Calcium chloride wastewater treatment device
By removing sulfate and colloids through pretreatment, and combining ultrafiltration, nanofiltration and reverse osmosis, the problems of high cost and low resource conversion rate in traditional calcium chloride wastewater treatment are solved, achieving low-cost and high-efficiency resource conversion.
Patent Information
- Application Number
- CN202520196635.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-08
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-02-08
AI Technical Summary
Traditional calcium chloride wastewater treatment methods are costly and have low resource conversion rates, mainly because the amount of calcium carbonate sludge formed by sodium carbonate precipitation is large and requires further treatment.
A pretreatment unit is used to remove sulfate and colloids from calcium chloride wastewater. The wastewater is then concentrated using ultrafiltration, nanofiltration, and reverse osmosis to prevent sulfate ion scaling, reduce treatment costs, and improve resource conversion rate.
It achieves low-cost calcium chloride wastewater treatment, improves resource conversion rate, and extends the service life of nanofiltration and reverse osmosis systems.
Smart Images
Figure CN223823473U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of water treatment technology, and in particular to a calcium chloride wastewater treatment device. Background Technology
[0002] Fracturing flowback fluid is a liquid produced during oil and gas field development, particularly in hydraulic fracturing operations. Hydraulic fracturing is a production enhancement technique that injects high-pressure fluid into oil and gas reservoirs to create fractures in the rocks, thereby increasing the flowability and production of oil and gas. This process uses large quantities of fracturing fluid, which typically contains water, sand, chemical additives, and other components. Fracturing flowback fluid primarily contains calcium chloride. Traditional techniques address the high calcium content of fracturing flowback fluid by using sodium carbonate to remove calcium, resulting in calcium carbonate-containing sludge. However, this method suffers from high reagent costs and large sludge volumes. Utility Model Content
[0003] Based on this, this application provides a calcium chloride wastewater treatment device with low treatment cost and high resource conversion rate.
[0004] This application provides a calcium chloride wastewater treatment device, the calcium chloride wastewater treatment device comprising:
[0005] The pretreatment unit is used to coagulate and filter calcium chloride wastewater to remove colloids;
[0006] A sulfate removal mechanism is connected to the drain end of the pretreatment mechanism and is used to remove sulfate from the calcium chloride wastewater.
[0007] An ultrafiltration unit is connected to the drain end of the sulfate removal unit. The ultrafiltration unit is used to filter the calcium chloride wastewater and remove particulate matter from the calcium chloride wastewater.
[0008] A nanofiltration unit, connected to the drain end of the ultrafiltration unit, is used to concentrate the calcium chloride wastewater to form a first product water containing sodium chloride and a first concentrated water containing calcium chloride; and,
[0009] A reverse osmosis unit is connected to the drain end of the first product water in the nanofiltration unit. The reverse osmosis unit is used to concentrate the first product water to form a second product water and a second concentrated water containing sodium chloride.
[0010] In some embodiments, the pretreatment unit includes a mixing processor, a coagulant storage tank, and a filter. The coagulant storage tank is connected to the mixing processor and is used to add coagulant to the calcium chloride wastewater in the mixing processor to cause the colloids in the calcium chloride wastewater to coagulate and form coagulates.
[0011] The filter is connected to the outlet of the mixing processor and is used to filter and remove the coagulants formed in the calcium chloride wastewater.
[0012] In some embodiments, the pretreatment unit further includes an adsorbent storage tank connected to the mixing processor. The adsorbent storage tank is used to add adsorbent to the calcium chloride wastewater in the mixing processor to adsorb and remove organic matter from the calcium chloride wastewater.
[0013] In some embodiments, the sulfate removal mechanism is connected to a sulfate removal agent storage tank, which is used to add sulfate removal agent to the sulfate removal mechanism to remove sulfate from the calcium chloride wastewater in the sulfate removal mechanism.
