JPS6315570B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water surface projection screen device that uses a water surface as a projection screen surface by making the water surface cloudy.

Conventionally, as a water surface projection screen device,
There is one disclosed in Publication No. 41-21189. This system consists of a water tank for storing water, a circulation pipe line equipped with a pressurizing pump that circulates the water in the water tank, and a circulation pipe provided on the discharge pipe side of the circulation pipe to direct air from the compressor to the discharge pipe. The air dissolving tank is equipped with an air dissolving tank that dissolves air in water, and the air dissolving water discharged from the air dissolving tank is reduced in pressure with a pressure reducing valve attached to the tip of the discharge pipe to make it cloudy, and the cloudy water is passed through a nozzle to the water surface of the water tank. The water surface is then used as a projection screen surface.

By the way, in such a water surface projection screen device, the higher the output of the pressurizing pump, that is, the discharge pressure of the pressurizing pump, the better the water can be clouded. However, in the above-mentioned conventional device, an air dissolution tank is provided on the discharge water side discharged by the pressurizing pump, that is, on the discharge piping side, and air is mixed into the water having a high discharge pressure in this air dissolution tank. Therefore, in order to mix in that air, it is necessary to use a compressor with very high output, that is, a compressor that produces the same pressure as the discharge pressure of the pressurizing pump. For this reason, if a pressure pump with high discharge pressure is used in order to properly cloud the water, a compressor with a high output must be used to match the pressure pump, which makes it difficult to save energy today. The domestic situation faced by the government was extremely uneconomical.

The present invention has been made in view of the above circumstances, and its purpose is to provide a water surface projection screen device that can effectively make the projection screen surface cloudy even when using a low-pressure compressor. There is a particular thing.

In order to achieve the above object, the water surface projection screen device of the present invention includes a screen pond that stores water and uses the water surface as a projection screen surface, and a circulation pipe equipped with a multistage pump that circulates the water in the screen pond. The multi-stage pump includes an air injection device for injecting air from an air injection hole formed on the suction side of the pump section of the low-pressure side stage of the multi-stage pump.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, 1 is a screen pond, and this screen pond 1 has, for example, a rectangular shape in plan, has a side wall 1a of a predetermined height, and has water 2 inside.
is stored on the ground 3 to a predetermined depth. The water surface of water 2 stored in this screen pond 1 serves as a projection screen surface 4 onto which a projection is projected from above in the direction of arrow X by a projector (not shown). The screen pond 1 is equipped with a makeup water pipe 5 for replenishing water into the screen pond 1, a drain pipe 6 for draining the water in the screen pond 1, and an overflow pipe 7. The water level is kept almost constant.

Further, a circulation pipe 8 for circulating water in the screen pond 1 is provided. This circulation pipe 8 has one end connected to a discharge port of a multi-stage centrifugal pump 10 (see FIG. 2), and the other end connected to a discharge pipe 8a' having an opening 8a' in the center of the bottom of the screen pond 1, and one end connected to a discharge port of a multi-stage centrifugal pump 10 (see FIG. 2). The suction pipe 8b is connected to the suction port of the centrifugal pump 10 (see FIG. 2) and has an opening 8b' at the other end on one side of the bottom surface of the screen pond 1.

Furthermore, in order to mix external air into the water in the circulation pipe 8 and make it cloudy, as shown in FIG.
Pump parts 14a and 1 of each stage of the multistage centrifugal pump 10
Among the pump parts 4b, 14c, and 14d, an air injection hole 15 is formed on the suction side of the intermediate stage pump part, that is, the low-pressure stage pump part, for example, the second stage pump part 14b. Then, pressurized air is injected from this air injection hole 15 by a compressor (not shown) which is an air injection device, and thereby the aerated water is agitated by the impellers of the second and subsequent pump parts 14b and 14c14d. By pressurizing and dissolving the air mixed in the water and making the bubbles finer, the water becomes cloudy effectively.

Note that 13 in FIG. 1 is the floor surface.

Therefore, in FIG. 1, the multistage centrifugal pump 1
0, the water 2 in the screen pond 1 is sucked in through the opening 8b' of the suction pipe 8b and circulated through the circulation pipe 8. Stage pump section 14
Pressure air is injected by a compressor from the air injection hole 15 formed in b, and the pump section 14 of the second stage and subsequent stages is
The liquid is stirred by impellers b, 14c, and 14d to become cloudy, and is circulated and discharged into the screen pond 1 from the opening 8a' of the discharge pipe 8a. By continuing this circulating discharge, the water 2 in the screen pond 1 becomes cloudy and opaque as a whole, and an image can be projected by reflecting the image light rays from the projector onto the projection screen surface 4.

Then, when it is no longer necessary to project an image, the mixture of pressurized air can be stopped, or the operation of the multistage centrifugal pump 10 can be stopped to stop water circulation.
The water in the screen pond 1 is restored to its original clear state.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, the screen pond 1 may be configured with a portion of a large pond, and the water surface projection screen device may be incorporated into a portion of an existing pond. The present invention may be implemented by.

As is clear from the above description, according to the present invention, the water in the screen pond is circulated through the circulation pipe by the operation of the multistage pump, and the water flowing in the circulation pipe is transferred to the low-pressure side stage of the multistage pump. Air is injected by an air injection device through the air injection hole formed on the suction side of the pump part, and the air becomes cloudy when it is agitated by the impeller of the pump part after the pump part where it was injected. By continuing this circulation, the water in the screen pond becomes cloudy and opaque, and the image light from the projector is reflected on the projection screen surface to project the image. In this case, the clouding phenomenon occurs because the bubbles are minute and there is no boiling on the water surface, and the projection screen surface can be effectively clouded, making it possible to form a fine-grained water surface projection screen.

Moreover, since the device of the present invention uses a multi-stage pump and injects air from the pump section of the low-pressure side stage, the air injection device only needs to have a small output, effectively achieving energy savings. be able to. Furthermore, the device of the present invention does not require a special stirrer to atomize the air mixed into the water, and the air injection device only needs to have a small output, so it has the advantage of being low cost. .

[Brief explanation of the drawing]

FIG. 1 is a sectional side view showing an embodiment of the present invention, and FIG. 2 is a side view showing an air injection portion of a multistage pump. DESCRIPTION OF SYMBOLS 1... Screen pond, 2... Water stored in the screen pond, 4... Projection screen surface, 8... Circulation pipe, 8a... Discharge pipe, 8b... Suction pipe, 9...
...Pump, 10...Multistage centrifugal pump, 14a, 1
4b, 14c, 14d...Each pump part of the multistage centrifugal pump, 15...Air injection hole.

Claims (1)

[Claims] 1. A screen pond that stores water and uses the water surface as a projection screen surface, a circulation pipe equipped with a multi-stage pump that circulates the water in the screen pond, and a circulation pipe formed on the suction side of the pump section of the low-pressure side stage of the multi-stage pump. and an air injection device for injecting air through an air injection hole.