JPH0648228B2 - Air flow visualization device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a device for visualizing an invisible gas flow,
Especially for understanding the air flow in an industrial clean room,
In particular, the present invention relates to a device for generating a clean mist and visualizing a gas flow by using the mist.

[Conventional technology]

Conventional devices that visualize the flow of gas include devices that use mosquito coil smoke, devices that use smoke generated by the chemical reaction of titanium tetrachloride and other chemicals, devices that use oil mist generated by heating oil, As with the ultrasonic humidifier, a device that uses pure water to generate pure water mist is used.

[Problems to be solved by the invention]

Among the above-mentioned conventional devices, those that use mosquito coil, smoke caused by the reaction of chemicals, and those that use oil mist are clean when the flow of clean air sent to an industrial clean room is visualized. Not only is the air itself contaminated, but it also contaminates the clean room, the machines and devices installed in the clean room, and the processes in which products that require cleanliness are manufactured, making them unusable, especially chemicals. When using smoke from the reaction, there is a problem that it is toxic and dangerous, and the one that produces pure water mist has a small amount of mist, and if a large amount of mist is produced, The drops of mist fall on the floor or workbench, and when the mist is sent out into the airflow, it immediately disappears, disappears, and becomes distant. Not only can not visualize the flow,
Due to the influence of gravity, it gradually flows downward, is easy to separate from the airflow, and there is a problem that the airflow cannot be accurately visualized.

In the present invention, the clean vapor generated by the vapor generator is sent to an adiabatic tank containing any of liquid nitrogen, liquid oxygen, liquefied carbon dioxide, and other liquid refrigerant to rapidly cool it, and then visualized. It is an object of the present invention to provide an air flow visualization device that can solve the above-mentioned conventional problems by being configured so as to send the air flow into the intended air flow.

[Means for solving problems]

The present invention will be described in detail below with reference to the drawings. (1)
A steam generator is a water supply pipe (4) for supplying water (3) to the tank (2), a heater (5) for heating the water (3), and a water level gauge (6) for measuring the water level of the water (3). ) And a steam discharge pipe (7). (8) is an adiabatic tank containing liquid nitrogen (9), which is an example of a liquid refrigerant, and has a constant distance D from the liquid surface (10) of liquid nitrogen (9).
And the inlet pipe (11), which is supported so that steam is ejected to the liquid surface (10) to generate fog at a temperature slightly higher than the temperature of the airflow to be investigated, and inside the heat insulation tank (8). An outlet pipe (12) for discharging the steam cooled by is provided.
(13) is a pipe for sending steam from the steam generator (1) to the heat insulation tank (8), one end of which is connected to the steam discharge pipe (7),
The other end is connected to the inlet pipe (11). (14) is a heater attached to the pipe (13), (15) is a liquid level controller for detecting the liquid level (10), (16) is the liquid level (10) and the inlet pipe (11)
It is a control mechanism that controls so that the distance D between and is kept constant, and operates by the detection signal of the liquid level controller (15).
(17) is a pressure switch provided in the steam generator (1), which detects a change in the pressure of steam in the tank (2) and controls ON / OFF of the switch for energizing the heater (5). (18) is a temperature controller installed in the outlet pipe (12), (19) is the outlet pipe (1
It is a mist discharge pipe that is connected to 2) and discharges mist into the air flow.

[Action]

Water (3) is supplied to the tank (2) through the water supply pipe (4), and the water (3)
Is heated by the heater (5) to generate steam. The generated steam is sent to the heat insulation tank (8) through the steam discharge pipe (7), the pipe (13) and the inlet pipe (11). The sent-in steam is sprayed on the liquid surface of liquid nitrogen (9) and cooled rapidly, and then passes through the outlet pipe (12) and the mist discharge pipe (19) into the air flow to be slightly lower than the temperature of the air flow. High temperature fog (2
It is released as 0). This fog (20) has a long visible state and has a good ride on the airflow.

While the mist (20) is being discharged into the air stream as described above, the liquid nitrogen (9) gradually evaporates and the liquid level (10) descends. (15) detects and the control signal (16) operates by the detection signal,
The distance D between the inlet pipe (11) and the inlet pipe (11) is controlled to be kept constant, and when the vapor pressure in the tank (2) becomes higher than a predetermined pressure, the pressure switch (17) detects it. Then, the power supply to the heater (5) is controlled so as to stop, and the generation of steam is quantitatively controlled. Heater (14) pipe (13)
Is heated to prevent the steam passing through the pipe from returning to water due to the temperature drop.

