JP2007327476A - Metering pump and chemical injection system using this pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metering pump and a chemical injection system using this pump, capable of setting the concentration in a fine range. <P>SOLUTION: This metering pump is constituted to be intermittently driven in response to an input state of a pulse signal inputted from an external part. The fixed volume pump is characterized by being constituted for changing an operation preset value (the dividing ratio) in a multistage shape, by changing a pump driving frequency to the reference unit number within the predetermined number, by setting the operation preset value (the dividing ratio) to 100%, when the pump driving frequency to the reference unit number of the inputted pulse signal, becomes the predetermined number. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pulse signal input type metering pump and a chemical solution injection system using the same, and is useful as, for example, a chlorine water supply system.

  For example, as a chlorine water supply system, a water distribution part, a chlorine supply part that supplies chlorine according to the amount of tap water flowing through the water distribution part, and chlorine water prepared by dissolving the tap water and chlorine The thing provided with the chlorine water distribution | circulation part which distribute | circulates is known (patent document 1). A water circulation part and a chlorinated water circulation part are pipes in which tap water circulates inside, for example, on the upstream side and on the downstream side. In addition, a pulse transmission flow meter that transmits a pulse signal for each predetermined flow rate of the circulated tap water is disposed at a location corresponding to the water circulation portion of the pipe. The chlorine supply unit includes, for example, a chemical liquid tank that stores a sodium hypochlorite aqueous solution and a metering pump that quantitatively conveys, for example, the sodium hypochlorite aqueous solution in the chemical liquid tank to a pipe.

According to the chlorine water supply system having such a configuration, the metering pump inputs the pulse signal transmitted from the pulse transmission flow meter, and the metering pump is preset according to the input state of the pulse signal. A predetermined amount (set amount) of sodium hypochlorite aqueous solution is injected into the tube. The injected sodium hypochlorite aqueous solution is mixed with the flowing tap water having a predetermined flow rate. As a result, chlorine water having a predetermined concentration is generated.
Japanese Patent Laid-Open No. 11-299868

  By the way, the metering pump uses frequency division control as a method of realizing the set amount. However, in the conventional frequency division control, as shown in FIG. 6, the injection amount (supply amount) 100% is set to the operation set value (frequency division ratio) 1/1, the operation set value 1/2 (injection amount 50%), Since the control content is the operation set value 1/3 (injection amount 33%),..., There is a problem that it is difficult to set the concentration in a fine range.

  In more detail with reference to FIG. 7, it is assumed that the metering pump is driven once (for one stroke) every time a pulse signal is input from the pulse flow meter, and the operation set value 1/1 When the signal is input twice, the metering pump is driven once when the operation set value is 1/2. When the pulse signal is input three times, the metering pump is driven once when the operation set value is 1/3. As mentioned above, since the conventional frequency division control is the control content of the operation set value based on 1 / integer with the same number of pump driving times for the input pulse signal as the operation set value 1/1. As is clear from FIG. 6, there is a problem that it is difficult to set the concentration in a fine range particularly in a region where the injection amount (supply amount) is large.

  Then, this invention is made | formed in view of the said problem, and makes it a subject to provide the metering pump which enables the density | concentration setting in a fine range, and a chemical | medical solution injection | pouring system using the same.

  The metering pump according to the present invention is a metering pump configured to be intermittently driven according to an input state of a pulse signal input from the outside, and the number of times the pump is driven with respect to the reference unit number of the input pulse signal. When the predetermined number is set as a reference operation set value, the operation set value can be changed in multiple steps by changing the number of times of pump driving with respect to the reference unit number within the predetermined number and / or more than the predetermined number. It is characterized by.

  A metering pump according to another invention is a metering pump configured to be intermittently driven according to an input state of a pulse signal input from the outside, and a pulse input every time a pulse signal is input. A calculation process is performed based on a predetermined relationship between the cumulative number of signals and the operation set value, and if the calculation result satisfies a predetermined condition, a drive pulse signal for driving the pump according to the pulse signal is generated. It is characterized by being made.

