JPS6186903A - Ultrafiltration apparatus - Google Patents

Abstract

PURPOSE:To save power, by forming a closed recirculation system for directly returning the concentrate discharged from an ultrafiltration apparatus to the suction port of a recirculation pump and assembling an inverter for controlling the number of rotations to the pump of said recirculation system. CONSTITUTION:The concentrate passed through an ultrafiltration apparatus 1 is directly supplied to the suction side of a recirculation pump 5 by a recirculation pipe 9 without being returned to a raw water tank 2. Because of this, energy applied in order to be supplied to the ultrafiltration apparatus 1 is effectively utilized as a result and the energy of the recirculated liquid discharged from the ultrafiltration apparatus 1 recovered as a kind of water wheel effect. By assembling an inverter 11 for controlling the number of rotations in the pump 5 of a closed recirculation system, more power saving effect is obtained.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is a circulating p-filtration type ultrafiltration device in which an inverter for controlling the rotation speed of the circulation pump is incorporated into the circulation pump of the closed circulation system. This invention relates to an energy-saving filtration device that saves power.

[Prior art]

When separating substances using an ultrafiltration device, economical separation is carried out by supplying the liquid to be treated (raw water) to the ultrafiltration device under certain conditions (e.g. pressure, flow rate). When performing economical separation using ultrafiltration, power consumption is considered to be a problem because the separation mechanism requires a high flow rate to be applied to the liquid to be treated.

In order to solve the above problems, sufficient consideration is given to the selection of a circulation pump when designing the equipment, but in order to obtain the necessary pressure and flow rate, it is necessary to use a circulation pump with a larger capacity. Recently, it has been proposed and put into practical use to save power by incorporating an inverter that controls the rotation speed of the circulation pump into the circulation pump. In Fig. 2, reference numeral 1 indicates that raw water is supplied from a raw water tank 2, which is a reservoir for the liquid to be treated (raw water) to be filtered by an ultrafiltration device, through a supply pipe 3 using a circulating pump 5. The necessary pressure and flow rate are applied by the circulation pump 5, and the water is supplied to the filtration device 1 from the liquid supply pipe 6, and the filtered water filtered by the filtration device 1 is sent to the required location from the F water supply pipe 7. be done.

8 is a concentrated liquid return pipe for storing the concentrated liquid that has passed through the filtration device 1 and returning it to the raw water tank 2, and 10 is attached to the pipeline of the liquid supply pipe 6 to supply liquid to the filtration device. A pressure transmitter 11 detects the pressure of raw water in the liquid supply pipe 6 using the pressure transmitter 10, and compares and amplifies the pressure signal with a preset signal ft. death,
The inverter foot, which varies the output voltage and frequency according to the deviation signal, controls the circulation pump 5 by the inverter 11.
control the rotation speed. In addition, 12 is a flow rate transmitter that is attached to the door water supply pipe 7 to detect the flow rate of the door water, and instead of detecting the pressure at the entrance of the transit device 1 described in vIJ, it detects the amount of F water and sends the signal. Alternatively, the rotation speed of the circulation pump 5 may be controlled in the same manner as described above by sending it to the inverter 11. 15 and 16 are pressure gauges provided at the inlet and outlet of the filtration device 10.

In the conventional device described above, the pressure at the inlet of the raw water filtration device or the flow rate of F water is detected and the signal is sent to the inverter 11, thereby controlling the rotation speed of the motor of the circulation pump 5 and saving power. It's on. However, since the concentrated raw water that has passed through the filtration device 1 is returned to the raw water tank 2 via the raw water return pipe 8, the energy given to the raw water by the circulation pump 5 is absorbed by the raw water being returned to the raw water tank and stored. The disadvantage was that the energy would be lost.

[Problem that the invention seeks to solve]

The present invention solves the drawbacks and difficulties of the conventional device described above, and in order to more effectively utilize the pressure and other energy provided by the circulation pump, the concentrated liquid discharged from the ultrafiltration device is A closed circulation system is formed in which the water is returned directly to the suction port of the circulation pump.