[0014] In some embodiments, the sulfate removal agent storage tank is filled with barium salt, ettringite, or sulfate adsorption resin.
[0015] In some embodiments, the calcium chloride wastewater treatment device further includes a first evaporation mechanism, which is connected to the drain end of the first concentrated water in the nanofiltration mechanism. The first evaporation mechanism is used to evaporate the first concentrated water to form calcium chloride.
[0016] In some embodiments, the first evaporation mechanism includes an evaporator and a spray dryer, wherein the evaporator is used to evaporate and concentrate the first concentrated water, and the spray dryer is used to spray dry the evaporated and concentrated first concentrated water to form calcium chloride.
[0017] In some embodiments, the calcium chloride wastewater treatment device further includes a second evaporation mechanism connected to the drain end of the second concentrated water in the reverse osmosis mechanism. The second evaporation mechanism is used to evaporate the second concentrated water to form sodium chloride.
[0018] In some embodiments, the calcium chloride wastewater treatment device further includes a recycled water storage tank, which is connected to the drain end of the second product water in the reverse osmosis unit for collecting the second product water.
[0019] In some embodiments, the calcium chloride wastewater treatment device further includes an equalization tank connected to the inlet of the pretreatment unit, the equalization tank being used to store the calcium chloride wastewater.
[0020] Compared with traditional technologies, this application has at least the following beneficial effects:
[0021] This application pre-treats calcium chloride wastewater by employing a sulfate removal unit to remove sulfate ions and their precipitates, and uses an ultrafiltration unit to remove colloids. This allows for concentration treatment of the calcium chloride wastewater using nanofiltration and reverse osmosis units, preventing sulfate ions from forming scale during nanofiltration and reverse osmosis processes, which would affect the treatment efficiency and service life of these units. Compared to traditional processes that require large amounts of sodium carbonate to remove calcium ions, this calcium chloride wastewater treatment device offers advantages such as low cost and high resource conversion rate. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of a calcium chloride wastewater treatment device provided in one embodiment of this application.
[0023] Among them, 10-pretreatment unit; 11-mixing processor; 12-coagulant storage tank; 13-filter; 20-sulfate removal unit; 21-sulfate removal agent storage tank; 30-ultrafiltration unit; 40-nanofiltration unit; 50-reverse osmosis unit; 60-first evaporation unit; 61-evaporator; 62-spray dryer; 70-second evaporation unit; 80-reclaimed water storage tank; 90-equalization tank. Detailed Implementation
[0024] The present application will be further described in detail below with reference to the accompanying drawings, embodiments, and examples. These embodiments and examples are for illustrative purposes only and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to enable a more thorough and comprehensive understanding of the disclosure of the present application. It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and the equivalent forms obtained also fall within the protection scope of the present application. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.
[0025] It should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0026] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," "fixed," and "set" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the meaning of the above terms in this application according to the specific circumstances.
[0027] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.
[0028] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.
[0029] In this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.
[0030] All references to this application are incorporated herein by reference as if each document were individually incorporated herein by reference. Unless they conflict with the purpose and / or technical solution of this application, all cited references are incorporated herein by reference in their entirety and for all purposes. When references are cited in this application, the definitions of relevant technical features, terms, nouns, phrases, etc., are also incorporated herein by reference. Examples and preferred embodiments of the cited technical features may also be incorporated herein by reference, but only to the extent that they enable the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, this application shall prevail or modifications shall be made adaptably to the description in this application.
[0031] Traditional techniques involve adding sodium carbonate to calcium chloride wastewater to precipitate calcium ions and form calcium carbonate, thereby removing calcium chloride from the wastewater. However, this method is costly in terms of sodium carbonate and produces a large amount of sludge containing calcium carbonate, requiring further sludge treatment. Therefore, traditional techniques are low in cost but have low resource conversion rates.
[0032] Based on this, this application provides a calcium chloride wastewater treatment device, such as... Figure 1 As shown, the calcium chloride wastewater treatment device includes a pretreatment unit 10, a sulfate removal unit 20, an ultrafiltration unit 30, a nanofiltration unit 40, and a reverse osmosis unit 50.
