JPH0550336B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Purpose of the Invention [Field of Industrial Application] The present invention relates to a chemical injection device, and particularly includes a diaphragm pump equipped with an electromagnetic drive device, and is used in a water treatment plant or a chemical plant. The present invention relates to a chemical injection device for injecting chemicals in, etc. [Prior Art] Conventionally, this type of drug injection device supplies a desired amount of drugs by supplying an appropriate number of pulses from a control device to an electromagnetic drive device and operating a diaphragm pump a number of times corresponding to the number of pulses. It has been proposed to inject it into water treatment plants, chemical plants, etc. [Problems to be Solved] However, with conventional drug injection devices, it was not possible to automatically read the travel distance of the operating rod of the electromagnetic drive device, that is, the stroke length.
When changing the stroke length, it is necessary to visually detect the amount of change and change the setting value of the control device, which has the disadvantage that the adjustment work is complicated. Therefore, the present invention aims to eliminate this drawback by:
It is an object of the present invention to provide a drug injection device that automatically reads the moving distance of an operating rod of an electromagnetic drive device, that is, the stroke length, and constantly maintains a set value of a control device appropriately in accordance with the stroke length. (2) Structure of the invention [Means for solving the problem] The means for solving the problem provided by the present invention consists of: ``(a) a medicine dosage setting device for setting the medicine dosage; (c) a diaphragm pump that injects the medicine according to the number of pulses generated by the control device; (d) ) a detection device that detects a stroke length of the diaphragm pump; (e) a calculation device that calculates an actual drug injection amount from the stroke length detected by the detection device and the number of pulses generated by the control device; ) Calculate the difference between the actual drug injection amount calculated by the calculation device and the drug injection amount set by the drug injection amount setting device, and increase or decrease the number of pulses generated by the control device according to the difference. A chemical injection device characterized in that it is equipped with a discriminating device for determining [Function] The drug injection device according to the present invention injects the drug by generating a number of pulses in the control device according to the drug injection amount set by the drug injection amount setting device and giving them to the diaphragm pump, At the same time, the stroke length of the first diaphragm pump is detected by a detection device and sent to a calculation device to calculate the actual drug injection amount from the number of pulses generated by the control device, and calculate the actual drug injection amount calculated by the calculation device and the The discriminator calculates the difference between the drug injection amount set by the drug injection amount setting device, and
It has the effect of increasing or decreasing the number of pulses generated by the control device according to the difference, and injects the medicine according to the predetermined amount of medicine in response to changes in the stroke length of the diaphragm pump. This serves to simplify the adjustment work associated with changing the stroke length. [Example] Next, the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a block circuit diagram showing an embodiment of a chemical injection device according to the present invention. FIG. 2 is a partially enlarged sectional view showing a part of the embodiment of FIG. 1 on an enlarged scale. First, the configuration of the chemical injection device according to the present invention will be explained. Reference numeral 10 denotes a chemical injection device of the present invention, which is installed at an appropriate location such as a water treatment plant or a chemical plant, for example, with respect to the pipe line 20 . Reference numeral 11 denotes a flow meter installed at the installation location of the chemical injection device 10 , here the pipe line 20 , which detects and outputs the flow rate Q of the fluid flowing through the pipe line 20 . Reference numeral 12 denotes a chemical injection rate setting device of the chemical injection device 10 , in which the injection rate of the chemical into the conduit 20 , that is, the chemical injection rate W _A1 is set by manual operation or other means. 13 is a chemical dosing rate setting device connected to the flow meter 11 and the chemical dosing rate setting device 12;
W _A1 are multiplied together to calculate the drug injection amount R=QW _A1 . Reference numeral 14 denotes a control device connected to the drug injection amount setting device 13, which generates a number of pulses P according to the drug injection amount R given from the drug injection amount setting device 13 within a unit time. Reference numeral 15 denotes a diaphragm pump connected to the control device 14, which communicates with the other end of a chemical supply pipe 15A, one end of which is immersed in the chemical 16A of the chemical tank 16, and one end of which is immersed in the chemical 16A of the chemical tank 16 . It includes a pump chamber 15C that is communicated with the other end of another chemical supply pipe 15B that is communicated with it. A diaphragm 15D is disposed in the pump chamber 15C, and is capable of reciprocating movement by one end of an operating rod 15E of an electromagnetic drive device 15S. The operating rod 15E is
Solenoid coil 15 connected to control device 14
F, and a magnetic plate 15G is fixed to the other end. A locking plate 15H is fixed to the center of the operating rod 15E, and locks the return spring 15I between it and the outer wall of the pump chamber 15C. 15J
is a setter for setting the moving distance of the operating rod 15E, that is, the stroke length, and the housing 15K
A central shaft 15L is screwed into the central shaft 15L and has one end that can come into contact with the magnetic plate 15G, a knob 15M disposed on the other end of the central shaft 15L, and a central shaft 15L.
