JP2012166131A - Ion exchange device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ion exchange device capable of efficiently discharging a stagnant water and of obtaining a high-quality treatment water in a range of practical water collection amount.SOLUTION: The ion exchange device includes: a pressure tank 2 housing an ion exchange resin bed 211; a cleaning unit 3 which cleans the inside of the pressure tank 2 by introducing a cleaning liquid W1 into the tank 2 and discharging the liquid outside a system; a stagnant time calculator 51 for calculating the stagnant time T of the liquid in the tank 2; a stagnant time determinator 52 for determining whether the stagnant time T reaches a prescribed set time T3 or not; and a cleaning unit controller 53 for controlling the cleaning unit 3 to clean the inside of the tank 2 based on the determination result by the stagnant time determinator 52. The cleaning unit controller 53 sets up the linear velocity of the cleaning liquid W1 in the ion exchange resin bed 211 to the range of 5 to 60 m/h, and also sets up the amount of the cleaning liquid W1 to the resin bed 211 in response to the set time T3.

Description

  The present invention relates to an ion exchange device such as a water softening device.

  Conventionally, treated components are produced by adsorbing and removing hardness components (calcium ions and magnesium ions) and nitrate nitrogen (nitrate ions and nitrite ions) contained in raw water such as tap water and groundwater with ion exchange resins. An ion exchange device is known. The ion exchange device includes an ion exchange resin bed and a pressure tank into which a liquid such as raw water is introduced.

In such an ion exchange device, if water is not passed into the pressure tank for a long time, stagnant water may be generated inside the pressure tank, and there is a possibility that various germs may propagate. Not preferable. Further, organic substances such as resin components are eluted from the ion exchange resin bed into the stagnant water, and when the water flow is resumed, the odor and color are attached to the treated water, which may deteriorate the quality of the treated water.
Therefore, a technique for preventing stagnant water from being generated in the pressure tank for a long time is provided (for example, see Patent Document 1).

JP 2009-178666 A

The technique described in Patent Document 1 focuses on the cleaning timing for discharging the accumulated water. However, since the environment in which the ion exchange apparatus is used is various, it is difficult to constantly obtain high-quality treated water by controlling only the cleaning timing.
For this reason, it is desired to wash the inside of the pressure tank under an operation condition that allows the accumulated water to be efficiently discharged and high-quality treated water to be constantly obtained.

  An object of the present invention is to provide an ion exchange device that can efficiently discharge stagnant water and can constantly obtain high-quality treated water.

  The present invention contains an ion exchange resin bed, a pressure tank into which a liquid is introduced, a cleaning means for cleaning the inside of the pressure tank by introducing a cleaning liquid into the pressure tank and discharging it outside the system, Residence time calculation means for calculating the residence time of the liquid located inside the pressure tank, and residence time determination means for judging whether or not the residence time calculated by the residence time calculation means has reached a predetermined set time. And cleaning means control means for controlling the cleaning means so as to clean the inside of the pressure tank based on the determination result by the residence time determination means, the cleaning means control means comprising the ion exchange resin bed In addition, the linear velocity of the cleaning liquid is set in a range of 5 to 60 m / h, and the amount of cleaning liquid with respect to the ion exchange resin bed is set according to the set time. .

  Moreover, when the set time is set to 6 to 24 hours, it is preferable that the cleaning means control means sets the amount of cleaning liquid for the ion exchange resin bed in the range of 6 to 12 BV.

  The cleaning liquid flowing through the pressure tank is water containing chlorine, and the cleaning means control means contacts a chlorine amount of at least 0.5 mg Cl / LR with respect to a unit resin amount of the ion exchange resin bed. It is preferable to control the cleaning means so that the

  The ion exchange resin bed is preferably formed from cation exchange resin beads produced without using a halogen-based organic solvent.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to discharge | emit stagnant water efficiently, the ion exchange apparatus which can obtain high quality treated water constantly can be provided.

1 is an overall configuration diagram of a water softening device 1 as an embodiment of an ion exchange device of the present invention. It is a state transition diagram which shows the process in each operation mode and operation mode of the water softening apparatus. It is a figure which shows the open / close state of the process control valve 3 in each process. It is a functional block diagram which concerns on control of the water softening apparatus. It is a flowchart which shows the control which concerns on the stagnant water discharge | emission of the hard water softening apparatus.

  Hereinafter, a water softening device 1 as an embodiment of an ion exchange device of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a water softening device 1 as an embodiment of the ion exchange device of the present invention.

  The hard water softening device 1 generates soft water by replacing hardness components contained in raw water such as tap water, ground water, and industrial water with sodium ions or potassium ions. The hard water softening device 1 is used for the purpose of supplying soft water as various types of water to demand points. The water softening device 1 is connected to residential buildings such as houses and condominiums, customer-collecting facilities such as hotels and public baths, refrigeration equipment such as boilers and cooling towers, and water-using equipment such as food processing devices and cleaning devices.

  As shown in FIG. 1, the water softening device 1 of this embodiment mainly includes a process control valve 3 so as to clean the inside of the pressure tank 2, the process control valve 3, the salt water tank 4, and the pressure tank 2. And a control device 5 for controlling.

The pressure tank 2 includes a pressure tank body 21 and a lid member 22.
The pressure tank main body 21 is a bottomed cylindrical body having an opening at the top, and accommodates an ion exchange resin bed 211 as a processing material. The ion exchange resin bed 211 is formed from cation exchange resin beads produced without using a halogen-based organic solvent.

  The reason for forming the ion exchange resin bed 211 from such cation exchange resin beads is as follows. Since halogen-based organic solvents are chemically stable, they are often used in the production of ion exchange resins. For example, in a step of introducing an ion exchange group into a resin matrix (for example, a sulfonation process), it is preferable to swell the resin matrix in advance in order to promote the reaction, and a halogen-based organic solvent is used as the swelling agent. Is used. On the other hand, many halogen-based organic solvents are considered harmful to the human body. For this reason, when the use of soft water includes drinking water or bath water, if the halogen-based organic solvent remaining in the ion exchange resin beads is leached into the soft water W2 in the water treatment process, the flavor of the soft water W2 is only impaired. It is because there is a possibility of adversely affecting the human body.

Whether or not the ion exchange resin beads are manufactured without using a halogen-based organic solvent is, for example, “Water Supply Practice 6 Law / 2002 Edition” (supervised by the Water Supply Legislation Research Group, issued on October 1, 2002) 142- Evaluation can be based on the leaching test described on page 144. If the leaching amount of the substance related to the halogen-based organic solvent satisfies the reference value, it can be determined that the halogen-based organic solvent is not substantially used.
Examples of the substance relating to the halogen-based organic solvent include dichloromethane; 1,2-dichloroethane; cis-1,2-dichloroethylene; trichloroethylene; tetrachloroethylene; carbon tetrachloride. In addition, as for the above-mentioned standard value for each substance, refer to the lower column of Appendix 1 of “Ministerial Ordinance on Structural and Material Standards for Water Supply Equipment” (Ministry of Health, Labor and Welfare Ordinance No. 18 on February 17, 2010).

