JPS5839717B2 - Emergency drain for floating roof tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an emergency drain for a floating roof tank installed in a refinery or the like.

Generally, in this type of floating roof tank, if the drainage system malfunctions or if the upper surface of the floating roof of the storage tank receives more rainfall than its drainage capacity, the floating roof will sink and the oil inside the tank will be washed away to the outside. In order to prevent such adverse effects, the necessary number of emergency drains are installed at appropriate locations on the floating roof.In order to prevent backflow of oil and evaporation loss of oil during normal operation, the lower pot of the emergency drain is installed. It has a structure that is filled with water and sealed.

However, in tanks that store oil with a particularly high pour point and maintain the oil temperature at a constant level (60 to 70'C) by putting a heater coil inside the tank, water sealing of the emergency drain can occur for a short period of time. When the water evaporated, the operator had to check and pour water each time it evaporated.

1 to 4 show conventional examples of emergency drains.

The emergency drain shown in Fig. 1 has the most common structure, and has one end opened in a water seal pot 1 installed in the oil tank of a floating roof tank, and is fixed to a deck plate 2. An emergency drain pipe 3 is provided extending to a predetermined height from the surface of the plate 2, and a wire mesh 4 for removing dust is provided at the part of the emergency drain pipe 3 protruding from the deck plate 2.

With this structure, if there is rain that exceeds the drainage capacity on the upper surface of the deck plate 2, the water is drained from the upper opening 3a of the emergency drain pipe 3 into the water seal pot 1 (tank), causing the deck plate 2 to sink. However, the water in the water sealing pot 1 usually evaporates significantly, and the operator has to check and pour water more frequently, which is a difficult task.

The emergency drain shown in FIG. 2 has a structure in which a sealing lid 5 is attached to the upper end opening 3a of the emergency drain pipe 3 via a hinge 5a so as to be openable and closable, and is fastened with a thumbscrew 6 or the like.

In this case, evaporation in the water seal pot 1 can be prevented by closing the sealing lid 5, but the effectiveness of the emergency drain will be lost in an emergency, so open and close the sealing lid 5 each time. There are drawbacks such as the need for work and the work being cumbersome.

The emergency drain shown in Fig. 3 has a structure in which a funnel-shaped funnel 7 for collecting rainwater is fixed to the upper end of the emergency drain pipe 3, and a wire mesh 8 is installed inside the funnel 7 to remove dust.
It has been established.

In this case, since the rainwater collection area is wide, the frequency of water injection by the operator is reduced, but the amount of water evaporation under normal conditions is the same as that in FIG. 1.

The emergency drain shown in Fig. 4 has a funnel-shaped funnel 7 for collecting rainwater installed above the upper end opening 3a of the emergency drain pipe 3 via funnel legs 7b so that the small hole 7a of the funnel 7 is located. The structure is such that a wire mesh 9 is installed around the funnel 7 to remove dust.

In this case, like the emergency drain shown in FIG. 3, the ability to collect water in the water seal pot 1 is limited, but the amount of water evaporated under normal conditions is the same as that in FIG.

Therefore, O is a liquid to be stored, such as petroleum.

This invention was made in order to improve the problems of the conventional example described above, and in addition to collecting rainwater with a water collection funnel, the emergency drain pipe is almost completely closed in order to prevent water evaporation under normal conditions. This provides an emergency drain for a floating roof tank with a structure that is sealed.

. Hereinafter, embodiments of the present invention will be described in detail based on FIGS. 5 to 10.

In the drawings, parts and parts corresponding to those of the conventional example will be described with the same reference numerals.

FIGS. 5 and 6 show an embodiment according to the present invention,
The water seal pot 1 installed in the oil tank of the tank has an upper end 1
A is formed to be narrow and slope upward inwardly, and the lower end of the emergency drain pipe 3 is held at a predetermined height from the bottom surface 1c within the water sealing pot 1 via a support Nb.

Further, the emergency drain pipe 3 is fixed to the deck plate 2 via a flange 10, and a sealing material 11 such as lead or rubber is fixed around the upper end opening 3a that projects upward from the deck plate 2. has been done.

On the other hand, a funnel-shaped funnel 7 for collecting rainwater is placed on the top surface of the emergency drain pipe 3, and a funnel T is provided at the center of the funnel T for collecting rainwater. A small hole 7 through which the water seal is dropped into the water pot 1.
a is formed to be extremely small (about 5 to 10 ml m in diameter).

A pipe 12 for preventing evaporation is connected below the small hole 7a and extends into the emergency drain pipe 3.
The lower end is submerged in water.

In addition, a donut-shaped float 13 is fixed to the lower surface of the outer peripheral side of the funnel 7, except for the part that contacts the emergency drain pipe 3, and when there is a large amount of rain on the upper surface of the deck plate 2, the float 13 floats up, and a funnel 7 integrated with the funnel 7 is raised to open the upper end of the emergency drain pipe 3, thereby draining rainwater into the water seal pot 1.

Further, a guide metal fitting 14 is fixed to the outside of the float 13, and is fitted into a guide column 15 erected on the deck plate 2 so as to be vertically movable.