[0033] The pretreatment unit 10 is used to coagulate and filter calcium chloride wastewater to remove colloids. The sulfate removal unit 20 is connected to the drain end of the pretreatment unit 10 and is used to remove sulfate ions from the calcium chloride wastewater. The ultrafiltration unit 30 is connected to the drain end of the sulfate removal unit 20 and is used to filter the calcium chloride wastewater to remove particulate matter. The nanofiltration unit 40 is connected to the drain end of the ultrafiltration unit 30 and is used to concentrate the calcium chloride wastewater to form a first product water containing sodium chloride and a first concentrated water containing calcium chloride. The reverse osmosis unit 50 is connected to the drain end of the first product water in the nanofiltration unit 40 and is used to concentrate the first product water to form a second product water and a second concentrated water containing sodium chloride.
[0034] This application pre-treats calcium chloride wastewater by employing a sulfate removal unit 20 to remove sulfate ions and their precipitates, and an ultrafiltration unit 30 to remove colloids. This allows for concentration treatment of the calcium chloride wastewater using a nanofiltration unit 40 and a reverse osmosis unit 50, preventing sulfate ions from forming scale during nanofiltration and reverse osmosis, which would affect the treatment efficiency and service life of the nanofiltration unit 40 and the reverse osmosis unit 50. Compared to traditional processes that require large amounts of sodium carbonate to remove calcium ions, this calcium chloride wastewater treatment device offers advantages such as low cost and high resource conversion rate.
[0035] In some embodiments, the pretreatment unit 10 includes a mixing processor 11, a coagulant storage tank 12, and a filter 13. The coagulant storage tank 12 is connected to the mixing processor 11 and is used to add coagulant to the calcium chloride wastewater in the mixing processor 11 to cause the colloids in the calcium chloride wastewater to coagulate and form coagulates. The filter 13 is connected to the outlet of the mixing processor 11 and is used to filter and remove the coagulates formed in the calcium chloride wastewater.
[0036] This application introduces a coagulant into calcium chloride wastewater to coagulate and precipitate colloids and organic matter in the wastewater, thereby removing them through filtration, reducing the impact on the ultrafiltration unit 30, and improving the service life of the ultrafiltration unit 30.
[0037] Optionally, the coagulant filled in the coagulant storage tank 12 can be a commonly used coagulant such as PAC (polyaluminum chloride).
[0038] In some embodiments, filter 13 may be a plate and frame filter 13.
[0039] In some embodiments, the pretreatment unit 10 further includes an adsorbent storage tank connected to the mixing processor 11. The adsorbent storage tank is used to add adsorbent to the calcium chloride wastewater in the mixing processor 11 to adsorb and remove organic matter from the calcium chloride wastewater.
[0040] This application adds an adsorbent to the calcium chloride wastewater in the pretreatment unit 10, and uses the adsorbent to adsorb and remove organic matter in the calcium chloride wastewater, thereby avoiding damage to the ultrafiltration unit 30.
[0041] Optionally, the adsorbent filled in the adsorbent storage tank may be activated carbon or the like.
[0042] In some embodiments, the sulfate removal mechanism 20 is connected to a sulfate removal agent storage tank 21, which is used to add sulfate removal agent to the sulfate removal mechanism 20 to remove sulfate from the calcium chloride wastewater in the sulfate removal mechanism 20.
[0043] This application uses a sulfate removal agent to remove sulfate ions from calcium chloride wastewater, thereby effectively preventing the formation of calcium sulfate precipitates during ultrafiltration, nanofiltration, and reverse osmosis, and improving the filtration efficiency and service life of ultrafiltration, nanofiltration, and reverse osmosis.
[0044] In some embodiments, the sulfate removal agent storage tank 21 is filled with barium salt, ettringite, or sulfate adsorption resin.
