Salt-containing wastewater treatment device

Abstract

The utility model discloses a salt-containing wastewater treatment device. The salt-containing wastewater treatment device is provided with a preheating unit, an MVR (mechanical vapor recompression) evaporation system and a triple-effect evaporation system which are sequentially communicated, mVR evaporation is combined with triple-effect evaporation to improve the wastewater treatment capacity and the utilization rate of secondary steam, in addition, the upper part of a double-effect separator is communicated with a heater of a triple-effect separation unit, and the upper part of a triple-effect separator is communicated with a preheating unit, so that heat at multiple positions is fully utilized, the steam consumption is effectively reduced, and the production cost is convenient to control.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a device for treating saline wastewater. Background Art

[0002] Industrial wastewater often contains salt compounds, and the amount of saline wastewater is increasing rapidly. At present, a large amount of saline wastewater generated in wastewater from industries such as new energy, printing and dyeing, papermaking, chemicals, hospitals and pesticides has always been a difficult problem for wastewater treatment in various industries.

[0003] Taking polysilicon production as an example, a large amount of CaCl 2 If the CaCl in the system is not removed in time, 2 , then its CaCl 2 The concentration will become higher and higher, which will have a negative impact on the normal operation of the system. Evaporation and crystallization is an effective way to remove CaCl from the system. 2 The traditional evaporation crystallization adopts single-effect or general multi-effect evaporation system, which has small processing capacity, large steam consumption and high operating cost, which is not conducive to large-scale industrial processing. Utility Model Content

[0004] The utility model aims to provide a salt-containing wastewater treatment device, which is used to solve the defects of the prior art that the treatment capacity is small and the steam consumption is large, resulting in high operating costs.

[0005] In view of this, the solution of the utility model is:

[0006] The salt-containing wastewater treatment device comprises a preheating unit, an MVR evaporation system and a three-effect evaporation system which are connected in sequence; wherein:

[0007] The preheating unit is used to preheat the feed wastewater;

[0008] The three-effect evaporation unit comprises a three-effect separator, a two-effect separator, and a one-effect separator which are connected in sequence, and a heater four, a heater three, and a heater two which are connected in sequence to the separators respectively; the MVR evaporation system is connected to the feed end of the three-effect separator; the upper part of the two-effect separator is connected to the heater four; the upper part of the three-effect separator is connected to the preheating unit.

[0009] Furthermore, the MVR evaporation system includes an MVR separator and a heater 1 connected thereto; the preheating unit includes a hot water tank, the return water end of the heater 1 is connected to the upper part of the hot water tank, the upper part of the three-effect separator is connected to the lower part of the hot water tank via the condenser 2, and the middle part of the hot water tank is connected to the preheating unit.

[0010] Preferably, the return water end of the heater 4 is connected to the upper part of the hot water tank.

[0011] Preferably, the upper portion of the first-effect separator is connected to the upper portion of the hot water tank via a condenser.

[0012] Furthermore, the salt-containing wastewater treatment device also includes a condensed water tank; the return water ends of the heater 2 and the heater 3 are respectively connected to the condensed water tank.

[0013] Preferably, the preheating unit comprises preheater 1 and preheater 2 connected in series, and preheater 2 is connected to the feed end of the MVR evaporation system; the upper part of the three-effect separator is connected to preheater 1, and the return water end of preheater 2 is connected to the condensed water tank.

[0014] Further, the first-effect separator is connected to a first vacuum pump; and / or the third-effect separator is connected to a second vacuum pump.

[0015] Furthermore, the salt-containing wastewater treatment device also includes a crystal slicer arranged at the discharge end of the first-effect separator.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] The salt-containing wastewater treatment device of the utility model is provided with a preheating unit, an MVR evaporation system and a triple-effect evaporation system which are connected in sequence; the MVR evaporation is combined with the triple-effect evaporation to improve the wastewater treatment capacity and the utilization rate of the secondary steam; in addition, the upper part of the second-effect separator is connected to the heater of the triple-effect separation unit, and the upper part of the triple-effect separator is connected to the preheating unit, so that full utilization of heat in multiple places is achieved, steam consumption is effectively reduced, and production cost is convenient to control. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an overall schematic diagram of the saline wastewater treatment device provided by the utility model.