A wire mesh 8 is installed on the upper surface of the funnel 7 to remove dust when collecting and collecting rainwater, and the tip of the guide column 15 is bent in one direction so that the float 13 is When moving, the lower surface of the float 13 is regulated so as not to rise above a certain height above the upper end opening surface 3a of the emergency drain pipe 3.

The inside of the water seal pot 1 is designed to prevent water falling from the emergency drain pipe 3 from splashing up from inside the water seal pot 1 and splashing into the oil tank, and to prevent sludge from settling. In order to keep the stored liquid uniform, a rectifying plate 16 made of punched metal or the like is installed to prevent the stirred stored liquid from entering the emergency drain pipe 3.

Therefore, the emergency drain of the floating roof tank according to the present invention configured as described above collects rainwater through the water collection funnel 7 and has a structure that closes the opening 3a of the emergency drain pipe 3, so that It works like.

First, under normal conditions on a clear day, the water collection funnel 7 closes the upper end opening 3a of the emergency drain pipe 3 via the sealing material 11, and the small hole 1a in the center of the funnel 7 closes.
Since is extremely small, evaporation of water in the water-sealing water pot 1 can be suppressed to a minimum.

Further, the water that has temporarily evaporated in the emergency drain pipe 3 adheres to the back side of the funnel 7 in the form of water droplets, and these water droplets flow along the slope of the funnel 7 and return again from the center.

Note that the amount of evaporation from the small hole 7a of the funnel 7 is very small, and in the case shown in which the pipe 12 for preventing evaporation is fixed below the small hole 7a, the lower end of the pipe 12 is submerged in the water seal. Since the surface of the sealed water that is in contact with the outside air is only the inner diameter of the pipe 12, there is almost no evaporation.

Further, under normal conditions during rain, rainwater falling into the funnel 7 is replenished into the water sealing pot 1 through the small hole 7a and the emergency drain pipe 3.

In this way, when the inside of the water sealing pot 1 exceeds the full state, rainwater overflows from the top surface of the water sealing pot 1 and falls into the tank.

At this time, the funnel 7 and the upper end opening 3a of the emergency drain pipe 3 are in a closed state.

Furthermore, if rainwater accumulates on the upper surface of the deck plate 2, such as when the deck drain malfunctions or the amount of rainfall exceeds the drainage capacity, the float 13 floats up and rises along the guide column 15. .

Therefore, water enters from the upper end opening 3a of the emergency drain pipe 3 and is collected in the water sealing pot 1, and the water that overflows from the water sealing pot 1 falls into the tank, preventing the floating roof from sinking. It becomes preventable.

7 to 8 show other embodiments of the present invention, in which a float 1 is attached to the lower surface of the outer peripheral side of the funnel 7.
3 is divided into a plurality of parts and arranged equally, and the other structure and operation are completely the same as the above-mentioned embodiment.

9 and 10 show another application example of the present invention, in which a float 13 is not directly attached to the funnel 7, but a float 18 is attached to the guide column 15 via a wire 17 so as to be vertically movable. It has a structure connected to 7.

Here, 19 is a float stand fixed to the deck plate 2,
A pulley 20 is rotatably supported by the support column 15 and the deck plate 2 and guides the wire 17.

Reference numeral 14 designates a plurality of pairs of guide tools attached to the float 18 to guide the float as it moves up and down along the guide column 15.

As explained in detail above, according to the present invention, it is possible to prevent water from evaporating in the water sealing pot better than any of the conventional types, and the operator can check and remove the water. Not only does it reduce manual work such as pouring water into the water sealing pot, it also prevents the floating roof from sinking in the event of a breakdown of the drainage system or in the event of rainfall exceeding the drainage capacity. be.

[Brief explanation of the drawing]

1 to 4 are vertical cross-sectional views of main parts of each type of conventional drain, FIGS. 5 to 6 are vertical cross-sectional views and top views showing one embodiment of the present invention, and FIGS. 7 to 4 are FIG. 8 is a longitudinal sectional view and a top view showing another embodiment of the invention, and FIGS. 9 and 10 are a longitudinal sectional view and a top view showing other applied examples of the invention. 1...Water seal pot, 2...Deck plate, 3...Emergency drain pipe, 7...
...Funnel, 7a...Small hole, 13...
···float.

Claims (1)

[Claims] 1. A water seal pot installed in the oil tank of a floating roof tank, and an emergency drain pipe whose lower end faces into the water seal pot and whose upper end opening projects above the deck plate at a predetermined height. In the emergency drain for a floating roof tank, a funnel for collecting rainwater is placed on the top surface of the emergency drain pipe so as to close the upper end opening of the emergency drain pipe, and approximately in the center of the funnel, A small hole is provided to allow the collected rainwater to fall into the water sealing pot via an emergency drain pipe, and the funnel is raised to allow an emergency drain pipe to be installed when there is a large amount of rain on the top of the deck plate. An emergency drain for a floating roof tank, characterized in that a float is associated with the tank so that water drains into a water-sealing pot from an opening at the upper end of the tank.