JPS6119109Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a floating roof ladder device mainly used in underground tanks for storing crude oil.

By the way, in a general tank with a floating roof,
In order to inspect and maintain the tank, workers must climb down from the upper edge of the tank onto the floating roof. A ladder 1, which can freely swing downward, is lowered from one place on the upper edge of the tank 2 onto the floating roof 3, and the worker descends and ascends to the floating roof 3 through this ladder 1. Therefore, the rudder 1 is supported by the buoyancy of the floating roof 3 with its lower end sliding on the upper surface of the floating roof 3.

If the above-mentioned rolling ladder structure is adopted for the structure of the ladder device attached to the underground tank, the span of the ladder will be approximately 70 m because the height of the tank liquid level is nearly 50 m. It gets longer,
As a result, the following problems arise.

(a) In order to provide sufficient rigidity to the rudder, the weight per unit length of the span increases, placing an excessive load on the floating roof.

(b) The eccentricity of the loading point of the load applied to the floating roof increases, resulting in not only an unstable slope of the floating roof, but also the sliding structure of the lower end of the rudder becoming difficult, and furthermore, the rudder is subject to lateral sway. Occurs and makes it difficult for workers to walk.

(c) Gives workers a fear of heights.

(d) Designing for wind pressure resistance, earthquake resistance, etc. becomes complicated.

As a countermeasure to the above-mentioned problem, a landing 4 is provided on the floating roof 3 as shown in FIG.
It is also conceivable to construct a ladder device with a fixed ladder 6 passed between the landing 4 and the roof surface, thereby shortening the span of the ladder 5 as much as possible, but such a structure If this method is adopted, the structure of the floating roof will become complex and large-scale, the center of gravity will become higher, which will worsen the safety of the floating roof, and further problems will arise, such as making wind pressure and earthquake resistant design even more difficult. Therefore, it is not an effective countermeasure.

The present invention has been made in order to solve the above-mentioned problems. Namely, the purpose of the present invention is to shorten the span of the equipment ladder without making the support mechanism for the ladder large or unstable. An object of the present invention is to provide a roof ladder device.

Hereinafter, the present invention will be explained based on an illustrated embodiment.

As schematically shown in FIGS. 3 and 4, the ladder device of the embodiment includes a landing 9 that can move up and down while being guided by a shaft 8 in an underground crude oil tank 7;
An upper ladder 10 whose base end is pivotally connected to the landing 9 and can be oriented freely; and a lower ladder 11 whose base end is pivotally connected to the landing 9 so that it can be oriented in the diametrical direction and can be freely controlled and rocked. , a support mechanism at each tip of both the ladders 10 and 11, and an operation drive mechanism for adjusting the height of the landing 9.

Therefore, the tip of the upper ladder 10 is connected to the tank 7.
The lower ladder 11 is attached via a swivel to a saddle 12 which slides on the upper edge thereof as a runway, and the tip of the lower ladder 11 is pivotally supported by a slider 14 which slides on the diameter line of the upper surface of the floating roof 13.

Next, a landing 9 consisting of a circular platform is fitted onto the shaft 8 and is suspended by a pair of wire ropes 15 on both sides, and the wire ropes 15 are attached to the upper edge of the tank 7. It penetrates upward through the bracket 16 and is led to the side of the tank 7, and its base end is installed on the ground and wound around a winch 17 for operating and driving.

Next, the operation and operation of the ladder device of the embodiment configured as described above will be described.

When the ladders 10 and 11 are not in use, the landing 9 is fully raised to just below the bracket 16. In this state, the upper ladder 10 is almost horizontal, and the lower end of the lower ladder 11 is on the upper surface of the floating roof 13. The ladder 11 is on the floating roof 1.
It swings up and down as the number 3 moves up and down.

However, when using ladders 10 and 11,
By operating the winch 17, if the height of the landing 9 is lowered to around the center height between the height of the upper edge of the tank 7 and the height of the floating roof 13, both rudders 10,
The slopes of the ladders 11 are approximately equal, so that the worker can safely and easily land on the floating roof 13 by continuously moving along both ladders 10 and 11.

In such a construction system, each ladder 10, 11
Since the height handled by the ladder is reduced by dividing it into two parts, the span of each rudder can be shortened, and as a result, the weight per unit length of the span does not increase unnecessarily. The structures of the slider 12 and the slider 14 are also simplified, so there is no need to place an unnecessary burden on the floating roof 13 or
It does not harm the stability of 3.

Furthermore, since the existing shaft 8 is used to guide the landing 9, there is no need to add a support mechanism for the landing, and since each part of the device is simple, the wind pressure resistance and earthquake resistance of the device are improved. No special consideration is required regarding gender.

Incidentally, the landing 9 does not have to have a structure that allows people to get on and off.

As described above, according to the floating roof ladder device according to the present invention, the upper ladder is installed between the landing that can be raised and lowered guided by the existing shaft in the tank, and the upper edge of the tank and the upper surface of the floating roof. Since the span of each ladder is shortened by installing the upper and lower ladders across each other, a stable and safe stair passage can be obtained with a simple structure. This has the effect of increasing the practicality of the ladder device.

[Brief explanation of the drawing]

1 and 2 are side sectional views of a tank schematically showing two examples of the structure of a ladder device, and FIG. 3 is a schematic side view of a ladder device for a floating roof showing one embodiment of the present invention. , FIG. 4 is a plan view of the same. 7...Tank, 8...Shaft, 9...Landing, 10...Upper ladder, 11...Lower ladder,
13...Floating roof.

Claims (1)

[Scope of utility model registration request] In a floating roof ladder device that is interposed between the upper edge of an underground tank with a floating roof and the upper surface of the same floating roof, and forms a staircase passage for climbing up and down the floating roof, the above-mentioned tank A movable landing is guided by the existing shaft inside the tank and is operated to move up and down in response to the vertical movement of the floating roof.The base end is pivoted to the landing and the tip slides onto the upper edge of the tank. The floating roof is characterized by comprising an upper ladder that can swing freely, and a lower ladder that can swing freely, the base end of which is pivotally connected to the landing, and the tip of which slides on the upper surface of the floating roof. Roof ladder device.