JP2021003368A - Water treatment device - Google Patents

Abstract

To provide a control method of an RO water pump in a water treatment device.SOLUTION: (a) When a water level changes from higher than a high water level to lower than the high water level, a time required for the water level drop is measured from that point of time to a point of time when the water level becomes lower than a middle water level. After the water level becomes lower than the middle water level, an RO pump is designed to be driven so that the water level drop is compensated at a speed corresponding to the speed of the water level drop. (c) When the water level changes from lower than the low water level to higher than the low water level, a time required for the water level rise is measured from that point of time to a point of time when the water level becomes higher than the middle water level. After the water level becomes higher than the middle water level, the RO pump is designed to be decelerated so that the water level rise is offset at a speed corresponding to the speed of the water level rise.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water treatment apparatus for producing water for artificial dialysis used for dialysis treatment.

A conventional water production apparatus for artificial dialysis will be described with reference to FIG. As shown in FIG. 3, the artificial dialysis water is typically produced from tap water or raw water which is well water.

The raw water is first stored in the raw water tank 51. A heating heater 51h is provided inside the raw water tank 51 to heat the temperature of the raw water to 25 ° C. This is because if the temperature of the raw water remains lower than 25 ° C., silica components and the like in the raw water may precipitate in the subsequent apparatus and cause a problem.

The raw water heated to 25 ° C. is then sent to the pretreatment unit 53 by the raw water pump 52. The pretreatment unit 53 has a pre-filter 53a, a water softening device 53b, and a carbon filter 53c in this order. The pre-filter 53a mainly filters impurities (dust) in the raw water, the water softening device 53b mainly removes calcium ions (Ca ²⁺ ) and magnesium ions (Mg ²⁺ ) in the raw water, and the carbon filter 53c uses the carbon filter 53c. It mainly removes residual chlorine (total chlorine: free chlorine + combined chlorine) in raw water.

The raw water after the pretreatment in the pretreatment unit 53 is sent to the RO unit 54 (reverse osmosis membrane treatment device). The RO unit 54 uses the RO pump 54p to supply the pretreated raw water to the RO module 54m. The RO module 54m removes all inorganic ions contained in the raw water. The RO water (about 50 to 90% of the raw water) that has been treated with the RO module 54 m is sent to the RO water supply unit 55, and the RO wastewater generated by the treatment with the RO module 54 m is partially (“circulated”). (Also called "water") is recharged into the RO module 54m via the RO pump 54p, and the other part (about 10 to 50% of the raw water, also called "concentrated water") is treated as wastewater.

The RO water supply unit 55 has an RO water tank 55t in which RO water is stored. A UV irradiation device 55u is provided inside the RO water tank 55t so that the RO water can be subjected to UV irradiation treatment. Further, the RO water tank 55t is provided with an air filter 55f in order to remove airborne bacteria and dust in the external air that flows in depending on the change in the water level of the RO water in the RO water tank 55t.

The RO water stored in the RO water tank 55t is sent to the UF 57 (ultra filter, also referred to as "microfiltration membrane") via the water supply pump 56. UF57 removes biological impurities from RO water. The RO water from which biological impurities have been removed by UF57 is sent to various medical devices for dialysis treatment as dialysis water. Usually, in those medical devices, dialysis water is heated to around 36 ° C. and used for various dialysis treatments. Then, the dialysis water returns to the UF58 (ultrafilter, also called "microfiltration membrane") after circulation of the medical device, and further returns to the RO water tank 55t.

The above-mentioned artificial dialysis water production apparatus shown in FIG. 3 has already been put into practical use, and stably produces artificial dialysis water for dialysis treatment.

In addition, Patent Document 1 proposes a method and a purification device capable of efficiently removing a bacterial-derived DNA fragment in artificial dialysis water by simple equipment and operation.

JP-A-2010-279461

The applicant is a manufacturer that manufactures the water production apparatus for artificial dialysis shown in FIG. Then, the present inventor has been diligently studying further improvement of the water production apparatus for artificial dialysis shown in FIG.