  Examples of strongly acidic cation exchange resins produced without using halogen-based organic solvents include, for example, Mitsubishi Chemical Corporation product names “DIAION UBK10”, “DIAION UBK12”, LANXESS Corporation product names “LEWITIT S1468”. , Manufactured by Dow Chemical Co., Ltd .: product names: “IMAC HP1220”, “AMBERLITE 1220”, manufactured by Purolite: product name “PUROLITE C100 × 10NS”, and the like.

The lid member 22 closes the opening at the top of the pressure tank body 21. The process control valve 3 is integrally attached to the lid member 22.
Details of the pressure tank 2 will be described later.

As will be described in detail later, the process control valve 3 lowers the raw water W1 by collecting the raw water W1 to the top screen 241 of the pressure tank 2 while collecting the raw water W1 on the bottom screen 242 in relation to sampling and regeneration. A flow of water (raw water W1, soft water W2) of water treatment process ST1 that produces a flow to produce soft water W2 that is treated water;
While the salt water W4, which is a regenerated liquid, is distributed to the top screen 241 of the pressure tank 2, the bottom screen 242 collects the salt water W4 to generate a downward flow, thereby regenerating the entire ion exchange resin bed 211. Flow of salt water W4 of 1 regeneration process ST4; and
A second regeneration process for regenerating the lower part of the ion exchange resin bed 211 by generating an upward flow of the salt water W4 by collecting the salt water W4 to the bottom screen 242 of the pressure tank 2 and collecting the salt water W4 on the intermediate screen 243. This is a valve capable of switching the flow of the salt water W4 of ST6.

  The salt water tank 4 stores salt water W4 as a regenerating liquid for regenerating the ion exchange resin bed 211. In the water softening device 1 using cation exchange resin beads, sodium chloride and potassium chloride aqueous solutions can be used as the regenerating solution. Details of the salt water tank 4 will be described later.

  The pressure tank 2 will be further described. The lid member 22 includes a first lid channel 221, a second lid channel 222, and a third lid channel 223 that supply and discharge fluid. Each of these lid flow paths 221, 222, and 223 is connected to various lines constituting the process control valve 3 as described later. “Line” is a general term for lines capable of flowing fluid such as flow paths, paths, and pipelines.

  In the pressure tank 2, a top screen 241 for preventing the resin beads from flowing out is provided on the lower surface side of the lid member 22 and on the top of the ion exchange resin bed 211. The top screen 241 has a large number of apertures smaller than the resin beads (the same applies to the bottom screen 242 and the intermediate screen 243 described later). The first lid channel 221 communicates with the inside of the pressure tank 2 via the top screen 241. The water distribution position and the water collection position by the top screen 241 are set near the top of the ion exchange resin bed 211. The top screen 241 functions as a top liquid distribution unit provided at the top of the ion exchange resin bed 211 and a top liquid collection unit provided at the top of the ion exchange resin bed 211.

  In the pressure tank 2, a first liquid collection and distribution pipe 231 that extends to the vicinity of the bottom of the pressure tank body 21 is connected to the second lid channel 222. A bottom screen 242 that prevents the resin beads from flowing out is provided at the lower end of the first liquid collection and distribution tube 231. The first liquid collection / delivery pipe 231 communicates with the second lid flow path 222. The water distribution position and the water collection position by the bottom screen 242 are set near the bottom of the ion exchange resin bed 211. The bottom screen 242 functions as a bottom liquid distribution unit provided at the bottom of the ion exchange resin bed 211 and a bottom liquid collection unit provided at the bottom of the ion exchange resin bed 211.

  In the pressure tank 2, a second liquid collection and distribution pipe 232 extending to the vicinity of the intermediate portion in the depth direction of the ion exchange resin bed 211 is connected to the third lid flow path 223. An intermediate screen 243 that prevents the resin beads from flowing out is provided at the lower end of the second liquid collection and distribution tube 232. The second liquid collection and distribution tube 232 communicates with the third lid channel 223. The water collection position by the intermediate screen 243 is set near the intermediate part in the depth direction of the ion exchange resin bed 211. That is, the intermediate screen 243 is provided in the intermediate portion in the depth direction of the ion exchange resin bed 211. The intermediate part screen 243 functions as an intermediate part liquid collecting part provided in an intermediate part in the depth direction of the ion exchange resin bed 211.

  The inner diameter of the second collection and distribution pipe 232 is set to be larger than the outer diameter of the first collection and distribution pipe 231. The axial centers of the first collection and distribution pipe 231 and the second collection and distribution pipe 232 are both set coaxially with the axial center of the pressure tank 2. That is, the first collection / distribution pipe 231 and the second collection / distribution pipe 232 form a double pipe structure in which the first collection / distribution pipe 231 is set as an inner pipe and the second collection / distribution pipe 232 is set as an outer pipe. The pressure tank 2 is attached.

  A raw water line L <b> 1 is connected to the first lid channel 221 through a process control valve 3. A soft water line L2 is connected to the second lid channel 222 via the process control valve 3. A fifth drain line L55 is connected to the third lid channel 223. The fifth drain line L55 is connected to the connection part J51 of the first drain line L51 inside the process control valve 3. The raw water line L1, the soft water line L2, and the first drainage line L51 extend to the outside of the process control valve 3. That is, each of the raw water line L 1, the soft water line L 2, and the first drainage line L 51 is provided inside the process control valve 3, and the remaining part is provided outside the process control valve 3.

  Although details will be described later, the control device 5 receives signals from a raw water flow switch 61, a salt water flow meter 62, and the like, which will be described later, and controls the process control valve 3 based on the input signals and the like.

The process control valve 3 includes various lines, valves, and the like therein, and functions as a cleaning unit that cleans the inside of the pressure tank 2.
Specifically, the process control valve 3 includes a raw water line L1, a soft water line L2, a dilution water line L3, a first salt water line L41, a second salt water line L42, and a third salt water line L43 as lines. The fourth saltwater line L44, the first drainage line L51, the second drainage line L52, the third drainage line L53, the fourth drainage line L54, the fifth drainage line L55, and the bypass line L6 are provided.

