JP2008201425A - Method and device for following liquid level of filling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for following the liquid level of a filling device capable of correctly elevating the position of a discharging port of a filler liquid to the liquid level without being affected by the shape of a container, presence/absence of a lid, or the property of the filler liquid when filling with the liquid in the container. <P>SOLUTION: The device comprises a metering instrument 5 such as a load cell capable of loading a container Y for filling with a filler liquid B thereon, a computing means 6 which computes the liquid level elevating speed v from the opening sectional area A at the liquid level height h of the container Y and the specific gravity of the filler liquid B from the metered mass of the filled liquid to fill the container Y measured by the metering instrument 5 at every predetermined time, and computes the displacement speed as the displacement quantity of the liquid level height per unit time, and a control means 7 for controlling the elevating speed V of an elevating/lowering means 4 to the liquid level elevating speed v computed by the computing means 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a filling device that mainly fills liquid in a large container such as a storage tank or a drum can into small containers and fills it according to the upper surface (liquid level) of the liquid filled in the small container. The present invention relates to a liquid level tracking method and apparatus for following a liquid level by moving a liquid discharge port up and down. Here, the above “mainly liquid” means containing a granular material and a fluid in addition to the liquid.

  In a filling device that automatically fills a small container with a liquid to be filled via a pump or the like, if the gap between the discharge port of the liquid to be filled and the liquid level becomes too large, the liquid to be filled will hit the liquid surface. The filling liquid may scatter to form a mist or form a foam containing air, and the filling liquid may blow out from the container at the end of filling. In addition, when the filling liquid to be discharged becomes a bubble, the liquid level rises from the actual height, and the discharge port of the filling liquid may come into contact with the filling liquid. There is also a possibility that the liquid level further rises or the discharge port is lifted by receiving buoyancy. Therefore, although it depends on the type of liquid to be filled, it is generally desirable to fill with the interval between the discharge port and the liquid level in the container kept at, for example, about 0 to several millimeters.

Conventionally, in this type of filling device, in the case of liquids that tend to foam when filled from above or liquids that dislike the entrainment of air, for example, as shown in FIG. A sensor 71 for measuring the liquid level, such as a sound wave type, is provided to measure the level of the liquid level, and the level of the liquid to be filled is raised and lowered according to the measured level of the liquid level to follow the liquid level. To prevent foaming and air entrainment. However, this method has the following disadvantages. That is,
1. In the case of a container such as the funnel can Y where the inlet D is only part of the upper surface of the container, the position of the liquid level cannot be accurately measured by the sensor 71 (see FIG. 5A).

  2. When a lid is attached to the upper end opening of the container Y in order to prevent dust and the like from entering during filling, As in the case of, the liquid level position cannot be measured by the sensor 71, and even when the transparent lid Z is used, the irradiation wave and the reflected wave from the sensor 71 are attenuated and the liquid level position cannot be measured accurately. (See FIG. 5B).

  3. When the liquid to be filled B is a highly viscous liquid such as chocolate, for example, the liquid level rises and is not horizontal, so the liquid level is not constant, and the irradiation wave from the sensor 71 is irregularly reflected. Is difficult to accurately measure (see FIG. 5C).

By the way, as a prior art related to this type of filling apparatus, a fixed-quantity filling apparatus that fills a small container with a liquid to be filled in a large container is proposed (for example, see Patent Document 1). In this filling device, when filling the liquid to be filled in a large container into a small container with a pump or the like, the container is placed on a measuring instrument such as a load cell and filled while measuring the mass (weight) of the liquid to be filled. However, even if the pump is stopped when the specified weight is reached, there is a response delay until the pump actually stops. It is a fixed-quantity filling device that can be filled at a constant mass.
JP 2007-3343 A

  In the quantitative filling device described in Patent Document 1 described above, a preset volume can be filled almost accurately in a small container, but when filling the container, the discharge port of the filling liquid is the liquid level in the container. The idea of following the liquid level by moving it up and down according to the height of the is not taken in.

