JP2000002185A - Filtration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish energy saving by making use of the primary side water level of a pump effectively and shortening the pump operation time. SOLUTION: This filtration device is equipped with a filtrating pump 4 operated at a fixed speed, a reverse washing pump 5 and surface washing pump 6, and is furnished with a calculating device 1 to calculate the pump operation time from the pump primary side water level input signal, and on the basis of the calculations, the drive and control of the pumps 4, 5, 6 are conducted, and thereby the operating efficiency can be enhanced and the energy saving be established.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration device including a filtration pump, a backwashing pump and a front washing pump which are operated at a constant speed, and more particularly to a drive / control device therefor.

[0002]

2. Description of the Related Art In general, it is known that a pump is operated for a fixed time by a timer in a washing and draining process of a filtration device. However, when a fixed speed pump operated at a constant speed is used, the water level on the primary side of the pump is large or small. Increases or decreases the discharge flow rate,
It has been pointed out that when the water level on the pump primary side is large, the flow rate in the washing and draining steps is increased, wasteful energy is consumed, and the operation efficiency is deteriorated.

[0003]

That is, the conventional pump does not effectively use the water level on the primary side of the pump, has a problem that the operation time of the pump is constant and energy saving is not achieved. Therefore, an object of the present invention is to effectively use the water level on the primary side of the pump, shorten the operation time of the pump, and save energy.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a filter provided with a filtration pump, a backwashing pump and a facewashing pump, which is operated at a constant speed. An arithmetic unit for calculating a pump operation time by receiving a water level signal is provided, and based on the pump operation time calculated by the arithmetic unit, the filter pump, the backwash pump and the front wash pump are driven and controlled. I have.

[0005]

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 1 is an arithmetic unit, 2
Is a switchboard, 3 is a filtration device, 4 is a filtration pump, 5 is a backwash pump, 6 is a front wash pump, 7 is a water level gauge for a filtration pump well,
8 is a water level gauge for a washing pump well, 9 is a filtration pump well, 10
Is a washing pump well, 11 is a raw water inflow valve, 12 is a drainage outflow valve, 13 is a backwash inflow valve, 14 is a front washing inflow valve, 15 is a waste water outflow valve, and 16 is a purified water outflow valve.

The operation method of such a system is as follows.
For example, as shown in FIG. 2, it is common to cyclically execute a filtering operation, a washing operation, a backwashing operation, and a drainage operation. Here, the filtration operation is an operation in which raw water flows in from the upper part of the filtration device 3 through the raw water inflow valve 11, passes through a filter material (not shown) and a supporting bed stone, and flows out (treated water) from the lower part of the filtration device. In addition, if the filtration operation is continued, the filtration capacity is reduced due to the retention of suspended substances, and the following washing and backwashing operations are performed to recover the filtration ability.

In the washing operation, the washing water flows from the upper part of the filtering device 3 through the washing valve 14, and pressurized water is injected into the surface layer of the filter medium (not shown) to form a muddy layer by the shear energy of the water flow. It is an operation to crush and improve the washing effect,
In the backwashing operation, backwash water flows from the lower part of the filtration device 3 through the backwash inflow valve 13 to flow the supporting bed stone and the filter medium at a flow rate of 0.8 m.
Per minute. Depending on the flow rate, about 20
The backwash operation is to expand the suspension by about 30% and to flow out (drain) the suspended material outside the filtration device 3.

[0008] The drainage operation is the same operation as the filtration operation. By discarding the water remaining in the filtration device 3 in the backwash operation,
We are preparing for the next filtration operation. The following table shows the open / closed state of each valve and the operating state of the pump in the operation as described above. Table Filtration operation Front wash operation Backwash operation Drainage operation Raw water inflow valve Open Closed Close Open Purified water outflow valve Open Closed Closed Backwash inflow valve Closed Closed Open Closed tablewash inflow valve Closed Open Closed Closed Drain outflow valve Closed Open Closed Water outflow valve Close Close Close Open Filter pump Run Stop Stop Run Front wash pump Stop Run Stop Stop Backwash pump Stop Stop Run Stop

Although the above-described operation has been conventionally performed, the present invention has the following additional functions. That is, the water level gauges 7 and 8 respectively detect the water levels of the filtration pump well 9 and the washing pump well 10, and the arithmetic unit 1 performs predetermined calculations based on the detected primary water level H. 5, Each of the front washing pumps 6 is operated for a predetermined time.

The arithmetic expression of the operation time of each pump based on the water level H in the arithmetic unit 1 is, for example, K = a water level-flow rate conversion coefficient obtained from a pump performance curve and a loss curve as shown in FIG. , The pump operation reference time is T
Assuming that 0 and the primary water level are H, it is expressed by the following equation (1). T ≧ T0 · Q1 / Q = T0 · Q1 / (Q1 + KH _N ) (1) where T: pump operation time T0: pump operation reference time Q1: reference water amount Q: pump discharge flow rate (Q1 + KH _N ) H _N : Pump primary water level H at sampling frequency N
Average value of K: Water level-flow rate conversion coefficient However, if there is an actually measured value, Q shall adopt that value.

It is assumed that the average value of the water level H on the primary side of the pump at the sampling frequency N is obtained from the following equation (2). H _N = {H + (N-1) H _N-1 } / N (2) where, N: Number of samplings H: Primary water level of the pump H _N-1 : Pump at the time of completion of the number of samplings (N-1) Average value of primary water level H

The water level-flow rate conversion coefficient K is obtained from FIG. 3 as the rate of change of P1 → P2, P1 → P′1 and Q1 → Q2, where (P1-P′1) and (P1-P′1).
Since 2) generally has a small value, K is regarded as a substantially straight line, and an arithmetic expression such as the following expression (3) is used. K = (Q2-Q1) / (P1-P'1) (3) where, Q2: pump discharge flow rate at pump discharge pressure P2 P1: pump discharge pressure at reference water volume Q1 P'1: P1- (pump primary (The maximum value of the fluctuation of the side water level) The invention is not limited to pressure type and gravity type filtration devices.
It can be widely applied to pump control in general.

[0013]

According to the present invention, since the pump operation time is determined according to the water level on the primary side of the pump, the operation efficiency can be increased and energy saving can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment according to the present invention.

FIG. 2 is an explanatory diagram of an operation method of the filtration device of FIG.

FIG. 3 is an explanatory diagram of a calculation operation in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Calculation device, 2 ... Distribution board, 3 ... Filtration device, 4 ... Filtration pump, 5 ... Backwash pump, 6 ... Surface wash pump, 7,8 ... Water level gauge, 9 ... Filtration pump well, 10 ... Wash pump well, 11: Raw water inflow valve, 12: Drainage outflow valve, 13: Backwash inflow valve, 14
… Flushing inflow valve, 15… Waste water outflow valve, 16… Purified water outflow valve.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshihiro Oumi 984-3 Kokuracho, Wakaba-ku, Chiba-shi, Chiba F-term (reference) 3H020 AA07 BA12 CA07 DA23 3H045 AA23 BA32 CA16 CA25 DA39 DA43 DA47 EA15 EA35

Claims (1)

[Claims] An arithmetic unit for inputting a pump primary-side water level signal and calculating a pump operation time is provided for a filtration device provided with a filtration pump, a backwashing pump, and a front-washing pump operated at a constant speed, A filtration control device for driving and controlling the filtration pump, the backwash pump, and the front-wash pump based on the pump operation time calculated by the calculation device.