〔Example〕

The tank (2) has a drain valve (21), a relief valve (22) for allowing excess steam to escape, and a heater () when the amount of water (3) becomes small to prevent the tank (2) from being heated. Provide a float switch (23) to stop the energization to 5). The water supply pipe (4) is provided with a water supply valve (24). Steam discharge pipe
(7) is equipped with a control valve (25) that adjusts the flow rate of steam and stops the supply of steam. Outlet pipe
Attach a heat insulating material or heater to (12), and fog (20)
May be controlled to be released at a temperature higher than the temperature of the air stream. The temperature controller (18) is the outlet pipe (12)
It is used to investigate how the fog (20) flows in response to changes in the temperature of the cooling steam passing through, and the liquid nitrogen in the adiabatic tank (8) becomes empty and When the temperature rises, it may be used to control the energization of the heater (5) or to close the control valve (25). The control mechanism (16) has a motor (26) so that the adiabatic tank (8) rises as the liquid level (10) descends as shown in the first figure.
In some cases, the motor (26) is used so that the inlet pipe (11) drops as the liquid level (10) drops, as shown in the second illustration. In some cases, the inlet pipe (11) may be manually controlled instead of the control mechanism (16). The steam generator (1) and the heat insulation tank (8) may be installed on a carriage (28) equipped with a caster (27) so that they can be freely moved, or even installed in a specific place. Good.

〔The invention's effect〕

Since the present invention is configured as described above, when the generated vapor is not cooled by the refrigerant, the visible amount of fog is a part of the generated vapor amount. The liquid level of the refrigerant rapidly cools, and the frost and ice formed on the liquid level sink below, and a new liquid level is always secured, and there is no decrease in cooling efficiency.
It can be increased to near 0%, and stable generation of fog for a long time becomes possible.

By adjusting the discharge temperature of the fog to a temperature slightly higher than the temperature of the air flow, it is possible to maintain a long floating time in the air flow, and the fog moves only under the influence of the air flow.
The state of the airflow can be accurately visualized to a distant place.

A large amount of clean, non-toxic, safe mist can be generated easily without producing liquid drops.

When grasping how clean air is flowing in an industrial clean room, etc., not only the clean room, but also the machines and devices installed in or about to be installed in the clean room, and the manufacturing processes, etc., caused by adverse effects such as pollution. You don't have to give it.

It becomes possible to grasp the gas flow during the operation of machines and devices, and during the work of workers.

It can be used as a device for grasping the flow of clean air in an ultra-clean space, and as a device for examining the installation position and layout of machines and devices in industrial clean rooms and other spaces with airflow.

It is possible to ensure safety during operation of the device.

And other effects.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a diagram schematically showing the configuration of an air flow visualization device according to the present invention, and FIG. 2 is a diagram schematically showing a modified example of a part of the same configuration. Is. (1) …… Steam generator, (2) …… Tank, (5) …… Heater, (6) …… Water level gauge, (8) …… Insulation tank, (9) …… Refrigerant, (1
0) …… Liquid level, (11) …… Inlet pipe, (12) …… Outlet pipe, (13) …… Pipe, (14) …… Heater, (15) …… Liquid level controller, (16)… … Control mechanism, (17) …… Pressure switch, (18) …… Temperature controller

Claims (7)

[Claims] 1. A steam generator and an adiabatic tank for containing a liquid refrigerant such as liquid nitrogen are connected by a pipe for sending steam from the steam generator to the adiabatic tank, and the vapor is a liquid refrigerant in the adiabatic tank. In an air flow visualization device provided with an outlet pipe for discharging the mist generated by cooling, a desired distance from the liquid surface of the refrigerant of the liquid contained in the heat insulating tank is placed in the heat insulation tank, and steam is applied to the liquid surface. An air flow visualization device in which an inlet pipe is provided that is supported so as to generate a mist having a temperature slightly higher than the temperature of the air flow to be inspected, and the pipe for sending the above steam is connected to the inlet pipe. 2. A control mechanism for moving the inlet pipe to the inlet pipe while maintaining a constant distance from the liquid surface with a displacement of the liquid surface by a liquid surface controller for detecting the liquid surface of the liquid refrigerant contained in the heat insulation tank. The airflow visualization device according to claim 1, which is provided. 3. An adiabatic tank is provided in the adiabatic tank so that the inlet pipe keeps a constant distance from the liquid surface with the displacement of the liquid level by a liquid level controller that detects the liquid level of the liquid refrigerant contained in the adiabatic tank. The airflow visualization device according to claim 1, further comprising a control mechanism for moving the airflow. 4. The air flow visualization device according to claim 1, wherein a heating device is provided in the pipe for feeding the steam into the heat insulation tank. 5. The steam generator is provided with a pressure switch for detecting the change in the pressure of steam and controlling the operation of a heating device such as a heater.
The airflow visualization device according to any one of items. 6. The airflow visualization device according to claim 1, wherein a water gauge for measuring the water level in the tank is provided in the tank constituting the steam generator. 7. The air flow visualization device according to claim 1, wherein a temperature controller for detecting the temperature of the discharged steam is provided at the steam discharge port of the heat insulation tank.