Regeneration method of soft water resin
By preparing and soaking regenerated brine when the resin reaches its critical saturation state, the problem of idle brine crystallization in traditional resin regeneration methods is solved, enabling the immediate preparation and use of brine and improving resin regeneration efficiency.
Patent Information
- Application Number
- CN202511200069.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-25
- Publication Date
- 2025-11-21
AI Technical Summary
Traditional resin regeneration methods fail to accurately prepare brine based on the resin's saturation state, leading to problems such as brine crystallization or excess brine forming scale.
Water is injected into the salt tank when the resin reaches the set critical saturation state, and the regenerated salt is allowed to melt to prepare the regenerated brine. The brine is then injected into the resin chamber for soaking when the resin reaches saturation, ensuring that the brine is prepared and used immediately.
It enables the immediate preparation and use of brine, avoids the crystallization of idle brine, prevents scale formation, and improves resin regeneration efficiency.
Smart Images
Figure CN120984357A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of soft water preparation, in particular to a regeneration method of soft water resin. BACKGROUND
[0002] Daily drinking water, especially well water or mountain spring water in some areas, usually contains a high concentration of hardness ions such as calcium and magnesium. Long-term excessive intake of such ions not only may pose a potential risk to health (such as increasing the incidence of kidney stones and other diseases), but also affects the taste of water and causes scale formation, reducing the performance. To address this problem, water softening technology based on ion exchange resin has become the mainstream solution on the market (such as household water softener). This technology uses the ion exchange properties of the resin. When water flows through the resin bed, the resin can effectively adsorb calcium, magnesium and other ions in the water, significantly reducing the hardness of the water.
[0003] However, the adsorption capacity of ion exchange resin is limited. After continuous use, it will reach a saturated state due to the adsorption of a sufficient amount of target ions, resulting in a significant decrease or even failure of its ion exchange capacity, and it cannot continue to provide effective softening function. In the traditional ion exchange resin water softening technology, a high-concentration sodium chloride solution (brine) is usually used periodically to regenerate the saturated resin. The sodium ions in the brine exchange the adsorbed calcium and magnesium ions on the resin through a displacement reaction, so that the resin regains its adsorption capacity. However, the existing technology has obvious defects in the preparation of brine. One case is to prepare brine immediately after each regeneration program ends, which will cause the brine prepared when the resin is not saturated to be idle. If the brine is left for too long, the salt will crystallize and form salt scale. Another case is to prepare brine at a set time interval. This method cannot accurately prepare brine according to the actual saturation state of the resin, and may also cause the prepared brine to remain idle, forming salt scale. SUMMARY
[0004] The present application provides a regeneration method of soft water resin, which aims to solve the problem of salt water crystallization caused by the preparation of salt water without considering the saturation state of the resin in the traditional resin regeneration method.
[0005] The regeneration method of soft water resin provided by the present application comprises the following steps: injecting the water to be softened into a resin cavity provided with soft water resin; when the soft water resin reaches a set critical saturation state, injecting water into a salt tank provided with regeneration salt; when the soft water resin reaches a saturation state, stopping the injection of water to be softened into the resin cavity; waiting for the regeneration salt to melt to obtain regeneration brine; injecting the regeneration brine into the resin cavity and soaking for a first set period of time.
[0006] In an embodiment, the total amount of water softened by the softening resin is a total softening water amount, and the regeneration control method further comprises the following steps: measuring a current softening water amount injected into the resin cavity since the last regeneration by a flow meter; determining that the softening resin reaches a saturation critical state when the current softening water amount reaches a first set water amount, the first set water amount being less than the total softening water amount; determining that the softening resin reaches a saturation state when the current softening water amount reaches the total softening water amount.
[0007] In an embodiment, the first set water amount is less than or equal to the total softening water amount minus the unit water injection amount of the resin cavity times (the salt tank water amount / the unit water injection amount of the salt tank+the first set time length).
[0008] In an embodiment, the flow meter is restarted after the softening resin reaches the saturation state and the injection of the water to be softened into the resin cavity is stopped.
[0009] In an embodiment, the method further comprises the following steps: detecting the concentration of calcium and magnesium ions in the resin cavity; determining that the softening resin reaches a set saturation critical state when the concentration of calcium and magnesium ions in the resin cavity reaches a first set concentration; determining that the softening resin reaches a saturation state when the concentration of calcium and magnesium ions in the resin cavity reaches a second set concentration, the second set concentration being greater than the first set concentration.