As shown in FIG. 4, the conventional RO water tank 55t has a water level of RO water stored in the RO water tank 55t.
(1) A full water sensor S51 for warning that the RO water tank 55t is full, and
(2) An excessive water level sensor S52 that detects whether the water level is above or below a predetermined excessive water level, and
(3) A high water level sensor S53 that detects whether the water level is above or below a predetermined high water level.
(4) A medium water level sensor S54 that detects whether the water level is above or below a predetermined medium water level.
(5) A low water level sensor S55 that detects whether the water level is above or below a predetermined low water level.
(6) An underwater level sensor S56 for detecting and warning whether the water level is above or below a predetermined underwater level.
(7) A drought sensor S57 for detecting drought in the RO water tank, and
have.

For example, the total volume of the RO water tank 55t is 291L (liter).
The full water sensor S51 is provided at the position of 270L and is provided.
The excessive water level sensor S52 is provided with the position of 249L as the excessive water level.
The high water level sensor S53 is provided with a high water level at the position of 228L.
The medium water level sensor S54 is provided with the position of 183L as the medium water level.
The low water level sensor S55 is provided at the position of 144L as the low water level.
The underwater level sensor S56 is provided with the position of 69L as the underwater level.
The drought sensor S57 is provided at the position of 21L.

A control device for controlling the RO pump 54p is provided, and the control device controls the RO pump 54p in the following two patterns according to the operating state of the dialysis device to which dialysis water is supplied and used. ..

<First pattern: The dialysis machine is stopped>
When the dialysis machine is not in operation, the control device
(Pa) Even if the water level changes from above the high water level to below the high water level, the RO pump 54p is not yet driven, and after the water level falls below the medium water level, the RO pump 54p is operated at a low speed (for example, 32 L / min). ), And
(Pb) When the water level changes from above to below the low water level, the RO pump 54p is increased to a high speed (for example, 40 L / min).
(Pc) Even if the water level changes from below the low water level to above the low water level, the RO pump 54p continues to be driven at a high speed, and after the water level rises above the middle water level, the RO pump 54p is decelerated at a low speed. And
(Pd) Even if the water level changes from below the high water level to above the high water level, the RO pump 54p continues to be driven at a low speed, and after the water level rises above the excessive water level, the driving of the RO pump 54p is stopped. To do.

To supplement the explanation, it is considered that the water level of the RO water tank 55t drops when the dialysis machine is not operating when the dialysis machine is performing the washing process. Therefore, when the water level drops, the RO pump 54p is driven at high speed in order to quickly supply water.

<Second pattern: dialysis machine in operation>
When the dialysis machine is in operation, the control device
(Qa) Even if the water level changes from above the high water level to below the high water level, the RO pump 54p is not yet driven, and after the water level falls below the medium water level, the RO pump 54p is operated at a low speed (for example, 32 L / min). ), And
(Qb) When the water level changes from above to below the low water level, the RO pump 54p is increased to a medium speed (for example, 35 L / min).
(Qc) Even if the water level changes from below the low water level to above the low water level, the RO pump 54p continues to be driven at a medium speed, and after the water level rises above the medium water level, the RO pump 54p is lowered. It is designed to slow down, and
(Qd) Even if the water level changes from below the high water level to above the high water level, the RO pump 54p continues to be driven at a low speed, and after the water level rises above the excessive water level, the driving of the RO pump 54p is stopped. To do.

To supplement the explanation, it is considered that the water level of the RO water tank 55t drops while the dialysis machine is operating when the dialysis machine is performing the dialysis process. Therefore, even when the water level drops, it is not necessary to supply water at a very high speed, so that the RO pump 54p is driven at a medium speed.

By controlling the two patterns as described above, the RO pump 54p can maintain the driving time longer than the case where the control is performed only by the first pattern. As a result, the time during which the supply of raw water to the RO module 54m is stopped and the RO module 54m is in the "retained" state can be shortened, and deterioration of water quality can be suppressed.

However, in order to realize the above two patterns of control, it is necessary to grasp the operating status of the dialysis machine and input the corresponding signal to the control device. There is a problem that the construction of the hardware for that purpose and the maintenance of the hardware are troublesome or complicated for the user of the water treatment apparatus.

The present invention has been devised based on the above findings. An object of the present invention is to provide an artificial dialysis water production apparatus capable of realizing control that does not stop the supply of raw water to the RO module as much as possible without requiring a signal input for operation / stop of the dialysis apparatus. Further, the RO water produced by the present invention is not limited to water for artificial dialysis, and can be used as water for washing instruments, water for inspection, water for hand washing, water for dispensing, and the like. That is, the present invention broadly provides a water treatment device capable of realizing control that does not stop the supply of raw water to the RO module as much as possible without inputting an operation / stop signal of the water utilization device.