  The present invention has been made in view of the above points. When filling a container, the position of the discharge port of the filling liquid is not affected by the shape of the container, the presence or absence of a lid, and the properties of the filling liquid. It is an object of the present invention to provide a liquid level tracking method for a filling device and the same device that can be accurately raised in accordance with the above.

  In order to achieve the above object, the liquid level tracking method of the filling apparatus according to the present invention supplies the liquid to be filled in a large container such as a storage tank with a supply pump via a pipe, and divides the liquid into small containers. In this filling apparatus, a liquid level tracking method is used in which the discharge port of the liquid to be filled is moved up and down by an elevating means in accordance with the upper surface (hereinafter referred to as a liquid level) of the liquid filled in the small container to follow the liquid level. Measuring the mass of the filling liquid filled in the small container with a measuring device such as a load cell on which the small container filled with the filling liquid can be placed, and measuring the liquid level of the small container The displacement speed of the liquid level is calculated from the opening cross-sectional area and the specific gravity of the liquid to be filled, and the rising speed of the elevating means is controlled according to the calculated displacement speed of the liquid level. .

According to the liquid level tracking method of the filling apparatus according to the present invention having the above-described configuration, in the apparatus for automatically filling the small container with the liquid to be filled in the large container by the supply pump, the empty small container is placed on the measuring instrument. Usually, the container weight (mass) is subtracted by taring, and the measured value by the measuring instrument becomes zero. Here, for example, when the small container is formed of a cylindrical body with a radius r, the opening cross-sectional area is π × r ² , and therefore, the specific gravity of the liquid to be filled is γ, and the mass of the liquid to be filled filled in the container If the measured value of w1 is w1, the liquid level height h1 = w1 / (π × r ² × γ)
It becomes. If the measured value of the mass of the liquid to be filled after a lapse of a certain time (t) is w2, the liquid level height h2 = w2 / (π × r ² × γ). Therefore, the rising speed of the liquid level is v = (h2−h1) / t = (w2−w1) / (π × r ² × γ × t). Therefore, when the rising speed v of the liquid level is kept constant, if the discharge port of the filling liquid is raised at the speed V = v by the elevating means, the liquid level of the filling liquid in the container and the filling level are increased. The liquid discharge port always rises at a constant interval, and liquid bubbling and liquid scattering are prevented.

  As described in claim 2, a quantitative pump in which the supply amount is proportional to the pump rotation speed is used as the supply pump, and the rotation speed of the quantitative pump and the ascending speed of the discharge port of the filling liquid by the elevator It is preferable to perform correction control so that is proportional.

  The amount of liquid supplied by a quantitative pump, for example, a uniaxial eccentric screw pump, that is, a filling speed, is directly proportional to the rotational speed p of the pump. In other words, since the pump rotational speed p and the liquid level displacement speed v are directly proportional, the pump rotational speed p is also one of the parameters. By increasing / decreasing the discharge port ascending speed V in accordance with the increase / decrease rate of the pump rotation speed p, the discharge port of the filling liquid can be made to follow the liquid level more accurately.

In order to achieve the above object, a liquid level follower of a filling device according to the present invention (Claim 3) supplies a liquid to be filled in a large container such as a storage tank with a supply pump via a pipe. In a filling apparatus that divides the liquid into small portions, the discharge port of the liquid to be filled at the lower end of the pipe is raised by an elevating means in accordance with the upper surface (hereinafter referred to as the liquid level) of the liquid filled in the small container. A liquid level tracking device for tracking
Based on a weighing value such as a load cell capable of mounting the small container to be filled with the liquid to be filled, and a weight value of the liquid to be filled to be filled in the small container measured at regular intervals by this weighing machine, Calculation of the displacement level of the liquid surface height from the opening cross-sectional area at the liquid level height of the small container and the specific gravity of the liquid to be filled, and the displacement speed that is the displacement amount of the liquid level height per unit time And a control means for controlling the rising speed of the elevating means in accordance with the displacement speed of the liquid level calculated by the calculating means.