  A part of the raw water line L1 on the first lid channel 221 side also functions as a fifth salt water line L45. A part of the soft water line L2 on the second lid flow path 222 side also functions as the sixth salt water line L46. Raw water line L1, part of soft water line L2 (sixth salt water line L46 described later), part of fourth salt water line L44 (part between connecting part J21 and connecting part J42 in fourth salt water line L44), The three drainage lines L53, the second drainage line L52, and the first drainage line L51 function as cleaning means.

The process control valve 3 is a raw water flow valve 311, a soft water flow valve 312, a bypass valve 313, an ejector valve 314, a third drain valve 315, a second drain valve 316, and a first drain valve as valves. A valve 317, a salt water valve 318, a first constant flow valve 322, and a second constant flow valve 34 are provided.
The process control valve 3 includes an ejector strainer 321, an ejector 323, a first orifice 324, a second orifice 325, and a soft water strainer 33.

In the raw water line L1, the raw water flow switch 61, the connection part J11, the raw water flow valve 311, the connection part J12, and the connection part J13 are sequentially provided from the supply side of the raw water W1 toward the first lid channel 221. Are provided. The part between the connection part J12 and the 1st cover flow path 221 in the raw | natural water line L1 functions also as the 5th salt water line L45.
The raw water flow switch 61 is provided outside the process control valve 3. The raw water flow switch 61 detects the presence or absence of the flow (pressure) of the raw water W1. A detection signal from the raw water flow switch 61 is input to the control device 5.

The soft water line L2 is provided with a connection portion J21, a soft water strainer 33, a soft water flow valve 312 and a connection portion J22 in order from the second lid flow path 222 toward the supply destination of the soft water W2. The portion of the soft water line L2 between the second lid flow path 222 and the connection portion J21 also functions as the sixth salt water line L46.
The soft water strainer 33 captures contaminants (crushed pieces of resin beads, dust, etc.) in the soft water W2 flowing through the soft water line L2 from the second lid flow path 222 toward the supply destination of the soft water W2.

  The dilution water line L3 is connected to the connection portion J11 of the raw water line L1 at its upstream end, and is connected to the primary side of the ejector 323 at its downstream end. In the dilution water line L3, an ejector strainer 321, a first constant flow valve 322, and an ejector 323 are provided in order from the upstream side (connection portion J11 side) to the downstream side (ejector 323 side).

The ejector strainer 321 removes suspended substances contained in the dilution water composed of the raw water W1, and prevents the first constant flow valve 322 and the ejector 323 from being clogged. The first constant flow valve 322 adjusts the dilution water supplied to the ejector 323 to a predetermined flow rate.
The ejector 323 is connected to the downstream end of the first salt water line L41 on the discharge side of the nozzle portion. The ejector 323 is configured to be capable of sucking salt water W4 (for example, a saturated aqueous solution of sodium chloride) from the salt water tank 4 using a negative pressure generated when dilution water (raw water W1) is discharged from the nozzle portion. ing. In the ejector 323, the salt water W4 from the salt water tank 4 is diluted to a predetermined concentration (for example, 8 to 12% by weight) with dilution water (raw water W1).

  The bypass line L6 connects the connection part J11 and the connection part J22. That is, the bypass line L6 connects the raw water line L1 and the soft water line L2.

The regenerating liquid supply line is a line connecting the pressure tank 2 and the salt water tank (regenerating liquid tank) 4. In the first embodiment, two regeneration liquid supply lines are formed.
The first regenerated liquid supply line includes a first salt water line L41, a second salt water line L42, a third salt water line L43, and a fifth salt water line L45 (part of the raw water line L1). The second regeneration liquid supply line is composed of a first salt water line L41, a second salt water line L42, a fourth salt water line L44, and a sixth salt water line L46 (a part of the soft water line L2).

  One end of the first salt water line L41 is disposed in the salt water tank 4. The other end portion of the first salt water line L41 is connected to the nozzle portion of the ejector 323. The first salt water line L41 is provided with a salt water flow meter 62 and a salt water valve 318 in order from the salt water tank 4 toward the ejector 323.

  The salt water flow meter 62 is provided outside the process control valve 3. The salt water flow meter 62 detects the flow rate of the salt water W4 flowing through the first salt water line L41 or the raw water W1 as makeup water. A detection signal from the salt water flow meter 62 is input to the control device 5. The salt water flow meter 62 is a flow sensor configured to be able to detect a bidirectional instantaneous flow rate and an integrated flow rate. For example, a tangential flow rate sensor, an axial flow rate sensor, a Karman vortex flow rate sensor, or the like can be used. it can.

  The upstream end portion of the third salt water line L43 and the upstream end portion of the fourth salt water line L44 are connected at the connection portion J41. The second salt water line L42 connects the secondary side of the ejector 323 and the connection portion J41.

The downstream end of the third salt water line L43 is connected to the fifth salt water line L45 (raw water line L1) at the connection portion J12. A first orifice 324 is provided in the middle of the third salt water line L43.
The downstream end of the fourth salt water line L44 is connected to the sixth salt water line L46 (soft water line L2) at the connection portion J21. The fourth salt water line L44 is provided with a second orifice 325 and an ejector valve 314 in order from the upstream side to the downstream side.
In the second regeneration process ST6 and the second extrusion process ST7, which will be described later, the first orifice 324 and the second orifice 325 are used to supply the salt water W4 that is the regeneration solution or the raw water W1 that is the extrusion water to the second lid channel 222 and the first lid. This is for evenly distributing the flow paths 221.

  Various drainage water W5 is discharged from the downstream end of the first drainage line L51. The upstream end of the first drain line L51 is connected to the downstream end of the second drain line L52 and the downstream end of the fifth drain line L55 at the connection J51. The upstream end of the second drain line L52 is connected to the downstream end of the third drain line L53 and the downstream end of the fourth drain line L54 at the connection J52. The upstream end of the third drainage line L53 is connected to the fourth saltwater line L44 at the connection J42. The upstream end of the fourth drainage line L54 is connected to the raw water line L1 (fifth brine line L45) at the connection J13. The upstream end of the fifth drain line L55 is connected to the third lid channel 223.

A second constant flow valve 34 is provided in the middle of the second drainage line L52. The second constant flow valve 34 adjusts the flow rate of the drainage W5 discharged from the pressure tank 2 and flowing through the second drainage line L52 to a predetermined range.
A first drain valve 317 is provided in the middle of the third drain line L53. A third drain valve 315 is provided in the middle of the fourth drain line L54. A second drain valve 316 is provided in the middle of the fifth drain line L55.

  In the process control valve 3, the various valves 311 to 318 can employ various operating mechanisms and valve structures. Specifically, a lift type or diaphragm type channel opening / closing valve operated by a cam mechanism, a slide piston type channel opening / closing valve operated by a link mechanism, and the like are suitable.