[0010] In an embodiment, the method further comprises the following steps: backwashing the softening resin after the softening resin reaches the saturation state and the injection of the water to be softened into the resin cavity is stopped, and during the process of waiting for the regeneration salt to melt, the direction of the water to be softened into the resin cavity is a first direction, and the direction of the water flow during the backwashing of the softening resin is a second direction opposite to the first direction.
[0011] In an embodiment, the method further comprises the following steps: after the regeneration salt water is injected into the resin cavity and soaked for a first set time length, water is injected into the resin cavity along the first direction, and the waste water in the resin cavity is drained.
[0012] In an embodiment, the method further comprises the following steps: during the process of waiting for the regeneration salt to melt, detecting whether the concentration of the regeneration salt water reaches a set concentration value, and when the concentration of the regeneration salt water reaches the set concentration value, the regeneration salt water is injected into the resin cavity and soaked for a first set time length.
[0013] In an embodiment, the method further comprises the following steps: during the process of waiting for the regeneration salt to melt, waiting for the regeneration salt to melt for a second set time length to obtain the regeneration salt water, and after the second set time length is up, the regeneration salt water is injected into the resin cavity and soaked for a first set time length.
[0014] In an embodiment, the method further comprises the steps of: detecting whether the amount of salt in the salt tank is below a salt threshold; when the amount of salt in the salt tank is below the salt threshold, emitting a prompt signal.
[0015] The regeneration method of the soft water resin provided by the application comprises the following steps: injecting water to be softened into a resin cavity provided with soft water resin; when the soft water resin reaches a set critical saturation state, injecting water into a salt tank provided with regeneration salt; when the soft water resin reaches a saturation state, stopping the injection of water to be softened into the resin cavity; waiting for the regeneration salt to melt to obtain salt water for regeneration; and injecting the salt water for regeneration into the resin cavity and soaking for a first set time. During the soft water treatment process, the water to be softened (hard water) flows into the resin cavity along a first direction and contacts the soft water resin in the resin cavity, and the sodium ions on the soft water resin are replaced by the calcium and magnesium ions in the water. When the soft water resin reaches the critical state, the soft water resin still has a certain softening capacity, and the water to be softened can continue to be injected into the resin cavity, and at the same time, water is injected into the salt tank containing the regeneration salt, and the regeneration salt is waited to melt to obtain the salt water for regeneration. When the soft water resin reaches the saturation state, the salt water for regeneration has been prepared, and the salt water for regeneration can be injected into the resin cavity and soaked for a first set time, so as to ensure that the calcium and magnesium ions on the resin are fully replaced and the regeneration reaction is fully carried out. The regeneration method of the soft water resin provided by the application starts to prepare the salt water when the soft water resin still has a part of exchange capacity but is about to reach the saturation state, and the salt water has been prepared when the soft water resin formally reaches the saturation state, so that the regeneration soaking link can be entered, the "salt water zero idling" is realized, and the problem of salt analysis and salt scale formation caused by the idling of the salt water is avoided. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.
[0017] Figure 1 is a flowchart of an embodiment of the regeneration method of the soft water resin provided by the application; Figure 2 is a flowchart of another embodiment of the regeneration method of the soft water resin provided by the application; Figure 3 is a flowchart of another embodiment of the regeneration method of the soft water resin provided by the application. DETAILED DESCRIPTION
[0018] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.
[0019] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0020] In addition, in the embodiments of the present application, the terms indicating the orientation or positional relationship such as "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientation or positional relationship shown in the drawings or the conventional placement state or use state, which is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the structures, features, devices or elements referred to must have a particular orientation or positional relationship, nor must be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.
[0021] In the specific technical features and embodiments described in the specific embodiments, any suitable combination can be combined without contradiction, for example, different specific technical features / embodiments can form different embodiments by combination. In order to avoid unnecessary repetition, various possible combinations of each specific technical feature / embodiment in the present application are not described again.
[0022] Daily drinking water, especially well water or mountain spring water in some areas, usually contains a high concentration of hardness ions such as calcium and magnesium. Long-term excessive intake of such ions not only may pose a potential risk to health (such as increasing the incidence of kidney stones and other diseases), but also affects the taste of water and causes scale formation, reducing the performance. To address this problem, water softening technology based on ion exchange resin has become the mainstream solution on the market (such as household water softener). This technology uses the ion exchange properties of the resin. When water flows through the resin bed, the resin can effectively adsorb calcium, magnesium and other ions in the water, significantly reducing the hardness of the water.