[0045] In some embodiments, the calcium chloride wastewater treatment device further includes a first evaporation mechanism 60, which is connected to the drain end of the first concentrated water in the nanofiltration mechanism 40. The first evaporation mechanism 60 is used to evaporate the first concentrated water to form calcium chloride.
[0046] In some embodiments, the first evaporation mechanism 60 includes an evaporator 61 and a spray dryer 62. The evaporator 61 is used to evaporate and concentrate the first concentrated water, and the spray dryer 62 is used to spray dry the evaporated and concentrated first concentrated water to form calcium chloride. Optionally, the mass concentration of the first concentrated water after evaporation and concentration is 30% to 50%.
[0047] In some embodiments, the calcium chloride wastewater treatment device further includes a second evaporation mechanism 70, which is connected to the drain end of the second concentrated water in the reverse osmosis mechanism 50. The second evaporation mechanism 70 is used to evaporate the second concentrated water to form sodium chloride.
[0048] In some embodiments, the calcium chloride wastewater treatment device further includes a recycled water storage tank 80, which is connected to the drain end of the second product water in the reverse osmosis unit 50 for collecting the second product water. It is understood that the second product water meets the requirements for recycled water and can be recovered and reused.
[0049] In some embodiments, the calcium chloride wastewater treatment device further includes an equalization tank 90, which is connected to the inlet of the pretreatment unit 10. The equalization tank 90 is used to store the calcium chloride wastewater. By storing the calcium chloride wastewater in the equalization tank 90, this application ensures the stability of the composition of the calcium chloride wastewater during the treatment process and avoids fluctuations in the composition of the calcium chloride wastewater from affecting the treatment effect.
[0050] It is understood that agitators can be installed in various mechanisms and devices of the calcium chloride wastewater treatment device of this application to improve treatment efficiency.
[0051] Exemplarily, a method for treating fracturing flowback fluid using the aforementioned calcium chloride wastewater treatment device is provided, comprising the following steps:
[0052] S1. Pass the fracturing flowback fluid into the equalization tank 90 and let it stand for storage;
[0053] S2. The fracturing flowback fluid in the equalization tank 90 is fed into the mixing processor 11. Then, coagulant is added through the coagulant storage tank 12 to coagulate and remove colloids. Adsorbent is introduced through the adsorbent storage tank to remove organic matter. After stirring and reacting for a period of time, the treated fracturing flowback fluid is fed into the filter 13 for filtration.
[0054] S3. Pass the calcium chloride wastewater filtered in step S2 into the sulfate removal unit 20, add sulfate removal agent into the sulfate removal unit 20, stir and react for a period of time to remove sulfate precipitate, and then pass it into the ultrafiltration unit 30 to remove colloids, etc.
[0055] S4. The calcium chloride wastewater after ultrafiltration in step S3 is passed into nanofiltration unit 40 and concentrated to obtain first product water containing sodium chloride and first concentrated water containing calcium chloride.
[0056] S5. The first concentrated water from step S4 is passed into evaporator 61 for evaporation and concentration to a mass concentration of 30%~50%, and then passed into spray dryer 62 for spray drying to form wastewater calcium chloride.
[0057] S6. The first product water from step S4 is passed into the reverse osmosis unit 50 for concentration treatment to form the second product water and the second concentrated water containing sodium chloride. The second product water is passed into the recycled water storage tank 80 for collection, and the second concentrated water is passed into the second evaporation unit 70, such as an evaporation crystallizer, for evaporation and crystallization to form sodium chloride.
[0058] In summary, this application pre-treats calcium chloride wastewater by using a sulfate removal unit 20 to remove sulfate ions and their precipitates, and an ultrafiltration unit 30 to remove colloids. This allows for concentration treatment of the calcium chloride wastewater using a nanofiltration unit 40 and a reverse osmosis unit 50, preventing sulfate ions from forming scale during nanofiltration and reverse osmosis, which would affect the treatment efficiency and service life of the nanofiltration unit 40 and the reverse osmosis unit 50. Compared to traditional processes that require large amounts of sodium carbonate to remove calcium ions, this calcium chloride wastewater treatment device offers advantages such as low cost and high resource conversion rate.