[0019] Among them: 1. MVR separator; 2. Three-effect evaporation system; 3. Hot water tank; 4. Condensate tank; 5. Crystal slicer; 11. Compressor; 21. Single-effect separator; 22. Double-effect separator; 23. Three-effect separator; C1. Condenser 1; C2. Condenser 2; E1. Preheater 1; E2. Preheater 2; P1. Circulating pump 1; P2. Circulating pump 2; P3. Circulating pump 3; P4. Circulating pump 4; S1. Heater 1; S2. Heater 2; S3. Heater 3; S4. Heater 4; V1. Vacuum pump 1; V2. Vacuum pump 2; The double arrows in the figure represent the material pipeline and its direction, and the single arrows represent the steam or condensate return pipeline and its direction. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] It should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installation", "connection", "connection", "fixation", "setting" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be determined according to specific circumstances.

[0023] In one embodiment, Figure 1 As shown, a salt-containing wastewater treatment device is provided, comprising a preheating unit, an MVR evaporation system and a triple-effect evaporation system 2 connected in sequence; wherein:

[0024] The preheating unit is used to preheat the feed wastewater;

[0025] The MVR evaporation system includes an MVR separator 1 and a heater S1 and a compressor 11 connected thereto; the heater S1 is used to circulate and heat the material, and the compressor 11 compresses the secondary steam generated at the top of the MVR separator 1 and provides heat energy to the heater S1; the material is concentrated to a certain concentration and then transported to the three-effect evaporation unit 2 through the bottom of the MVR separator 1;

[0026] The three-effect evaporation unit 2 includes a three-effect separator 23, a two-effect separator 22, and a one-effect separator 21 which are connected in sequence, and are connected in sequence with a heater four S4, a heater three S3, and a heater two S2 to supply heat to the material. After the material in the previous one-effect separator is concentrated to a certain concentration, it is taken out from the bottom and enters the next one-effect separator for concentration; the MVR evaporation system is connected to the feed end of the three-effect separator 23; the upper part of the two-effect separator 22 is connected to the heater four S4; the upper part of the three-effect separator 23 is connected to the preheating unit.

[0027] When the above-mentioned production system is working, the salt-containing wastewater is first preheated through the preheating unit and enters the MVR evaporation system. The steam generated by the MVR evaporation system during the evaporation process is used for self-heating, and the material is quickly concentrated and enters the three-effect evaporation unit 2, which effectively improves the wastewater treatment capacity; in addition, the upper part of the second-effect separator 22 is connected to the heater four S4, and the upper part of the three-effect separator 23 is connected to the preheating unit, the steam generated by the material in the second-effect separator 22 is used to heat the three-effect separator 23, and the steam generated by the material in the three-effect separator 23 is used to preheat the preheating unit, so that full utilization of heat in multiple places is achieved, steam consumption is effectively reduced, and production costs are convenient to control.

[0028] In the above embodiment, the wastewater concentration increases from the MVR separator 1, the three-effect separator 23, the two-effect separator 22, and the first-effect separator 21 in sequence. Under the same conditions, the greater the energy required for evaporation, the heater 2 S2 can be used to heat the first-effect separator 21 using medium-pressure steam alone, while the heater 3 S3 can use low-pressure steam to heat the two-effect separator 22 to achieve a higher production capacity with a lower steam cost.

[0029] In a preferred embodiment, the preheating unit includes a hot water tank 3, the return water end of the heater S1 is connected to the upper part of the hot water tank 3, the upper part of the three-effect separator 23 is connected to the lower part of the hot water tank 3 via the condenser C2, and the middle part of the hot water tank 3 is connected to the preheating unit. The hot water tank 3 collects the material steam return water with heat recovered from the condenser C2 and the heating steam return water of the heater S1, which can collect the salt content of the material steam return water on the one hand, and collect heat for preheating the preheating unit on the other hand.

[0030] In a more preferred embodiment, the return water end of the heater 24 S4 is connected to the upper part of the hot water tank 3. Since the heater 24 S4 uses the steam generated by the material itself in the second-effect separator 22, it may also contain salts that need to be collected in the hot water tank 3 and recycled for energy. Similarly, the upper part of the first-effect separator 21 is connected to the condenser 1 C1, and is further connected to the upper part of the hot water tank 3 to recover the steam return water and energy of the material containing salt from the first-effect separator 21.

[0031] In a preferred embodiment, the salt-containing wastewater treatment device also includes a condensate tank 4; the return water ends of the heater 2 S2 and the heater 3 S3 are respectively connected to the condensate tank 4; the condensate tank 4 is used to collect steam return water generated by external non-materials, which does not contain salt and does not require additional treatment.