[0023] However, the adsorption capacity of ion exchange resin is limited, and it will reach saturation state after continuous use due to adsorption of sufficient target ions, resulting in a significant decrease or even failure of ion exchange capacity, and thus unable to continue to provide effective softening function. In the traditional ion exchange resin water softening technology, a high concentration sodium chloride solution (brine) is usually used to regenerate the saturated resin periodically. The sodium ions in the brine exchange the calcium and magnesium ions adsorbed on the resin through a displacement reaction, so that the resin regains the adsorption capacity. However, the preparation method of brine in the prior art has obvious defects. In one case, brine is prepared immediately after each regeneration procedure, which will cause the brine prepared when the resin is not saturated to be idle, and the brine will crystallize and form salt scale if left for too long. In another case, brine is prepared at a set time interval, which cannot accurately prepare brine according to the actual saturation state of the resin, and the prepared brine may also be idle, resulting in salt scale.
[0024] To avoid this phenomenon, the embodiment of the present application provides a regeneration method of soft water resin.
[0025] As shown in Figure 1 The embodiment of the present application provides a regeneration method of soft water resin, which comprises the following steps: S10: injecting water to be softened into a resin cavity provided with soft water resin; S20: when the soft water resin reaches a set saturation critical state, injecting water into a salt tank provided with regeneration salt; S30: stopping injecting water to be softened into the resin cavity when the soft water resin reaches a saturation state; S40: waiting for the regeneration salt to melt to obtain brine for regeneration; S50: injecting the brine for regeneration into the resin cavity and soaking for a first set time.
[0026] The regeneration method of soft water resin can be used in soft water treatment equipment with water quality softening function such as water heaters, water purifiers, water dispensers, etc. The soft water treatment equipment has a control assembly, which includes a controller, a valve body provided on a waterway and controlled by the controller, and various electronic devices, etc. The soft water treatment equipment also has a salt tank assembly and a soft water assembly. The salt tank assembly includes a salt tank, and a salt cavity for placing regeneration salt is formed inside the salt tank. The soft water assembly includes a resin tank, and a resin cavity is formed inside the resin tank, and sodium type cation exchange resin is placed in the resin cavity. During the soft water treatment process, water to be softened (hard water) flows into the resin cavity along a first direction and contacts the soft water resin in the resin cavity. The sodium ions on the soft water resin will displace the calcium and magnesium ions in the water, and the chemical reaction process is as follows: wherein R is a resin group. Calcium and magnesium ions are adsorbed by the resin, and the concentration of sodium ions in the water increases, thereby reducing the hardness of the water and making it "soft water". The adsorption capacity of the soft water resin is limited, and after continuous use, it will gradually reach a saturated state after adsorbing a sufficient amount of target ions. When the soft water resin reaches a critical state, the soft water resin still has a certain softening capacity, and the softened water can continue to be injected into the resin cavity, while water is injected into the salt tank containing the regeneration salt, and the regeneration salt is melted to obtain salt water for regeneration. When the soft water resin reaches a saturated state, the salt water for regeneration has been prepared, and the salt water for regeneration can be injected into the resin cavity and soaked for a first set period of time to ensure that the calcium and magnesium ions on the resin are fully replaced, and the regeneration reaction is fully carried out: The regeneration method of the soft water resin begins to prepare salt water when the soft water resin still has partial exchange capacity but is about to be saturated, and when the soft water resin is formally saturated, the salt water has been prepared, and the regeneration soaking link can be entered, realizing "zero idling of salt water" and thereby avoiding salt analysis and salt scale problems caused by idling of salt water.
[0027] wherein the first set period of time should be the period of time required for the saturated resin to fully contact the salt water and be fully regenerated, and can be determined through experiments or empirical formulas.
[0028] The total amount of water that can be softened by soft water resin with a certain volume is the total soft water amount, which is referred to as Figure 2 An embodiment of the regeneration control method further includes the following steps: S21: Measure the current softened water amount injected into the resin cavity since the last regeneration by a flow meter; S22: When the current softened water amount reaches a first set water amount, determine that the soft water resin reaches a set saturated critical state, and the first set water amount is less than the total soft water amount; S31: When the current softened water amount reaches the total soft water amount, determine that the soft water resin reaches a saturated state.