  In addition, the chemical injection system according to the present invention transmits a pulse signal at every predetermined flow rate of the target liquid in the chemical injection system that generates a liquid mixture having a predetermined concentration by intermittently injecting a fixed quantity of chemical into the circulating target liquid. A flow meter and any one of the above-described metering pumps are provided, and the metering pump is configured to perform the metering injection of the chemical solution according to the input state of the pulse signal input from the flow meter.

  As described above, according to the present invention, it is possible to set the density in a fine range.

  Hereinafter, a chlorine water supply system will be described as an embodiment of a chemical liquid injection system according to the present invention with reference to the drawings.

  As shown in FIG. 1, the chlorine water supply system according to the present embodiment includes a water circulation unit 1 that circulates water from a water supply or the like, a chlorine supply unit 2 that supplies a chemical solution containing a chlorine component, and a water circulation unit 1. A chlorine water preparation unit 3 that prepares a predetermined concentration of chlorine water by dissolving the water that circulates and the chemical solution supplied from the chlorine supply unit 2, and the chlorine that distributes the chlorine water prepared by the chlorine water preparation unit 3 Using the water distribution unit 4 and a control unit (not shown) that controls setting and driving in each of these units (water distribution unit 1, chlorine supply unit 2, chlorine water preparation unit 3, chlorine water distribution unit 4). Composed.

  The water circulation part 1 is comprised using the pipe | tube 1a and the flowmeter 1b arrange | positioned in the appropriate location on the pipe | tube 1a in order to measure the flow volume of the circulating tap water. Here, the pipe 1a is configured by combining, for example, a pipe formed of PVC (polyvinyl chloride) or SUS, or a plurality of pipes formed of these materials. Further, as the flow meter 1b, a pulse transmission flow meter that transmits a pulse signal at every predetermined flow rate of the flowing tap water is used.

  The chlorine supply unit 2 includes a chemical solution tank 2a for storing a chemical solution, and a downstream portion of the pipe 1a (a connection portion between the water circulation unit 1 and the chlorine water preparation unit 3 or a case where the chlorine water preparation unit 3 is not essential. The connecting part between the water circulation part 1 and the chlorine water circulation part 4) and the pipe 2b for connecting the chemical liquid tank 2a and the metering pump 2c capable of supplying the chemical liquid in the chemical liquid tank 2a to the chlorine water preparation part 3 Is done. Here, the pipe 2b is configured using a pipe or the like formed of a material having high oxidation resistance such as PVC (polyvinyl chloride). Moreover, as a chemical | medical solution, the aqueous solution containing chlorine components, such as sodium hypochlorite aqueous solution, is used.

  Further, as the metering pump 2c, a piston is fitted into a reciprocating pump that performs a pump operation by reciprocating a diaphragm, a plunger, a bellows, or the like, or a cylinder having a suction port and a discharge port on a peripheral wall, and the piston is rotated. However, it is a reciprocating pump having a simple structure that sucks and discharges fluid in the cylinder (pump chamber) by reciprocating while eliminating the need for a check valve, and uses a pulse signal input type pump.

  The chlorinated water preparation unit 3 is connected to the pipe 1a and is configured using a mixing unit that mixes the water introduced from the water circulation unit 1 and the chemical solution introduced from the chlorine supply unit 2. Here, the chlorine water preparation unit 3 is formed of a material having high oxidation resistance such as PVC (polyvinyl chloride).

  The chlorine water circulation part 4 is configured using a pipe 4a. Here, the tube 4a is formed of a material having oxidation resistance capable of withstanding a desired chlorine water concentration (for example, PVC (polyvinyl chloride)). Although not shown in the figure, a storage tank is provided on the downstream side of the chlorine water passage portion 4, and the generated chlorine water is temporarily stored in the storage tank.