[0032] In a more preferred embodiment, Figure 1In the embodiment, the preheating unit includes a preheater E1 and a preheater E2 connected in series, and the preheater E2 is connected to the feed end of the MVR evaporation system; the middle of the hot water tank 3 is connected to the preheater E1, and the return end of the preheater E2 is connected to the condensed water tank 4. The heat supply from the hot water tank 3 to the preheater E1 is relatively stable, and the preheater E2 only needs to be connected to low-pressure steam to meet the preheating requirements of the wastewater, thereby reducing energy consumption while ensuring the wastewater treatment efficiency.

[0033] In the above embodiment, in order to reduce energy consumption, the first-effect separator 21 is connected to a vacuum pump 1 V1; the third-effect separator 23 is connected to a vacuum pump 2 V2, and concentration is performed under a low-pressure environment to improve processing efficiency and energy consumption.

[0034] In a preferred embodiment, the salt-containing wastewater treatment device further includes a crystal slicer 5 disposed at the discharge end of the first-effect separator 21, which is used to slice the discharged salt crystals to facilitate subsequent transportation processes.

[0035] In the above embodiments, the salt-containing wastewater treatment device also includes a circulation pump 1 P1, a circulation pump 2 P2, a circulation pump 3 P3, a circulation pump 4 P4 for circulating and transporting materials in the MVR separator 1, the first effect separator 21, the second effect separator 22, and the third effect separator 23, respectively, and a circulation pump 5 P5 connected to the hot water tank 3 and used to pump hot water.

[0036] In the above embodiments, the high-salt wastewater treatment device also includes valves, instruments and meters commonly used in the art, and their settings and functions are conventional means and will not be repeated here.

[0037] In the above embodiments, the salt-containing wastewater treatment device can, on the one hand, make full use of the MVR evaporation system and the three-effect evaporation system to improve the treatment efficiency, and also make full use of the steam energy generated by each evaporation, and only use a small amount of external steam to achieve efficient wastewater treatment; on the other hand, the steam return water collection from two sources is realized by separately arranged hot water tank 3 and condensed water tank 4, which is clean and reliable.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A salt-containing wastewater treatment device, characterized in that: It comprises a preheating unit, an MVR evaporation system and a three-effect evaporation system (2) which are connected in sequence; wherein: The preheating unit is used to preheat the feed wastewater; The three-effect evaporation system (2) comprises a three-effect separator (23), a two-effect separator (22), and a one-effect separator (21) which are connected in sequence, and a heater four (S4), a heater three (S3), and a heater two (S2) which are connected in sequence to the separators respectively; the MVR evaporation system is connected to the feed end of the three-effect separator (23); the upper part of the two-effect separator (22) is connected to the heater four (S4); and the upper part of the three-effect separator (23) is connected to the preheating unit.

2. The device according to claim 1, characterized in that The MVR evaporation system comprises an MVR separator (1) and a heater 1 (S1) connected thereto; the preheating unit comprises a hot water tank (3); the return water end of the heater 1 (S1) is connected to the upper part of the hot water tank (3); the upper part of the three-effect separator (23) is connected to the lower part of the hot water tank (3) via a condenser 2 (C2); and the middle part of the hot water tank (3) is connected to the preheating unit.

3. The device according to claim 2, characterized in that The return water end of the heater four (S4) is connected to the upper part of the hot water tank (3).

4. The device according to claim 2, characterized in that The upper part of the first-effect separator (21) is connected to the upper part of the hot water tank (3) via the condenser 1 (C1).

5. The device according to claim 1, characterized in that It also includes a condensed water tank (4); the return water ends of the second heater (S2) and the third heater (S3) are respectively connected to the condensed water tank (4).

6. The device according to claim 5, characterized in that The preheating unit comprises a preheater 1 (E1) and a preheater 2 (E2) connected in series, and the preheater 2 (E2) is connected to the feed end of the MVR evaporation system; the upper part of the three-effect separator (23) is connected to the preheater 1 (E1), and the return water end of the preheater 2 (E2) is connected to the condensed water tank (4).

7. The device according to claim 1, characterized in that The first-effect separator (21) is connected to a vacuum pump one (V1); and / or the third-effect separator (23) is connected to a vacuum pump two (V2).

8. The device according to claim 1, characterized in that It also includes a crystal slicer (5) arranged at the discharge end of the first-effect separator (21).

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