JPS6365392B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pure water production apparatus that obtains pure water by passing raw water through a raw water treatment tank comprising a water tower filled with ion exchange resin.

Conventionally, in continuous water purification equipment, the load on the continuous water equipment, that is, the amount and quality of raw water, fluctuates, so the amount of chemicals injected into the ion exchange resin regeneration tower is limited when the amount of raw water is at its maximum and the water quality is at its worst. It was decided based on the assumption that For this reason, when the amount of raw water decreases or the water quality improves, extra chemicals are injected, resulting in an increased amount of chemicals used and a large amount of waste.

In order to solve these drawbacks, a control system that performs calculation processing to inject the optimal chemicals based on the amount of treated water and the quality of the raw water could be considered, but since the amount of treated water is batch (intermittent), ion exchange resin If the performance deteriorates rapidly or exceeds the processing capacity, purification of the treated water becomes insufficient, resulting in non-uniform quality of the purified water.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pure water production apparatus that can automatically control the optimum amount of chemicals to be injected, reduce the amount of chemicals used, and prevent the quality of treated water from deteriorating.

The present invention provides a computing unit that calculates the amount of medicine to be dispensed based on signals from a water quality meter that detects the quality of raw water and a flow meter that measures the flow rate of treated water, and the operation of these computing units and storage means; The above object is attempted to be achieved by providing a sequencer that controls the switching of the processing and delivery direction or the regeneration operation of the ion exchange resin.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, the outline of the chemical injection amount control system for the pure water production apparatus of the present invention will be explained with reference to the block diagram shown in FIG.

The chemical injection amount control system includes a continuous water purifier 1, a water quality meter 2 and a flow meter 3 that respectively detect the quality of raw water and the flow rate of treated water supplied to the continuous water purifier 1, and the continuous water purifier 1. A sequencer 4 that controls the operation of It is comprised of a compound calculator 7 that calculates the injection amount based on commands from the sequencer 4 and operates the chemical injection pumps 5 and 6. The compound arithmetic unit 7 includes a multiplication circuit 8 that multiplies the detected amounts from the water quality meter 2 and the flow meter 3, a hold circuit 9 that starts and stops calculation based on the hold signal and start/stop signal from the sequencer 4, and a multiplication circuit. a memory circuit 10 that stores the output from 8 using a signal from a hold circuit 9;
, the time lag between detecting the water quality and flow rate, activating the chemical injection pumps 5 and 6 after calculation, until the chemicals actually flow and being supplied to the continuous water purifier 1, and the ion exchange after the raw water is passed through. Time delay circuit 11 for correcting the time lag until resin is regenerated
2, which receives the signal from the multiplication circuit 8 via a hold circuit 9, a memory circuit 10, and a time delay circuit 11, and multiplies it by a proportionality constant corresponding to each drug to generate a signal to the drug injection pumps 5 and 6. Here, the multiplier circuit 8 and the arithmetic circuits 12 and 13 constitute the arithmetic unit of the present invention, and the hold circuit 9 and the memory circuit 10
and the time delay circuit 11 constitute the storage means of the present invention.

Of these, the multiplier circuit 8 utilizes the fact that the load on the continuous water purifier 1 is proportional to the product of the amount of treated water and the quality of raw water, and the hold circuit 9
The storage circuit 10 integrates and stores the load amount for each time so that a constant output signal can be obtained even if the amount of treated water is an intermittent amount. Furthermore, the time delay circuit 11 is for compensating for process time delays as described above.

The continuous pure water apparatus 1 and this continuous pure water apparatus 1
The system diagram between the control equipment and each control device is as shown in Figure 2.

The continuous water purification device 1 has a water tower 14 filled with ion exchange resin and serves as a raw water treatment tank.
A raw water quality meter 2 and a treated water quality meter 32 are provided at the inlet and outlet sides of the water tower 14, respectively. Further, the water passage tower 14 is connected to the inlet side of the cation exchange resin regeneration tower 17 and the anion exchange resin regeneration tower 18 via the valve 15 and the ion exchange resin separation tower 16.
And each outlet of the anion exchange resin regeneration tower 18 is connected again to the water passage tower 14, forming an ion exchange resin circulation regeneration cycle system.