[Failure to solve the problem]

The present invention provides an ultrafiltration device of a circulation p-filtration chamber, in which the rotation speed of the circulation pump is controlled by a pressure signal of raw water supplied to the filtration device by the circulation pump or a flow rate signal of the p-water filtered by the filtration device. This is an ultra-filter device that is equipped with an inverter for control and is closed by directly returning the concentrated liquid from the filtration device to the suction side of the circulation pump.

〔Example〕

The present invention will be described with reference to the embodiment shown in FIG.
Components having the same functions as those of the conventional device shown in the figure will be described using the same reference numerals.

1 is a filtration device, and the filtration device is constituted by a hollow fiber type ultrafiltration module.

Reference numeral 2 denotes a raw water tank for preparing raw water, which is a liquid to be treated, and the raw water is supplied to a liquid supply pipe 6 by a supply pump 4 via a supply pipe 3.
The filter is provided with a circulation pump 5 for supplying the raw water to the filtration device with constant filtration pressure and circulation flow rate. 7 is a p-water supply pipe for sending the filtered water from which impurities in the raw water have been separated by the filtration device to a necessary location; This is a circulation pipe for the return reservoir, and the circulation pipe 9
The filtration device forms a closed circulation system. In the closed circulation system described above, a part of the concentrated raw water is discarded from the concentrated water discharge pipe 14 to keep the concentration ratio in the circulation system constant. 10 is a pressure transmitter for detecting the pressure of raw water required for filtration, which is attached to the circulation pipe at the entrance of the filtration device 1;
This is an inverter that detects the pressure of the raw water inside at the inlet of the filtration device 1, compares and amplifies the pressure signal with a preset set pressure signal, and varies the output voltage and frequency according to the deviation signal, 13 is a control panel. 15.16 are pressure gauges provided on the inlet and outlet sides of the filtration device.

In the RIA device described above, the raw water in the raw water tank 2 is supplied to the circulation pipe 9 by the supply pump 4, and the circulation pop 5 is used to send the supplied raw solution to the filtration device 1.
A constant pressure and flow rate are applied to the filtration device δ1 by the circulation pump 5, and the filtered water from which impurities in the raw water have been separated is sent to nine locations from the water supply pipe 7. The concentrated raw water is returned to the suction port of the circulation pump 5 through the circulation pipe 9, which is a filtration device having a so-called closed circulation system. A portion of the water is discarded through the concentrated water discharge pipe 14 to keep the concentration ratio in the circulation system constant. A circulation pipe 9 constituting the above-mentioned circulation system
The supply pump 4 supplies raw water from the raw water tank 2, mixes it into concentrated water at a constant concentration ratio, and supplies the liquid to the filtration device 1 from the circulation pump 5. At this time, a constant filtration pressure necessary for filtration is applied. The pressure of the circulating fluid (liquid to be treated) supplied to the filtration device 1 is detected by a pressure transmitter 10 installed near the inlet of the filtration device 1 in the circulation pipe 9, and the water pressure signal is set in advance. The filtration pressure is kept constant by comparing the output voltage and frequency of the inverter 11 according to the deviation signal and controlling the rotation speed of the motor of the circulation pump 5. The filtered water filtered by 1 is supplied to necessary locations through the F water supply pipe 7, and the flow rate transmitter 12 provided at the outlet side of the P water supply pipe 70p filtration device 1 detects the amount of water at the door. Control similar to that described above can also be performed using the signal.

In devices F, J, the concentrated liquid that has passed through the filtration device 1 is directly supplied to the suction side of the circulation pump 5 through the circulation pipe 9 without being returned to the raw water tank 2. The energy given to the filtration device 1 is used more effectively, and the energy of the circulating fluid discharged from the filtration device 1 is recovered as a kind of water wheel effect.

Furthermore, by incorporating an inverter for controlling the rotation speed into the pump of the closed circulation system as described above, further power saving effects can be obtained.