  Next, the salt water tank 4 will be described. The salt water tank 4 includes a salt water tank body 41, a salt water well 42, and a salt water plate 44. The salt water tank main body 41 has a bottomed shape with an open top. The salt water well 42 has a cylindrical shape and is disposed inside the salt water tank main body 41. The salt water plate 44 divides the salt water storage part (lower part) and the storage part (upper part) of the regenerated salt 43 (for example, granular or pellet sodium chloride) into the upper and lower sides outside the salt water well 42. It consists of a plate.

  A salt water line arrangement space 46 is formed inside the salt water tank body 41 and inside the salt water well 42. In the salt water line arrangement space 46, an upstream end of the first salt water line L41 is arranged. A communication hole 45 is provided in the lower side wall of the salt water well 42. The communication hole 45 communicates between the salt water reservoir and the salt water line arrangement space 46. Therefore, the salt water W4 or makeup water can freely flow between the salt water storage section and the salt water line arrangement space 46.

  Next, the operation mode of the water softening device 1 and the process executed in the operation mode will be described with reference to FIGS. FIG. 2 is a state transition diagram showing operation modes of the water softening device 1 and processes in each operation mode. FIG. 3 is a diagram showing an open / close state of the process control valve 3 in each process.

The water softening device 1 operates as a water treatment mode for producing soft water W2 as treated water by introducing raw water W1 into the pressure tank 2 as an operation mode, and by introducing salt water W4 as a regenerated liquid into the pressure tank 2. A regeneration mode for regenerating the ion exchange resin bed 211, a cleaning mode for cleaning the inside of the pressure tank 2 by introducing the raw water W1 as a cleaning liquid into the pressure tank 2, and a water replenishment mode for replenishing the salt water tank 4 with the raw water W1. And a standby mode in which no fluid is introduced into the pressure tank 2.
The flow of fluid in the processes executed between these operation modes and in the operation modes is controlled by the process control valve 3 as follows.

As shown in FIG. 2, the process control valve 3 switches each operation mode and switches the process in each of these operation modes.
Each operation mode is switched based on a predetermined transition condition (event). In FIG. 2, the arrow described between each operation mode shows the event E1-E8.
Event E1 shows a case where the water treatment mode is shifted to the regeneration mode. As the transition condition, for example, when the accumulated amount of water (accumulated usage) of the soft water W2 reaches a predetermined set amount Q1, or when the accumulated water passing time of the raw water W1 reaches a predetermined set time T1. be able to.
Event E2 indicates a case where the regeneration mode is shifted to the cleaning mode. As this transfer condition, the case where the back washing process ST3 to 2nd extrusion process ST7 is completed can be mentioned, for example.
Event E3 indicates a case where the mode is changed from the cleaning mode to the water replenishment mode. As the transition condition, for example, the operation mode immediately before the transition to the cleaning mode is the regeneration mode, and the cumulative circulation time of the cleaning liquid in the pressure tank 2 reaches a predetermined set time T2. it can.
Event E4 indicates a case where the water supply mode is shifted to the water treatment mode. As this transfer condition, for example, a case where the amount of water replenishment reaches a predetermined set amount Q2 can be cited.
Event E5 indicates a case where the water treatment mode is shifted to the cleaning mode. As this transition condition, the case where the residence time T of the water in the pressure tank 2 has reached the predetermined set time T3 can be mentioned, as will be described later.
Event E6 indicates a case where the cleaning mode is shifted to the water treatment mode. Examples of the transition condition include a case where the operation mode immediately before the transition to the cleaning mode is the water treatment mode, and the accumulated circulation time of the cleaning liquid in the pressure tank 2 has reached a predetermined set time T4. .
Event E7 shows a case where the cleaning mode is shifted to the standby mode. As this transfer condition, for example, a case where the continuous detection time without the flow of the raw water W1 in the raw water line L1 reaches a predetermined set time T5 can be mentioned.
Event E8 indicates a case of transition from the standby mode to the cleaning mode. As this transition condition, for example, a case where the continuous detection time with the circulation of the raw water W1 in the raw water line L1 reaches a predetermined set time T6 can be mentioned.

The process control valve 3 performs the following processes ST1 to ST10 in each operation mode while switching the flow path.
(ST1) Water treatment process (water softening process) for passing raw water W1 from the top to the bottom with respect to the entire ion exchange resin bed 211
(ST2) Strainer cleaning process for backwashing the soft water strainer 33 (ST3) Backwashing process for passing raw water W1 as cleaning water from the bottom to the top with respect to the entire ion exchange resin bed 211 (ST4) Salt water as a regenerating solution First regeneration process for passing W4 from the top to the bottom with respect to the entire ion-exchange resin bed 211 (ST5) First to pass the raw water W1 as the extrusion water from the top to the bottom with respect to the entire ion-exchange resin bed 211 Extrusion process (ST6) Second regeneration process in which salt water W4 as a regeneration solution is passed from the top to the bottom of the ion exchange resin bed 211 and from the bottom to the bottom of the ion exchange resin bed 211 (ST7) The raw water W1 as the extrusion water is passed from the top to the bottom with respect to the upper part of the ion exchange resin bed 211, and the ion exchange resin bed 21 is passed. The raw water W1 as a cleaning liquid (rinsing water) that passes from the bottom to the top of the bottom of the raw water W1 is passed from the top to the bottom with respect to the entire ion exchange resin bed 211, and the inside of the pressure tank 2 Cleaning process (rinsing process or accumulated water discharge process) for cleaning (ion exchange resin bed 211)
(ST9) Replenishment process for supplying raw water W1 to the salt water tank 4 (ST10) Standby process for waiting for supply of cleaning liquid

The opening and closing of the valves 311 to 318 in the process control valve 3 is controlled by the control device 5 for each of the processes ST1 to ST10 as shown in FIG. As a result, in the pressure tank 2, a fluid flow is generated for each of the processes ST1 to ST10, or no fluid flow is generated.
In the regeneration mode, a strainer cleaning process ST2 for back cleaning the soft water strainer 33 is provided before the reverse cleaning process ST3. This strainer cleaning process ST2 is not shown in FIG. 2 but is shown only in FIG. 3 for convenience of explanation. Further, a regeneration standby process (not shown) for waiting for the supply of the salt water W4 is provided between the strainer cleaning process ST2 and the back cleaning process ST3.

Next, main control (operation) of the water softening device 1 according to the present embodiment will be described in detail. Hereinafter, in the present specification, discharging the liquid (residual water) inside the pressure tank 2 to the outside of the system under a predetermined condition is also referred to as “performing stagnant water discharge” as appropriate.
In each process ST2 to ST10 excluding the water treatment process ST1, the bypass valve 313 is open. Therefore, the excess raw water W1 that circulates upstream from the connection portion J11 in the raw water line L1 flows from the connection portion J12 to the bypass line L6, and to the demand point of the soft water W2 via the connection portion J22 and the soft water line L2. Temporarily supplied.

[Water treatment process ST1]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / close state indicated by ST1 in FIG. As a result, raw water W1 such as tap water, groundwater, and industrial water flowing through the raw water line L1 is supplied to the inside of the pressure tank main body 21 via the raw water line L1 and the first lid channel 221 and distributed from the top screen 241. Is done. The raw water W1 distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow. In the process, the hardness component of the raw water W1 is replaced with sodium ions, and the raw water W1 is softened.

  The treated water (soft water W <b> 2) that has passed through the ion exchange resin bed 211 is collected on the bottom screen 242 at the bottom of the pressure tank 2. Thereafter, the soft water W2 is supplied to a predetermined demand point of the soft water W2 through the first collection and distribution pipe 231, the second lid flow path 222, and the soft water line L2. When a predetermined amount of soft water W2 is collected and the ion exchange resin bed 211 cannot replace the hardness component, a regeneration process is performed.

[Strainer cleaning process ST2]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / closed state indicated by ST2 in FIG. As a result, the raw water W1 flowing through the raw water line L1 is the raw water line L1, the connecting portion J11, the bypass line L6, the connecting portion J22, the soft water line L2, the soft water strainer 33, the connecting portion J21, the fourth salt water line L44, the connecting portion J42, It is discharged out of the system through the third drainage line L53, the second drainage line L52, and the first drainage line L51. In this process, the soft water strainer 33 is back-washed by the raw water W1 flowing through the soft water strainer 33 from the secondary side to the primary side, and contaminants captured by the soft water strainer 33 are discharged out of the system together with the raw water W1. .

[Regeneration process]
In the regeneration process, in order to recover the hardness component removal ability (ion exchange capacity) of the ion exchange resin bed 211, the reverse cleaning process ST3 to the water replenishment process ST9 are sequentially performed (see FIG. 2). Among these processes, the reverse cleaning process ST3, the water replenishment process ST9, and the standby process ST10 are well known as disclosed in Patent Documents 1 and 2, and the description thereof is omitted.

[Regeneration process: first regeneration process ST4]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / close state shown in ST4 of FIG. As a result, the raw water W1 flowing upstream from the connection portion J11 in the raw water line L1 is supplied to the primary side of the ejector 323 via the dilution water line L3 as the dilution water of the salt water W4.
At this time, the suspended substances in the raw water W1 are removed by the ejector strainer 321. The flow rate of the raw water W1 is adjusted to a predetermined range by the first constant flow valve 322.

In the ejector 323, a negative pressure is generated on the discharge side of the nozzle portion (reference number omitted) by the passage of the raw water W1, and the first salt water line L41 also has a negative pressure. As a result, the saturated salt water W4 in the salt water tank 4 is sucked into the ejector 323 via the first salt water line L41. In the ejector 323, the saturated salt water W4 is diluted to a predetermined concentration using the raw water W1 as dilution water, and salt water W4 as a regenerating solution is prepared.
The prepared salt water W4 passes through the second salt water line L42, the third salt water line L43, the fifth salt water line L45 (a part of the raw water line L1), and the first lid channel 221 to the inside of the pressure tank body 21. And water is distributed from the top screen 241.

  The salt water W4 distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow, and regenerates the entire ion exchange resin bed 211 in the process. The regenerated liquid (salt water W 4) that has passed through the ion exchange resin bed 211 is collected on the bottom screen 242 at the bottom of the pressure tank 2. The used salt water W4 includes the first collection and distribution pipe 231, the second lid flow path 222, the soft water line L2, the connection portion J21, the fourth salt water line L44, the connection portion J42, the third drainage line L53, and the second drainage line L52. And it is discharged out of the system via the first drainage line L51.

The first regeneration process ST4 is so-called cocurrent regeneration. In this co-current regeneration, when the supply capacity of the salt water W4, which is the regeneration liquid, reaches the set regenerant amount (= regeneration level × ion exchange resin bed capacity), the process ends and the process proceeds to the first extrusion process ST5. .
The amount of the regenerant, the concentration of the regenerated liquid, the specific gravity of the regenerated liquid, and the supply capacity of the regenerated liquid have the following relationship.
Regenerant amount = concentration of regenerated solution x specific gravity of regenerated solution x supply capacity of regenerated solution (1)

[Regeneration process: first extrusion process ST5]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / closed state indicated by ST5 in FIG. As a result, the raw water W1 flowing upstream from the connection portion J11 in the raw water line L1 is supplied to the primary side of the ejector 323 through the dilution water line L3 as the extruded water. The raw water W1 that has passed through the ejector 323 passes through the second salt water line L42, the third salt water line L43, the fifth salt water line L45 (a part of the raw water line L1), and the first lid channel 221, and the pressure tank body 21 , And water is distributed from the top screen 241.

  The raw water W1 as the extrusion water distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow while extruding the salt water W4 as the regeneration solution supplied in advance, and then continues to the ion exchange resin bed 211. Play. The regenerated liquid (salt water W4) and the extruded water (raw water W1) that have passed through the ion exchange resin bed 211 are collected on the bottom screen 242 at the bottom of the pressure tank 2. The used salt water W4 and raw water W1 are the first collection and distribution pipe 231, the second lid flow path 222, the soft water line L2, the connection portion J21, the fourth salt water line L44, the connection portion J42, the third drainage line L53, the second. It is discharged out of the system through the drainage line L52 and the first drainage line L51.

[Regeneration process: second regeneration process ST6]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / closed state indicated by ST6 in FIG. As a result, the raw water W1 flowing upstream from the connection portion J11 in the raw water line L1 is supplied to the primary side of the ejector 323 via the dilution water line L3 as the dilution water of the salt water W4.

  The salt water W4 prepared in the ejector 323 is supplied to the pressure tank main body via the second salt water line L42, the third salt water line L43, the fifth salt water line L45 (a part of the raw water line L1), and the first lid channel 221. 21 and supplied from the top screen 241.

  The salt water W4 distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow, and regenerates the upper part of the ion exchange resin bed 211 in the process. The regenerated liquid (salt water W4) that has passed through the upper part of the ion exchange resin bed 211 is collected on the intermediate screen 243 at the intermediate part in the depth direction of the pressure tank 2. The used salt water W4 is discharged out of the system through the second collection and distribution pipe 232, the third lid channel 223, the fifth drainage line L55, the connecting portion J55, and the first drainage line L51.

