JP4432122B1 - Method of operating water softening device and water softening device - Google Patents

Abstract

Even when poor raw water is used as extrusion water, high economic efficiency is achieved by securing treated water with a purity less than the allowable leak hardness and ensuring the same amount of water sampled as other water softening equipment To do. When performing a split flow regeneration process using raw water having a predetermined electrical conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mg CaCO ₃ / L, (a) a predetermined regeneration level R = 60 to 240 g / A regenerant passing mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution of LR is passed at a predetermined regenerant concentration C = 5 to 15 wt% and a predetermined regenerative linear velocity V1 = 0.7 to 2 m / s; and (b) a regenerant. Subsequent to the passing mode, raw water having a predetermined extrusion amount N = 0.4 to 2.5 BV is passed through the lower resin bed having a predetermined depth D2 of 150 to 750 mm at a predetermined extrusion linear velocity V2 = 0.7 to 2 m / s. At least a raw water extrusion mode.
[Industrial applicability]
[0113]
INDUSTRIAL APPLICABILITY The present invention can be widely used for water softening devices connected to equipment that requires low hardness water supply such as boiler devices and reverse osmosis membrane devices.
[Selection] Figure 1

Description

  The present invention relates to a method of operating a water softening device that performs split flow regeneration and a water softening device.

  Many common water softening devices employ co-current regeneration because of their simple structure. However, since co-current regeneration has a relatively high hardness leak level, scale failure is likely to occur in thermal equipment that uses treated water. For this reason, in order to obtain high-purity treated water, it is necessary to set the regeneration level (the amount of the regenerant used per liter of the ion exchange resin) high. On the other hand, in split flow regeneration, high-purity treated water can be obtained even if the regeneration level is set low, so that highly efficient regeneration can be achieved. Accordingly, when the regeneration level is set to the same level as that of the cocurrent regeneration, the hardness removal capacity is relatively increased, and thus there is a feature that the economical efficiency of the regenerant use amount is good.

  In split flow regeneration, the regeneration mode and the extrusion mode in the regeneration process are generally performed using treated water (softened water) as in Patent Document 1. However, when treated water is used, a treated water storage tank and a water pump are required, and the structure of a process control valve for switching the flow path of the water softening device becomes complicated. These problems can be solved by performing the regeneration mode and the extrusion mode using raw water as in Patent Document 2.

Prior art documents

JP-A-1-307457 JP 2007-260574 A

When the present inventors tried to perform the regeneration mode and the extrusion mode using raw water, it was found that other problems exist. The problem is that when the extrusion mode is performed with raw water, the hardness leak level in the water softening process is high and the purity of the treated water is lowered. This decrease in the purity of the treated water becomes remarkable when poor raw water (total hardness 200 to 300 mg CaCO ₃ / L or more) is used. For this reason, if the adjustment of the hardness leak level is mistaken, a serious scale failure may be caused in the boiler device or the reverse osmosis membrane device.

  Therefore, the present inventors conducted tests and studies on what factor the hardness leak level is related to and governed. As a result, the average leak hardness in the water softening process is as follows: bottom resin bed depth, regeneration level, extrusion linear velocity, extrusion amount (a number indicating how many times the amount of water is used for extruding the regenerant), total It has been found to be related to hardness and electrical conductivity.

And as a result of research based on this knowledge, even when poor raw water is used as extrusion water, the purity (average leak hardness is ₃ mgCaCO ₃ / L or less, preferably not causing scale obstacles to the boiler device or reverse osmosis membrane device) Is 1 mg CaCO ₃ / L or less, more preferably 0.1 mg CaCO ₃ / L or less), and by securing the same amount of water sampled as that of other water softening devices, it is highly economical. Has led to the completion of a split flow regeneration process.

  That is, the present invention ensures treated water having a purity equal to or lower than the allowable leak hardness even when inferior raw water is used as extrusion water, and ensures a water sampling amount equivalent to that of other water softening devices of the regeneration method. The purpose is to achieve high economic efficiency.

In the first invention for achieving the above object, the raw water having a predetermined electric conductivity K and a predetermined total hardness H is passed through a cation exchange resin bed having a predetermined total resin bed depth D1 in a descending flow, and treated water is passed through. And a split flow regeneration process in which a regenerant or raw water is collected from both sides of the upper and lower ends of the resin bed and collected at a substantially central portion of the resin bed, the regeneration process comprising: (a) A regenerant passing mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R is passed through the resin bed at a predetermined regenerant concentration C and a predetermined regeneration linear velocity V1, and (b) the lower resin following the regenerant pass mode. At least a raw water extrusion mode in which raw water of a predetermined extrusion amount N passes through the floor at a predetermined extrusion linear velocity V2, and (c) in a water softening process after a regeneration process at a predetermined water temperature. By utilizing the fact that the leakage hardness y of the treated water is related to the lower resin bed depth d2, the electrical conductivity k, the total hardness h, the regeneration level r, the extrusion linear velocity v2, and the extrusion amount n, the predetermined electrical conductivity K In addition, this is a water softening device operating method in which a predetermined extrusion linear velocity V2 and a predetermined extrusion amount N when raw water having a predetermined total hardness H is used are set by the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that is equal to or higher than the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set.

  According to the first invention, even when inferior raw water is used, treated water having a purity equal to or lower than the allowable leak hardness Y can be secured, and a water sampling amount equivalent to that of other water softening devices of the regeneration system can be secured. Thus, high economic efficiency can be realized.

  The second invention is a method for operating a water softening device, wherein the predetermined extrusion linear velocity V2 in step (3) is determined according to a correlation with a predetermined regeneration linear velocity V1.

  According to the second invention, in addition to the effect of the first invention, the predetermined extrusion linear velocity V2 can be automatically set by setting the predetermined regeneration linear velocity V1.

The third invention relates to the predetermined lower resin bed depth D2, the predetermined electrical conductivity K, the predetermined total hardness H, the predetermined regeneration level R, the predetermined regenerant concentration C, the desired hardness removal capacity X and the allowable leak hardness Y in step (1). Are the following ranges: D2 = 150 to 750 mm, K ≦ 1500 μS / cm, H ≦ 500 mg CaCO ₃ / L, R = 60 to 240 g / LR, C = 5 to 15 wt%, X = 30 to 60 g CaCO ₃ / L -R, set at Y ≦ 3mgCaCO ₃ / L, a method of operating water softener.

According to the third invention, in addition to the effects of the first and second inventions, when raw water having a predetermined electrical conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L is used, a desired hardness removal capacity X = 30 it can be set ~60gCaCO ₃ / L-R and allowable leak hardness Y ≦ 3mgCaCO ₃ / L purity of the treated water given extrusion line speed it is possible to generate the V2 and the predetermined extrusion rate N.

4th invention is the operating method of the water softening apparatus which sets predetermined regeneration linear velocity V1 and predetermined extrusion linear velocity V2 in step (2), (3) in the range of 0.7-2 m / s.

  According to the fourth invention, in addition to the effects of the first to third inventions, a stable regeneration operation can be realized by setting the predetermined regeneration linear velocity V1 and the predetermined extrusion linear velocity V2 to 0.7 m / s or more.

The fifth invention for achieving the above object is that, for a cation exchange resin bed having a predetermined total resin bed depth D1 = 300 to 1500 mm , a predetermined electric conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / A softening process in which the raw water of L is passed in a downward flow to obtain treated water, and a split flow in which the regenerant or raw water is distributed from both sides of the upper and lower ends of the resin bed and collected at approximately the center of the resin bed. The regeneration process includes (a) a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R = 60 to 240 g / LR with respect to the resin bed, and a predetermined regenerant concentration C = 5 to 15 wt%. a regenerant passage mode for passing a predetermined reproduction linear velocity V1 = 0.7~2m / s, (b ) Following the regenerant passage mode, a predetermined depth D2 = 0.2 to 0.8 × For one of the lower resin bed, including at least a raw water extrusion mode for passing a predetermined extrusion rate N = a predetermined extrusion line speed raw water 0.4~2.5BV V2 = 0.7~2m / s, water softener This is the driving method.

According to the fifth aspect of the present invention, when raw water having a predetermined electrical conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L is used, the same amount of water sample as that of other regeneration-type water softening devices is secured. As a result, it is possible to realize high economic efficiency and to generate treated water having a purity of allowable leak hardness Y ≦ ₃ mg CaCO ₃ / L. Further, by setting the predetermined regeneration linear velocity V1 and the predetermined extrusion linear velocity to 0.7 m / s or more, a stable regeneration operation can be realized.