A chemical injection pump 5 for supplying an acid such as hydrochloric acid to the cation exchange resin regeneration tower 17 as needed.
Further, the discharge sides of chemical injection pumps 6 for supplying alkali such as caustic soda are respectively connected to the anion exchange resin regeneration tower 18, and these two pumps 5 and 6 perform a complex operation as explained in FIG. Vessel 7
The amount of medicine dispensed is adjusted based on the signal from. Further, a chemical injection system is constituted by these chemical injection pumps 5 and 6 and the ion exchange resin circulation and regeneration cycle system.

Furthermore, the outlet side pipe of the water tower 14 in which the treated water quality meter 32 is provided is connected to a pure water tank (not shown) via a valve 21, and a flow meter 3 is disposed in the middle. Furthermore, the pipe line 24A branched from before the valve 21 is connected to the valve 24 on the way.
It is connected to a raw water tank 25 provided in the inlet side pipe of the water tower 14 via the water tower 14 .

Each of the valves 15, 21, and 24 is a valve operated by a signal from the sequencer 4, and is connected to the positive and anion exchange resin regeneration tower 1.
The regeneration process of the ion exchange resin in the water tower 14 at steps 7 and 18 can be controlled by the valve 15.

Next, the action will be explained.

The raw water supplied to the water tower 14 is treated to pure water by the action of an ion exchange resin in the water tower 14, and is sent to a pure water tank. The ion exchange resin in the water tower 14 is extracted in a fixed amount every 10 minutes, for example, and separated into a cation exchange resin and an anion exchange resin in a separation tower 16, and then transferred to a cation exchange resin regeneration tower 17 and It is sent to an anion exchange resin regeneration tower 18.

The ion exchange resin regenerated in the cation exchange resin regeneration tower 17 and the anion exchange resin regeneration tower 18 is sent to the water passage tower 14 again. Further, when the treated water quality meter 32 detects that the quality of the treated water at the outlet of the water tower has deteriorated, the valve 21 is closed and the valve 24 is opened under control from the sequencer 4 to allow the water to flow out of the water tower 14. The treated water is returned to the raw water tank 25 on the inlet side of the water tower 14 through the valve 24 without being sent to the pure water tank. This kind of circulation of treated water is carried out by the water quality meter 32.
The process is repeated until the water quality detected by the method is good. Based on the water quality detection, the opening and closing of each valve is automatically controlled by the sequencer 4 as described above.

The ion exchange resin is regenerated in the ion exchange resin regeneration towers 17 and 18, but this requires injection of a predetermined chemical.

A chemical injection pump 5 is connected to the cation exchange resin regeneration tower 17.
Anion exchange resin regeneration tower 18
A predetermined amount of alkali such as caustic soda is supplied to each from the chemical injection pump 6. The amount of chemicals supplied from each of these pumps 5 and 6 is calculated by a compound calculator 7 based on the quality of raw water and the flow rate of treated water, and is controlled by signals output to each pump 5 and 6. Ru.

That is, as described above, the amount of chemicals such as hydrochloric acid and caustic soda injected into the cation exchange resin regeneration tower 17 and the anion exchange resin regeneration tower 18 is proportional to the quality and flow rate of raw water. Therefore, the discharge amount of each chemical injection pump 5.6 is determined by the following equation.

(Pump stroke output) = (Required amount of chemicals for 1 ton of raw water, 1 μv/cm) x (Water quality x Flow rate) x Coefficient / Discharge amount per 1% of pump stroke The data calculated based on the above formula is based on the water tower 14
Considering that it takes several hours for the ion exchange resin to move from the cation exchange resin regeneration tower 17 to the anion exchange resin regeneration tower 18, the ion exchange resin is temporarily stored in the storage circuit 10, and is further stored in the time delay circuit 11. After a predetermined period of time has elapsed, it is output to the pumps 5 and 6.

The start and stop of computation of the complex arithmetic unit 7 accompanying the start and stop of the continuous water purification apparatus 1 are performed by start and stop signals from the sequencer 4. While the calculation is stopped, the output to pumps 5 and 6 is set to 0.
%, and when operation resumes, output is based on the data before stopping. Furthermore, in the extraction step of the ion exchange resin from the water tower 14 and the above-mentioned circulation step when the water quality of the treated water deteriorates, the flowmeter indication of the treated water becomes zero, so the hold circuit 9 is activated by the hold signal from the sequencer 4. Stop calculation.