  The control unit includes a chlorine water concentration setting unit that sets the concentration of the chlorine water supplied by the chlorine water supply system, a flow rate detection unit that detects the flow rate measured by the flow meter 1b, and the chlorine water in the chlorine water concentration setting unit. Based on the concentration and the flow rate in the flow rate detection unit, the amount of the chemical solution to be supplied from the chemical solution tank 2a is determined, and the drive control unit that drives the metering pump 2c according to the value is configured. That is, in the control unit, the chemical solution is proportional to the flow rate from the water circulation unit 1 so that the chlorine water in the storage tank on the downstream side of the chlorine water circulation unit 4 has the concentration set by the chlorine water concentration setting unit. The so-called flow rate proportional control is performed in which the supply amount is determined. In addition, the chlorine concentration setting part, the flow rate detection part, and the drive control part which constitute the control part are arranged integrally with the main body of the metering pump.

  Next, the operating state of the chlorine water supply system according to this embodiment configured as described above will be described.

  First, in the chlorine water concentration setting unit (control unit), the required concentration of chlorine water is set (operation setting value is set). Next, tap water circulates in the water circulation part 1, and at this time, the flow rate is measured by the flow meter 1b, and a signal (pulse signal) of the measured value is sent to the flow rate detection part (control part). And the water measured here flows in into the chlorine water preparation part 3 via the pipe | tube 1a.

  Next, in order to prepare the chlorine water having the concentration set by the chlorine water concentration setting unit, the supply amount of the chemical solution proportional to the flow rate (pulse signal) in the flow rate detection unit is determined in the drive control unit (control unit). The Next, a drive pulse signal corresponding to the determined amount is output from the drive control unit, and the metering pump 2c is driven according to the drive pulse signal. And the chemical | medical solution sent from the chemical | medical solution tank 2a by driving the metering pump 2c flows into the chlorine water preparation part 3 via the pipe | tube 2b.

  Next, the water from the water circulation unit 1 and the chemical solution from the chlorine supply unit 2b are mixed and dissolved in the mixing unit of the chlorine water preparation unit 3 to prepare a set concentration of chlorine water. Next, the chlorinated water prepared in the mixing unit is discharged through the pipe 4a, and appropriately stored in a storage tank (for example, a sterilization tank provided for sterilizing a floor surface of a hospital or a kitchen or a food). Supplied. The time lag between the water and the chemical solution flowing into the mixing unit of the chlorinated water preparation unit 3 is not particularly mentioned in the present embodiment, but it is set so as to be suitable for the use state by providing a pipe length or some valve. That's fine. However, since chlorine water once becomes a still water state in the downstream storage tank, such a time lag is not particularly problematic.

  The overall description of the chlorine water supply system according to the present embodiment is as described above. Next, the metering pump 2c that is characteristic in the present embodiment will be described.

<Embodiment 1>
The characteristic of the metering pump according to the present embodiment is that the conventional dividing control is not adopted, and the injection amount (supply amount) is 100%, 95%, 90%, as shown in FIG. .., 15%, 10%, and frequency division control that allows fine density setting is adopted.

  In more detail with reference to FIG. 3, it is assumed that the metering pump 2 c is driven once (for one stroke) every time a pulse signal is input from the flow meter 1 b with an operation set value of 100%. The metering pump is driven 19 times until the meter is input 20 times, and the operation set value 95% is driven, and the metering pump is driven 18 times before the pulse signal is input 20 times. %, ..., the metering pump is driven three times before the pulse signal is input 20 times, the operation set value is 15%, and the metering pump is driven twice until the pulse signal is input 20 times The frequency division control according to the present embodiment is driven by the operation setting value 10%. In the frequency division control according to the present embodiment, the same number of pump driving times with respect to the reference unit number of the input pulse signal (20 times in the above example) is the reference operation setting value. (Reference division ratio, in the above example 00%), the operation setting value is controlled based on the subtraction of the number of times the pump is driven. Therefore, the pitch between the operation setting values is constant (5% in the above example) in any region of the injection amount. The density can be set in a fine range.