The sixth invention for achieving the above object obtains treated water by passing raw water having a predetermined electric conductivity K and a predetermined total hardness H in a downward flow through a cation exchange resin bed having a predetermined total resin bed height D1. A controller that performs a water softening process and a split flow regeneration process that collects the regenerant or raw water from the both sides of the upper and lower ends of the resin bed and collects at a substantially central portion of the resin bed, In the regeneration process, (a) a regeneration agent passage mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R is passed through the resin bed at a predetermined regeneration agent concentration C and a predetermined regeneration linear velocity V1, and (b) a regeneration agent. Subsequent to the passing mode, at least a raw water extruding mode in which a predetermined amount of raw water N is passed through the lower resin bed at a predetermined extrusion linear velocity V2 is executed, and (c) regeneration at a predetermined water temperature. Using the fact that the leakage hardness y of the treated water in the water softening process after the process is related to the lower resin bed depth d2, the electrical conductivity k, the total hardness h, the regeneration level r, the extrusion linear velocity v2, and the extrusion amount n. , A water softening device in which a predetermined extrusion linear velocity V2 and a predetermined extrusion amount N when raw water having a predetermined electrical conductivity K and a predetermined total hardness H is set in advance by the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that sets the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set.

  According to the sixth aspect of the invention, even when poor raw water is used, treated water having a purity equal to or lower than the allowable leak hardness Y can be ensured, and the amount of water sampled equivalent to that of other water softening devices of the regeneration system can be ensured. Thus, high economic efficiency can be realized.

A seventh invention is the water softening device according to the sixth invention, wherein the predetermined extrusion linear velocity V2 in step (3) is determined according to a correlation with a predetermined regeneration linear velocity V1.

  According to the seventh invention, in addition to the effects of the sixth invention, the predetermined extrusion linear velocity V2 can be automatically set by setting the predetermined regeneration linear velocity V1.

In an eighth aspect based on the seventh aspect, the predetermined lower resin bed depth D2, the predetermined electrical conductivity K, the predetermined total hardness H, the predetermined regeneration level R, the predetermined regenerant concentration C, the desired hardness removal capacity X in step (1). The allowable leak hardness Y is in the following ranges: D2 = 150 to 750 mm, K ≦ 1500 μS / cm, H ≦ 500 mg CaCO ₃ / L, R = 60 to 240 g / LR, C = 5 to 15 wt%, X = 30 ~60gCaCO ₃ / L-R, is set in Y ≦ 3mgCaCO ₃ / L, a water softener.

According to the eighth invention, in addition to the effects of the sixth and seventh inventions, when raw water having a predetermined electrical conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L is used, a desired hardness removal capacity X = 30 it can be set ~60gCaCO ₃ / L-R and allowable leak hardness Y ≦ 3mgCaCO ₃ / L purity of the treated water given extrusion line speed it is possible to generate the V2 and the predetermined extrusion rate N.

The ninth aspect of the invention for achieving the above object is that, for a cation exchange resin bed having a predetermined total resin bed depth D1 = 300 to 1500 mm , a predetermined electric conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / A softening process in which raw water of L is passed in a downward flow to obtain treated water, and a split that collects regenerant or raw water from both sides of the upper and lower ends of the resin bed and collects at approximately the center of the resin bed A controller for performing a flow regeneration process is provided, and the controller, in the regeneration process, (a) predeterminedly supplies a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R = 60 to 240 g / LR to the resin bed. A regenerant passing mode in which the regenerant concentration is C = 5 to 15 wt% and a predetermined regenerating linear velocity V1 is 0.7 to 2 m / s; and (b) following the regenerant passing mode, Lower resin bed depth D2 = 0.2 to 0.8 × D1 to pass the raw water having a predetermined extrusion amount N = 0.4~2.5BV at a predetermined extrusion linear speed V2 = 0.7~2m / s A water softening device that executes at least the raw water extrusion mode.

According to the ninth invention, when raw water having a predetermined electric conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L is used, a water sampling amount equivalent to that of other water softening devices of other regeneration methods is secured. As a result, it is possible to realize high economic efficiency and to generate treated water having a purity of allowable leak hardness Y ≦ ₃ mg CaCO ₃ / L. Further, by setting the predetermined regeneration linear velocity V1 and the predetermined extrusion linear velocity to 0.7 m / s or more, a stable regeneration operation can be realized.

  According to the present invention, even when inferior raw water is used, it is possible to ensure treated water having a purity equal to or lower than the allowable leak hardness, and to secure a water collection amount equivalent to that of other water softening devices of a regenerating system, thereby achieving high economic efficiency. Can be realized.

The process flow and conditions of the water softener are shown. The relationship between the extrusion linear velocity v2 and the extrusion amount n in the allowable leak hardness Y is shown. The relationship between the reproduction linear velocity v1 and the hardness removal capacity x is shown. An appropriate range of the regeneration linear velocity v1 and the extrusion amount n is shown. The whole structure of a water softening device is shown. The flow of the water softening process is shown. The flow of regenerant passage mode is shown. The flow of raw water extrusion mode is shown. The change in the leak hardness y and the hardness removal capacity x when the predetermined regeneration linear velocity V1 is changed under the condition of the predetermined extrusion amount N = 2.5 BV is shown. The changes in the leak hardness y and the hardness removal capacity x when the predetermined regeneration linear velocity V1 is changed under the condition of the predetermined extrusion amount N = 2.25 BV are shown. The change in the leakage hardness y and the hardness removal capacity x when the predetermined regeneration linear velocity V1 is changed under the condition of the predetermined extrusion amount N = 1.5 BV is shown. The change in the leak hardness y and the hardness removal capacity x when the predetermined regeneration linear velocity V1 is changed under the condition of the predetermined extrusion amount N = 0.4 BV is shown. The structure of the boiler system using a water softening device is shown. The structure of the reverse osmosis membrane system using a water softening apparatus is shown.

Explanation of symbols

1 Water softening device 1C Controller 5 Cation exchange resin bed 5A Lower resin bed c Regenerant concentration C Predetermined regenerant concentration d1 Total resin bed depth D1 Predetermined total resin bed depth d2 Lower resin bed depth D2 Predetermined lower resin bed Depth h Total hardness H Predetermined total hardness k Electrical conductivity K Predetermined electrical conductivity n Extrusion amount N Predetermined extrusion amount r Regeneration level R Predetermined regeneration level v1 Regeneration linear velocity V1 Predetermined regeneration linear velocity v2 Extrusion linear velocity V2 Predetermined extrusion linear velocity x Hardness removal capacity X Desired hardness removal capacity y Leak hardness Y Allowable leak hardness

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment of operation method of water softening device)
In the operation method of the water softening device according to the present embodiment, the raw water having a predetermined electrical conductivity K and a predetermined total hardness H is passed through the cation exchange resin bed having the predetermined total resin bed depth D1 in a descending flow. A water softening process for obtaining water, and a split flow regeneration process in which a regenerant or raw water is collected from both sides of the upper and lower ends of the resin bed and collected at a substantially central portion of the resin bed. The predetermined electrical conductivity K corresponds to the amount of dissolved ions in the raw water, and can be replaced with the soluble evaporation residue TDS. In the case of tap water or industrial water, the relationship is generally TDS [mg / L] ≈0.5 to 0.7 × K [μS / cm].

The regeneration process includes at least the following modes (a) and (b).
(A) A regenerant passing mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R is passed through the resin bed at a predetermined regenerant concentration C and a predetermined regeneration linear velocity V1.
(B) A mode in which the raw water is passed through the lower resin bed and the upper resin bed following the regenerant passing mode, and the lower resin bed has a predetermined extrusion amount N (what is the resin amount for extruding the regenerant)? A raw water extrusion mode in which raw water) is passed at a predetermined extrusion linear velocity V2.