The present invention comprises an RO module that separates raw water into RO water and RO drainage, an RO water tank that stores the RO water, an RO pump that supplies the raw water to the RO module, and a control that controls the RO pump. The RO water tank comprises an apparatus, and the RO water tank has an excessive water level sensor that detects whether the RO water level stored in the RO water tank is above or below a predetermined excessive water level, and a predetermined high water level. It has a high water level sensor that detects whether it is above or below, a medium water level sensor that detects whether it is above or below a predetermined medium water level, and a low water level sensor that detects whether it is above or below a predetermined low water level. The control device is
(A) When the water level changes from above the high water level to below the high water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the middle water level, the RO pump is driven so as to compensate for the water level drop at a speed corresponding to the speed of the water level drop.
(B) The water treatment apparatus is characterized in that when the water level changes from above to below the low water level, the RO pump is accelerated to the maximum speed.

According to the present invention
(A) When the water level changes from above the high water level to below the high water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the medium water level, the RO pump is driven so as to compensate for the water level decrease at a speed corresponding to the water level decrease, so that the water level becomes the medium water level. After the water level becomes lower, control will be implemented so that the water level is maintained at the middle water level as much as possible (if the same RO water usage conditions as when the water level dropped until then continue, the water level will be medium. Maintained as much as possible at the water level (actually RO water usage conditions can fluctuate). As a result, it is possible to gain time for the water level to subsequently fall below the low water level or rise above the high water level, that is, the operating time of the RO pump can be maintained longer.

In addition, the control device further
(C) When the water level changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump is decelerated so as to offset the water level rise at a speed corresponding to the speed of the water level rise.
(D) When the water level changes from below the high water level to above, it is preferable that the RO pump is decelerated to the minimum speed.

in this case,
(C) When the water level changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump is decelerated so as to offset the water level rise at a speed corresponding to the speed of the water level rise, so that the water level is medium. After the water level rises above the water level, control will be implemented so that the water level is maintained at the middle water level as much as possible (if the same RO water usage conditions as when the water level rose up to that point continue, the water level will rise. Maintained to medium water level as much as possible (actually RO water usage conditions can fluctuate). As a result, it is possible to gain time for the water level to subsequently fall below the low water level or rise above the high water level, that is, the operating time of the RO pump can be maintained longer.

In addition, the control device further
(E) It is preferable that the RO pump is stopped when the water level changes from below to above the excessive water level.

Alternatively, the present invention includes a water treatment including an RO module that separates raw water into RO water and RO wastewater, an RO water tank that stores the RO water, and an RO pump that supplies the raw water to the RO module. In a method of controlling an apparatus, the RO water tank has a predetermined excessive water level, a predetermined high water level, a predetermined medium water level, and a predetermined water level of the RO water stored in the RO water tank. The low water level of is specified,
The method is
(A) When the water level changes from above the high water level to below the high water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the middle water level, the RO pump is driven so as to compensate for the water level drop at a speed corresponding to the water level drop rate.
(B) A process in which the RO pump is increased to the maximum speed when the water level changes from above to below the low water level.
It is a method characterized by having.

In this case, the method is
(C) When the water level changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump is decelerated so as to offset the water level rise at a speed corresponding to the water level rise.
(D) A step of decelerating the RO pump to the minimum speed when the water level changes from below the high water level to above the high water level.
It is preferable to further provide.

In this case, the method is
(E) It is preferable to further include a step of stopping the RO pump when the water level changes from below to above the excessive water level.

According to the present invention
(A) When the water level changes from above the high water level to below the high water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the medium water level, the RO pump is driven so as to compensate for the water level decrease at a speed corresponding to the water level decrease, so that the water level becomes the medium water level. After the point of lowering, the control is carried out so that the water level is maintained at the middle water level as much as possible. As a result, it is possible to gain time for the water level to subsequently fall below the low water level or rise above the high water level, that is, the operating time of the RO pump can be maintained longer.

