Forced circulation evaporation device for treating high-salinity wastewater

Abstract

The utility model provides a forced circulation evaporation device for treating high salinity wastewater, which comprises a crystallizer, a first heater and a circulating pump, the crystallizer is provided with a circulating feed port and a circulating discharge port, the bottom of the crystallizer is provided with a salt leg, and the salt leg is provided with an anti-settling port and a mother liquor elutriation port. One end of the first heater is connected with the outlet end of the circulating pump through a first conveying pipe, the other end of the first heater is connected with the circulating feeding port through a second conveying pipe, a third conveying pipe connected with the anti-settling port is arranged on the second conveying pipe, and the inlet end of the circulating pump is connected with the circulating discharging port through a fourth conveying pipe. The fourth conveying pipe is provided with a mother liquor discharging pipe, the mother liquor washing opening is connected with a first feeding pipe, and the first feeding pipe is provided with a second feeding pipe connected with the fourth conveying pipe. According to the utility model, salt crystals larger than the target particle size can be gathered in the salt leg, the concentration multiple of the system can be improved, the COD (Chemical Oxygen Demand) circulating concentration is improved, the mother liquor discharge is reduced, and the cleaning period of the crystallizer is greatly shortened.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-salt wastewater treatment, in particular to a forced circulation evaporation device for treating high-salt wastewater. Background Art

[0002] Common salts in high-salt wastewater include sodium chloride, potassium chloride, ammonium sulfate, etc., and usually contain a certain amount of COD and other impurities. They are basically treated by evaporation crystallization and salt precipitation. High-salt wastewater is gradually evaporated in the evaporation crystallizer, and the COD and other impurity contents in the wastewater gradually increase, resulting in smaller and smaller salt crystals, lower salt quality, and higher boiling points. Regardless of the particle size, once the salt crystals in the evaporation crystallizer fall into the salt legs, they can no longer return to the crystallization area and can no longer continue to grow. They can only go to the thickener for centrifugal separation, which leads to increased thermal resistance of the heat exchanger fouling and decreased evaporation efficiency, which is manifested as steaming failure. In severe cases, the salt crystals are too small to be separated by the centrifuge, causing production to stop. A more effective way is to continuously extract COD and other impurities to achieve stable operation of the system and normal growth of crystals. However, the discharge of a large amount of mother liquor undoubtedly increases the disposal cost and risk. Utility Model Content

[0003] The purpose of the utility model is to provide a forced circulation evaporation device for treating high-salt wastewater, which can accumulate salt crystals larger than the target particle size in the salt leg, increase the system concentration multiple, reduce the mother liquor discharge, and significantly shorten the crystallizer cleaning cycle.

[0004] The utility model is realized through the following technical solutions:

[0005] A forced circulation evaporation device for treating high-salt wastewater includes a crystallizer, a first heater and a circulation pump, wherein the crystallizer is provided with a circulation feed port and a circulation discharge port, the bottom of the crystallizer is provided with a salt leg, the salt leg is provided with an anti-sedimentation port and a mother liquor washing port, one end of the first heater is connected to the outlet end of the circulation pump through a first delivery pipe, the other end of the first heater is connected to the circulation feed port through a second delivery pipe, the second delivery pipe is provided with a third delivery pipe connected to the anti-sedimentation port, the inlet end of the circulation pump is connected to the circulation discharge port through a fourth delivery pipe, the fourth delivery pipe is provided with a mother liquor effluent pipe, the mother liquor effluent pipe is provided with an effluent valve, the mother liquor effluent port is connected to the first feed pipe, and the first feed pipe is provided with a second feed pipe connected to the fourth delivery pipe.

[0006] Furthermore, it also includes a second heater, which is arranged at the position where the fourth conveying pipe is located between the second feeding pipe and the circulation pump.

[0007] Furthermore, a first viewing mirror and a second viewing mirror are provided on the side wall of the salt leg, and the height of the second viewing mirror is higher than that of the first viewing mirror.

[0008] Furthermore, the first feed pipe is provided with a feed elutriation valve, and the third delivery pipe is provided with an anti-sedimentation elutriation valve.

[0009] Furthermore, a COD concentration screening device is provided on the fourth conveying pipe at a position between the circulating discharge port and the second feed pipe.