  According to the liquid level follower of the filling apparatus having the above-described configuration, the opening cross-sectional area A of the container does not change with the height, the specific gravity of the liquid to be filled is γ, and the liquid level when the liquid level is h1. When the mass is w1 and the mass of the liquid to be filled when the liquid level height h2 after t seconds elapses is w2, the rising speed of the liquid level v = (h2-h1) / t = (w2-w1) / ( A × γ × t). Therefore, if the discharge port of the liquid to be filled is raised at the rising speed V = v (the liquid level rising speed) by the lifting means, the liquid level of the liquid to be filled in the container and the discharge port of the liquid to be filled are always constant. Thus, the liquid to be filled is filled in the container while maintaining the interval, and foaming of the liquid and scattering of the liquid are prevented. That is, the mass (filling amount) of the liquid to be filled in the small container with the measuring instrument is sequentially measured at regular time intervals, and the change in the mass (filling amount) w for each measurement time and the liquid level in the small container The change in the length h is calculated by the calculation means, and the position of the discharge port for the liquid to be filled rises in accordance with the rising speed of the liquid level. Therefore, the interval between the liquid level in the container and the discharge port for the liquid to be filled is always constant. In this state, the container can be filled with the filling liquid.

  As described in claim 4, the elevating means has a ball screw that is rotated by a variable speed motor (for example, a servo motor) and a female screw portion that is screwed to the ball screw, and can be moved up and down along a guide post. And a lifting / lowering portion to which a pipe can be attached above the discharge port, and the rotation speed of the variable speed motor can be controlled by the control means.

  In this way, the change in the mass (filling amount) of the liquid to be filled per unit time and the displacement of the liquid surface height are calculated, and the rising speed of the discharge port of the liquid to be filled, in other words, the rotation of the ball screw by the variable speed motor Since the speed can be changed in accordance with the change in the mass (filling amount) of the liquid to be filled, the liquid level in the container and the discharge port of the liquid to be filled can be always maintained at a constant interval.

  According to a fifth aspect of the present invention, an electromagnetic open / close filling valve capable of opening and closing the discharge port of the pipe can be provided.

  In this way, when the mass of the liquid to be filled in the small container reaches a preset weight (set mass by the measuring device), the filling valve is closed by a command signal from the control means. Can be stopped immediately.

  As described in claim 6, it is preferable that a return pipe to the large container is connected to the pipe between the supply pump and the filling valve, and a relief valve is interposed in the middle of the return pipe. .

  In this way, when the filling liquid in the small container reaches a predetermined filling amount and the filling valve is closed, the rotation of the supply pump does not stop immediately due to the inertial force and the supply of the filling liquid continues. Even in this case, the relief valve is opened and the liquid to be filled is returned from the return pipe to the large container. Therefore, even if complicated control is not performed, if the filling valve is closed, the supply of the filling liquid into the small container is immediately stopped, and the set filling amount can be accurately filled.

  As described in claim 7, a quantitative pump whose supply amount is proportional to the pump rotation speed is used as the supply pump, and the raising / lowering means is raised in response to an increase (decrease) in the rotation speed of the quantitative pump. It is preferable to control the speed to increase or decrease.

  In this way, since the supply amount per unit time of the liquid to be filled by the quantitative pump, that is, the filling speed is directly proportional to the rotational speed p of the pump, the rotational speed p of the pump and the displacement speed v of the liquid surface height. Both are directly proportional. Accordingly, the pump rotation speed p can be one of the parameters. When the pump rotation speed p increases or decreases, the rising speed V of the discharge port of the filling liquid is increased or decreased according to the increase / decrease rate of the pump rotation speed p. Therefore, the discharge port of the filling liquid can be made to follow the liquid level more accurately.

  Since the liquid level tracking method of the filling device and the same device according to the present invention are configured as described above, the following excellent effects are obtained.

  1) Applicable regardless of the shape of the container filled in small portions.

  2) If the lid has an opening that allows the filling valve and liquid discharge outlet to enter and exit, unlike the conventional sensor that measures the position of the liquid level, the measured value attenuates due to the effect of the lid. Therefore, the position (height) of the liquid level can be measured stably.

  3) The liquid level can be accurately followed without being affected by the properties of the liquid to be filled, such as viscosity.