It is a schematic explanatory drawing of the water treatment apparatus which concerns on one Embodiment of this invention. It is the schematic of the RO water tank of the water treatment apparatus of FIG. It is a schematic explanatory drawing of the conventional water production apparatus for artificial dialysis. It is the schematic of the RO water tank of the water treatment apparatus of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic explanatory view of a water treatment apparatus according to an embodiment of the present invention. As shown in FIG. 1, in the water treatment device 10 of the present embodiment, the raw water tank 11 provided with the heating heater 11h for storing the raw water and heating the raw water, and the temperature in the raw water tank 11 are adjusted. A pretreatment unit 13 that pretreats the raw water, and an RO module 14m that separates the raw water into RO water and RO wastewater by using a reverse osmosis membrane (ROM) for the raw water pretreated by the pretreatment unit 13. , Is equipped.

In this embodiment, tap water is used as raw water. Raw water, which is tap water, is stored in the raw water tank 11. The raw water tank 11 is provided with a raw water tank temperature sensor 21.

The raw water whose temperature has been adjusted to 25 ° C. to 33 ° C. is sent to the pretreatment unit 13 by the raw water pump 12. The pretreatment unit 13 has a pre-filter 13a, a water softening device 13b, and a carbon filter 13c in this order. The pre-filter 13a is designed to mainly filter impurities (dust) in the raw water, and the water softening device 13b is designed to mainly remove calcium ions (Ca ²⁺ ) and magnesium ions (Mg ²⁺ ) in the raw water. The carbon filter 13c is designed to mainly remove residual chlorine (total chlorine: free chlorine + bound chlorine) in raw water.

The raw water after the pretreatment in the pretreatment unit 13 is sent to the RO unit 14 (reverse osmosis membrane treatment device). The RO unit 14 uses the RO pump 14p to supply the pretreated raw water to the RO module 14m. The RO module 14m is designed to remove all inorganic ions contained in the raw water. The RO water (about 50 to 90% of the raw water) that has been treated with the RO module 14 m is sent to the RO water supply unit 15, and the RO wastewater generated by the treatment with the RO module 14 m is discharged. A part (also called "circulating water") is recharged into the RO module 14m via the RO pump 14p, and the other part (about 10 to 50% of the raw water, also called "concentrated water"). ) Is designed to be treated as wastewater.

The RO water supply unit 15 has an RO water tank 15t in which RO water is stored. A UV irradiation device 15u is provided inside the RO water tank 15t so that the RO water can be subjected to UV irradiation treatment. Further, the RO water tank 15t is provided with an air filter 15f in order to remove airborne bacteria and dust in the external air that flows in depending on the change in the water level of the RO water in the RO water tank 15t.

The RO water stored in the RO water tank 15t is sent to the UF 17 (ultra filter, also referred to as "microfiltration membrane") via the water supply pump 16. UF17 is designed to remove biological impurities from RO water. RO water from which biological impurities have been removed by UF17 is sent to various medical devices (not shown) for dialysis treatment as dialysis water. Usually, in those medical devices, dialysis water is used for various dialysis treatments. Then, the dialysis water returns to UF18 (ultrafilter, also called "microfiltration membrane") after circulation of medical equipment, and is further returned to the RO water tank 15t.

As shown in FIG. 2, the RO water tank 15t has a water level of RO water stored in the RO water tank 15t.
(1) A full water sensor S1 for warning that the RO water tank 15t is full, and
(2) An excessive water level sensor S2 that detects whether the water level is above or below a predetermined excessive water level.
(3) A high water level sensor S3 that detects whether the water level is above or below a predetermined high water level.
(4) A medium water level sensor S4 that detects whether the water level is above or below a predetermined medium water level.
(5) A low water level sensor S5 that detects whether the water level is above or below a predetermined low water level.
(6) An underwater level sensor S6 for detecting and warning whether the water level is above or below a predetermined underwater level.
(7) A drought sensor S7 for detecting drought in the RO water tank, and
have.

For example, the total volume of the RO water tank 15t is 291L (liter).
The full water sensor S1 is provided at the position of 270L and is provided.
The excessive water level sensor S2 is provided at the position of 249L as the excessive water level.
The high water level sensor S3 is provided with the position of 228L as the high water level.
The medium water level sensor S4 is provided with the position of 183L as the medium water level.
The low water level sensor S5 is provided with the position of 144L as the low water level.
The underwater level sensor S6 is provided with the position of 69L as the underwater level.
The drought sensor S7 is provided at the position of 21L.