  As shown in FIG. 1, in the water softening process, raw water is passed through the resin bed in a downward flow. A solid line arrow S11 indicates raw water, and a one-dot chain line arrow S12 indicates that ion exchange is performed in the middle and finally flows out as treated water. In the regenerant passing mode, as indicated by broken line arrows S21 and S22, the regenerant is distributed from both sides of the upper end and the lower end of the resin bed while being collected by the collector located at the approximate center of the resin bed, and then the broken line As shown by arrow S23, it shows flowing out of the resin bed. In the raw water extrusion mode, as indicated by solid line arrows S31 and S32, raw water is distributed from both sides of the upper and lower ends of the resin bed, and collected by a collector located at substantially the center of the resin bed while extruding the regenerant. After that, as shown by a solid line arrow S33, it indicates that the resin flows out of the resin bed.

  In the raw water extrusion mode, if the amount of raw water extruded to the resin bed (lower resin bed) located below the collector is excessive, ion exchange is performed near the lower end of the lower resin bed, and the hardness component contained in the raw water Adsorption of (Ca ions and Mg ions) occurs. Then, in the water softening process, the hardness component in which Na ions and K ions released into water by ion exchange with the hardness component are adsorbed in the vicinity of the lower end is desorbed, and the hardness leak level of the treated water is increased. On the other hand, in the resin bed (upper resin bed) located above the collector, adsorption of the same hardness component occurs in the vicinity of the upper end portion, and the desorption of the hardness component occurs in the softening process. . However, most of the resin floor other than the vicinity of both ends is sufficiently regenerated and is not contaminated by hardness components. For this reason, since the desorbed hardness component is removed again at the intermediate portion of the resin bed, there is no problem that the hardness component leaks from the resin bed. For this reason, in the raw water extrusion mode, it is necessary to adjust the extrusion amount of raw water to the lower resin bed, that is, the predetermined extrusion amount N, in order to reduce the hardness leak level in the water softening process.

Further, the reproduction process includes the following setting method (C). In this setting method (C), a desired hardness removal capacity X is ensured as the hardness removal capacity x, and the average leakage hardness y of treated water (hereinafter simply referred to as “leak hardness y”) is equal to or less than the allowable leakage hardness Y. In this method, the extrusion linear velocity v2 and the extrusion amount n are set or adjusted to the predetermined extrusion linear velocity V2 and the predetermined extrusion amount N. The leak hardness y is defined as the average value of the leak hardness of the treated water collected from immediately after the start of the water softening process to the through point (for example, 1 mg CaCO ₃ / L). The allowable leak hardness Y is the hardness of water that is allowed at the treated water supply destination. When the supply destination of the treated water is a boiler device or a reverse osmosis membrane device, the allowable leak hardness Y is determined based on the concentration rate in the device and the solubility of scale species such as calcium carbonate.

  The predetermined extrusion linear velocity V2 and the predetermined extrusion amount N are set in such a manner that the leakage hardness y of the treated water in the water softening process performed after the regeneration process is lower resin bed depth d2, electrical conductivity k, total hardness h, regeneration level. It was created based on the new knowledge that it is related to and controlled by parameters including r, extrusion linear velocity v2 and extrusion amount n. And this new knowledge is represented by the following formula 1 which shows the relation between leak hardness y and each above-mentioned parameter.

The unit of each parameter in Equation 1 is as follows.
d2: Lower resin floor depth [mm]
k: Electric conductivity of raw water [μS / cm]
h: Total hardness of raw water [mgCaCO ₃ / L]
r: regeneration level [g / LR (g · NaCl / LR or g · KCl / LR)]
v2: extrusion linear velocity [m / s]
n: Extrusion amount [BV (Bed Volume)]

Further, α, β, γ, and δ are constants, and their values vary depending on the structure of the water softening device, but are set in the following ranges.
α = 0.5-2 × 10 ⁻¹⁰
β = 1-3
γ = 0.1 to 0.5
δ = 0.1-0.5

  Formula 1 is obtained by the present inventors by performing various experiments and approximating experimental results under the condition that the raw water temperature is constant. The approximate expression is not limited to Expression 1 as long as it includes the above-described parameters.

As shown in Equation 1, the leakage hardness y of the treated water can be made equal to or less than the allowable leakage hardness Y by adjusting the value of each parameter on the right side. Incidentally, the allowable leak hardness Y of the boiler device is ₃ mgCaCO ₃ / L or less, preferably 1 mgCaCO ₃ / L or less. In particular, in a once-through boiler of the type in which a water tube group is disposed in the combustion reaction section, the amount is preferably 0.1 mgCaCO ₃ / L or less. Further, the allowable leak hardness Y of the reverse osmosis membrane device is ₃ mgCaCO ₃ / L or less, preferably 1 mgCaCO ₃ / L or less.

  Further, when adjusting the leakage hardness y of the treated water to the allowable leakage hardness Y or less using Equation 1, among the parameters, the lower resin bed depth d2, the electrical conductivity k, the total hardness h, and the predetermined regeneration level r are set. On the other hand, the following condition values are given from the viewpoint of designing a practical water softening device.

  The predetermined lower resin bed depth D2 given to the lower resin bed depth d2 is D2≈0.2 to 0.8 × D1 in relation to the predetermined total resin bed depth D1. The reason is as follows. When the upper resin floor depth (depth from the upper end of the resin floor to the collector) and the lower resin floor depth (depth from the collector to the lower end of the resin floor) are greatly different, various problems arise. First, when the difference between the ratio of the upper resin bed depth and the ratio of the lower resin bed depth is extremely large, if the regenerant is distributed almost evenly, the substantial regeneration level of the upper resin bed and the lower resin bed The difference of r becomes extremely large. That is, the regeneration level r on the side where the floor depth is shallow (the side where the amount of resin is small) is excessively higher than the regeneration level r on the side where the floor depth is deep (the side where the amount of resin is large). For this reason, the regeneration efficiency on the side where the floor depth is deep is lowered, and as a result, the regeneration efficiency of the entire resin bed is also lowered. Second, when the difference between the ratio of the upper resin bed depth and the ratio of the lower resin bed depth is extremely large, when the regenerant is distributed according to the ratio of the bed depth, the side with the shallow bed depth (resin The reproduction linear velocity v1 on the side where the amount is small is extremely smaller than the reproduction linear velocity v1 on the side where the bed depth is deep (the side where the amount of resin is large). As will be described later, if the reproduction linear velocity v1 on the side where the floor depth is shallower than the lower limit value of the reproduction linear velocity v1, the reproduction may be insufficient. For this reason, the regeneration efficiency on the side where the floor depth is shallow is lowered, and consequently the regeneration efficiency of the entire resin bed is also lowered. Third, if the ratio of the upper resin bed to the entire resin bed is small, the resin flow restraining force during regeneration is reduced, which may cause regeneration failure. Therefore, a ratio of 1: 1 between the upper resin bed depth and the lower resin bed depth is most suitable from the viewpoint of stability and economy of regeneration. However, since it is acceptable even if the balance is somewhat bad, the ratio of the predetermined lower resin bed depth D2 to the predetermined total resin bed depth D1 is set in the range of 0.2 to 0.8.

  On the other hand, the predetermined total resin bed depth D1 defines a lower limit and an upper limit for the following reason. First, the lower limit will be described. When the predetermined total resin bed depth D1 is extremely low, a regenerant drift and a short pass are likely to occur, resulting in a decrease in regeneration efficiency. Further, the formation of an ion exchange zone shortens the layer length that can be effectively used, and the ion exchange capacity (through-flow exchange capacity) decreases. Therefore, in the design of a water softening device in which the amount of cation exchange resin exceeds 20 L, a bed depth of 800 mm or more is usually recommended. However, in particular, in the case of a small-capacity water softening device, it is practical if a floor depth of 300 mm or more is secured. For this reason, the lower limit is 300 mm. Next, the upper limit will be described. Essentially, no upper limit is needed. However, a water softening device having a floor depth of 1500 mm or more is unlikely to be manufactured due to transportation reasons and vessel manufacturing reasons for accommodating a cation exchange resin. Therefore, the upper limit is 1500 mm. For the above reasons, the predetermined total resin bed depth D1 is set in the range of 300 to 1500 mm. The predetermined lower resin bed depth is set in a range of 150 to 750 mm by setting D2≈0.5 × D1.

The predetermined electric conductivity K given to the electric conductivity k is 1500 μS / cm or less, and the predetermined total hardness H given to the total hardness h is 500 mgCaCO ₃ / L or less. The water softening device according to the present embodiment is intended to be used particularly in the Chinese continent and the North American continent. In these continents, most of the natural water used for boiler feed water and the like has an electric conductivity of 1500 μS / cm or less and a total hardness of 500 mg CaCO ₃ / L or less.

  The predetermined reproduction level R given to the reproduction level r is 60 to 240 g / LR. When the playback level is extremely high, the playback efficiency decreases. That is, it is uneconomical. Conversely, when the playback level is extremely low, the playback frequency increases. Along with this, the time during which treated water cannot be supplied increases, and the amount of water used for regeneration increases, so the total running cost deteriorates. Therefore, the predetermined reproduction level R is set to the above range as a common sense range.

  Therefore, the parameters for adjusting the leakage hardness y are substantially given by giving predetermined values D2, K, H and R to the lower resin bed depth d2, the electrical conductivity k, the total hardness h and the regeneration level r. It is summarized in the extrusion amount n and the extrusion linear velocity v2. Of course, in setting parameters other than the extrusion amount n and the extrusion linear velocity v2, these parameters can be set to values that reduce the leak hardness y.

  As is clear from Equation 1, in order to reduce the leak hardness y, the extrusion linear velocity v2 in the raw water extrusion mode may be increased. This means that if the passing speed of the raw water is increased, the amount of adsorption of the hardness component in the lower resin bed is reduced. Further, Equation 1 means that the leakage hardness y is reduced by reducing the extrusion amount n. The degree of decrease in the leak hardness y with respect to the increase in the extrusion linear velocity v2 or the decrease in the extrusion amount n indicates that the decrease in the extrusion amount n has a larger influence than the increase in the extrusion linear velocity v2. In short, in Equation 1, the extrusion amount n that achieves an allowable leak hardness Y or less such as boiler feed water can be expressed as the following Equations 2 and 3 using the extrusion linear velocity v2 as a parameter.

  Expression 2 is represented by a line Q1 in FIG. 2 when Y = 1. The leak hardness y exceeds the allowable leak hardness Y in the region above the line Q1, and is less than the allowable leak hardness Y in the region below.

  As is apparent from Equation 2, when the extrusion linear velocity v2 is set, the extrusion amount n that realizes the allowable leak hardness Y or less can be obtained. On the contrary, if the extrusion amount n is set, the extrusion linear velocity v2 that realizes the allowable leak hardness Y or less can be obtained. As described above, the extrusion linear velocity v2 can decrease the leak hardness y as the value thereof is increased, but generally has a constraint condition. The restriction condition is that the extrusion linear velocity v2 and the regeneration linear velocity v1 depend on the raw water pressure and the structure of the water softening device, and have a correlation unless individually equipped with a flow rate adjusting means. is there. In the present embodiment, the present invention is not limited to the case where both have a correlation, but when they have a correlation, they can be handled as follows.

  In Equation 2, if the extrusion linear velocity v2 and the regeneration linear velocity v1 have a correlation, and the extrusion linear velocity v2 can be approximated by the regeneration linear velocity v1, the extrusion amount n is an equation 4 with the regeneration linear velocity v1 as a variable. It is expressed by When the extrusion linear velocity v2 is not approximated by the reproduction linear velocity v1, the relational expression corresponding to Expression 4 can be obtained by substituting the relational expression between v2 and v1 into Expression 2.

By the way, as described above, since the expression representing the leak hardness y is not limited to Expression 1, Expression 2 and Expression 4 are not limited to this. Therefore, when Formula 2 and Formula 4 are generalized, they can be expressed as the following Formula 5, Formula 6, and Formula 7, respectively.

In Equation 5, f ₁ (n) is a function of the extrusion amount n, and the value increases as n increases. When this function is approximated by Equation 1, f ₁ (n) = n. F ₂ (v2) is a function of the extrusion linear velocity v2, and increases as v2 decreases. When this function is approximated by Equation 1, f ₂ (v2) = exp (−δ × v2). Further, a ₂ is a coefficient that varies depending on the lower resin bed depth d1, the raw water conductivity e, the total hardness h, and the regeneration level r, and when approximated by Equation 1, a ₂ = 1 / a ₁ .

In Equation 6, f ₃ (v2) is a function of the extrusion linear velocity v2, and the value increases as v2 increases. When this function is approximated by Equation 2, f ₃ (v2) = 1 / exp (−δ × v2). Further, a ₃ is a coefficient that varies depending on the allowable leak hardness Y. When approximated by Equation 2, a ₃ = Y × a ₁ .

In Expression 7, f ₄ (v1) is a function of the reproduction linear velocity v1, and the value increases as v1 increases. Further, a ₄ is a coefficient that varies depending on the allowable leak hardness Y. When approximated by Equation 4, f ₄ (v1) = f ₃ (v2); a ₄ = a ₃ .

  The reproduction linear velocity v1 is a main dominant factor that determines the hardness removal capacity x together with the reproduction level r. The hardness removal capacity x of the water softening device has substantially the same meaning as the ion exchange capacity. A method for calculating the hardness removal capacity of the water softening device has been proposed for a long time, and the following equation 8 is shown as an example.

In Equation 8, x1 is a basic hardness removal capacity and is represented by a function depending on the reproduction level r. This x1 is slightly different depending on the type of cation exchange resin. Further, g ₁ to g ₈ is a factor to increase or decrease the x1 in accordance with the conditions of the water softener. Factors g _{1 to} g ₈ are respectively the raw water electrical conductivity k, the raw water temperature t, the ratio s of sodium ions to the total cations, the ratio b of the pour point hardness to the raw water hardness, the water flow velocity w, the total resin bed Normally, it is set to about 1 (substantially in the range of about 0.5 to 1.5) according to changes in the depth d1, the regeneration linear velocity v1 and the regeneration agent concentration c. The regenerant concentration c is set in the range of 5 to 15 wt% in the case of a standard water softening device. Furthermore, the method for obtaining the hardness removal capacity x is not limited to the above equation 8, but can be generalized to the following equation 9.

In Equation 9, f ₅ (v1) is a function of the reproduction linear velocity v1, and the value increases as v1 increases. Further, a ₅ are coefficients that change depending on the conditions of the water softener.

In other words, the hardness removal capacity x expressed by the equations 8 and 9 is the amount of treated water collected. As indicated by the line Q2 in FIG. 3, the hardness removal capacity x has a characteristic that increases as the reproduction linear velocity v1 decreases. In the present embodiment, the desired hardness removal capacity X is set in a range of _{30 to} 60 g CaCO ₃ / LR from the viewpoint of ensuring the same economic efficiency as that of the water-flow softening device of the cocurrent regeneration method. This desired hardness removal capacity X corresponds to the case where the desired regeneration level R is 60 to 240 g / LR.

As is clear from Equations 8 and 9, the reproduction linear velocity v1 is determined by the hardness removal capacity x. That is, given the desired hardness removal capacity X, the predetermined reproduction linear velocity V1 is determined. However, the upper and lower limits are determined for the following reasons. First, the upper limit will be described. Split flow regeneration tends to shorten the contact time between the cation exchange resin bed and the regenerant compared to cocurrent regeneration. For this reason, it is necessary to suppress the upper limit of the reproduction linear velocity and to promote the reproduction by extending the contact time. Therefore, the predetermined regeneration linear velocity V1 is preferably set to 2 m / s or less in order to secure 43 g CaCO ₃ / LR as the desired hardness removal capacity X equivalent to the cocurrent regeneration. This upper limit is represented by the line Q3 in FIGS. 3 and 4, and the region on the left side of the line Q3 indicates the range of the reproduction linear velocity v1 in which the hardness removal capacity x exceeds the desired hardness removal capacity X. Conversely, the region on the right side of the line Q3 indicates the range of the reproduction linear velocity v1 in which the hardness removal capacity x is less than the desired hardness removal capacity X. Next, the lower limit will be described. According to the knowledge of the present inventors, when the regeneration linear velocity v1 is less than 0.7 m / s, the regenerant drift and short path are likely to occur in the resin bed. This lower limit is represented by a line Q4 in FIG. 4, and in the region on the left side of the line Q4, regeneration is likely to be insufficient, and the resin bed may break through in a short time. Therefore, the predetermined reproduction linear velocity V1 is not more than the upper limit (the region on the left side of the line Q3 in FIG. 4), and preferably in the range of 0.7 to 2 m / s (between the line Q3 and the line Q4 in FIG. 4). Area).