  Hereinafter, an embodiment of a liquid level tracking device for a filling apparatus according to the present invention will be described with reference to the drawings, and a liquid level tracking method will also be described.

  1 to 4 are drawings showing an embodiment of the liquid level follower of the filling apparatus of the present invention. FIG. 1 is a small container in which a filling liquid (liquid B) in a large container is pumped up by a quantitative supply pump 2. FIG. 2 is a front view showing the filling side of the liquid level following device 3 including the filling valve and the elevating means of the discharge port of the filling liquid and the filling side of the filling device 1. FIG. 3 is a block diagram showing an embodiment of the liquid level tracking method of the present invention, and FIG. 4 is an enlarged sectional view showing a part of a vertical uniaxial eccentric screw pump as a quantitative supply pump.

  As shown in these drawings, the liquid filling apparatus 1 of this example includes a pump 2 that pumps up the liquid B in a drum can X as a large container and supplies the liquid B to the small container Y, and the liquid B filled in the small container Y. And a liquid level follower 3 that causes the liquid discharge port 14 below the filling valve 12 to be raised by the elevating means 4 so as to follow the liquid level in accordance with the liquid level that is the upper surface of the liquid level. The measuring device 5 for sequentially measuring the mass (weight) of the liquid B filled therein, and the liquid level height h are sequentially calculated from the mass of the filling liquid B measured by the measuring device 5, and the liquid level A calculating means 6 for calculating the rising speed and a control means 7 for controlling the rising speed by the lifting means 4 in accordance with the rising speed of the liquid level height h calculated by the calculating means 6 are provided. ing.

  The supply pump 2 is a vertical uniaxial eccentric screw pump. As shown in FIG. 4, a stator 2b is connected to the lower end of a substantially cylindrical pump casing 2a, and the lower end of the stator 2b constitutes a suction port 2c. As shown in FIG. 1, an electric motor 2e is connected to the upper end of the pump casing 2a via a speed reducer 2d. Also, a coupling rod 2j is connected to the lower end of a drive shaft (not shown) extending downward from the speed reducer 2d via a universal joint as shown in FIG. 4, and the lower end of the coupling rod 2j on the stator 2b side. Also, the upper end of the rotor 2f is connected via the universal joint 2h. Further, a discharge port 2k is provided at the upper end of the pump casing 2a as shown in FIG. Specifically, the stator 2b is made of a soft synthetic resin or rubber (in this example, rubber), and a female screw hole having an elliptical cross section having a pitch twice that of the rotor 2f is formed in a spiral shape as shown in FIG. A male screw rotor 2f having a circular cross section is fitted in the female screw hole so as to be rotatable and reciprocally movable in the major axis direction. As described above, the uniaxial eccentric screw pump 2 is configured. In the case of this embodiment, as shown in FIG. 1, the electric motor 2e is connected to the rotational speed sensor 33 that constantly detects the rotational speed of the motor. .

  One end of a pipe 11 is connected to the discharge port 2k of the supply pump 2, and the other end of the pipe 11 is another pipe that can open and close the discharge port 14 at the lower end by an electromagnetic open / close filling valve 12 as shown in FIG. 13 is connected to the upper end (injection port 13a; see FIG. 6). The pipe 11 is shown as a pipe bent at a right angle at two locations in FIG. 1, but is made of a flexible pipe material that can follow, for example, bendable as the discharge port 14 on the small container Y side rises and lowers. In this embodiment, the pipe 13 is made of a pipe material extending in a straight line in the vertical direction, and this pipe material is combined with the filling valve 12 and is configured as a part of the filling valve 12. Specifically, as shown in FIG. 6, for example, the filling valve 12 includes a valve body 12a capable of opening and closing a discharge port 14 at the lower end in a pipe 13, and a rod 12c by an electromagnetic cylinder 12b provided at the upper end of the pipe 13. The valve body 12a is opened and closed by moving it up and down by remote control. In addition, a fitting 15 that is detachably attached to an elevating unit 25 described later is attached to the upper portion of the pipe 13.