(Control step a)
A control device 14c for controlling the RO pump 14p is provided. The control device 14c is
(A) When the water level of the RO water tank 15t changes from above the high water level to below the middle water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the middle water level, the RO pump 14p is driven so as to compensate for the water level drop at a speed corresponding to the water level drop rate.

(Specific example a-1)
A case where the drive control range of the RO pump 14p is 32 L / min to 40 L / min will be described.

When RO water is used at a rate of 32.5 L / min (corresponding to 45-bed dialysis treatment) from the excessive water level provided with the excessive water level sensor S2 (at the water level, the RO pump 14p is stopped). The time required until the water level falls below the medium water level is 45 L ÷ 32.5 L / min = 1.38 min.

The water treatment device 10 of the present embodiment measures the time required for the water level to drop (45 L / 32.5 L / min) from the time when the water level changes from above the high water level to the time when the water level falls below the medium water level. Then, the rate of the water level drop is calculated based on the time (32.5 L / min).

Since the calculated rate of water level drop (32.5 L / min) is within the drive control range of the RO pump 14p, the water level is after the time when the water level falls below the middle water level (after 1.38 min has elapsed). At the rate of decrease (32.5 L / min), the RO pump 14p is driven to compensate for the decrease in water level.

With such control, the water level can be generally maintained at a medium water level while the RO water is used at a rate of 32.5 L / min.

In the prior art, since the RO pump 54p is driven at 35 L / min, the water level rises at a speed of 35-32.5 = 2.5 L / min. When the water level reaches an excessive water level, the RO pump 54p is stopped and the flushing process is performed. The flushing treatment consumes 70 L of water in one treatment. According to the water treatment device 10 of the present embodiment, the number of such flushing treatments can be reduced, and a remarkable water saving effect can be obtained.

(Another specific example a-2)
When RO water is used at a rate of 22.5 L / min (corresponding to 25-bed dialysis treatment) from the excessive water level provided with the excessive water level sensor S2 (at the water level, the RO pump 14p is stopped). The time required until the water level falls below the medium water level is 45 L ÷ 22.5 L / min = 2 min.

The water treatment device 10 of the present embodiment measures the time required for the water level to drop (45 L / 22.5 L / min) from the time when the water level changes from above the high water level to the time when the water level falls below the medium water level. Then, the rate of the water level drop is calculated based on the time (22.5 L / min).

Since the calculated rate of water level drop (22.5 L / min) is outside the drive control range of the RO pump 14p, the water level drops after the time when the water level drops below the middle water level (after 2 min has elapsed). The RO pump 14p is driven at a driving speed (32 L / min) closest to the speed so as to compensate for the drop in water level.

By such control, the water level rises at a rate of 32-22.5 = 9.5 L / min (the situation does not change even after the control step d described later). When the water level reaches an excessive water level, the RO pump 14p is stopped and a flushing process is performed. However, in the prior art, since the RO pump 54p is driven at 35 L / min, the water level rises at a speed of 35-22.5 = 12.5 L / min. The water treatment device 10 of the form can reduce the number of flushing treatments and can achieve a remarkable water saving effect.

(Control step b)
In addition, the control device 14c is
(B) When the water level of the RO water tank 15t changes from above to below the low water level, the RO pump 14p is increased to the maximum speed.

(Specific example b)
Similar to the above, the case where the drive control range of the RO pump 14p is 32 L / min to 40 L / min will be described.

By the control of Specific Example a-1, the amount of RO water used is increased to a rate of 37.5 L / min while the water level is maintained at a medium water level (corresponding to dialysis treatment of 75 beds). Then, the water level drops at a rate of 37.5-32.5 = 5 L / min. The time required until the water level falls below the low water level is 39L ÷ 5L / min = 7.8min.

After the water level drops below the low water level (after 7.8 min has elapsed), the RO pump 14p is driven at the maximum speed (40 L / min) to compensate for the water level drop. After that, the water level rises at a rate of 40-37.5 = 2.5 L / min.

(Control step c)
In addition, the control device 14c is
(C) When the water level of the RO water tank 15t changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump 14p is decelerated so as to offset the water level rise at a speed corresponding to the speed of the water level rise.

(Specific example c)
Similar to the above, the case where the drive control range of the RO pump 14p is 32 L / min to 40 L / min will be described.