  Next, when a condition of a predetermined regeneration linear velocity V1 = 0.7 to 2 m / s is given to the regeneration linear velocity v1, an upper limit of the predetermined extrusion amount N that realizes the allowable leak hardness Y or less is obtained by Equation 4. Can do. Since this upper limit is represented by the line Q1 in FIG. 4, the maximum value of the predetermined extrusion amount N is 2.5 BV corresponding to the intersection of the line Q1 and the line Q3. On the other hand, the lower limit of the predetermined extrusion amount N is 0.4 BV corresponding to the porosity of the resin bed. This lower limit is represented by the line Q5 in FIG. In the region below the line Q5, the extrusion amount N is extremely small, and the contact time between the regenerant and the resin bed becomes insufficient, so that the regeneration efficiency decreases. In addition, since the regenerant remains in the resin bed, the regenerant may flow into the subsequent equipment during the water softening process and cause a failure such as corrosion damage. Therefore, the predetermined extrusion amount N is equal to or less than the upper limit, and is preferably set in a range of 0.4 to 2.5 BV (a region between the line Q1 and the line Q5 in FIG. 4).

  From the above, the preferable appropriate range of the predetermined regeneration linear velocity V1 and the predetermined extrusion amount N is the region A surrounded by the line Q1, the line Q3, the line Q4, and the line Q5 as shown in FIG. The line Q1 indicating the allowable leak hardness Y is according to Equation 3. That is, the operation method of this embodiment can be said to be a method of obtaining the line Q1 by giving various conditions and setting the predetermined regeneration linear velocity V1 and the predetermined extrusion amount N within the range of the region A. In the case where there is no restriction described above, the predetermined extrusion amount N that realizes the allowable leak hardness Y or less can be obtained from Equation 2 by setting the predetermined extrusion linear velocity V2 separately from the predetermined regeneration linear velocity V1. .

After all, the method (C) for setting or adjusting the predetermined extrusion linear velocity V2 and the predetermined extrusion amount N based on the new knowledge includes the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that sets the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set.

In steps (1) to (3), the values of the parameters affecting the leak hardness y are preferably set as follows. First, in step (1), a predetermined lower resin bed depth D2, a predetermined electrical conductivity K, a predetermined total hardness H, a predetermined regeneration level R, a predetermined regenerant concentration C, a desired hardness removal capacity X and an allowable leak hardness Y. Is the following range: D2 = 0.2 to 0.8 × D1 (where D1 = 300 to 1500 mm) , K ≦ 1500 μS / cm, H ≦ 500 mg CaCO ₃ / L, R = 60 to 240 g / L -R, C = 5-15 wt%, X = 30-60 g CaCO ₃ / LR, Y ≦ ₃ mg CaCO ₃ / L. Next, in step (2), the predetermined reproduction linear velocity V1 at which the desired hardness removal capacity X is set is set in the range of 0.7 to 2 m / s. In step (3), the predetermined extrusion linear velocity V2 is obtained according to a correlation with a predetermined reproduction linear velocity V1. Thereafter, the predetermined extrusion amount N is set in the range of 0.4 to 2.5 BV according to Equation 4. By such setting, the treated water of the water softening device can have a purity with an allowable leak hardness Y of ₃ mgCaCO ₃ / L or less.

In summary, the present embodiment includes the following method of operating the water softening device. That is, raw water having a predetermined electric conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L is passed in a downward flow through a cation exchange resin bed having a predetermined total resin bed depth D1 = 300 to 1500 mm. A softening process for obtaining treated water, and a split flow regeneration process in which a regenerant or raw water is collected from both sides of the upper and lower ends of the resin bed and collected at a substantially central portion of the resin bed. (A) A sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R = 60 to 240 g / LR with respect to the resin bed, a predetermined regenerant concentration C = 5 to 15 wt%, and a predetermined regeneration linear velocity V1 = 0.7. a regenerant passage mode for passing in to 2 m / s, following the (b) regenerant passage mode, to lower resin bed predetermined depth D2 = 0.2 to 0.8 × D1 Comprising at least a raw water extrusion mode for passing a predetermined extrusion rate N = a predetermined extrusion line speed raw water 0.4~2.5BV V2 = 0.7~2m / s, a method of operating water softener.

  In this operating method, if there is a case where the allowable leak hardness Y is not satisfied in a combination of numerical values that can be taken by each parameter, the predetermined extrusion amount N and the like are adjusted so as to satisfy the allowable leak hardness Y. That is, the predetermined reproduction linear velocity V1 is set within the range of 0.7 to 2 m / s below the upper limit at which the desired hardness removal capacity X is secured. And predetermined extrusion linear velocity V2 is calculated | required according to the correlation with predetermined reproduction linear velocity V1 set beforehand. Thereafter, the predetermined extrusion amount N is set in the range of 0.4 to 2.5 BV according to Equation 4.

  In this embodiment, the regeneration process can include a well-known backwash mode, wash mode, water replenishment mode, and the like.

(Embodiment of water softening device)
The present embodiment is a water softening device that realizes the above operation method. The water softening device includes a softening process for obtaining treated water by passing raw water having a predetermined electrical conductivity K and a predetermined total hardness H in a downward flow through a cation exchange resin bed having a predetermined total resin bed depth D1. A controller that performs a split flow regeneration process that collects the regenerant or raw water from both sides of the upper and lower ends of the resin bed and collects at a substantially central part of the resin bed, (A) A regeneration agent passing mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R is passed through the resin bed at a predetermined regeneration agent concentration C and a predetermined regeneration linear velocity V1, and (b) a regeneration agent passage mode. Subsequently, at least a raw water extrusion mode in which raw water of a predetermined extrusion amount N is passed through the lower resin bed at a predetermined extrusion linear velocity V2, and (c) a regeneration process at a predetermined water temperature The leakage hardness y of the treated water in the water softening process is related to the lower resin bed depth d2, the electrical conductivity k, the total hardness h, the regeneration level r, the extrusion linear velocity v2, and the extrusion amount n. A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N in the case of using raw water having an electrical conductivity K and a predetermined total hardness H are preset by the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that sets the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set.

  In this embodiment, the predetermined extrusion amount N is set in advance by steps (1) to (3), and the raw water extrusion step is controlled so that the extrusion amount n in the raw water extrusion mode becomes the predetermined extrusion amount N. . This control can be easily performed by a timer, but it is also possible to provide a flow meter so that when the flow meter counts the predetermined extrusion amount N, the raw water extrusion mode is terminated.

In steps (1) to (3), the values of the parameters affecting the leak hardness y are preferably set as follows. First, in step (1), a predetermined lower resin bed depth D2, a predetermined electrical conductivity K, a predetermined total hardness H, a predetermined regeneration level R, a predetermined regenerant concentration C, a desired hardness removal capacity X and an allowable leak hardness Y. Is the following range: D2 = 0.2 to 0.8 × D1 (where D1 = 300 to 1500 mm) , K ≦ 1500 μS / cm, H ≦ 500 mg CaCO ₃ / L, R = 60 to 240 g / L -R, C = 5-15 wt%, X = 30-60 g CaCO ₃ / LR, Y ≦ ₃ mg CaCO ₃ / L. Next, in step (2), the predetermined reproduction linear velocity V1 at which the desired hardness removal capacity X is set is set in the range of 0.7 to 2 m / s. In step (3), the predetermined extrusion linear velocity V2 is obtained according to a correlation with a predetermined reproduction linear velocity V1. Thereafter, the predetermined extrusion amount N is set in the range of 0.4 to 2.5 BV according to Equation 4. By such setting, the treated water of the water softening device can have a purity with an allowable leak hardness Y of ₃ mgCaCO ₃ / L or less.

  FIG. 5 shows the overall configuration of the water softening device according to this embodiment. The water softening device 1 is connected to residential buildings such as houses and condominiums, customer collection facilities such as hotels and public baths, refrigeration equipment such as boilers and cooling towers, and water-using equipment such as food processing equipment and cleaning equipment.

  In FIG. 5, the water softening device 1 mainly includes a resin storage tank 2, a process control valve 3, and a salt water supply device 4. The resin storage tank 2 includes a bottomed vessel 6 filled with a cation exchange resin bed 5 (predetermined bed depth: D1). The opening of the vessel 6 is closed with a cap 7. A process control valve 3 is integrally attached to the cap 7, and the flow path of the water softening process and the flow path of the regeneration process of the water softening device 1 can be switched by a command signal from the controller 1C. It is configured as follows. The cap 7 is formed with a first flow path 8, a second flow path 9 and a third flow path 10 for supplying and discharging fluid. Each of these flow paths 8, 9, and 10 is connected to various lines constituting the process control valve 3, as will be described later.

  A first collecting pipe 11 extending near the bottom of the vessel 6 is connected to the first flow path 8. A first screen 12 that prevents the resin beads from flowing out is attached to the tip of the first collection tube 11. That is, the inside of the first collection pipe 11 is communicated with the first flow path 8, and the collection position by the first screen 12 is set near the bottom of the vessel 6.

  Connected to the second flow path 9 is a second collection pipe 13 that extends to a substantially central portion (predetermined bed depth: D2) of the cation exchange resin bed 5. A second screen 14 for preventing the resin beads from flowing out is attached to the tip of the second collection tube 13. That is, the inside of the second collection tube 13 is communicated with the second flow path 9, and the collection position by the second screen 14 is set at a substantially central portion of the cation exchange resin bed 5.

  The inner diameter of the second collection tube 13 is set to be larger than the outer diameter of the first collection tube 11. Further, the axial cores of both the collecting pipes 11 and 13 are set coaxially with the axial core of the resin storage tank 2. That is, both the collecting pipes 11 and 13 are attached to the resin storage tank 2 as a collector of a double pipe structure in which the first collecting pipe 11 is set as an inner pipe and the second collecting pipe 13 is set as an outer pipe. .

  Further, a third screen 15 for preventing the resin beads from flowing out is mounted on the lower surface side of the cap 7. That is, the third flow path 10 communicates with the inside of the resin storage tank 2 through the third screen 15.

  The raw water line 16 is connected to the third flow path 10 via the process control valve 3. A treated water line 17 is connected to the first flow path 8 via the process control valve 3. That is, a part of the raw water line 16 and the treated water line 17 are formed in the process control valve 3, respectively.

  The raw water line 16 is provided with a pressure switch 18 and a first valve 19 in order from the upstream side. The pressure switch 18 is provided in order to detect the presence or absence of raw water pressure in the regeneration process, and is, for example, a type that turns on and off at a pressure of about 0.1 MPa necessary for normally performing the regeneration process. On the other hand, a second valve 20 is provided in the treated water line 17. The pressure switch 18, the first valve 19 and the second valve 20 are all incorporated in the process control valve 3.

  The configuration of the process control valve 3 will be described in more detail. In the process control valve 3, the raw water line 16 on the upstream side of the first valve 19 is connected to the treated water line 17 on the downstream side of the second valve 20 by a bypass line 21. The bypass line 21 is provided with a third valve 22.

  The raw water line 16 upstream of the first valve 19 is connected to the treated water line 17 upstream of the second valve 20 by a first regenerant line 23. In the first regenerant line 23, a strainer 24, a first constant flow valve 25, an ejector 26, a fourth valve 27, and a first orifice 28 are provided in this order from the raw water line 16 side. The strainer 24 is for removing suspended substances contained in the raw water and preventing the first constant flow valve 25 and the ejector 26 from being clogged. The first constant flow valve 25 is for adjusting the raw water supplied to the ejector 26 to a flow rate within a predetermined range.

  The first regenerant line 23 between the ejector 26 and the fourth valve 27 is connected to the raw water line 16 and the second regenerant line 29 on the downstream side of the first valve 19. The second regenerant line 29 is provided with a second orifice 30. The first orifice 28 and the second orifice 30 are for evenly distributing the regenerant or the raw water to the first flow path 8 and the third flow path 10 in the regenerant passage mode and the raw water extrusion mode described later. is there.

  A salt water line 31 extending from the salt water supply device 4 is connected to the discharge side of the nozzle portion of the ejector 26. The salt water line 31 is provided with a fifth valve 32. In other words, the ejector 26 is configured to be able to suck salt water (for example, a saturated aqueous solution of sodium chloride) from the salt water supply device 4 using negative pressure generated when raw water is discharged from the nozzle portion. In the ejector 26, the salt water from the salt water supply device 4 is diluted with raw water to a predetermined regenerant concentration C (5 to 15 wt%).

  A first drain line 33 extending to the outside of the process control valve 3 is connected to the treated water line 17 upstream of the second valve 20. The first drainage line 33 is provided with a sixth valve 34 and a second constant flow valve 35 in order from the treated water line 17 side. The second regenerant line 29 on the downstream side of the second orifice 30 is connected to the first drain line 33 and the second drain line 36 on the downstream side of the sixth valve 34. The second drain line 36 is provided with a seventh valve 37. Furthermore, the second flow path 9 is connected to the first drain line 33 and the third drain line 38 on the downstream side of the sixth valve 34. The third drain line 38 is provided with an eighth valve 39. The second constant flow valve 35 is for adjusting the amount of drainage from the resin storage tank 2 to a predetermined range of flow rate. The third drain line 38 is connected to the downstream side of the second constant flow valve 35, but can be connected to the downstream side of the second constant flow valve 35 in order to reduce pressure loss.

  Next, the configuration of the salt water supply device 4 will be described in detail. The salt water supply device 4 includes a salt water tank 40. In the salt water tank 40, a cylindrical salt water well 41, and a water permeable plate 43 that partitions a salt water storage part and a storage part of regenerated salt 42 (for example, granular or pellet sodium chloride) are arranged. Yes. A communication hole 44 is provided in the lower side wall of the salt water well 41 so that salt water or makeup water can freely flow therethrough.

  A strainer 45 is accommodated in the salt water well 41. The strainer 45 incorporates an air check ball 46 and a valve seat 47 with which the air check ball 46 abuts or separates. The valve seat 47 is connected to the salt water line 31. That is, the process control valve 3 is connected to the salt water tank 40 by the salt water line 31. The salt water line 31 is provided with a flow meter 48 that detects the flow rate in the salt water supply direction and the flow rate in the makeup water supply direction. The detection signal from the flow meter 48 is input to the controller 1C.

  Next, an operation method of the water softening device according to the present embodiment will be described. Hereinafter, basic operations of the water flow process and the regeneration process that are directly related to the present invention will be described.

(Water flow process)
As shown in FIG. 6, in the water flow process, the first valve 19 and the second valve 20 are each set to the open state by a command signal from the controller 1C. On the other hand, the third valve 22, the fourth valve 27, the fifth valve 32, the sixth valve 34, the seventh valve 37, and the eighth valve 39 are each set in a closed state. The raw water flowing through the raw water line 16 is distributed through the third screen 15 after being supplied through the third flow path 10 as indicated by a solid arrow S11.

  The raw water distributed from the third screen 15 is softened by replacing hardness components with Na ions or K ions in the process of passing through the cation exchange resin bed 5 in a downward flow. The treated water that has passed through the cation exchange resin bed 5 is collected by the first screen 12, and then flows through the first collection pipe 11, the first flow path 8, and the treated water line 17 as indicated by a one-dot chain line arrow S12. , Supplied to youth points. Then, when the cation exchange resin bed 5 cannot replace the hardness component by collecting a predetermined amount of treated water, a regeneration process is performed.

(Reproduction process)
In the regeneration process, in order to recover the hardness removal capacity of the cation exchange resin bed 5, a backwash mode, a regeneration agent passing mode, a raw water extrusion mode, a rinsing mode, and a water replenishment mode are performed in this order. Among these, the backwash mode, the rinse mode, and the water replenishment mode are not directly related to the present invention and are well known as shown in Patent Document 2, and thus the description thereof is omitted.

  As shown in FIG. 7, in the regenerant passing mode, the third valve 22, the fourth valve 27, the fifth valve 32, and the eighth valve 39 are each set to an open state by a command signal from the controller 1C. . On the other hand, the first valve 19, the second valve 20, the sixth valve 34, and the seventh valve 37 are each set to a closed state. The raw water flowing through the raw water line 16 is supplied as dilution water to the primary side of the ejector 26 via the first regenerant line 23. At this time, suspended substances in the raw water are removed by the strainer 24. The flow rate of the raw water is adjusted to a predetermined range by the first constant flow valve 25.

  In the ejector 26, when negative pressure is generated on the discharge side of the nozzle portion due to the passage of raw water, the salt water line 31 also has negative pressure. As a result, the salt water in the salt water tank 40 is sucked into the ejector 26 through the salt water line 31. In the ejector 26, salt water is diluted with raw water to a predetermined regenerant concentration C to prepare a regenerant.

  A part of the regenerant is supplied via the first regenerant line 23, the treated water line 17, the first flow path 8 and the first collection pipe 11, as indicated by the broken line arrow S <b> 21, and then the first screen 12. Distributed from. On the other hand, the remainder of the regenerant is supplied from the third screen 15 after being supplied via the second regenerant line 29, the raw water line 16 and the third flow path 10 as indicated by the broken line arrow S22. At this time, the regenerant is evenly distributed by the first orifice 28 and the second orifice 30.

  The regenerant distributed from the first screen 12 passes through the cation exchange resin bed 5 in an upward flow and regenerates the lower resin bed 5A. On the other hand, the regenerant distributed from the third screen 15 passes through the cation exchange resin bed 5 in a downward flow and regenerates the upper resin bed. That is, in this embodiment, split flow regeneration of the cation exchange resin bed 5 is performed. At this time, the downward flow regenerant presses the resin bed downward, and the upward flow regenerant prevents the resin bed from spreading and flowing. Then, after the regenerant that has passed through the cation exchange resin bed 5 is collected by the second screen 14, the second collection pipe 13, the second flow path 9, and the third drainage line 38, as indicated by the dashed arrow S <b> 23. And discharged from the first drainage line 33 to the outside of the system.

  As shown in FIG. 8, in the raw water extrusion mode, the third valve 22, the fourth valve 27, and the eighth valve 39 are each set to an open state by a command signal from the controller 1C. On the other hand, the 1st valve 19, the 2nd valve 20, the 5th valve 32, the 6th valve 34, and the 7th valve 37 are set as a closed state, respectively. The raw water flowing through the raw water line 16 is supplied to the primary side of the ejector 26 through the first regenerant line 23 as extruded water. At this time, suspended substances in the raw water are removed by the strainer 24. The raw water flow rate is the first constant flow rate.

  A part of the raw water from the ejector 26 is supplied through the first regenerant line 23, the treated water line 17, the first flow path 8 and the first collection pipe 11 as indicated by the solid arrow S31. It is distributed from one screen 12. On the other hand, the remainder of the raw water from the ejector 26 is supplied from the third screen 15 after being supplied through the second regenerant line 29, the raw water line 16 and the third flow path 10 as indicated by the solid arrow S32. The At this time, the raw water is evenly distributed by the first orifice 28 and the second orifice 30.

  The raw water distributed from the first screen 12 passes through the cation exchange resin bed 5 in an upward flow while pushing out the regenerant, and continuously regenerates the lower resin bed 5A. On the other hand, the raw water distributed from the third screen 15 passes through the cation exchange resin bed 5 in a downward flow while pushing out the regenerant, and continuously regenerates the upper resin bed. At this time, the raw water in the downward flow presses the resin bed downward and suppresses the development and flow of the resin bed by the raw water in the upward flow. Then, after the regenerant and raw water that have passed through the cation exchange resin bed 5 are collected by the second screen 14, as shown by the solid line arrow S33, the second collection pipe 13, the second flow path 9, and the third waste water are collected. It is discharged from the first drainage line 33 through the line 38 to the outside of the system.

In the operation method of the water softening device 1 described above, the feature is the operation method described in the embodiment. That is, this operation method is to soften water to obtain treated water by allowing raw water having a predetermined electrical conductivity K and a predetermined total hardness H to pass through the cation exchange resin bed 5 having a predetermined total resin bed depth D1 in a downward flow. And a split flow regeneration process that collects at approximately the center of the resin bed while distributing the regenerant or raw water from both sides of the upper and lower ends of the resin bed, the regeneration process comprising: (a) On the other hand, a regenerant passing mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R is passed at a predetermined regenerant concentration C and a predetermined regeneration linear velocity V1, and (b) following the regenerant passing mode, At least a raw water extrusion mode in which raw water of a predetermined extrusion amount N is passed at a predetermined extrusion linear velocity V2, and (c) treatment in a water softening process after a regeneration process at a predetermined water temperature. By utilizing the fact that the water leak hardness y is related to the lower resin bed depth d2, the electrical conductivity k, the total hardness h, the regeneration level r, the extrusion linear velocity v2, and the extrusion amount n, the predetermined electrical conductivity K and The predetermined extrusion linear velocity V2 and the predetermined extrusion amount N when using raw water having a predetermined total hardness H are set by the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that is equal to or higher than the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set.

The leak hardness y is expressed by Equation 1. When the allowable leak hardness Y is set to 1 mgCaCO ₃ / L which is preferable in the boiler apparatus, and the extrusion linear velocity v2 is approximated by the regeneration linear velocity v1, the extrusion amount n that realizes the allowable leak hardness Y is expressed as a function of the regeneration linear velocity v1. 4 is expressed. In Equation 4, Y = 1 mgCaCO ₃ / L. In addition, the constant of Formula 1-Formula 4 can be calculated | required when creating Formula 1 based on an experimental result.

Hereinafter, application examples of the present invention will be described. Predetermined lower resin bed depth D2 = 750 mm, predetermined electrical conductivity K = 1500 μS / cm, predetermined total hardness H = 500 mgCaCO ₃ / L, predetermined regeneration level R = 120 g · NaCl / LR and raw water temperature T = 18 ° C. Under the conditions, the predetermined regeneration linear velocity V1 is changed between 0.7 to 2 m / s of the appropriate range, and the predetermined extrusion amount N is changed between 0.4 to 2.5 BV of the appropriate range, The leak hardness y was obtained from Equation 1. Further, the hardness removal capacity x was obtained by Equation 8. The results are applied examples SP11 to SP14 (N = 2.5 BV), application examples SP21 to SP24 (N = 2.25 BV), application examples SP31 to SP34 (N = 1.5 BV), and application examples SP41 to SP44 (N = 0.4BV) are shown in FIGS. 9 to 12, respectively. The cation exchange resin is set to “IMAC HP1220Na” manufactured by Rohm and Haas. It has been confirmed that the result of each application example almost matches the actual measurement value using the water softening device 1. In other words, the data in FIGS. 9 to 12 can be said to be experimental results.

Application examples for generating treated water having an allowable leak hardness of Y = 1 mgCaCO ₃ / L or less are SP41 to SP44 shown in FIG. Moreover, the application example which produces | generates the treated water of the purity close | similar to the allowable leak hardness Y is SP33 and SP34 shown in FIG. As in the application examples SP41 to SP44, by setting the predetermined regeneration linear velocity V1 and the predetermined extrusion amount N, the object of the present invention can be achieved. That is, it is possible to achieve high economic efficiency by securing treated water having a purity equal to or lower than the allowable leak hardness Y and securing the amount of water sampled equivalent to that of other water softening devices of the regeneration method. Note that the allowable leak hardness Y may be set to about ₃ mg CaCO ₃ / L depending on the use of the treated water, such as a reverse osmosis membrane device. In that case, the present invention is applied to all the application examples shown in FIGS. Can achieve the purpose. Needless to say, in the application examples SP11 to SP44, various conditions of parameters other than the predetermined regeneration linear velocity V10 and the predetermined extrusion amount N are set on the side where the hardness leak level is likely to increase. For this reason, if various conditions are set to the side where the hardness leak level is further reduced, a leak hardness y of 0.1 mgCaCO ₃ / L or less can be easily achieved.

As described above, according to the operation method of the present embodiment, even if poor raw water having a predetermined electric conductivity K of 1500 μS / cm and a predetermined total hardness H of 500 mgCaCO ₃ / L is used, the allowable leak hardness Y is 1 mgCaCO _3. Treated water having a purity of / L or less or a purity close to this purity can be easily produced. Further, by setting the predetermined regeneration linear velocity V1 in the range of 0.7 to 2 m / s, it is possible to prevent regeneration failure due to regenerant drift and short path, and equivalent to a cocurrent regeneration type water softening device. Hardness removal capacity can be ensured. In addition, by using Formulas 1 to 4, it is possible to easily design a split flow regeneration process.

As shown in FIG. 13, the water softening device 1 can be used by being connected to the boiler device 50 via a treated water tank 51 as necessary. In this case, the water softening device 1 adjusts the desired hardness removal capacity X = 30 to 60 gCaCO ₃ / LR and the allowable leak hardness Y = 1 mgCaCO ₃ / L or less, and treats the treated water obtained in the water softening process to the boiler device 50. To supply. The boiler device 50 has different allowable leak hardness Y depending on its can structure. Therefore, it is desirable that the water softening device 1 is configured to change the predetermined extrusion amount N according to the allowable leak hardness Y.

As shown in FIG. 14, the water softening device 1 can be used by being connected to a reverse osmosis membrane device 52 via a treated water tank 51 as necessary. In this case, the water softening device 1 adjusts the desired hardness removal capacity X = 30 to 60 gCaCO ₃ / LR and the allowable leak hardness Y = 1 mgCaCO ₃ / L or less to treat the treated water obtained by the water softening process with a reverse osmosis membrane Supply to device 52.

  Various modifications can be made to the embodiment described above. For example, in the embodiment, the predetermined extrusion amount N is obtained in advance, and the raw water extrusion mode is terminated by the timer function of the controller 1C. However, an arbitrary parameter related to the predetermined extrusion amount N is detected, and the predetermined extrusion amount is detected. N can be configured to adjust. Further, the fourth valve 27 can be controlled so that only the lower resin bed 5A is terminated before the raw water extrusion mode is terminated. In this case, the amount of contamination of the lower resin bed 5A due to the hardness component can be minimized.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. For this reason, the above-described embodiments or examples are merely examples in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the scope of claims, and is not restricted to the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

Claims (9)

A water softening process for obtaining treated water by passing raw water having a predetermined electrical conductivity K and a predetermined total hardness H in a downward flow with respect to the cation exchange resin bed having a predetermined total resin bed depth D1, and an upper end of the resin bed And a split flow regeneration process in which a regenerant or raw water is distributed from both sides of the lower end portion and collected at a substantially central portion of the resin bed, and the regeneration process includes (a) chlorination at a predetermined regeneration level R with respect to the resin bed. A regenerant passing mode in which an aqueous solution of sodium or potassium chloride is passed at a predetermined regenerant concentration C and a predetermined regeneration linear velocity V1, and (b) following the regenerant passing mode, raw water of a predetermined extrusion amount N is supplied to the lower resin bed. And (c) the leakage hardness y of the treated water in the water softening process after the regeneration process at a predetermined water temperature is lower than the raw water extrusion mode. When raw water having a predetermined electrical conductivity K and a predetermined total hardness H is used by utilizing the relation to the floor depth d2, the electrical conductivity k, the total hardness h, the regeneration level r, the extrusion linear velocity v2 and the extrusion amount n. The method of operating the water softening device, wherein the predetermined extrusion linear velocity V2 and the predetermined extrusion amount N are set by the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that is equal to or higher than the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set. The operation method of the water softening device according to claim 1, wherein the predetermined extrusion linear velocity V2 in step (3) is obtained according to a correlation with a predetermined regeneration linear velocity V1. The predetermined lower resin bed depth D2, the predetermined electrical conductivity E, the predetermined total hardness H, the predetermined regeneration level R, the predetermined regenerant concentration C, the desired hardness removal capacity X and the allowable leak hardness Y in step (1) are as follows. : D2 = 150 to 750 mm, K ≦ 1500 μS / cm, H ≦ 500 mg CaCO ₃ / L, R = 60 to 240 g / LR, C = 5 to 15 wt%, X = 30 to 60 g CaCO ₃ / LR, Y ≦ The operation method of the water softening device according to claim 2, which is set at ₃ mg CaCO ₃ / L. The operation method of the water softening device according to claim 3, wherein the predetermined regeneration linear velocity V1 and the predetermined extrusion linear velocity V2 in steps (2) and (3) are set in a range of 0.7 to 2 m / s. A cation exchange resin bed having a predetermined total resin bed depth D1 = 300-1500 mm is treated by passing raw water having a predetermined electrical conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L in a descending flow. Including a water softening process for obtaining water and a split flow regeneration process in which a regenerant or raw water is collected from both sides of the upper and lower ends of the resin bed and collected at a substantially central portion of the resin bed. a) A sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R = 60 to 240 g / LR with respect to the resin bed, a predetermined regenerant concentration C = 5 to 15 wt%, and a predetermined regeneration linear velocity V1 = 0.7 to 2 m. a regenerant passage mode for passing in / s, (b) Following the regenerant passage mode, to lower resin bed predetermined depth D2 = 0.2 to 0.8 × D1, predetermined extrusion N = raw water 0.4~2.5BV comprising at least a raw water extrusion mode for passing at a predetermined extrusion linear speed V2 = 0.7~2m / s, the method operation of the water softening device. A water softening process for obtaining treated water by passing raw water having a predetermined electrical conductivity K and a predetermined total hardness H in a downward flow with respect to the cation exchange resin bed having a predetermined total resin bed depth D1, and an upper end of the resin bed And a split flow regeneration process that collects the regenerant or raw water from both sides of the lower end portion and collects at a substantially central portion of the resin bed, and the controller includes (a) a resin bed in the regeneration process. On the other hand, a regenerant passing mode in which a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R is passed at a predetermined regenerant concentration C and a predetermined regeneration linear velocity V1, and (b) following the regenerant passing mode, On the other hand, at least a raw water extrusion mode for passing raw water of a predetermined extrusion amount N at a predetermined extrusion linear velocity V2, and (c) a water softening process after a regeneration process at a predetermined water temperature By utilizing the fact that the leakage hardness y of the treated water is related to the lower resin bed depth d2, the electrical conductivity k, the total hardness h, the regeneration level r, the extrusion linear velocity v2, and the extrusion amount n, the predetermined electrical conductivity K In addition, the water softening device in which the predetermined extrusion linear velocity V2 and the predetermined extrusion amount N when using raw water having a predetermined total hardness H are set in advance by the following steps (1) to (3).
(1) Predetermined lower resin bed depth D2, predetermined electrical conductivity K, predetermined total hardness H, predetermined regeneration level R, predetermined regenerant concentration C, desired hardness removal capacity X in the water softening process after the regeneration process, and treated water Various conditions including the allowable leak hardness Y are given.
(2) Using the fact that the hardness removal capacity x is related to the reproduction level r and the reproduction linear velocity v1, a predetermined reproduction linear velocity V1 that sets the desired hardness removal capacitance X is set.
(3) A predetermined extrusion linear velocity V2 and a predetermined extrusion amount N at which the leakage hardness y of the treated water is equal to or less than the allowable leakage hardness Y are set. The water softening device according to claim 6, wherein the predetermined extrusion linear velocity V2 in step (3) is obtained according to a correlation with a predetermined regeneration linear velocity V1. The predetermined lower resin bed depth D2, the predetermined electrical conductivity K, the predetermined total hardness H, the predetermined regeneration level R, the predetermined regenerant concentration C, the desired ion exchange capacity X and the allowable leak hardness Y in step (1) are in the following ranges. : D2 = 150 to 750 mm, K ≦ 1500 μS / cm, H ≦ 500 mg CaCO ₃ / L, R = 60 to 240 g / LR, C = 5 to 15 wt%, X = 30 to 60 g CaCO ₃ / LR, Y ≦ The water softening device according to claim 7, which is set at ₃ mgCaCO ₃ / L. A cation exchange resin bed having a predetermined total resin bed depth D1 = 300-1500 mm is treated by passing raw water having a predetermined electrical conductivity K ≦ 1500 μS / cm and a predetermined total hardness H ≦ 500 mgCaCO ₃ / L in a descending flow. A controller that performs a water softening process for obtaining water and a split flow regeneration process that collects the regenerant or raw water from the both sides of the upper and lower ends of the resin bed and collects it at substantially the center of the resin bed; In the regeneration process, the controller performs (a) a sodium chloride aqueous solution or a potassium chloride aqueous solution having a predetermined regeneration level R = 60 to 240 g / LR on the resin bed with a predetermined regenerant concentration C = 5 to 15 wt% and predetermined regeneration. a regenerant passage mode for passing at linear velocity V1 = 0.7~2m / s, (b ) Following the regenerant passage mode, a predetermined depth D2 = 0.2 to 0.8 × For one of the lower resin bed, performing at least a raw water extrusion mode for passing a predetermined extrusion rate N = a predetermined extrusion line speed raw water 0.4~2.5BV V2 = 0.7~2m / s, water softening apparatus.

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