Specific Example An experiment was conducted using the ultrafiltration apparatus 1 shown in FIG. 1 described above. The supply pump 3 and circulation pump 5 used are conventional centrifugal pumps, each with a motor capacity of 3.7KW.
and 55 KW, and the inverter 11 used to control the rotation speed of the motor was connected to the circulation pump 5, which had a large motor capacity. The control signal to the inverter 11 is the circulation pump 5
This was done using a pressure transmitter 10 installed near the discharge port.

The filtration device is equipped with 48 hollow fiber (inner diameter 1.4 mm) type ultra-modules (outer diameter 125 wn, length 1,200 in), which filters the raw water to be treated (0.1 μm ~
(containing colloidal particles of 1μ) by ultrafiltration.9
This yields filtered water that is completely free of 88%.

The filtration conditions are: module inlet pressure measured by pressure gauge 15;
5Kg/crn2G1 Module outlet pressure measured by pressure gauge 16 1.0Kg/cm''G, processing liquid temperature 30℃,
Raw water supply amount 254 A/min, IP filtration amount 250
t/min.

The concentration water amount was 4 t/ml (concentration ratio: about 60 times).

As a result of testing under the above conditions, the current value of the circulation pump was 30
It became an ampere. Still, the result measured by the integrating power meter was 9 KWH. In addition, if the inverter is not installed in the device shown in Figure 1, the power output will be 46KW at 150 amperes.
It was H.

Comparative Example An experiment was conducted using the ultrafiltration apparatus 1 shown in FIG. 2, which has been described as a conventional apparatus. The circulation pump 5 used is the same as that used in the specific example, and the motor capacity is s s
It is KW. The rotation speed control of the motor was also set to the motor of the circulation pump 5. A control signal to the inverter was provided by a pressure transmitter 10 attached near the discharge port of the circulation pump 5. In addition, the filtration device 1 was exactly the same as the specific example.

The filtration conditions are module inlet pressure and module outlet pressure of 1.5K47cm2G and 1.0K9, respectively.
/cnI-G and the treated raw water is returned to the raw water tank 2 from the raw water tank at a temperature of 30°C via a circulation pump and a filtration device. The amount of raw water flowing through the filtration device 1, that is, the circulating flow rate is determined by the difference between the module inlet pressure and outlet pressure, and is the same flow rate as in the specific example. The amount of excess water was 250 t/min.

The current value of the circulation pump obtained under the above conditions was 102 amperes and 32 KWH.

〔Effect of the invention〕

The ultrafiltration device according to the present invention is equipped with an inverter that controls the rotation speed of the circulation pump based on the pressure of the raw water supplied to the filtration device or the flow rate signal of the p water filtered by the filtration device. This device is characterized by a closed circulation system configured to directly return the concentrated liquid from the device to the suction side of the circulation pump, and as described above, the concentrated liquid discharged from the ultrafiltration device is directly returned to the suction side of the circulation pump. Since it is returned to the suction port of the circulation pump, the energy of the pressure and flow rate given by the circulation pump can be used more effectively, and the liquid discharged from the filtration device is returned to the raw water tank unlike the conventional method. It is possible to prevent energy loss and has the effect of power saving compared to the above-mentioned pump, and since it incorporates an inverter to control the rotation speed in the pump with a closed circulation system, it can prevent energy loss as described above. Together, they have a significant power saving effect.

FIG. 1 is a flow sheet for explaining the ultrafiltration device of the present invention, and FIG. 2 is a flow sheet for explaining the conventional device.

1: Ultrafiltration device 2: Raw water tank 3: Supply pipe
4: Supply pump 5: Circulation pump 6: Liquid supply pipe 7: P water supply pipe 9: Circulation pipe 10: Pressure transmitter 11: Inverter 12: Flow rate transmitter Patent applicant Asahi Kasei Corporation Figure 1 Figure 2

Claims (1)

[Claims] The circulating filtration type ultrafiltration device is equipped with an inverter that controls the rotation speed of the circulation pump based on a pressure signal of raw water supplied to the filtration device by the circulation pump or a signal of the flow rate of filtrate filtered by the filtration device. Also, a closed ultrafiltration device characterized in that the concentrated liquid from the filtration device is directly returned to the suction side of the circulation pump.