JPS58156815A - Measuring device for flow rate - Google Patents

Abstract

PURPOSE:To obtain a measuring device for flow rate which is easy to handle and is inexpensive, by providing a means of detecting the arrival of fluid at a prescribed level and a means for measuring the time since the inflow of the liquid until the arrival at the prescribed level in a storage vessel. CONSTITUTION:The outflow controlling valve 3 in the outflow port 1b of a storage vessel 1 is closed by the signal K2 from a control part 7, and the inflow controlling valve 2 is opened by the signal K1 to start inflow of fluid into the vessel 1; at the same time, clocking is started in the part 7. When the fluid attains a prescribed liquid level, a photoelectric sensor 6 detects a buoy 5, and feeds a signal L to the part 7. The part 7 sets the signals K1, K at ''0'' to close the valve 2 and the open the valve 3; at the same time, said part stops the clocking and feeds the required time to an arithmetic part 8. The flow rate is calculated in the part 8 and the calculated value is printed with a printer 9. The measuring device for flow rate which is easy to handle and is inexpensive is thus obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow rate measuring device, and is suitable for measuring small flow rates in, for example, characteristic tests of liquid separation devices.

Conventional devices that automatically measure the flow rate using electrical signals are expensive, and because a slight pressure difference occurs between the fluid inlet and the fluid outlet during measurement, it is difficult to measure minute flow rates such as those in which the fluid naturally falls. was not suitable.

Therefore, the present inventors have constructed a siphon container consisting of a storage section with an inflow port at the top and a siphon tube that communicates with the bottom of the storage section and opens downward at a predetermined height. When fluid starts to flow out from the siphon pipe outlet after a predetermined amount of fluid has been stored in the inflow control valve, the outflow detection means detects this and stops the fluid inflow. At the same time as the outflow is completed, the fluid is allowed to flow in from the inflow port again, the above-mentioned series of operations are repeated, and the output of the above-mentioned fluid outflow detection means is introduced to measure the time from detection to detection. Devices have already been proposed that use known storage volumes to calculate fluid flow rates. This flow rate measuring device using a siphon tube can measure minute flow rates, such as those caused by free fall, more accurately than conventional devices, and can be manufactured at a lower cost.

However, depending on the flow measurement device using this siphon tube, when detecting the fluid flowing out from the siphon tube outlet, droplets remaining at the tip of the siphon tube outlet may fall, and these droplets may be removed from the regular flow. In order to distinguish it from the signal, it was necessary to control it using a computer or the like, and this control was complicated.

The present invention has been made in view of the above, and an object of the present invention is to provide a flow measuring device suitable for measuring minute flow rates, which has a simpler structure and is capable of accurate measurement.

A feature of the present invention is that fluid is allowed to flow into a storage container having an inlet at the top and an outlet at the bottom via an inflow control valve that controls the inflow of fluid from the inlet, and the level of the fluid in the storage container is A means for detecting that the level has reached a predetermined level, and a means for measuring the time from when the fluid starts flowing into the storage container until it reaches the predetermined level are provided.+1. The purpose is to calculate the fluid flow rate from that time and the volume of the storage container up to a predetermined 1 bel.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

An inlet 1 is provided at the upper part of the storage container 1 to protrude upward.
An inflow control valve 2 for switching the fluid flow path is provided above a. The inflow control valve 2 is a three-way solenoid valve, and can switch the flow path of the fluid from the inlet 1a into the storage container 1 or into another container based on a control signal.