The gear 15N is disposed near one end of the gear 15N. 15P is a detection device that detects the moving distance of the operating rod 15E, that is, the stroke length;
Other gear 15Q meshed with gear 5N and gear 1
It includes a detection section 15R that is arranged with respect to the rotation axis of 5Q and outputs the ratio to the maximum stroke length as stroke length S (%). 17 is a calculation device connected to the control device 14 and the detection device 15P of the diaphragm pump 15;
Using the pulse number P given from the control device 14, the stroke length S given from the detection device 15P of the diaphragm pump 15 , and the coefficient k associated with the diaphragm pump 15, the actual drug injection amount R ^* = kPS
Calculate. Reference numeral 18 denotes a discriminator connected to the drug dosing amount setting device 13 and the computing device 17, which determines the drug dosing amount R given from the drug dosing amount setting device 13 and the computing device 17.
The difference between the actual drug injection amount R ^* given by △
R=R-R ^* is calculated and given to the control device 14. The control device 14 maintains a predetermined number of pulses P when the difference ΔR is zero, and controls the diaphragm pump 1.
When the difference ΔR is positive, the pulse number P is gradually increased and outputted to the diaphragm pump 15. When the difference ΔR is negative, the pulse number P is gradually decreased and the pulse number P is output to the diaphragm pump 15. It is outputting against. Furthermore, the operation of the chemical injection device according to the present invention will be explained. The injection rate of the chemical into the conduit 20 , that is, the chemical injection rate W _A1 is set by manual operation or the like with the chemical injection rate setting device 12. As a result, when the flow rate Q of the fluid flowing through the pipe line 20 is given from the flow meter 11, the drug injection amount setting device 13 calculates the drug injection amount R=QW _A1 and provides it to the control device 14. The control device 14 generates a number of pulses P according to the drug injection amount R given from the drug injection amount setting device 13 within a unit time and applies them to the electrode drive device 15S of the diaphragm pump 15. Electromagnetic drive device 15S of diaphragm pump 15
The solenoid coil 15F is excited within a unit time a number of times according to the number of pulses P given from the control device 14, and attracts the magnetic plate 15G. As a result, the operating rod 15E reciprocates against the return spring 15I, causing the diaphragm 15D to reciprocate. As the diaphragm 15D reciprocates, the chemical 16A is sucked up from the chemical tank 16 to the pump chamber 15C via the chemical supply pipe 15A, and the pump chamber 15
The medicine 16A is pushed out from C toward the conduit 20 through the medicine supply pipe 15B. In the diaphragm pump 15 , by rotating the knob 15M of the setter 15J, the center shaft 15L is adjusted.
The position of the center axis 15L is set by moving the
The moving distance of the operating rod 15E, that is, the stroke length is set. The moving distance of the operating rod 15E, that is, the stroke length, is determined by operating the detection part 15R of the detection device 15P by the gear 15Q meshed with the gear 15N disposed on the central axis 15L, and the ratio S to the maximum stroke length is determined.
