of drainage shafts 9, 15 are required, and the same number of drainage pumps 12 are also required. It has the disadvantages of requiring a long construction period and high cost, and also has the drawbacks of being extremely cumbersome to maintain.

In addition, the drainage shaft 9 for the floating roof is connected to the floating roof 7.
Because it is inserted into the tank, it is susceptible to sloshing during earthquakes, which can easily cause damage, and there is a risk of petroleum leaking during drainage.
Whether in the storage tank or the service tank, if there is a large amount of precipitation when the floating roof 7 is opened for inspection or when the lower limit of the stored liquid drops, the drain pump 1
2 had the disadvantages of high frequency of start and stop, difficulty in capacity design, and inability to set up a drainage system.

<Objective of the Invention> The object of the present invention is to solve the problems associated with the drainage system of a floating roof underground tank based on the above-mentioned prior art, and to solve the problem of the drainage system of a floating roof underground tank. Tanks in the energy industry are constructed by installing a shaft with its bottom lower than the water collection level of the water collection layer at a set depth, giving it an adjustable capacity, and connecting the water collection pipe and roof drain pipe together to ensure reliable and smooth drainage. It is an object of the present invention to provide an excellent drainage system for a floating roof underground tank that is beneficial to the field of technical application.

<Means/effects for solving the problems> In order to solve the above-mentioned problems, the structure of the present invention, which is based on the above-mentioned claims, is to prevent precipitation on the floating roof when the tank is operated and opened. Water is drained from the roof drain pipe to a vertical drainage shaft installed outside the tank body via a water conduit pipe, and groundwater in the water collection layer below the bottom plate of the tank body is drained via a water collection pipe. The water is collected in the shaft, and the bottom of the drainage shaft is located at a depth below the water collection level of the water collection layer by a set amount to form a regulating capacity, and the amount of water stored in the regulating capacity is The drain pump's start switch sensor operates to drain water out of the system to a level where the top surface does not exceed the water collection level, and the stop switch sensor at the bottom of the drain shaft operates to reduce the frequency of starting and stopping the drain pump. , technical measures have been taken to avoid the effects of sloshing caused by earthquakes.

<Embodiment - Configuration> Next, one embodiment of the present invention will be described below based on FIG. 2. Note that the same parts as in FIG. 1 will be explained using the same reference numerals.

A continuous underground wall 2 is constructed on a predetermined ground 1, a water catchment layer 3 of a sand and gravel layer is laid at a predetermined depth position, and the frame 4 of a floating roof type underground tank for storing petroleum is constructed with a bottom plate 5, It is constructed with side plates 6 and a floating roof 7, and is operated by storing and receiving petroleum 8 inside.

Reference numeral 16 denotes this shaft-type drainage shaft, whose bottom 16' is located in the ground 1 outside the tank body 4 at a set depth H lower than the water collection level 17 of the water collection layer 3, and has a set adjustment capacity along with its diameter. It is constructed to have W.

An appropriate well-known start switch sensor 18 for the drain pump is provided inside the drain shaft 16 at a set depth lower than the water collection level 17, and a stop switch sensor 19 is provided at the bottom. It is electrically connected to a drainage pump 12 installed in the drain pump 12 via a control device (not shown).

Thus, the roof drain pipe 11 connected to the center of the floating roof 7 via the water collection basin 10 is connected to the drain shaft 16 via the water guide pipe 20 that penetrates the side plate 6 and the continuous underground wall 2 in a fluid-tight manner. A water collection pipe 14 provided at the water collection level 17 of the water collection layer 3 is also connected to the drainage shaft 16.

Note that 13 is a drain pipe, which is connected to the drain pump 12, and is connected from the drain shaft 16 to a wastewater treatment facility outside the system as appropriate.

<Embodiment - Effect> In the above-described configuration, when there is precipitation on the floating roof 7 while the petroleum 8 is stored, the precipitation is conducted into the drainage shaft 16 via the roof drain pipe 11 and the water conduit 20, On the other hand, groundwater within the continuous underground wall 2 of the ground 1 is also constantly guided into the drainage shaft 16 through the water collection pipe 14 from the water collection layer 3, especially after rainfall. The water is stored in the adjusting capacity W of the water, and even if the amount of water introduced is large, the level of the stored water reaches the starting switch sensor 1.
When the water reaches 8, the drain pump 12 is activated to start draining water, and the water is drained out of the system through the drain pipe 13.