When the water level rises at a rate of 2.5 L / min under the control of the specific example b, the water treatment device 10 of the present embodiment has a water level above the middle water level from the time when the water level changes from below the low water level to above the middle water level. The time required for the water level to rise (39L ÷ 2.5L / min = 15.6min) is measured, and the speed of the water level rise is calculated based on the time (2.5L / min).

Since the difference (37.5 L / min) between the maximum drive speed of the pump (40 L / min) and the calculated speed of water level rise (2.5 L / min) is within the drive control range of the RO pump 14p, the water level After the time when the water level rises above the middle water level (after 15.6 min elapses), the RO pump 14p is decelerated to the speed of the difference (37.5 L / min) so as to compensate for the water level rise up to that point.

With such control, the water level can be maintained at approximately medium water level while the RO water is subsequently used at a rate of 37.5 L / min.

(Control step d)
In addition, the control device 14c is
(D) When the water level of the RO water tank 15t changes from below the high water level to above the high water level, the RO pump 14p is decelerated to the minimum speed.

(Specific example d)
Similar to the above, the case where the drive control range of the RO pump 14p is 32 L / min to 40 L / min will be described.

By controlling the specific example c, the amount of RO water used is reduced to a rate of 15 L / min (corresponding to dialysis treatment of 30 beds) while the water level is generally maintained at a medium water level. The water level rises at a rate of 5-15 = 22.5 L / min. The time required from the bottom to the top of the high water level is 45L ÷ 22.5L / min = 2min.

After the water level rises above the high water level (after 2 min has elapsed), the RO pump 14p is decelerated to the minimum speed (32 L / min). After that, the water level rises further at a speed of 32-15 = 17 L / min (in the prior art, the water level rises at a speed of 35-15 = 20 L / min).

(Control step e)
In addition, the control device 14c is
(E) When the water level of the RO water tank 15t changes from below to above the excessive water level, the RO pump 14p is stopped.

(Specific example e)
Similar to the above, the case where the drive control range of the RO pump 14p is 32 L / min to 40 L / min will be described.

When the water level rises at a speed of 17 L / min under the control of Specific Example d, the time required for the water level to rise from the high water level to the excessive water level is 21 L ÷ 17 L / min = 1.24 min (20 L ÷ in the prior art). 20 L / min = 1 min), and after the elapse of 1.24 min, the RO pump 14p is stopped and the flushing process is performed.

After that, it is substantially the same as the specific example a-2. That is, since RO water is used at a speed of 15 L / min from the excessive water level provided with the excessive water level sensor S2 (at the water level, the RO pump 14p is stopped), the water level becomes lower than the medium water level. The time required to reach the time point is 45L ÷ 15L / min = 3min.

The water treatment apparatus 10 of the present embodiment measures the time (45L ÷ 15L / min) required for the water level to drop from the time when the water level changes from above the high water level to the time when the water level falls below the medium water level. The rate of water level drop is calculated based on the time (15 L / min).

Since the calculated rate of water level drop (15 L / min) is outside the drive control range of the RO pump 14p, the rate of water level drop is set to the rate after the water level drops below the middle water level (after 3 min has elapsed). The RO pump 14p is driven at the closest driving speed (32 L / min) to compensate for the drop in water level.

By such control, the water level rises at a speed of 32-15 = 17 L / min (the situation does not change even after the above-mentioned control step d). When the water level reaches an excessive water level, the RO pump 14p is stopped and a flushing process is performed. However, in the prior art, since the RO pump 54p is driven at 35 L / min, the water level rises at a speed of 35-15 = 20 L / min. Compared with this, the water treatment of the present embodiment The device 10 can reduce the number of flushing treatments and can achieve a remarkable water saving effect.

(Specific example f)
Generally, a dialysis machine cleaning process is performed before and after dialysis treatment. The water treatment device 10 of the present embodiment can support the washing process without requiring a signal input from the dialysis machine.

When RO water is used at a rate of 37.5 L / min for the cleaning process from the excessive water level provided with the excessive water level sensor S2 (at the water level, the RO pump 14p is stopped), the water level is medium. The time required to reach the point below the water level is 45 L ÷ 37.5 L / min = 1.2 min.

The water treatment device 10 of the present embodiment measures the time required for the water level to drop (45 L ÷ 37.5 L / min) from the time when the water level changes from above the high water level to the time when the water level falls below the medium water level. Then, the rate of the water level drop is calculated based on the time (37.5 L / min).