<Embodiment 2>
In the first embodiment, the operation set value is controlled based on the subtraction of the pump drive count, where the same number of pump drive counts with respect to the reference unit number of the input pulse signal is set as the operation set value 100%. The fine frequency division control between the operation setting values at the setting value of 100% or less is made possible, but here, the control content that enables the frequency division control at the operation setting value of 100% or more will be described.

FIG. 4 shows an example of this, and the control contents at the operation set value of 100% or less are the same as those in the first embodiment (the description “○ drive pulse once” in the table below means that the drive pulse signal is output once. Means that the metering pump is driven once, and “× driving pulse through” means that the driving pulse signal is not output, and therefore the metering pump is not driven).
a. When the operation set value is set to 105 to 200%, in the table, the value of 5 to 100% is changed to 105 to 200%, ○ is a drive pulse twice, × is a drive pulse once, Read as
b. When the operation set value is set to 205 to 300%, in the table, the value of 5 to 100% is changed to 205 to 300%, ○ is the drive pulse 3 times, × is the drive pulse 2 times, Read as
c. When the operation set value is set to 305 to 400%, in the table, the value of 5 to 100% is changed to 305 to 400%, ○ is the drive pulse 4 times, × is the drive pulse 3 times, The control content that reads as follows, that is, the number of pump driving operations for each reference unit number of input pulse signals when the same number of pump driving operations with respect to the reference unit number of input pulse signals is set to 100% operation setting value. Operation by adopting the control content to be added (control content of the operation set value based on the addition of the number of pump drive, with the same number of pump drive times with respect to the reference unit number of the input pulse signal as 100% operation set value) It is possible to perform fine frequency division control between the set values of 100% or more and the operation set values.

FIG. 5 is another example that enables fine frequency division control between the operation set values of 100% or more, and the control content at the operation set values of 100% or less is the same as that of the first embodiment. There are
The metering pump is driven 21 times before the pulse signal is input 20 times, the operation set value is 105%,..., And the metering pump is driven 30 times until the pulse signal is input 20 times. The operation set value is 150%, ..., the metering pump is driven 40 times before the pulse signal is input 20 times, the operation set value is 200%, ..., the pulse signal is input 20 times The number of pump drivings is determined by setting the same number of pump driving times with respect to the reference unit number of the input pulse signal as the operation setting value 100%, such that the metering pump is driven 43 times until the operation setting value is 215%. Even if the control content of the operation set value based on the addition of the above is adopted, it is possible to perform the fine frequency division control between the operation set values of 100% or more and the operation set value.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

  For example, in the above-described embodiment, the chlorine water supply system has been described. However, the present invention is applicable to systems other than the system for supplying chlorine water. Therefore, the target liquid is not limited to tap water, and the chemical liquid is not limited to one containing a chlorine component. In short, the present invention is applicable to all systems for injecting a fixed amount of chemical solution into a target liquid to be circulated to generate a liquid mixture having a predetermined concentration.

  In the above embodiment, if the operation set value is 100%, each time a pulse signal is input from the flow meter 1b, the metering pump 2c is once (if the pump is a reciprocating pump, for example, one stroke). However, this is not limited to the one-to-one correspondence with the conventional metering pumps whose operation set values are 1/1. That is, when the pulse signal is input a plurality of times (for example, three times) from the flow meter 1b, the mode in which the metering pump 2c is driven once is set to 100% of the operation set value. In this case, the reference unit number of the input pulse signal (20 times as described above if the pitch between operation setting values is 5%) is proportionally multiplied (3 times 60 times if it is 3 times). Become.

  Moreover, in the said embodiment, although the pitch between operation setting values is demonstrated as 5%, it is not limited to this, For example, if the reference | standard unit number of the input pulse signal shall be 10 times, The pitch between operation settings is 10%.

In the above embodiment, the control contents shown in FIG. 3, FIG. 4, or FIG. 5 are tabulated, held in the control unit, and used to respond to the pulse signal input from the flow meter 1b. Although the drive control of the metering pump 2c is performed, the drive control of the metering pump 2c according to the pulse signal input from the flow meter 1b may be performed while calculating each time regardless of the table. . The image of the calculation is shown in the following figure (exemplification of the operation set value 62%). The concept of the calculation is that the number of input pulse signals is the reciprocal of the operation set value (if the operation set value is 62%, 1/0). .62), when the remainder is 1 or less, the pump is driven, and when it is 1 or more, the pump is not driven. According to this, it is possible to set the density in a finer range.