In this case, the capacity of the sump pump is based on experiments, data,
Based on theoretical analysis, etc., the set amount of drainage is designed to be larger than the maximum amount per hour for both water conveyances, so that the frequency of starting and stopping of the drainage pump 12 is not high.

In this way, the water level in the drain shaft 16 decreases, and when it drops to the level of the stop switch sensor 19 at the bottom, the drain pump 12 stops.

Therefore, using the adjusted capacity W as a cushion, the drainage pump 12 repeats starting and stopping as infrequently as possible.

The drainage process of starting and stopping the drainage pump 12 is performed not only during the receiving and receiving operation of the service tank, but also during regular inspections of the maintenance tank, and is not affected by the height of the floating roof 7 or the amount of precipitation. be.

Furthermore, even if slotzing occurs during an earthquake,
Since the drainage shaft 16 is formed separately from the inside of the tank body, it is not affected by this in any way.

It goes without saying that the embodiment of the present invention is not limited to the above-described embodiment, and various embodiments may be adopted, such as providing a plurality of drainage shafts, for example. It is also possible to make design changes such as providing an enlarged pit at the bottom of the drainage shaft.

<Effects of the Invention> As described above, according to the present invention, in the drainage system for a floating roof type underground tank, the roof drain pipe connected to the floating roof and the water collection pipe facing the water collection layer at the bottom of the bottom plate of the tank frame. By connecting the system to a single drainage shaft with a drainage pump, precipitation on the floating roof and groundwater are basically discharged out of the system through the drainage shaft, and there is no problem with tank operation or tank structure. The effect is produced.

In addition, by vertically installing the drainage shaft in the ground outside the tank body so that its bottom is lower than the water collection level of the water collection pipe, the drainage shaft acts as a cushion against water storage for the tank and water collection layer. This allows the drainage pump to operate on the accumulated water from the set water level to the bottom of the drainage shaft, regardless of the height of the floating roof, during tank operation, during open inspection, etc. Therefore, the frequency of starting and stopping the drainage pump can be set in advance, and the excellent effect that the drainage system can be reliably planned is achieved.

In addition, the drainage shaft is separate from the tank body and is configured as a common drainage shaft for the roof drainage pipe and water collection pipe, so the structure is simple and there is no sliding part on the floating roof. It also has the advantage of being easy to dispense, construct, and manage as it can also be used as a drainage pump.

In addition, a drain pump start switch sensor is installed in the drain shaft at a location lower than the water collection pipe connection level.
Further, by providing a stop switch sensor at the bottom, an excellent effect is achieved in that the drain pump can be operated reliably and smoothly at low frequencies within the adjusted capacity of the drain shaft.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of the structure of a floating roof underground tank for storing petroleum based on the prior art, and FIG. 2 is a schematic sectional view of one embodiment of the present invention. 7... Floating roof, 11... Roof drain pipe, 4... Tank frame, 3... Water collection layer, 5... Bottom plate, 14...
Water collection pipe, 16... Drain shaft, 12... Drain pump, 13... Drain pipe, 1... Ground, 16'...
Bottom, 17...Water level, 18...Start switch sensor, 19...Stop switch sensor.

Claims (1)

[Claims] 1. A roof drain pipe connected from the floating roof of a floating roof type underground tank and a water collection pipe facing the water collection layer at the bottom of the bottom plate of the tank body are connected to a drainage shaft, and are arranged at the inner bottom of the drainage shaft. In a drainage system in which a drainage pump is connected to a drainage pipe extending outside the system, the roof drainage pipe and the water collection pipe are both connected to a single drainage shaft suspended underground outside the tank body. The inner bottom of the drainage shaft is provided at a set height lower than the water collection level of the water collection pipe, and a start switch sensor for the drainage pump is provided at a portion lower than the water collection pipe, and a stop switch sensor for the drainage pump is provided at the bottom. A drainage system for a floating roof underground tank, characterized by: