JPS5939608Y2 - Drip type flow rate detection element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow rate detection element, particularly one that detects flow rate by counting droplets.

Monitoring and recording of the flow rate by counting droplets and controlling the flow rate have been practiced for a long time.

The well-known mechanism for counting droplets in this type of element, which is commonly used, is that the dropping nozzle and the suction pipe, which are arranged so as to protrude into the element space, are both electrically conductive, and the upper electrode and the lower electrode are connected to each other, respectively. It also serves as an electrode, and the distance between the tips of the two is adjusted so that they can be connected by a droplet, and when a droplet drips from the dripping nozzle, depending on the liquid flow rate of the suction pipe, the droplet and suction pipe are connected. Counting is made possible by utilizing the conductive path formed between the two.

However, the known device 1 of this kind illustrated in FIG. 1 inherently has the following drawbacks and is prone to erroneous counting, and the reliability of the measuring flow meter is not sufficient.

Namely, 1) The dripping nozzle 2 must be made of metal, which does not have sufficient water repellency, and must be placed facing the suction pipe 3 in the dripping space 4 in order to connect with the suction pipe 3 through droplets. Therefore, the state differs from the original natural droplet falling state.

For these reasons, the droplet of liquid acid is unstable, and the accuracy cannot be said to be sufficient based on the basic principle of measuring based on counted values.

2) Since the inside of the element space is always high humidity, condensation or "cloudiness" tends to occur on the inner wall, and in addition, the liquid may leak due to accidental splashing of droplets and the bursting of bubbles in the liquid film hanging from the dripping nozzle 2. Undesirable counting is often caused by adhesion to inner wall surfaces.

In addition, the liquid film bubbles may stagnate between the dropping nozzle 2 and the suction pipe 3, and when the liquid flows down through the liquid film, it becomes continuously conductive, making counting impossible.

3) In practice, in consideration of economy, operability, and ease of maintenance, it is common to arrange a plurality of detection elements in parallel and process individual counting information with a single device.

In such a case, even if each element is connected independently, the drip nozzle will be connected to the liquid in the liquid supply pipe, and the suction pipe will be connected to the common power supply of the processing equipment, and the independence for obtaining individual information will be lost. I end up.

In order to eliminate the above drawbacks, attempts have been made to increase the electrical resistance of the inner wall by increasing the threshold for starting counting or by increasing the length of the element, but the former method The latter is unsatisfactory in that it is difficult to make adjustments to prevent malfunctions when handling liquids with high concentrations, and the latter is unsatisfactory in that the response becomes poor due to the expansion of the internal space volume of the element, and it tends to affect other parallel elements. It turns out that there is something.

In order to overcome such problems, a detection element as set forth in the first registered claim has been proposed.The configuration and effects of the present invention will be explained in more detail with reference to the embodiments shown in the drawings below.

FIG. 2 is a longitudinal cross-sectional view of the device of the present invention, and the electrically insulating cylinder 10 (side wall 11, upper closed end wall 12, and lower closed end wall 13) constitutes a drip space 14.

The upper closed end wall 12 has a drip nozzle 22 that does not necessarily require conductivity and can maintain a natural falling state, and the lower closed end wall 13 has a suction pipe that communicates with the liquid distribution pipe 31. 32 are provided so as to face each other.

An inner cylindrical body 41 is attached to the upper closed end wall 12 so as to be in contact with and hang down therefrom.

The inner cylindrical body 41 is large enough to surround the protruding part of the dripping nozzle 22 at intervals, and prevents splashing when the droplet falls, liquid scattering due to the bursting of liquid film bubbles from the nozzle, and adhesion to the inner wall. prevention has been effectively achieved.

An upper electrode 52 is attached to the VC at an appropriate position on the side wall 11 (indicated by a terminal plate 52 in the figure), and its tip 53 is close to the tip of the suction pipe 32 (for example, about 2 mm away). We will meet face to face.

This configuration ensures that counting occurs only when a droplet is located at the tip of the suction tube 32.

Note that the stem of the upper electrode 52 should be as close to the side wall 11 as possible.
It is preferable to attach it to a position between this and the inner cylindrical body 41 for the reasons mentioned above.

Furthermore, if necessary, an electric heater 61 connected to an external power source 62 is installed on the side wall 11 to prevent dew condensation or fogging.
will be established.

For example, for a cylindrical body with an inner diameter of 18 mm and a length of about 30 mm, a power of about 250 mW is enough to achieve its purpose.

More preferably, the electric heater 61 may effectively heat the attachment portion of the upper electrode 52 to the side wall that shares the terminal plate 51.

It goes without saying that the electric heater 61 may be replaced with any semiconductor heating element if desired.

Furthermore, although the upper electrode 52 is connected to the external counting means 7 together with the suction pipe 32, even if a plurality of elements are combined with a single counting means, the same inconvenience occurs in processing while maintaining the independence of individual information. It is obvious that there are no points.

[Brief explanation of drawings]

FIG. 1 shows a longitudinal sectional side view of a known drip-type flow rate detection element, and FIG. 2 shows a longitudinal sectional side view of an element according to an embodiment of the present invention. 1.10... Element cylinder, 11, 12, 13... Element walls, 2, 22... Dripping nozzle, 3, 32... Suction pipe, 41... Inner cylinder, 51 ...Top electrode, 61.
... Electric heater, 7... Counting means.

Claims (1)

[Scope of utility model registration request] A drip nozzle that communicates with the supply pipe is provided at the upper closed end of the closed cylinder made of electrically insulating material, and a suction pipe that also serves as a lower electrode and communicates with the liquid distribution pipe is protruded from the lower closed end, and are spaced apart and facing each other. In the drip-type flow rate detection element arranged as shown in FIG. 1. An element comprising an upper electrode having a tip close to the tip of the tube.