  Further, in the case of this example, one end of the return pipe 16 for the filling liquid B is connected to the middle of the pipe 11 as shown in FIG. 1, and the other end is connected to the upper end of the drum can X. A relief valve 17 is provided near the entrance of the return pipe 16, and the pilot pipe 18 is connected to the valve body 17 a of the relief valve 17 so that the relief valve 17 is released by the pilot pressure from the pipe 11. It is connected. The relief valve 17 is a liquid supplied from the discharge port 2k when the rotation of the rotor 2f of the pump 2 does not stop immediately due to inertia when the filling valve 12 is closed by a command signal from the control means 7 described later. B is provided to return B to the drum X via the return pipe 16.

In this example, the small container Y that divides the liquid B in the drum can X and fills it in a fixed amount is a cylindrical container having an open upper end. Therefore, the opening cross-sectional area A does not change with the liquid surface height, and if the radius is r, A = π × r ² .

  As shown in FIG. 2, the liquid level follower 3 includes an elevating unit 4 that elevates and lowers the discharge port 14 at the lower end of a pipe 13 that is integrally provided with a filling valve 12. The lifting / lowering means 4 includes a ball screw 23 supported rotatably on a guide post 22 erected in a vertical direction on a base 21, and an AC servo motor 24 connected to the lower end of the ball screw 23. . The servo motor 24 is fixed to the lower end portion of the guide post 22 via a support tool 26. An elevating part 25 is screwed to the ball screw 23 via a ball nut (not shown), and the elevating part 25 extends in the vertical direction on both sides of the guide post 22 by rotating the ball screw 23 in one direction at a fixed position. Ascend or descend along the guide portion 22a. On the base 21, a measuring instrument having a flat receiving surface in a horizontal state on which the small container Y can be placed, in this example, a load cell 5 is installed.

As shown in FIG. 3, in the case of this example, the mass of the filling liquid B measured by the load cell 5 at regular intervals is output to the computing means 6 as an electrical signal. By inputting the specific gravity (γ) of B and the opening cross-sectional area A (π × r ² ) of the small container Y, the height h of the liquid level of the liquid B filled in the small container Y is filled. It is calculated from the mass w of the liquid B by the expression shown on the right. Liquid surface height h = w / (γ × π × r ² )
Then, the liquid level rising speed (v = Δh / Δt) is calculated from the displacement distance (Δh) of the liquid level height h every fixed time (Δt), and the calculated liquid level rising speed v is output to the control means 7. Is done. In this control means 7, the rotation speed R is commanded to the servo motor 24 of the lifting / lowering means 4 by an electrical signal, and the rising speed V of the discharge port 14 at the lower end of the filling valve 12 is a rotational speed that matches the rising speed v of the liquid level. The ball screw 23 rotates. As a result, the discharge port 14 at the lower end of the filling valve 12 and the liquid level always rise while maintaining a constant interval (for example, 0 to several mm). The calculation means 6 and the control means 7 are configured as a part (CPU) of a personal computer (PC) 30.

  By the way, in this embodiment, since the uniaxial eccentric screw pump excellent in quantitative performance is used as the supply pump 2, the rotational speed p of the electric motor 2e of the uniaxial eccentric screw pump 2 is detected by the rotational speed sensor 33. When the rotational speed p increases or decreases in a state where the rotational speed p is stable and constant, an electric signal for increasing or decreasing the rotational speed R of the servo motor 24 is sent to the control means 7 using ± Δp as a parameter. 7, the rotational speed R of the servo motor 24 of the elevating means 4 is controlled to increase or decrease at a rate of Δp / p. Thereby, with respect to the fluctuation of the liquid level height h based on the minute change in the rotational speed of the electric motor 2e, the supply amount of the filling liquid B by the uniaxial eccentric screw pump 2, in other words, the filling amount into the small container Y, The rising speed V of the discharge port 14 at the lower end of the filling valve 12 can be matched in real time, and more accurate liquid level tracking is possible. Note that the rotational speed R of the servo motor 24 is detected by the speed sensor 34 and fed back to the control means 7, so that variations in the rotational speed R are suppressed as much as possible to improve control accuracy.