[0029] The embodiment helps to determine whether the soft water resin reaches the saturation critical state and the saturation state through the flow meter. Specifically, the current softened water amount injected into the resin cavity since the last regeneration is accumulated through the flow meter. When the current softened water amount accumulated by the flow meter reaches the first set water amount, it is determined that the soft water resin reaches the set saturation critical state. At this time, water is injected into the salt tank containing the regeneration salt, and the regeneration salt is melted to obtain the salt water for regeneration. When the current softened water amount accumulated by the flow meter reaches the total softened water amount, it is determined that the soft water resin reaches the saturation state. At this time, the salt water for regeneration has also been prepared, and the salt water for regeneration can be injected into the resin cavity and soaked for the first set time length to ensure that the calcium and magnesium ions on the resin are fully replaced and the regeneration reaction is fully carried out. The embodiment is simple and reliable in helping to determine whether the soft water resin reaches the saturation critical state and the saturation state, and is responsive and sensitive.
[0030] The total softened water amount V (unit: liter, L) is the total volume of water that can be softened by the soft water resin, and the calculation formula is as follows: The volume V1 of the resin (unit: liter, L), the resin exchange capacity C1 (unit: eq / L, provided by the manufacturer), and the raw water hardness H1 (unit: eq / L). For example, assuming that the resin volume V1 is 10 L, the resin exchange capacity C1 is 2.0 eq / L, and the raw water hardness H1 is 0.002 eq / L, then V1=(10×2) / 0.002=10000 L. It is not difficult to understand that since the soft water resin reaches the saturation critical state, the soft water resin still has part of the exchange capacity, and therefore the first set water amount is less than the total softened water amount.
[0031] In order to ensure that the salt water for regeneration has been prepared when the soft water resin reaches the saturation state, it is necessary to ensure that the remaining softened water time is greater than or equal to (the salt tank water injection time + the first set time length).
[0032] The remaining softened water time=the remaining softened water amount / the resin cavity unit water injection amount; The remaining softened water amount=the total softened water amount-the first set water amount; The salt tank water injection time=the salt tank water capacity / the salt tank unit water injection amount; It is derived that the first set water amount≤the total softened water amount-the resin cavity unit water injection amount×(the salt tank water capacity / the salt tank unit water injection amount+the first set time length).
[0033] The resin cavity unit water injection amount can be calculated through the resin cavity water supply pipe diameter and the water flow rate, and the salt tank unit water injection amount can be calculated through the salt tank water supply pipe diameter and the water injection rate.
[0034] After the soft water resin reaches the saturation state, the flow meter re-measures after stopping the injection of the water to be softened into the resin cavity, and thus circulates to realize the cyclic regeneration of the resin. Specifically, the flow meter can be zeroed to re-measure the amount of the current softened water injected into the resin cavity after the waste water is discharged, and thus circulates to realize the cyclic regeneration of the resin.
[0035] Alternatively, the regeneration method of the soft water resin can help to determine whether the soft water resin reaches the saturation critical state and the saturation state by monitoring the concentration of calcium and magnesium ions in the resin cavity, referring to Figure 3 , and the regeneration method of the soft water resin further comprises the following steps: S21: detecting the concentration of calcium and magnesium ions in the resin cavity; S22: when the concentration of calcium and magnesium ions in the resin cavity reaches a first set concentration, determining that the soft water resin reaches a set saturation critical state; S31: when the concentration of calcium and magnesium ions in the resin cavity reaches a second set concentration, determining that the soft water resin reaches a saturation state, and the second set concentration is greater than the first set concentration.
[0036] Specifically, the resin cavity is provided with a calcium and magnesium ion concentration detection device to detect the concentration of calcium and magnesium ions in the resin cavity, when the calcium and magnesium ion concentration detection device detects that the concentration of calcium and magnesium ions reaches a first set concentration, it is determined that the soft water resin reaches a saturation critical state, at this time, water is injected into the salt tank containing regeneration salt, and the regeneration salt is melted to obtain salt water for regeneration. When the calcium and magnesium ion concentration detection device detects that the concentration of calcium and magnesium ions reaches a second set concentration, it is determined that the soft water resin reaches a saturation state, at this time, the salt water for regeneration has also been prepared, and the salt water for regeneration can be injected into the resin cavity and soaked for a first set time to ensure that the calcium and magnesium ions on the resin are fully replaced and the regeneration reaction is fully carried out.
[0037] The regeneration method of the soft water resin further comprises the following steps after the soft water resin reaches the saturation state and the injection of the water to be softened into the resin cavity is stopped, and during the process of waiting for the regeneration salt to melt: The soft water resin is backwashed, and the direction of the water to be softened into the resin cavity is a first direction, and the direction of the water flow for backwashing the soft water resin is a second direction opposite to the first direction.