  Further, the salt water W4 prepared in the ejector 323 is diverted from the connection portion J41 of the second salt water line L42, and the fourth salt water line L44, the sixth salt water line L46 (part of the soft water line L2), and the second lid channel. The water is supplied to the inside of the pressure tank main body 21 through 222, and is distributed from the bottom screen 242 through the first liquid collection and distribution pipe 231.

  The salt water W4 distributed from the bottom screen 242 passes through the ion exchange resin bed 211 in an upward flow, and regenerates the lower part of the ion exchange resin bed 211 in the process. The regenerated liquid (salt water W4) that has passed through the lower part of the ion exchange resin bed 211 is collected on the intermediate screen 243 at the intermediate part in the depth direction of the pressure tank 2. The used salt water W4 is discharged out of the system through the second collection and distribution pipe 232, the third lid channel 223, the fifth drainage line L55, the connecting portion J55, and the first drainage line L51.

The second regeneration process ST6 is so-called split flow regeneration in which partial cocurrent regeneration and partial countercurrent regeneration are performed simultaneously. In the partial countercurrent regeneration, the lower part of the ion exchange resin bed 211 that is difficult to be regenerated in the first regeneration process ST4 is efficiently regenerated. In the second regeneration process ST6, the flow below the ion exchange resin bed 211 is suppressed by the downward flow of the salt water W4 as the regeneration liquid.
When the supply capacity of the salt water W4, which is the regenerating liquid, reaches the set amount of the regenerating agent, the process ends and the process proceeds to the second extrusion process ST7.
The relationship between the amount of the regenerant, the concentration of the regenerating solution, the specific gravity of the regenerating solution, and the supply capacity of the regenerating solution is as shown by the above-described equation (1).

[Regeneration process: second extrusion process ST7]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / closed state indicated by ST7 in FIG. As a result, the raw water W1 flowing upstream from the connection portion J11 in the raw water line L1 is supplied to the primary side of the ejector 323 through the dilution water line L3 as the extruded water.
The raw water W1 that has passed through the ejector 323 is supplied as extrusion water to the primary side of the ejector 323 via the dilution water line L3. The raw water W1 that has passed through the ejector 323 passes through the second salt water line L42, the third salt water line L43, the fifth salt water line L45 (a part of the raw water line L1), and the first lid channel 221, and the pressure tank body 21 , And water is distributed from the top screen 241.

  The raw water W1 as the extrusion water distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow while extruding the salt water W4 as the regeneration solution supplied in advance, and then continues to the ion exchange resin bed 211. Play the top of. The regenerated liquid (salt water W4) and the extruded water (raw water W1) that have passed through the upper portion of the ion exchange resin bed 211 are collected on the intermediate screen 243 at the intermediate portion in the depth direction of the pressure tank 2. The used salt water W4 and raw water W1 are discharged out of the system through the second collection and distribution pipe 232, the third lid channel 223, the fifth drain line L55, the connecting portion J55, and the first drain line L51.

  The raw water W1 that has passed through the ejector 323 is diverted from the connection portion J41 of the second salt water line L42, and the fourth salt water line L44, the sixth salt water line L46 (a part of the soft water line L2), and the second lid channel 222. Is supplied to the inside of the pressure tank main body 21, and is distributed from the bottom screen 242 through the first liquid collection and distribution pipe 231.

The raw water W1 as the extrusion water distributed from the bottom screen 242 passes through the ion exchange resin bed 211 in an upward flow while extruding the salt water W4 as the regeneration solution supplied in advance, and then continues to the ion exchange resin bed 211. Play the bottom of. The regenerated liquid (salt water W4) and the extruded water (raw water W1) that have passed through the lower part of the ion exchange resin bed 211 are collected on the intermediate screen 243 at the intermediate portion in the depth direction of the pressure tank 2. The used salt water W4 and raw water W1 are discharged out of the system through the second collection and distribution pipe 232, the third lid channel 223, the fifth drain line L55, the connecting portion J55, and the first drain line L51.
In the regeneration mode described above, the salt water W4 as the regeneration liquid and the raw water W1 as the extrusion water also function as a cleaning liquid for cleaning the inside of the pressure tank 2.

[Cleaning process ST8]
In response to a command signal from the control device 5, the valves 311 to 318 of the process control valve 3 are set to an open / close state indicated by ST8 in FIG. As a result, raw water W1 such as tap water, groundwater, and industrial water flowing through the raw water line L1 is supplied to the inside of the pressure tank main body 21 via the raw water line L1 and the first lid channel 221 and distributed from the top screen 241. Is done. The raw water W1 distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow, and cleans the ion exchange resin bed 211. That is, the raw water W1 functions as a cleaning liquid for cleaning the inside of the pressure tank 2 (ion exchange resin bed 211). The hardness component of the raw water W1 is replaced with sodium ions in the process in which the raw water W1 passes through the ion exchange resin bed 211, and the raw water W1 is softened.

  The treated water (soft water W <b> 2) that has passed through the ion exchange resin bed 211 is collected on the bottom screen 242 at the bottom of the pressure tank 2. Thereafter, the soft water W2 passes through the first collection and distribution pipe 231, the second lid channel 222, the sixth salt water line L46, the fourth salt water line L44, the third drain line L53, the second drain line L52, and the first drain line L51. Then, it is discharged out of the system as drainage W5.

  In this specification, when the operation mode immediately before the transition to the cleaning process ST8 is the regeneration mode, the cleaning process ST8 is referred to as a “rinse process”, and the operation mode immediately before the transition to the cleaning process ST8 is the water treatment. In the case of the mode or the standby mode, it will be referred to as “stagnant water discharge process”.

Next, with reference to FIG. 4, the function which concerns on control of the water softening apparatus 1 which concerns on this embodiment is demonstrated. FIG. 4 is a functional block diagram relating to the control of the water softening device 1.
The control device 5 controls each part in the water softening device 1. As shown in FIG. 4, the control device 5 is electrically connected to the process control valve 3. The control device 5 is electrically connected to the raw water flow switch 61 and the salt water flow meter 62 in the hard water softening device 1, and receives a flow detection signal from the raw water flow switch 61 and a flow signal from the salt water flow meter 62.

  The control device 5 includes a residence time calculation unit 51 as a residence time calculation unit, a residence time determination unit 52 as a residence time determination unit, a valve control unit 53 as a cleaning unit control unit, and a memory unit 54. Consists of.

  The residence time calculation unit 51 calculates (timekeeping) the residence time T of water inside the pressure tank 2 when the raw water flow switch 61 detects that the raw water W1 is not flowing in the water treatment mode. It is. Here, the water in the pressure tank 2 means the raw water W1 and the soft water W2 existing in the pressure tank 2.

  Further, the “residence time” of water means a time during which water stays in the pressure tank 2 without flowing. Specifically, the “residence time” of water refers to the time from when the raw water flow switch 61 detects the stop of the flow of the raw water W1 to when the raw water flow switch 61 detects the start of the flow of the raw water W1 again. This is because, in the water treatment mode, if the raw water W1 does not circulate in the raw water line L1, it can be considered that water is staying inside the pressure tank 2.

  In addition, when the raw water flow switch 61 detects that the raw water W1 is circulating, the residence time calculation unit 51 resets the measured water residence time T.

  The residence time determination unit 52 reads the predetermined set time T3 from the memory unit 54, and the residence time T calculated by the residence time calculation unit 51 has reached the predetermined set time T3 (see step ST14 in FIG. 5). Whether or not. The set time T3 is a threshold value of the residence time T, and is a time during which it is possible to prevent germs from breeding in the pressure tank 2 due to the residence of water, and to prevent odors and colors from attaching to the soft water W2. . That is, the set time T3 is set in consideration of the upper limit threshold of the residence time that can obtain the high-quality soft water W2, and is set to 6 to 24 hours, for example.

  The valve control unit 53 controls the valves 311 to 318 of the process control valve 3 so as to clean the inside of the pressure tank 2 based on the determination result by the residence time determination unit 52. A specific control method will be described later.

  The memory unit 54 stores a control program and various data necessary for controlling the water softening device 1. Specifically, the memory unit 54 includes a control program for operating various operation modes of the water softening device 1, various calculated values (for example, the residence time T calculated by the residence time calculating unit 51), and various set values (for example, The set time T3) is stored.

Next, control related to the accumulated water discharge of the hard water softening device 1 will be described with reference to FIG. FIG. 5 is a flowchart showing the control relating to the accumulated water discharge of the water softening device 1. This flowchart shows processing in the water treatment mode (execution of the water treatment process ST1) except for step ST15 described later.
As shown in FIG. 5, in step ST <b> 11, the residence time determination unit 52 reads a predetermined set time T <b> 3 from the memory unit 54.

  In step ST12, the residence time calculation unit 51 determines whether or not the raw water W1 is distributed in the raw water line L1 based on the distribution detection signal from the raw water flow switch 61. That is, the residence time calculation unit 51 determines whether or not water is used at the demand point. If it is determined that the raw water W1 is not distributed (YES) in the raw water line L1, it can be determined that the water starts to stay in the pressure tank 2, and thus the process proceeds to step ST13. On the other hand, when it is determined that the raw water W1 is in circulation (NO) in the raw water line L1, since it can be determined that water is circulating in the pressure tank 2, the process proceeds to step ST16 described later.

  In step ST13, the residence time calculation unit 51 calculates (measures) the residence time T of water inside the pressure tank 2, and proceeds to step ST14.

  In step ST14, the residence time determination unit 52 determines whether or not the residence time T of the water calculated by the residence time calculation unit 51 has reached the set time T3 read in step ST11. If the water retention time T has reached the set time T3 (YES), the soft water W2 is considered to be unable to maintain the predetermined water quality, so the process proceeds to step ST15 (event E5 in FIG. 2 occurs). On the other hand, if the water retention time T has not reached the set time T3 (NO), it is considered that the soft water W2 can maintain the predetermined water quality, and the process returns to step ST12. That is, until it is determined in step ST12 that raw water W1 is circulating in the raw water line L1 (NO), or until the water residence time T reaches the set time T3 in step ST14, the residence time calculation unit 51 is Continue to measure the water residence time T.

  Step ST15 is a process in the cleaning mode. In step ST15, the valve control unit 53 controls each of the valves 311 to 318 of the process control valve 3 (see the cleaning process ST8 in FIG. 3) so as to perform the stagnant water discharge process (clean the inside of the pressure tank 2). To do.

  Specifically, as shown in ST8 of FIG. 3, the process control valve 3 opens the raw water flow valve 311, the bypass valve 313, and the first drain valve 317, and the other valves 312, 314, 315, 316, 318 is closed. Thereby, the raw water W1 is supplied to the inside of the pressure tank main body 21 via the raw water line L1 and the first lid channel 221 and distributed from the top screen 241. The raw water W1 distributed from the top screen 241 passes through the ion exchange resin bed 211 in a downward flow, and cleans the ion exchange resin bed 211.

  The treated water (soft water W <b> 2) that has passed through the ion exchange resin bed 211 is collected on the bottom screen 242 at the bottom of the pressure tank 2. Thereafter, the soft water W2 passes through the first collection and distribution pipe 231, the second lid channel 222, the sixth salt water line L46, the fourth salt water line L44, the third drain line L53, the second drain line L52, and the first drain line L51. Then, it is discharged out of the system as drainage W5. That is, the interior of the pressure tank 2 is washed by replacing the accumulated water in the pressure tank 2 with the new soft water 2.

When the water softening device 1 is used for home use, the staying water discharge process is specifically performed as follows.
The valve control unit 53 sets the linear velocity of the raw water W1 (cleaning liquid) in the ion exchange resin bed 211 in the range of 5 to 60 m / h. The linear velocity of the cleaning liquid is set by adjusting the flow rate of the waste water W5 discharged from the pressure tank 2 to a predetermined range by the second constant flow valve 34 incorporated in the process control valve 3 as a cleaning means. As another configuration, for example, the linear velocity can be set to a desired range by using the first drain valve 317 as a proportional control valve and adjusting its opening degree. The linear velocity of the raw water W1 (cleaning liquid) is obtained by dividing the flow rate of the raw water W1 by the cross-sectional area of the ion exchange resin bed 211, and is expressed by the following equation.
Linear velocity [m / h] = flow rate [m ³ / h] ÷ cross-sectional area [m ² ] (2)

  Further, the valve control unit 53 sets the amount of the raw water W1 with respect to the ion exchange resin bed 211 to be large when the set time T3 is long, and to be set to be small when the set time T3 is short. For example, when the set time T3 is set to 6 to 24 hours, the valve control unit 53 sets the amount of raw water W1 (cleaning liquid) with respect to the ion exchange resin bed 211 in the range of 6 to 12 BV. Since the flow rate of the waste water W5 is defined by the second constant flow valve 34 or the like, the amount of the cleaning liquid is set by changing the execution time of the cleaning process ST8.

  Moreover, the raw | natural water W1 as a washing | cleaning liquid can use the water containing chlorine. In this case, the valve control unit 53 sets the execution time of the cleaning process ST8 by the process control valve 3 so that a chlorine amount of at least 0.5 mg Cl / LR is brought into contact with the unit resin amount of the ion exchange resin bed 211. Control. The chlorine may be residual chlorine originally contained in the raw water W1, or a chlorine agent such as sodium hypochlorite added separately to the raw water W1.

  In step ST15, when the accumulated water flow time based on the flow detection signal from the raw water flow switch 61 reaches a predetermined set time T4, the accumulated water discharge process is terminated, and the process proceeds to step ST16 (event E6 in FIG. 2 occurs). ).

  In step ST16, the residence time calculation unit 51 resets the measured residence time T of the water and ends the control.

According to the water softening device 1 of the present embodiment, for example, the following effects are exhibited.
The water softening device 1 of this embodiment includes a pressure tank 2, a process control valve 3 for cleaning the inside of the pressure tank 2 by introducing raw water W 1 into the pressure tank 2 and discharging it outside the system, A residence time calculation unit 51 that calculates a residence time T of the liquid located inside, a residence time determination unit 52 that determines whether or not the residence time T has reached a predetermined set time T3, and a residence time determination unit 52 A valve control unit 53 for controlling the process control valve 3 so as to clean the inside of the pressure tank 2 based on the determination result. The valve control unit 53 sets the linear velocity of the raw water W1 at the ion exchange resin bed 211 in a range of 5 to 60 m / h, and sets the amount of the raw water W1 with respect to the ion exchange resin bed 211 according to the set time T3. .

  Therefore, according to this embodiment, since the inside of the pressure tank 2 is washed with the raw water W1 set to a linear velocity within a predetermined range, the accumulated water can be efficiently discharged from the pressure tank 2 in a short time. Moreover, according to this embodiment, since the inside of the pressure tank 2 is cleaned with the amount of the cleaning liquid (raw water W1) corresponding to the residence time of water, high-quality treated water (soft water W2) without causing insufficient cleaning. Can be obtained constantly.

  Moreover, in the water softening apparatus 1 of this embodiment, when the setting time T3 which is a threshold value related to the residence time of water is set to 6 to 24 hours, the valve control unit 53 performs raw water for the ion exchange resin bed 211. The amount of W1 is set in the range of 6-12 BV. Therefore, according to the present embodiment, since the inside of the pressure tank 2 is cleaned with the minimum required amount of cleaning liquid (raw water W1) according to the residence time of water, the amount of cleaning liquid used can be saved without causing insufficient cleaning. be able to.

  Moreover, in the water softening apparatus 1 of this embodiment, the raw water W1 which distribute | circulates to the pressure tank 2 is the water containing chlorine, and the valve | bulb control part 53 is at least 0 with respect to the unit resin amount of the ion exchange resin bed 211. The process control valve 3 is controlled so that a chlorine amount of 5 mg Cl / LR comes into contact. Therefore, according to this embodiment, since the ion exchange resin bed 211 is sterilized with a sufficient amount of chlorine each time it is washed, propagation of germs can be effectively suppressed inside the pressure tank 2.

  Moreover, in the water softening apparatus 1 of this embodiment, the ion exchange resin bed 211 is formed from the cation exchange resin bead manufactured without using a halogen-type organic solvent. Therefore, according to the present embodiment, there is no possibility that the halogen-based organic solvent is leached into the soft water W2, and it is possible to constantly obtain treated water (soft water W2) that is safe for the human body.

As mentioned above, although preferred embodiment of this invention was described, this invention can be implemented with a various form, without being limited to embodiment mentioned above.
For example, in the above-described embodiment, the raw water W1 is used as the cleaning liquid for cleaning the inside of the pressure tank 2. However, the present invention is not limited to this, and the soft water W2 or a separately prepared cleaning chemical is used. Also good.

  In the above-described embodiment, the cleaning means for cleaning the inside of the pressure tank 2 includes various lines (raw water line L1, part of the soft water line L2, each drainage line L51, 52, 53, a part of the salt water line L44, etc.) and the process control valve 3 that opens and closes various lines, but is not limited thereto. The cleaning means may be a cleaning device that can supply a chemical solution for cleaning into the pressure tank 2.

  In the above-described embodiment, the water retention time T in the pressure tank 2 is calculated based on whether or not the raw water W1 is passed through the raw water flow switch 61. However, the present invention is not limited to this. . The method for calculating the residence time T of water is not limited as long as various germs propagate within the pressure tank 2 or the smell or color is prevented from attaching to the soft water W2. For example, the water residence time T may be calculated as the residence time of water existing for the longest time among the water existing in the pressure tank 2.

  In the above-described embodiment, the ion exchange device of the present invention is applied to the water softening device, but is not limited thereto. For example, if the ion exchange resin in the water softening device is replaced from a cation exchange resin to an anion exchange resin, it can be used as a nitrate nitrogen removal device.

1 Water softener (ion exchanger)
2 Pressure tank 3 Process control valve (cleaning means)
51 Residence time calculation part (Residence time calculation means)
52 Residence time determination section (Retention time determination means)
53 Valve control unit (cleaning means control means)
211 Ion exchange resin bed L1 Raw water line (cleaning means)
L44 4th salt water line (cleaning means)
L46 6th salt water line (cleaning means)
L51 1st drainage line (cleaning means)
L52 Second drainage line (cleaning means)
L53 3rd drainage line (cleaning means)
T Residence time T3 Set time W1 Raw water (cleaning solution)

Claims (4)

A pressure tank containing an ion exchange resin bed and into which liquid is introduced;
Cleaning means for cleaning the inside of the pressure tank by introducing a cleaning liquid into the pressure tank and discharging it outside the system;
A residence time calculating means for calculating the residence time of the liquid located inside the pressure tank;
A residence time determination means for determining whether or not the residence time calculated by the residence time calculation means has reached a predetermined set time;
Cleaning means control means for controlling the cleaning means to clean the inside of the pressure tank based on the determination result by the residence time determination means;
With
The cleaning means control means sets the linear velocity of the cleaning liquid in the ion exchange resin bed in a range of 5 to 60 m / h, and sets the amount of the cleaning liquid for the ion exchange resin bed according to the set time. Exchange equipment.   2. The ion exchange apparatus according to claim 1, wherein when the set time is set to 6 to 24 hours, the cleaning unit control unit sets the amount of cleaning liquid with respect to the ion exchange resin bed in a range of 6 to 12 BV. The cleaning liquid flowing through the pressure tank is water containing chlorine,
3. The ion exchange apparatus according to claim 2, wherein the cleaning means control means controls the cleaning means so that a chlorine amount of at least 0.5 mg Cl / LR is brought into contact with a unit resin amount of the ion exchange resin bed. .   The ion exchange apparatus according to any one of claims 1 to 3, wherein the ion exchange resin bed is formed from cation exchange resin beads produced without using a halogen-based organic solvent.

Images