Note that the settings of the coefficients and delay time in the above-mentioned arithmetic expression are variable so that they can be adjusted as desired.

In this embodiment, the amount of chemicals to be injected into the cation exchange resin regeneration tower 17 and the anion exchange resin regeneration tower 18 is calculated by the complex calculation circuit 7 based on the amount of treated water and the quality of raw water, and the ion exchange resin is moved. Since the chemical injection pumps 5 and 6 are operated after a sufficient period of time for the chemical injection, it is economical because there is no need for multiple injections as in the conventional method, and when a drop in the quality of the treated water is detected, the treated water is sent out. The direction of the water is changed and the water is recirculated to the raw water treatment tank to improve water quality, which equalizes the quality of the treated water sent to the outside. Furthermore, even if the amount of treated water is an intermittent amount, the hold circuit 9 and the memory circuit 10
Since it is equipped with a constant output signal, it is possible to level out the operation of the system and also helps to equalize the quality.

Furthermore, since the operation of each valve and the operation of the complex computing unit 7 are performed using signals from the sequencer 4, it is possible to automate the operation. This makes it possible to reduce manufacturing costs without the need for

In addition, in this system, if the quality of the treated water discharged from the water tower 14 does not reach a predetermined water quality, the water supply to the pure water tank is stopped, and the bad treated water is returned to the water tower 14 again. This control system recycles the treated water until it becomes treated water, and since the recycled water is of good quality, it is a very effective control method for reducing the amount of chemical injection.

In addition, in implementation, the raw water treatment tank is not limited to the water tower 14 made of an ion exchange tower, as described above, but other types of treatment tanks may be used. Further, the sequencer 4 and the compound arithmetic unit 7 are not provided separately,
It can also be configured as a single device connected to a computer and a suitable interface.

Since the present invention has the above-described configuration in a pure water production apparatus, it has the advantage of being able to provide a pure water production apparatus that can reduce the amount of chemicals used and can be operated automatically.

[Brief explanation of drawings]

Figure 1 is a block diagram showing an overview of a chemical injection amount control system in which the present invention is applied to a continuous water purifier, and Figure 2 is a system diagram showing in detail the piping system of the water purifier in Figure 1. . 1... Continuous water purifier, 2... Water quality meter, 3... Flow meter,
4...Sequencer, 5, 6...Medicine injection pump, 7...Compound arithmetic unit, 8...Multiplication circuit, 9...Hold circuit, 10
...Memory circuit, 11...Time delay circuit, 12, 13...
Arithmetic circuit, 14... Water tower as raw water treatment tank, 1
5, 21, 24...Valve.

Claims (1)

[Claims] 1. A water quality meter that detects the quality of raw water on the inlet side and a flow meter that measures the flow rate of treated water on the outlet side, and is filled with an ion exchange resin inside and is used to treat the raw water. an ion exchange resin regeneration tower that is connected to the raw water treatment tank and has a chemical injection pump and that processes and regenerates the ion exchange resin taken out from the raw water treatment tank with chemicals; a treated water delivery direction switching means having a recirculation pipe connecting an inlet side and an outlet side of the treatment tank, and switching the delivery direction on the outlet side to recirculate the treated water to the raw water treatment tank; and an outlet of the raw water treatment tank. Based on the signal from the water quality meter installed between A sequencer that regenerates the ion exchange resin in the treatment tank in an ion exchange resin regeneration tower, a multiplication circuit that multiplies the signals from the flow meter and the water quality meter on the inlet side, and a calculation based on the value obtained from this multiplication circuit. It has an arithmetic circuit that performs
A computing unit that calculates the amount of medicine to be injected from the medicine injection pump, a hold circuit that operates according to the start/stop signal from the sequencer and holds the signal from the multiplier circuit using a hold signal, and a multiplier held by this hold circuit. A memory circuit that stores signals from the circuit, and a time delay circuit that releases the hold operation after a predetermined period of time and returns the signal stored in the memory circuit to the arithmetic circuit, and compensates for time delays in the process. 1. A pure water production apparatus comprising: means.