  Further, in the above embodiment, the number of pump drivings with respect to the reference operation set value is decreased (Embodiment 1) or increased or decreased (Embodiment 2), thereby reducing the reference operation set value or less (Embodiment 1) or the reference operation set value. Although it is possible to change the operation set value finely and vertically in the upper and lower sides (Embodiment 2), the operation set value can be finely changed in multiple steps above the reference operation set value by increasing the number of times the pump is driven with respect to the reference operation set value. It is the intent of the present invention to only allow it.

  In the second embodiment, the reference operation set value is set to the operation set value 100%. However, the present invention is not limited to this, and the maximum settable operation set value may be set as the reference operation set value. For example, in the example of FIG. 4, the reference operation setting value is the operation setting value 1000%, and in the example of FIG. 5, the reference operation setting value is the operation setting value 215%. In this case, the concept is the same as that of the first embodiment in that the control content is simply subtracting the number of times of pump driving from the reference operation set value.

The conceptual diagram of the chlorine water supply system which concerns on one Embodiment of this invention is shown. The relationship figure of the injection amount-frequency division ratio (operation setting value) as a result of the frequency division control in the metering pump used in the chlorine water supply system of the embodiment is shown. The timing chart for demonstrating the control content of the frequency division control in the metering pump of the embodiment is shown. The table which prescribes | regulates an example of the 2nd control content of the frequency division control in the metering pump of the embodiment is shown. The table which prescribes | regulates the other example of the 2nd control content of the frequency division control in the metering pump of the embodiment is shown. The relationship figure of the injection amount-frequency division ratio (operation setting value) as a result of the frequency division control in the conventional metering pump is shown. The timing chart for demonstrating the control content of the frequency division control in the conventional metering pump is shown.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Water distribution part, 1b ... Flow meter, 2 ... Chlorine supply part, 2a ... Chemical tank, 2c ... Metering pump, 3 ... Chlorine water preparation part, 4 ... Chlorine water distribution part

Claims (7)

  In the metering pump configured to intermittently drive according to the input status of the pulse signal input from the outside, the reference operation is performed when the pump drive count becomes a predetermined number with respect to the reference unit number of the input pulse signal. A quantitative value characterized in that the operation set value can be changed in multiple steps by setting the set value and changing the number of times of pump driving with respect to the reference unit number within the predetermined number and / or more than the predetermined number. pump.   2. The metering pump according to claim 1, wherein the number of times the pump is driven for each operation set value is distributed based on the reference unit number of the input pulse signal.   The metering pump according to claim 1 or 2, wherein the predetermined number of pump driving times is the same as the reference unit number of input pulse signals.   The metering pump according to claim 1, wherein the predetermined number of pump driving times is an integer of the reference unit number of the input pulse signal.   And a table in which the number of pump driving operations for each operation setting value with respect to the reference unit number of the input pulse signal is defined, and configured to drive based on the set operation setting value and the table. 5. The metering pump according to any one of 4 above.   In a metering pump configured to be intermittently driven in accordance with an input state of a pulse signal input from the outside, a predetermined number of accumulated pulse signals and an operation set value are input each time the pulse signal is input. A metering pump configured to perform a calculation process based on the relationship, and to generate a drive pulse signal for driving the pump according to the pulse signal when a calculation result satisfies a predetermined condition.   A chemical meter injection system that intermittently and quantitatively injects a chemical solution into a flowing target solution to generate a mixed solution having a predetermined concentration, and a flow meter that transmits a pulse signal for each predetermined flow rate of the target solution; Or a metering pump according to claim 1, wherein the metering pump is configured to perform metering of the medicinal solution according to an input state of a pulse signal input from a flow meter.

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