Since the calculated rate of water level drop (37.5 L / min) is within the drive control range of the RO pump 14p, the water level is after the time when the water level falls below the middle water level (after 1.2 min has elapsed). The RO pump 14p is driven at a rate of decrease (37.5 L / min) to compensate for the decrease in water level.

With such control, the water level can be maintained at approximately medium water level while RO water is used at a rate of 37.5 L / min.

In the prior art, the drive of the RO pump 54p at 35 L / min (medium speed) and the drive of the RO pump 54 p at 40 L / min (high speed) are switched by a signal input corresponding to the operating status of the dialysis machine. It was. In the present invention, the cleaning process can be supported without the need for such a signal input.

In addition, the full water sensor S1 can be used to warn of the fullness of the RO water tank 15t, and the drought sensor S7 can be used to detect the drought of the RO water tank 15t and stop and protect the water supply pump 16. ..

Next, the operation of the water treatment device 10 of the present embodiment as described above will be described.

The raw water is first stored in the raw water tank 11. A heating heater 11h is provided inside the raw water tank 11 to heat the temperature of the raw water to 25 ° C.

The raw water heated to 25 ° C. is sent to the pretreatment unit 13 by the raw water pump 12. In the pretreatment unit 13, the pre-filter 13a mainly filters and removes impurities (dust) in the raw water, and the water softening device 13b mainly filters and removes calcium ions (Ca ²⁺ ) and magnesium ions (Mg ²⁺ ) in the raw water. The carbon filter 13c mainly removes residual chlorine (total chlorine: free chlorine + bound chlorine) in the raw water.

The raw water after the pretreatment in the pretreatment unit 13 is sent to the RO unit 14 (reverse osmosis membrane treatment device). The RO unit 14 uses the RO pump 14p to supply the pretreated raw water to the RO module 14m. The RO module 14m is subjected to a treatment for removing all inorganic ions contained in the raw water, and the RO water (about 50 to 90% of the raw water) treated by the RO module 14m is sent to the RO water supply unit 15. ..

On the other hand, a part (also called "circulating water") of the RO wastewater generated by the treatment in the RO module 14m is re-injected into the RO module 14m via the RO pump 14p, and the other part (raw water 10 to 10). About 50% (also called "concentrated water") is treated as wastewater.

In the RO water supply unit 15, RO water is stored in the RO water tank 15t. If necessary, the UV irradiation treatment is performed by the UV irradiation device 15u.

After that, the RO water stored in the RO water tank 15t is sent to the UF 17 (ultra filter) via the water supply pump 16. UF17 removes biological impurities from RO water. The RO water from which biological impurities have been removed by UF17 is sent to various medical devices (not shown) for dialysis treatment, for example, as dialysis water. After circulating the medical device, the dialysis water returns to UF18 (ultra filter) and further returns to the RO water tank 15t.

Then, the control device 14c that controls the RO pump 14p is
(A) When the water level of the RO water tank 15t changes from above the high water level to below the middle water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the middle water level, the RO pump 14p is driven so as to compensate for the water level drop at a speed corresponding to the water level drop rate.

As a result, control is carried out so that the water level is maintained at the medium water level as much as possible after the time when the water level falls below the medium water level. As a result, it is possible to gain time for the water level to subsequently fall below the low water level or rise above the high water level, that is, the driving time of the RO pump 14p can be maintained longer. As a result, the number of flushing treatments can be reduced, and a remarkable water saving effect can be obtained.

Further, the control device 14c for controlling the RO pump 14p is
(B) When the water level of the RO water tank 15t changes from above to below the low water level, the RO pump 14p is increased to the maximum speed.

As a result, it is possible to effectively prevent the RO water tank 15t from becoming drought.

Further, the control device 14c for controlling the RO pump 14p is
(C) When the water level of the RO water tank 15t changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump 14p is decelerated so as to offset the water level rise at a speed corresponding to the speed of the water level rise.

As a result, control is carried out so that the water level is maintained at the medium water level as much as possible after the time when the water level rises above the medium water level. Therefore, it is possible to gain time for the water level to subsequently fall below the low water level or rise above the high water level, that is, the operating time of the RO pump can be maintained longer.

Further, the control device 14c for controlling the RO pump 14p is
(D) When the water level of the RO water tank 15t changes from below the high water level to above, the RO pump 14p is decelerated to the minimum speed.

