JPH0828499A - Liquid transfer device - Google Patents

Abstract

PURPOSE:To improve quantitative supply by calculating liquid transfer flow quantity from a tank level variation and a calculated discharge flow quantity and thus regulating the driving air low quantity on the basis of the comparison with a set flow quantity and so transferring with high accuracy in accordance with a demanded low quantity. CONSTITUTION:A set discharge flow quantity QS per unit time is inputted in advance to a comparative calculation means 17 by a liquid transfer flow quantity setting means 18. Driving air is sent to an air-lift pump 3 from a driving air supply system 5, so that transfer of stored liquid R from a tank 1 is started. A driving air flow quantity is detected by a driving air flow quantity meter 6, and a calculated discharge flow quantity QC is calculated from performance characteristic pump 3 by a calculated discharge quantity calculation means 12. The transfer is thus continued for a specific time. When a timer 16 turns on after lapse of a specific time, a correction discharge flow quantity QC and a tank level variation by a transfer flow quantity correction means 15, so that the comparison with a set discharge quantity QS is made by a comparative calculation means 17. When a low quantity difference is recognized, the opening of a regulation valve 7 is regulated via an air flow quantity control mans 19 and so the driving air low quantity is increased/decrease.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid transfer device, and more particularly to a technique for supplying a fixed amount of liquid when transferring high-level radioactive waste (waste liquid) using an air lift pump. Is.

[0002]

2. Description of the Related Art An air lift pump transfers liquid to a target position by utilizing the rising force of driving air. Although the transfer efficiency is low, it does not have a mechanical driving part.
It is used in areas where failure is averse to occur, such as when supplying high-level radioactive waste (waste liquid) to a glass melting furnace.

As a technique for quantitatively supplying high-level radioactive waste (waste liquid) or the like using an air lift pump, for example, Japanese Utility Model Publication No. 62-111595 is introduced.

[0004]

However, at the time of transfer by the air lift pump, since the liquid to be transferred becomes a gas-liquid mixed fluid in which air is mixed, the transfer liquid amount of the transfer target liquid is changed on the discharge side of the air lift pump. It is technically difficult to measure accurately, and although it is possible to detect the amount of liquid by placing a level gauge in the tank that stores the liquid to be transferred, If the area is large,
Due to the small transfer capacity of the air lift pump, it is difficult to accurately detect the liquid level with a liquid level gauge due to small changes in the liquid level, and it takes time to detect it and the responsiveness is low. .

The present invention effectively solves such problems and achieves the following objects. Perform transfer with the required flow rate value with high accuracy. Improve quantitative supply performance without the need for a special level gauge.

[0006]

A liquid transfer flow rate setting means for operating an air lift pump for sending a stored liquid in a tank to a liquid consumption system by setting a drive air flow rate, and a drive connected to the air lift pump for detecting a drive air flow rate. An air flow meter, a calculation discharge flow rate calculation means that is connected to the drive air flow meter and calculates a calculation discharge flow rate from the performance characteristics of an air lift pump, a liquid level meter that detects a change in the liquid level of a tank, and the liquid level meter. Between the air lift pump and the liquid transfer flow rate setting means, which is connected to the liquid transfer amount calculation means for calculating the liquid transfer flow rate within the operating time of the air lift pump and connected to the calculated discharge flow rate calculation means and the liquid transfer amount calculation means. An arrangement is provided which is provided in an intervening state and comprises an air flow rate control means for comparing the liquid transfer flow rate with a set flow rate and increasing or decreasing the drive air flow rate by the difference.

[0007]

[Operation] When the stored liquid in the tank is sent to the liquid consumption system,
The air lift pump is operated, the flow rate of the driving air is detected, the calculated discharge flow rate is calculated from the performance characteristics of the air lift pump, and the transfer of the stored liquid is continued for a specific time. When the liquid transfer flow rate during a specific time is calculated from the change in the tank liquid level and the calculated discharge flow rate, and when there is a difference by comparing the liquid transfer flow rate and the set flow rate, the difference in the driving air is used. Adjust to increase or decrease the flow rate. Detection of drive air flow rate after a specific time By repeating the steps below, the flow rate is brought to a constant supply state by the set flow rate.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the liquid transfer device according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1, in a tank 1, an air lift pump 3 for sending the stored liquid R toward a liquid consumption system 2, and a liquid level meter for detecting the liquid level L of the stored liquid R. 4 and are arranged.