[0038] Specifically, the direction of the water to be softened into the resin cavity can be from top to bottom, and the direction of the water flow for backwashing the soft water resin is from bottom to top. The time for waiting for the regeneration salt to melt is used to reverse flush the soft water resin, loosen the resin layer, and increase the distance between the resin particles, so as to facilitate the subsequent full contact between the salt water and the resin particles and improve the subsequent regeneration effect. The reverse flushing of the soft water resin is parallel to the process of waiting for the regeneration salt to melt, which can shorten the total process time.
[0039] The method for regenerating the soft water resin further comprises the following steps after the regenerating salt water is injected into the resin cavity and soaked for the first set time length: S60: water is injected into the resin cavity along the first direction, and the waste water in the resin cavity is drained.
[0040] As can be understood, when the salt water flows through the resin bed, the salt water exchanges the calcium and magnesium ions adsorbed on the resin, thereby generating calcium chloride and magnesium chloride waste liquid with extremely high hardness, which needs to be drained in time to avoid polluting the subsequent prepared soft water. Therefore, after the regenerating salt water is injected into the resin cavity and soaked for the first set time length, that is, after the regeneration reaction is fully performed, water is injected into the resin cavity, and the calcium chloride and magnesium chloride waste liquid generated after regeneration in the resin cavity is drained. The water flow direction of the injection and drainage is the first direction, and the dispersed resin can be compressed.
[0041] During the process of waiting for the regeneration salt to melt, the following steps can also be performed: S41: detecting whether the concentration of the regenerating salt water reaches a set concentration value; S42: when the concentration of the regenerating salt water reaches the set concentration value, the regenerating salt water is injected into the resin cavity and soaked for the first set time length.
[0042] Specifically, the salt cavity is provided with a salt water concentration detection device for detecting whether the concentration of the salt water reaches a set concentration value. When the salt water concentration detection device detects that the concentration of the salt water reaches the set concentration value, it indicates that the salt water preparation is complete at this time, and the pre-work of resin regeneration has been prepared. The salt water can be transported to the resin cavity to promote resin regeneration.
[0043] Further, the salt water concentration detection device can include a liquid level detection device and a sodium ion concentration detection device. The liquid level detection device is at least partially arranged in the salt cavity and is used to detect the water level in the salt cavity. The controller is electrically connected with the liquid level detection device and the valve body on the water injection channel of the salt tank. When the liquid level detection device detects that the water level in the salt cavity reaches a set value, the controller controls the corresponding valve body to close and stops injecting water into the salt tank. The sodium ion concentration detection device is at least partially arranged in the salt cavity and is used to detect the sodium ion concentration of the salt water. The controller is electrically connected with the concentration detection device and the valve body on the water flow channel between the salt cavity and the resin cavity. When the sodium ion concentration detection device detects that the sodium ion concentration reaches a set value, the controller controls the corresponding valve body to open, and the salt water is transported to the resin cavity to promote resin regeneration.
[0044] Alternatively, during the process of waiting for the regeneration salt to melt, the following steps are performed: S41: waiting for the regeneration salt to melt for a second set time length to obtain regenerating salt water, and after the second set time length is up, the regenerating salt water is injected into the resin cavity and soaked for the first set time length.
[0045] Specifically, the control assembly includes a timer, the controller is electrically connected with the timer and the valve body on the salt cavity water injection channel, when the valve body on the salt cavity water injection channel is closed, that is, the water amount in the salt cavity reaches the requirement to stop water injection to the salt cavity, the controller receives the signal and controls the timer to start timing, when the time counted by the timer reaches the second set time length, the controller controls the valve body on the water flow channel between the salt cavity and the resin cavity to open, to deliver brine to the resin cavity to promote resin regeneration. The second set time length should be the time length for the regenerated salt to fully soak and dissolve, which can be determined by test or empirical formula. The probe of the sodium ion concentration detection device needs to be soaked in brine, which may cause the probe to malfunction or misjudge, the embodiment uses the timer to count the melting time of the regenerated salt, and determines whether the brine can be delivered to the resin cavity according to the melting time of the regenerated salt, which is reliable and easy to implement.
[0046] Some embodiments of the soft water resin regeneration method can further include the following steps: detecting whether the salt amount in the salt tank is lower than a salt amount threshold value; when the salt amount in the salt tank is lower than the salt amount threshold value, issuing a prompt signal.