An outflow port 1b is provided at the bottom of the storage container 1, and an outflow control valve 3 is provided. The outflow control valve 3 is a two-way solenoid valve that can open and close the outflow port 1b based on a control signal. The storage container 1 is also provided with a thin tube 4 that communicates with the lower part of the container and extends upward, and the thin tube 4 is provided with a float 5 that can be freely displaced according to the liquid level displacement of the fluid. A photoelectric sensor 6 is provided that works with the float 5 to detect the liquid level. The photoelectric sensor 6 is installed at a level where the inlet port 1a protruding above the storage container 1 exists. The liquid level detection signal from the photoelectric sensor 6 is introduced into the control unit 7, and the control unit 7 controls the inflow control 2 and the outflow control valve 3 based on the signal and the required outflow time input in advance, which will be described later. Supply 1 and 2 to the control signals. Further, the control unit 7 inputs the control signal +,
Measure the time Ill i from when the fluid starts flowing into the storage container 1 until it reaches a predetermined liquid level and the liquid level detection signal arrives at step 1.7, and correspond to that value. The resulting signal is supplied to the calculation section 8. The calculation unit 8 inputs the signal and calculates the flow rate Qi using the following equation using the volume V of the storage container 1 up to a predetermined liquid level that has been input in advance.

Qi=V/Ti This arithmetic unit 8 can be constructed by a microcomputer. Also, the output of this calculation section 8 is output to a printer 9.
It is configured to be supplied to the printer and printed.

Next, the operation of the above embodiment will be explained.

FIG. 2 is an explanatory diagram of the operation of the control signals Ll and Kn of the control section 7 and the liquid level detection signal of the photoelectric sensor 6.

The control signal Kl is a control signal for the inflow control valve 2, and the state ".1" indicates the state in which the fluid flow path or storage container 1 is guided. The control a signal 2 is a control signal for the outflow control valve 3, and the state "1" indicates a closed state. When a measurement command is given from the outside, the control signal is positive.

K2 becomes state "1" and fluid starts flowing into the storage container 1, and at the same time, time measurement is started in the control section 7. When the fluid reaches a predetermined level in the storage container 1, the photoelectric sensor 6 detects the float 5, outputs a level detection signal, and supplies it to the control unit 7.

In response to this signal, the control unit 7 sets the control signal L1°K2 to the state "O", and the inflow control valve 2 stops the fluid flowing into the storage container 1, and opens the outflow control valve 3 to open the storage container 1. Drain the fluid inside. At the same time, time measurement is ended and TI is supplied to the calculation section 8.

The calculation unit 8 calculates the flow rate Ql using the above-mentioned formula and supplies it to the printer 9, which prints out the calculated value Ql. A predetermined time TO is inputted to the control unit 7 at 1 based on the measured outflow time required for the fluid stored in the storage container 1 to completely flow out. After time ゛1゛0 has passed since control well 3 was opened,
The above-mentioned moving object is repeated by setting 1°K2 to the state "l" in the control signal again.

In this way, the flow caps Qi are sequentially determined and printed by the printer 9.

In the above-described embodiment, a float and a photoelectric element are used as means for detecting the liquid level, but other known level detecting devices may be used.

As explained above, according to the present invention, it is possible to accurately measure a minute flow rate, such as in a free fall state, using a simple device, and experiments have shown that the measurement error is within 1%. found. Furthermore, according to the present invention, the flow rate measurement range can be changed by simply changing the capacity of the storage container, and a flow 1'' measurement device that is easy to handle and inexpensive can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing the operation of the control signal and liquid level detection signal of the control section. 1... Storage container 2... Inflow control valve 3... Outflow control valve 4... Thin tube 5... Float 6... Photoelectric sensor 7... Control section 8... Calculation section 9. ...Printer patent applicant Nitto Electric Industry Co., Ltd. agent Patent attorney Nishi 1) New construction Figure 1 Figure 2

Claims (1)

[Claims] A storage container with an inlet at the top and an outlet at the bottom,
an inflow control valve that switches a fluid flow path to control fluid inflow from an inlet of the storage container; an outflow control valve that opens and closes an outlet of the storage container; and an outflow control valve that controls the liquid level of the fluid in the storage container. and a timing means for measuring the time from when the fluid starts flowing into the storage container until it reaches a predetermined liquid level, and the volume and the time until the fluid reaches the predetermined liquid level in the storage container. A flow rate measuring device configured to determine the flow rate of a fluid from.