A drive air supply system 5 for supplying drive air is arranged in the air lift pump 3, and a drive air flow rate F per unit time is detected between the air lift pump 3 and the drive air supply system 5. Drive air flow meter 6 for
And an adjustment valve 7 for adjusting the flow rate F of driving air to the air lift pump 3.

The liquid level gauge 4, the driving air flow meter 6 and the adjusting valve 7 are provided with an air lift pump 3 as shown in FIG.
The electric devices, electric circuits, etc. for controlling and quantitatively supplying the electric power are arranged in a connected state.

The liquid level gauge 4 includes a liquid transfer amount calculation means 11
Is connected. In the liquid transfer amount calculation means 11, the liquid transfer within the operating time range of the air lift pump 3 described later is calculated from the product of the liquid level change ΔL of the stored liquid R inside the tank 1 and the cross-sectional area k of the tank 1. It calculates the amount V _R.

A calculation discharge flow rate calculation means 12 is connected to the drive air flow meter 6. The calculated discharge flow rate calculation means 1
2, the calculated discharge flow rate Q _c per unit time in the air lift pump 3 is calculated based on the performance characteristics of the air lift pump 3 shown in FIG. 2 (relation curve between the drive air flow rate F and the calculated discharge flow rate Q _c ), the liquid level. From L and the liquid specific gravity γ, calculation is performed as these functions.

A discharge amount calculation means 13 is connected to the calculated discharge flow rate calculation means 12. In the discharge amount calculation means 13, when the liquid level L in the liquid level gauge 4 has a significant difference in consideration of the detection accuracy and the like, the liquid level change ΔL of the stored liquid R.
Integrating the calculated discharge flow rate Q _c in operation time T of the air lift pump 3 causing it obtains the calculated discharge amount V _c.

A transfer amount ratio calculating means 14 is connected to the liquid transfer amount calculating means 11 and the discharge amount calculating means 13. In the transfer amount ratio calculation means 14, the liquid transfer amount calculation means 1
The ratio (correction value) β of the liquid transfer amount V _R obtained in 1 and the calculated discharge amount V _c obtained by the discharge amount calculation means 13 is calculated.

A transfer flow rate correction means 15 is connected to the calculated discharge flow rate calculation means 12 and the transfer amount ratio calculation means 14.
The transfer flow rate correction means 15 obtains the corrected discharge flow rate Q _R by multiplying the calculated discharge flow rate Q _c by the correction value β, and the open / close switch (contact) 16 a is interposed between the transfer flow rate correction means 15 and the transfer amount ratio calculation means 14. The open / close switch 16a is provided with a timer 16
Thus, the "ON" state is set every time the operating time T of the air lift pump 3 elapses. Therefore, from the transfer flow correction means 15, the signal of correcting the discharge flow rate Q _R at every elapse of the operation time T is output.

A comparison calculation means 17 is connected to the transfer flow rate correction means 15, and a liquid transfer flow rate setting means 18 is also connected to the comparison calculation means 17. In the comparison operation unit 17, a correction discharge flow rate Q _R of the transport flow correcting device 15,
The set discharge flow rate Q _s from the liquid transfer flow rate setting means 18 is compared, and if a difference is recognized, a correction signal for the difference is output.

An air flow rate control means 19 is connected to the driving air flow meter 6, the adjusting valve 7 and the comparison calculation means 17 in an intervening state. The air flow rate control means (valve opening degree control means) 19 adjusts the opening degree of the adjusting valve 7 based on each data to increase or decrease the drive air flow rate in the air lift pump 3.

When the stored liquid R in the tank 1 is sent to the liquid consuming system 2, it is carried out by the operation of the air lift pump 3. At that time, the liquid transfer flow rate setting means 18 sets the set discharge flow rate Q per unit time. _s is input to the comparison calculation means 17.

From the drive air supply system 5 to the air lift pump 3
Driving air to start the transfer of the stored liquid R in the tank 1, the driving air flow meter 6 detects the driving air flow rate, and the calculated discharge flow rate calculation means 12 calculates the air flow rate of the air lift pump 3 shown in FIG. The transfer is continued for the specific time T while calculating the calculated discharge flow rate from the performance characteristics.

The discharge amount calculating means 13 calculates the calculated discharge amount V _c from the calculated discharge flow rate Q _c until the timer 16 operates, and calculates the liquid transfer amount calculating means 11 and the calculated discharge flow rate calculating means 12 In this case, the liquid transfer amount V _R and the correction value β are calculated from the liquid level change ΔL of the stored liquid R.