[0047] Specifically, the salt tank is provided with a residual salt detection device for detecting the salt amount in the salt tank, and the control system further includes an alarm device. The controller is electrically connected with the residual salt detection device and the alarm device, when the residual salt detection device detects that the salt amount in the salt tank is lower than the salt amount threshold value, the controller controls the alarm device to issue a prompt signal, so as to remind the user to replace the salt block or add salt in time, to avoid insufficient salt amount in the salt tank leading to invalid resin regeneration. In specific application, the residual salt detection device can be a distance sensor, which is arranged at the top of the salt tank, to detect the salt height in the salt tank. By monitoring whether the distance between the height of the top surface of the salt block and the distance sensor exceeds the threshold value, if the distance exceeds the preset threshold value, it indicates that the salt is insufficient, and the controller controls the alarm device to issue an alarm signal, which can be a flashing light or a prompt sound, etc.
[0048] The above merely describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for regenerating a water softening resin, characterized by, The method comprises the following steps: injecting water to be softened into a resin cavity provided with softening resin; when the softening resin reaches a set saturation critical state, injecting water into a salt tank provided with regeneration salt; when the softening resin reaches a saturation state, stopping the injection of water to be softened into the resin cavity; waiting for the regeneration salt to melt to obtain salt water for regeneration; injecting the salt water for regeneration into the resin cavity and soaking for a first set time.
2. The method for regenerating a water softening resin according to claim 1, characterized by, The total amount of water that can be softened by the softening resin is a total softening water amount, and the regeneration control method further comprises the following steps: measuring the current softening water amount injected into the resin cavity since the last regeneration by a flow meter; when the current softening water amount reaches a first set water amount, determining that the softening resin reaches a set saturation critical state, the first set water amount being less than the total softening water amount; when the current softening water amount reaches the total softening water amount, determining that the softening resin reaches a saturation state.
3. The method for regenerating a water softening resin according to claim 2, characterized by, The first set water amount is less than the total softening water amount minus the unit water injection amount of the resin cavity multiplied by (the water storage amount of the salt tank / the unit water injection amount of the salt tank+the first set time).
4. The method for regenerating a water softening resin according to claim 2, characterized by, The flow meter is re-measured after the softening resin reaches the saturation state and the injection of water to be softened into the resin cavity is stopped.
5. The method for regenerating a water softening resin according to claim 1, characterized by, The method further comprises the following steps: detecting the concentration of calcium and magnesium ions in the resin cavity; when the concentration of calcium and magnesium ions in the resin cavity reaches a first set concentration, determining that the softening resin reaches a set saturation critical state; when the concentration of calcium and magnesium ions in the resin cavity reaches a second set concentration, determining that the softening resin reaches a saturation state, the second set concentration being greater than the first set concentration.
6. The method for regenerating a water softening resin according to claim 1, characterized by, After the softening resin reaches the saturation state and the injection of water to be softened into the resin cavity is stopped, and during the process of waiting for the regeneration salt to melt, the method further comprises the following steps: backwashing the softening resin, the direction of the water to be softened injected into the resin cavity being a first direction, and the direction of the water flow during the backwashing of the softening resin being a second direction opposite to the first direction.
7. The method for regenerating a water softening resin according to claim 6, characterized by, After the salt water for regeneration is injected into the resin cavity and soaked for the first set time, the method further comprises the following steps: injecting water into the resin cavity along the first direction and draining the waste water in the resin cavity.
8. The method for regenerating a water softening resin according to claim 1, characterized by, During the process of waiting for the regeneration salt to melt, the method further comprises the following steps: detecting whether the concentration of the salt water for regeneration reaches a set concentration value, and when the concentration of the salt water for regeneration reaches the set concentration value, injecting the salt water for regeneration into the resin cavity and soaking for the first set time.
9. The method for regenerating a water softening resin according to claim 1, characterized by, During the process of waiting for the regeneration salt to melt, the method further comprises the following steps: waiting for the regeneration salt to melt for a second set time to obtain the salt water for regeneration, and after the second set time is up, injecting the salt water for regeneration into the resin cavity and soaking for the first set time.
10. The method for regenerating a water softening resin according to claim 1, characterized by, The method further comprises the following steps: detecting whether the amount of salt in the salt tank is lower than a salt threshold value; when the amount of salt in the salt tank is lower than the salt threshold value, issuing a prompt signal.