As a result, it is possible to effectively prevent the RO water tank 15t from becoming full.

Further, the control device 14c for controlling the RO pump 14p is
(E) When the water level of the RO water tank 15t changes from below to above the excessive water level, the RO pump 14p is stopped.

As a result, it is possible to effectively prevent the RO water tank 15t from becoming full.

Further, the control device 14c that controls the RO pump 14p can support the cleaning process of the dialysis machine without requiring a signal input indicating the operating status of the dialysis machine. As a result, the trouble of constructing the hardware for inputting such a signal to the control device 14c and maintaining the hardware is released.

10 Water treatment device 11 Raw water tank 11h Heating heater 12 Raw water pump 13 Pretreatment unit 13a Pre-filter 13b Water softening device 13c Carbon filter 14 RO unit 14c Control device 14m RO module 14p RO pump 15 RO Water supply unit 15f Air filter 15t RO water Tank 15u UV irradiation device 16 Water supply pump 21 Raw water tank temperature sensor S1 Full water sensor S2 Excessive water level sensor S3 High water level sensor S4 Medium water level sensor S5 Low water level sensor S6 Underwater level sensor S7 Drought sensor 51 Raw water tank 51h Heating heater 52 Raw water pump 53 Pretreatment unit 53a Pre-filter 53b Water softener 53c Carbon filter 54 RO unit 54m RO module 54p RO pump 55 RO water supply unit 55f Air filter 55t RO water tank 55u UV irradiation device 56 Water supply pump S51 Full water sensor S52 Excessive water level sensor S53 High Water level sensor S54 Medium water level sensor S55 Low water level sensor S56 Underwater level sensor S57 Drought sensor

Claims (6)

RO module that separates raw water into RO water and RO wastewater,
The RO water tank that stores the RO water and
An RO pump that supplies the raw water to the RO module,
A control device that controls the RO pump and
With
The RO water tank relates to the water level of the RO water stored in the RO water tank.
An excessive water level sensor that detects whether the water level is above or below a predetermined excessive water level,
A high water level sensor that detects whether the water level is above or below a predetermined high water level,
A medium water level sensor that detects whether the water level is above or below a predetermined medium water level,
A low water level sensor that detects whether the water level is above or below a predetermined low water level,
Have and
The control device is
(A) When the water level changes from above the high water level to below the high water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the middle water level, the RO pump is driven so as to compensate for the water level drop at a speed corresponding to the speed of the water level drop.
(B) A water treatment apparatus characterized in that when the water level changes from above to below the low water level, the RO pump is accelerated to the maximum speed. The control device further
(C) When the water level changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump is decelerated so as to offset the water level rise at a speed corresponding to the speed of the water level rise.
(D) The water treatment apparatus according to claim 1, wherein when the water level changes from below the high water level to above, the RO pump is decelerated to the minimum speed. The control device further
(E) The water treatment apparatus according to claim 1 or 2, wherein the RO pump is stopped when the water level changes from below to above the excessive water level. RO module that separates raw water into RO water and RO wastewater,
The RO water tank that stores the RO water and
An RO pump that supplies the raw water to the RO module,
It is a method of controlling a water treatment device equipped with
In the RO water tank, a predetermined excessive water level, a predetermined high water level, a predetermined medium water level, and a predetermined low water level are defined with respect to the water level of the RO water stored in the RO water tank. Ori,
The method is
(A) When the water level changes from above the high water level to below the high water level, the time required for the water level to drop from that time to the time when the water level falls below the middle water level is measured. After the time when the water level falls below the middle water level, the RO pump is driven so as to compensate for the water level drop at a speed corresponding to the water level drop rate.
(B) A process in which the RO pump is increased to the maximum speed when the water level changes from above to below the low water level.
A method characterized by being equipped with. The method is
(C) When the water level changes from below the low water level to above the low water level, the time required for the water level to rise from that time to the time when the water level rises above the middle water level is measured. After the time when the water level rises above the middle water level, the RO pump is decelerated so as to offset the water level rise at a speed corresponding to the water level rise.
(D) A step of decelerating the RO pump to the minimum speed when the water level changes from below the high water level to above the high water level.
4. The method according to claim 4, further comprising. The method is
(E) The method according to claim 4 or 5, further comprising a step of stopping the RO pump when the water level changes from below to above the excessive water level.

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