When the open / close switch 16a is turned "ON" after the timer 16 has passed the specific time T, the transfer flow rate correction means 1
5 calculates the calculated discharge flow rate Q _c and correcting the discharge flow rate Q _R from the correction value beta, the comparison operation unit 17, is performed compared with the set discharge flow rate Q _s and corrected discharge flow rate Q _R. In other words, the set discharge flow rate Q _s for a reference when performing quantitative transfer desired, when is compared with the corrected discharge flow rate Q _R is the actual transfer flow rates are observed difference, air flow control means The opening of the adjusting valve 7 is adjusted via 19 to increase or decrease the drive air flow rate.

When the liquid level change ΔL obtained by the liquid level meter 4 is used as a reference, the fine adjustment of the driving air flow rate is repeated by the following steps of detecting the driving air flow rate described above. This leads to a fixed amount supply state that matches the set discharge flow rate Q _s .

[Other Embodiments] In the embodiment of FIGS. 1 and 2 described so far, electric devices, electric circuits, etc. are arranged in the liquid level meter 4, the driving air flow meter 6, and the adjusting valve 7. do it,
The air lift pump 3 is controlled and fixedly supplied. However, in addition to configuring some or most of these means by an electric circuit, they can be replaced by a computer, and the liquid according to the present invention can be used. In the transfer device,
Naturally, these techniques are also included. In addition, the liquid consumption system 2 includes a case where it is transferred to another tank or the like, a case where it is combined with a piping system, a case where it is combined with a liquid supply system to a glass melting furnace in a vitrification facility, and the like.

[0025]

As described above, the liquid transfer device according to the present invention has the following effects. (1) Liquid transfer flow rate setting means, drive air flow meter, calculated discharge flow rate calculation means for calculating calculated discharge flow rate from performance characteristics of air lift pump, liquid level meter, and liquid transfer flow rate within operating time Since the liquid transfer amount calculation means and the air flow rate control means for comparing the liquid transfer flow rate with the set flow rate and increasing or decreasing the drive air flow rate by the difference are provided, the liquid transfer of the calculated discharge flow rate is performed from the beginning. By correcting this, fixed quantity transfer according to the required flow rate value can be performed with high accuracy. (2) Even if the cross-sectional area of the tank that stores the transferred liquid is large, within a range where a significant difference is recognized,
Since the liquid level is detected by the liquid level meter, it is possible to improve the quantitative supply property without requiring a special liquid level meter. (3) Even when the transfer capacity is small, or when it is difficult to accurately detect the liquid amount due to a small change in the liquid level, the liquid is transferred at the calculated discharge flow rate, and the accuracy is gradually increased. It is possible to switch to the constant supply of.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an embodiment of a liquid transfer device according to the present invention.

FIG. 2 is a relationship curve between a drive air flow rate and a calculated discharge flow rate showing the performance characteristics of the air lift pump of FIG.

[Explanation of symbols]

 1 Tank 2 Liquid Consumption System 3 Air Lift Pump 4 Liquid Level Meter 5 Driving Air Supply System 6 Driving Air Flow Meter 7 Adjustment Valve 11 Liquid Transfer Amount Calculation Means 12 Calculation Discharge Flow Rate Calculation Means 13 Discharge Amount Calculation Means 14 Transfer Amount Ratio Calculation Means 15 Transfer flow rate correction means 16 Timer 16a Open / close switch (contact) 17 Comparison calculation means 18 Liquid transfer flow rate setting means 19 Air flow rate control means (valve opening control means)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G21F 9/04 AZAB // B67D 5/50

Claims (1)

[Claims] 1. A liquid transfer flow rate setting means (18) for operating an air lift pump (3) for feeding a stored liquid (R) of a tank (1) to a liquid consumption system (2) by setting a drive air flow rate.
A drive air flow meter (6) connected to the air lift pump for detecting the drive air flow rate; and a calculated discharge flow rate calculation means (12) connected to the drive air flow meter for calculating a calculated discharge flow rate from the performance characteristics of the air lift pump. ), A liquid level meter (4) for detecting a change in the liquid level in the tank, and a liquid transfer amount calculation means (11) connected to the liquid level meter for calculating the liquid transfer flow rate within the operating time of the air lift pump, The calculated discharge flow rate calculation means and the liquid transfer amount calculation means are connected to each other and are interposed between the air lift pump and the liquid transfer flow rate setting means. A liquid transfer device comprising: an air flow rate control means (19) for increasing or decreasing.