(%) is output from the detection unit 15R to the arithmetic unit 17. The calculation device 17 uses the pulse number P given from the control device 14, the stroke length S given from the detection device 15P of the diaphragm pump 15, and the coefficient k associated with the diaphragm pump 15 to determine the actual drug injection amount. R ^* =kPS is calculated and output to the discrimination device 18. The discrimination device 18 determines the difference ΔR=R− between the drug injection amount R=QW _A1 given from the drug injection amount setting device 13 and the actual drug injection amount R ^* given from the calculation device 17.
R ^* is calculated and given to the control device 14. The control device 14 maintains the number of pulses P being output to the solenoid coil 15F of the diaphragm pump 15 when the difference ΔR is zero, and maintains the number P of pulses being output to the solenoid coil 15F when the difference ΔR is positive.
is gradually increased, and when the difference ΔR is negative, the number of pulses P being output to the solenoid coil 15F is gradually decreased. As described above, according to the drug injection device according to the present invention, even if the stroke length of the operating rod 15E of the diaphragm pump 15 is changed, the actual drug injection amount R ^* to the pipe line 20 can always be made to match the drug injection amount R. I can do it. Note that in the above description, the flow meter 11 and the chemical injection rate setting device 12 are arranged separately from the chemical injection amount setting device 13; It may be included. (3) Effects of the invention As is clear from the above, the drug injection device according to the present invention includes (a) a drug injection amount setting device for setting the drug injection amount, and (b) a drug injection amount setting device for setting the drug injection amount. (c) a diaphragm pump that injects a medicine in accordance with the number of pulses generated by the control device; (d) a stroke of the diaphragm pump; (e) a calculation device that calculates an actual drug injection amount from the stroke length detected by the detection device and the number of pulses generated by the control device; (f) calculation by the calculation device. a discrimination device that calculates a difference between the actual drug injection amount and the drug injection amount set by the drug injection amount setting device, and increases or decreases the number of pulses generated by the control device according to the difference. Therefore, (i) it has the effect of being able to inject chemicals according to a predetermined amount of medicine in response to changes in the stroke length of the diaphragm pump, and (ii) it has the effect of being able to inject chemicals in accordance with changes in the stroke length of the diaphragm pump. This has the effect of simplifying work.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an embodiment of the chemical injection device according to the present invention, and FIG. 2 is a partially enlarged sectional view showing a part of the embodiment shown in FIG. 10 ... Chemical injection device, 11... Flow meter, 12
...Medicine injection rate setting device, 13...Medicine injection amount setting device,
14...control device, 15 ...diaphragm pump, 15A, 15B...drug supply pipe, 15C...
Pump chamber, 15D...Diaphragm, 15E...
Operating rod, 15F...Solenoid coil, 15G
...magnetic plate, 15H...locking plate, 15I...return spring, 15J...setting element, 15K...housing, 15L...center shaft, 15M...knob, 15
N...gear, 15P...detection device, 15Q...gear, 15R...detection unit, 15S...electromagnetic drive device, 16...chemical tank, 16A...medicine, 17...
Arithmetic device, 18...Discrimination device, 20 ...Pipeline.

Claims (1)

[Scope of Claims] 1. (a) A drug injection amount setting device for setting the drug injection amount; (b) A number of pulses corresponding to the drug injection amount set by the drug injection amount setting device. (c) a diaphragm pump that injects a chemical according to the number of pulses generated by the control device; (d) a detection device that detects a stroke length of the diaphragm pump; and (e) the detection device. (f) a computing device that calculates an actual drug injection amount from the stroke length detected by the controller and the number of pulses generated by the control device; 1. A drug injection device comprising: a discrimination device that calculates a difference from a set drug injection amount, and increases or decreases the number of pulses generated by the control device according to the difference.