[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0060] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A calcium chloride wastewater treatment device, characterized in that, The calcium chloride wastewater treatment device includes: The pretreatment unit is used to coagulate and filter calcium chloride wastewater to remove colloids; A sulfate removal mechanism is connected to the drain end of the pretreatment mechanism and is used to remove sulfate from the calcium chloride wastewater. An ultrafiltration unit is connected to the drain end of the sulfate removal unit. The ultrafiltration unit is used to filter the calcium chloride wastewater and remove particulate matter from the calcium chloride wastewater. A nanofiltration unit, connected to the drain end of the ultrafiltration unit, is used to concentrate the calcium chloride wastewater to form a first product water containing sodium chloride and a first concentrated water containing calcium chloride; and, A reverse osmosis unit is connected to the drain end of the first product water in the nanofiltration unit. The reverse osmosis unit is used to concentrate the first product water to form a second product water and a second concentrated water containing sodium chloride.
2. The calcium chloride wastewater treatment device as described in claim 1, characterized in that, The pretreatment unit includes a mixing processor, a coagulant storage tank, and a filter. The coagulant storage tank is connected to the mixing processor and is used to add coagulant to the calcium chloride wastewater in the mixing processor so that the colloids in the calcium chloride wastewater coagulate to form coagulates. The filter is connected to the outlet of the mixing processor and is used to filter out the coagulants formed in the calcium chloride wastewater.
3. The calcium chloride wastewater treatment device as described in claim 2, characterized in that, The pretreatment unit also includes an adsorbent storage tank connected to the mixing processor. The adsorbent storage tank is used to add adsorbent to the calcium chloride wastewater in the mixing processor to adsorb and remove organic matter from the calcium chloride wastewater.
4. The calcium chloride wastewater treatment device as described in claim 1, characterized in that, The sulfate removal mechanism is connected to a sulfate removal agent storage tank, which is used to add sulfate removal agent to the sulfate removal mechanism to remove sulfate from the calcium chloride wastewater in the sulfate removal mechanism.
5. The calcium chloride wastewater treatment device as described in claim 4, characterized in that, The sulfate removal agent storage tank is filled with barium salt, calcite, or sulfate adsorption resin.
6. The calcium chloride wastewater treatment device as described in claim 1, characterized in that, The calcium chloride wastewater treatment device further includes a first evaporation mechanism, which is connected to the drain end of the first concentrated water in the nanofiltration mechanism. The first evaporation mechanism is used to evaporate the first concentrated water to form calcium chloride.
7. The calcium chloride wastewater treatment device as described in claim 6, characterized in that, The first evaporation mechanism includes an evaporator and a spray dryer. The evaporator is used to evaporate and concentrate the first concentrated water, and the spray dryer is used to spray dry the evaporated and concentrated first concentrated water to form calcium chloride.
8. The calcium chloride wastewater treatment device according to any one of claims 1-7, characterized in that, The calcium chloride wastewater treatment device further includes a second evaporation mechanism, which is connected to the drain end of the second concentrated water in the reverse osmosis mechanism. The second evaporation mechanism is used to evaporate the second concentrated water to form sodium chloride.
9. The calcium chloride wastewater treatment device according to any one of claims 1-7, characterized in that, The calcium chloride wastewater treatment device also includes a recycled water storage tank, which is connected to the drain end of the second product water in the reverse osmosis mechanism for collecting the second product water.
10. The calcium chloride wastewater treatment device according to any one of claims 1-7, characterized in that, The calcium chloride wastewater treatment device also includes an equalization tank, which is connected to the inlet of the pretreatment unit and is used to store the calcium chloride wastewater.