JPH09253427A - Filtration method - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To perform filtration of the same liquid type in a plurality of tanks rationally in terms of equipment cost and operation cost. SOLUTION: A pump 3, a filter 4, and automatic valves 5, 6, 7, as one filtering device for a plurality of tanks 1, 2,
8 is installed, and a foreign matter concentration meter 9 is provided in each of the tanks 1 and 2,
The automatic valve 10 having the higher foreign matter concentration measurement value is opened, the pump 3 is started, and the liquid is passed through the filter 4. Foreign substance concentration meter 9, 1
When 0, the pump 3 is stopped when both the liquid in the tank 1 and the liquid in the tank 2 become the target concentrations or less.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a filtration method.
More specifically, the present invention relates to a technique in a system having two or more tanks of the same liquid type, in which the concentration of foreign matter in the internal liquid of each tank is kept below a target cleanliness level with a single filter.

[0002]

2. Description of the Related Art Generally, when a liquid in a plurality of tanks is filtered, even if the liquids are of the same liquid type, it is common to install one filtering device for each tank for continuous filtration. .

[0003]

The filtration method as described above has a problem in that the equipment related to the filtration device becomes large and continuous operation is performed, so that operating costs such as electric power are also required. An object of the present invention is to provide a filtration method that solves the above problems.

[0004]

In order to solve the above-mentioned problems, the present invention measures the concentration of foreign matter in the liquid in each tank in a system having two or more tanks of the same liquid type. One filtration device preferentially filters the tank liquid having a high foreign matter concentration, and stops the filtration when any of the tank liquids has a target concentration or less.

According to the present invention, in a system having two or more tanks of the same liquid type, the concentration of the foreign matter to be removed from each tank liquid is measured, and the tank liquid containing the high foreign matter concentration can be measured by one filtering device. Is preferentially filtered, and the filtration device is stopped when the foreign matter concentration of the liquid in the tank becomes equal to or less than the target value. Therefore, the equipment cost and the operation cost of the filtration device can be reduced.

[0006]

1 is a system diagram showing an embodiment of the present invention. The liquid in the tank 1 and the tank 2 is filtered by a single filtering device. A pump 3, a filter 4, and automatic valves 5, 6, 7, and 8 are installed as a filtering device. Foreign matter concentration meters 9 and 10 installed in the tanks 1 and 2, respectively
Continuously measures the concentration of foreign matter in the liquid in the tank. Then, the automatic valve with the higher concentration of foreign matter is opened, the pump 3 is started, and the liquid is passed through the filter 4. For example, when the foreign matter concentration in the tank 1 is higher, the automatic valves 5 and 6 are opened, and the automatic valves 7 and 8 are closed.

The pump 3 thus started continues to filter the liquid in the tank 1, but when the foreign substance concentration of the liquid in the tank 1 reaches the target concentration by the foreign substance concentration meter 9, the automatic valve 5 is activated. The automatic valve 6 is closed and the pump 3 is stopped. The same applies to the tank 2. In this way, the liquids in the tank 1 and the tank 2 are filtered by the information of the foreign matter concentration meters 9 and 10, and the measured values of the foreign matter concentration meters 9 and 10 should be below the target foreign matter concentration for both the liquids in the tanks 1 and 2. For example, stop pump 3.

FIG. 2 shows the transition of the foreign matter concentration in the tank 1 and the tank 2 when the filtration is performed by such a method. FIG. 2 shows a transition of the foreign matter concentration of the liquid in the tank 1 by a curve 11 and a transition of the foreign matter concentration of the liquid in the tank 2 by a curve 12. Tank 1
When the concentration of foreign matter in the liquid inside the tank 2 is high, the filtration of the liquid in the tank 1 is started at the time indicated by the arrow 21, and when the concentration becomes less than the target value, the concentration of the foreign matter in the liquid inside the tank 2 becomes the target value. Since it is higher, the filtering device stopped the filtration of the liquid in the tank 1 at the time of the arrow 22, and started the filtration for removing the foreign matters in the liquid in the tank 2. At the time of arrow 23, the concentration of foreign matter in the liquid in both tanks 1 and 2 was lower than the target value, so the operation of the filtration device was stopped. Filtration of the liquid in the tank 1 was started again at the time of arrow 24, and filtration of the liquid in the tank 2 was started at the time of arrow 25. The operation was stopped while the foreign matter concentration in the liquid in both tanks was lower than the target value.

In this embodiment, the case where the number of tanks is two is shown, but it is obvious that the invention may be applied to the case of three or more tanks. In any case, it goes without saying that it is necessary to properly select the capacity of the filter.

[0010]

According to the present invention, since the liquid in the tank of two or more tanks is filtered by one filtering device, the equipment cost for the filtering device can be reduced. Further, in any of the tanks, when the foreign matter concentration reaches the target value, the filtering device is stopped, so that the operating cost of the filtering device can be reduced.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing changes in the concentration of liquid foreign matter in the tank of the example.

[Explanation of symbols]

1, 2 Tanks 3 Pumps 4 Filters 5, 6, 7, 8
Automatic valve 9,10 Foreign matter concentration meter

Claims (1)

[Claims] 1. In a system having two or more tanks of the same liquid type, the concentration of foreign matter to be removed in the liquid inside each tank is measured, and the tank liquid with a high foreign matter concentration is prioritized by one filtering device. Filtration is performed, and the filtration is stopped when the concentration of foreign matter in the liquid in the tank falls below a target value.