  Next, the working mode of the liquid level follower 3 according to the present embodiment configured as described above will be described with reference to the drawings.

  As shown in FIG. 1, in the filling operation of the filling liquid B, the discharge port 14 at the lower end of the filling valve 12 is placed on the bottom surface of the container Y with the empty cylindrical container Y placed on the load cell 5 as a measuring device. Is set at a position separated by a predetermined distance (for example, 0 to several mm). In this state, the measured value of the load cell 5 is zeroed and becomes zero. Further, the appropriate distance (interval) between the discharge port 14 and the liquid level is usually determined based on the properties of the filling liquid B. In particular, in the case of a liquid having a bubble property or a liquid that is likely to scatter and become a mist, it is preferable to set the interval very close to, for example, about 2 to 3 mm.

Then, the electric motor 2 e is rotated to start the operation of the uniaxial eccentric screw pump 2, the liquid B in the drum can X is pumped up, and the filling operation is started while being supplied to the cylindrical container Y through the pipe 11. Thus, when the liquid B starts to be filled in the cylindrical container Y, the mass w of the liquid B filled in the container B is sequentially measured by the load cell 5. The specific gravity γ of the liquid B and the relational expression (h = w / A (opening cross-sectional area: π × r ² )) between the filling amount in the container Y and the liquid surface height are known, Since it is inputted, the displacement amount per unit time of the liquid level height in the small container B is calculated, and from this, the displacement speed v, which is the displacement amount of the liquid level height h per unit time, is calculated by the calculating means 6. In addition, the servo that rotates the ball screw 23 required to raise the discharge port 14 at the lower end of the filling valve 12 to follow the rising speed v of the liquid level from the rising speed v that is the displacement speed of the liquid level. The rotational speed R of the motor 24 is calculated, and the servo motor 24 rotates at this rotational speed R. As a result, the discharge port 14 at the lower end of the filling valve 12 follows the rising speed v of the liquid level in the container Y. It rises with the raising / lowering part 25. Moreover, rotation of the servomotor 24 The degree R is detected by the speed sensor 34 and finely adjusted by feeding back to the control means 7. Therefore, the rotational speed R is also accurately maintained, and in this embodiment, the electric motor 1e of the uniaxial eccentric screw pump 2 is maintained. The increase / decrease in the rotational speed p is also detected by the speed sensor 33 and reflected in the rising speed v of the liquid level via the control means 7, so that the discharge port 14 at the lower end of the filling valve 12 can be more accurately set to the liquid level. It can be made to follow and rise.

  Although the liquid level tracking device of the filling device according to the present invention has been described with reference to one embodiment, it can also be carried out as follows.

  ・ Small container Y is not only a container with a constant opening cross-sectional area, such as a cylinder or square tube, regardless of the change in liquid level, but also the relationship between the change in container height and the change in opening cross-section As long as it can be specified, the present invention can be applied to even a trapezoidal container whose opening cross-sectional area changes with a change in liquid level height.

  The change in the operation speed of the supply-side pump 2 (the rotation speed of the electric motor 2e in the above embodiment) may not be linked to the ascending speed of the discharge port 14 at the lower end of the filling valve 12.

  In the above embodiment, considering the possibility that the supply-side pump 2 will continue to operate with inertia when the filling valve 12 is closed, the relief valve 17 is provided to return the filling liquid B to the large container X. However, the relief valve 17 and the return pipe 16 can be omitted.

  The lifting / lowering means 4 that lifts and lowers the discharge port 14 of the filling liquid B has a structure in which the ball screw 23 is rotated and the lifting / lowering unit 25 is lifted / lowered. A structure may be adopted in which the wire is wound around a take-up drum or the like by a hanging or variable speed motor and moved up and down.

BRIEF DESCRIPTION OF THE DRAWINGS It is drawing which shows the Example about the liquid level tracking apparatus of the filling apparatus of this invention, The filling apparatus 1 of the state which pumps up the to-be-filled liquid (liquid B) in a large container with a quantitative supply pump, and is filled with a small container. It is a front view which shows the supply side. It is a front view which shows the filling side of the liquid level tracking apparatus 3 and the filling apparatus 1 containing the raising / lowering means of the discharge port of a filling valve and to-be-filled liquid. It is a block diagram which shows one Example of the liquid level tracking method of this invention. It is sectional drawing which expands and shows a part of vertical uniaxial eccentric screw pump as a quantitative supply pump. FIGS. 5A to 5C are views showing a state in which the liquid level is measured using a conventional liquid level measuring sensor 71, respectively. FIG. 6 (a) shows a state in which the discharge port 14 is closed, and FIG. 6 (b) shows a state in which the discharge port 14 is opened. ing.

Explanation of symbols

1 Liquid filling device 2 Supply pump (uniaxial eccentric screw pump)
3 Liquid level follower 4 Lifting means 5 Measuring device (load cell)
6 Calculation means 7 Control means 11/13 Piping 12 Filling valve 14 Discharge port 15 Mounting tool 16 Return pipe 17 Relief valve 21 Base 22 Guide post 23 Ball screw 24 AC servo motor 25 Lifting part 26 Supporting tool 30 PC
33 ・ 34 Rotational speed sensor B Filled liquid X Large container (drum)
Y small container

Claims (7)

In a filling device that supplies liquid to be filled in a large container such as a storage tank with a supply pump via a pipe and divides the liquid into small containers, the upper surface of the liquid filled in the small container (hereinafter referred to as the liquid level). In accordance with the liquid level following method, the discharge port of the filling liquid is moved up and down by the lifting means to follow the liquid level,
Measure the mass of the filling liquid filled in the small container with a measuring device such as a load cell capable of mounting the small container filled with the filling liquid at regular intervals, and at the liquid level of the small container A filling device which calculates a displacement speed of the liquid level from the opening cross-sectional area and the specific gravity of the liquid to be filled, and controls the rising speed of the elevating means according to the calculated displacement speed of the liquid level Liquid level following method.   A quantitative pump in which the supply amount is proportional to the pump rotational speed is used as the supply pump, and correction control is performed so that the rotational speed of the quantitative pump is proportional to the rising speed of the discharge port of the liquid to be filled by the elevator. The liquid level following method of the filling device according to claim 1. In a filling device that supplies liquid to be filled in a large container such as a storage tank with a supply pump via a pipe and divides the liquid into small containers, the upper surface of the liquid filled in the small container (hereinafter referred to as the liquid level). A liquid level tracking device that raises the discharge port of the liquid to be filled at the lower end of the pipe by the lifting and lowering means to follow the liquid level,
Based on a weighing value such as a load cell capable of mounting the small container to be filled with the liquid to be filled, and a weight value of the liquid to be filled to be filled in the small container measured at regular intervals by this weighing machine, Calculation of the displacement level of the liquid surface height from the opening cross-sectional area at the liquid level height of the small container and the specific gravity of the liquid to be filled, and the displacement speed that is the displacement amount of the liquid level height per unit time A liquid level follower for a filling apparatus, comprising: means; and control means for controlling a rising speed of the elevating means in accordance with a displacement speed of the liquid level calculated by the calculating means. The elevating means has a ball screw that is rotated by a variable speed motor, and a female screw portion that is screwed to the ball screw, can be raised and lowered along a guide post, and an elevating portion that can attach the pipe above the discharge port; With
4. The liquid level follower for a filling apparatus according to claim 3, wherein the control means controls the rotational speed of the variable speed motor.   5. The liquid level follower for a filling device according to claim 3, further comprising an electromagnetic open / close filling valve capable of opening and closing the discharge port of the pipe.   6. The filling apparatus according to claim 5, wherein a return pipe to the large container is connected to the pipe between the supply pump and the filling valve, and a relief valve is interposed in the middle of the return pipe. Liquid level tracking device.   A quantitative pump in which the supply amount is proportional to the pump rotation speed is used as the supply pump, and the control means controls the increase / decrease speed of the lifting / lowering means to increase / decrease in response to fluctuations in the rotation speed of the quantitative pump. The liquid level follower of the filling device according to any one of claims 3 to 6.

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