[0010] Compared with the existing technology, the beneficial effects of the present invention are as follows: using saturated superheated material from a circulating pump to perform countercurrent flotation on the salt crystals in the salt legs, since the upward flow velocity in the salt legs is greater than the natural sedimentation velocity of the target salt crystal particle size, the salt crystals larger than the target particle size continue to sink to the bottom of the salt legs, and the salt crystals smaller than the target particle size float upward and return to the crystallizer to continue growing, so that the salt crystals gathered in the salt legs are all larger than the target particle size; the mother liquor washing flow is controlled by a valve to adjust the liquid level and the salt leg concentration difference, thereby increasing the circulating concentration of COD in the system and reducing the amount of mother liquor discharged to increase the system concentration multiple; during production, the external discharge valve can be opened intermittently or continuously according to actual conditions, and the discharge of high-concentration COD and other impurities can be accurately controlled by combining flow control and other methods, thereby greatly shortening the crystallizer cleaning cycle. The present invention has a wide range of applications and can be applied to the crystallization of high-salt and high-COD salts such as sodium sulfate, sodium chloride, and ammonium sulfate. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a structural schematic diagram of the forced circulation evaporation device for treating high-salt wastewater in the utility model.

[0012] In the figure, 1-crystallizer, 2-first heater, 3-circulation pump, 4-salt leg, 5-first delivery pipe, 6-second delivery pipe, 7-third delivery pipe, 8-fourth delivery pipe, 9-mother liquor effluent pipe, 10-effluent valve, 11-first feed pipe, 12-second feed pipe, 13-second heater, 14-first sight glass, 15-second sight glass, 16-feed elutriation valve, 17-anti-sedimentation elutriation valve, 18-COD screening and concentration device. DETAILED DESCRIPTION

[0013] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0014] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0015] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this utility model, the terms "first", "second", etc. are used only to distinguish the description and should not be understood as indicating or implying relative importance.

[0016] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0017] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the present invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as a limitation on the present invention.

[0018] See also Figure 1 , Figure 1The present invention is a schematic structural diagram of a forced circulation evaporation device for treating high-salt wastewater. A forced circulation evaporation device for treating high-salt wastewater comprises a crystallizer 1, a first heater 2, and a circulation pump 3. The crystallizer 1 is provided with a circulation feed port and a circulation discharge port. The bottom of the crystallizer 1 is provided with a salt leg 4, which is provided with an anti-sedimentation port and a mother liquor elutriation port. One end of the first heater 2 is connected to the outlet end of the circulation pump 3 via a first delivery pipe 5, and the other end of the first heater 2 is connected to the circulation feed port via a second delivery pipe 6. The second delivery pipe 6 is provided with a third delivery pipe 7 connected to the anti-sedimentation port. The inlet end of the circulation pump 3 is connected to the circulation discharge port via a fourth delivery pipe 8. The fourth delivery pipe 8 is provided with a mother liquor effluent pipe 9, which is provided with an effluent valve 10. The mother liquor effluent pipe 9 is connected to the mother liquor elutriation port. The first feed pipe 11 is connected to the mother liquor elutriation port. The first feed pipe 11 is provided with a second feed pipe 12 connected to the fourth delivery pipe 8.

[0019] The utility model is a forced circulation evaporation device for treating high-salt wastewater when in use. The saturated materials such as evaporation feed or reflux mother liquor are pumped into the salt leg 4 through the circulation pump 3. The saturated materials are heated by the first heater 2 during the pumping process. The salt crystals in the salt leg 4 are subjected to countercurrent flotation by the heated saturated superheated materials. Since the upward flow velocity in the salt leg 4 is greater than the natural sedimentation velocity of the target salt crystal particle size, the salt crystals larger than the target particle size continue to sink to the bottom of the salt leg 4, and the salt crystals smaller than the target particle size float upward and return to the crystallizer 1 to continue growing. , so that the salt crystals gathered in the salt leg 4 are all larger than the target particle size. At this time, the salt crystals that meet the target particle size can be transported out through the salt discharge port at the bottom of the salt leg 4; the mother liquor washing flow is controlled by the valve to adjust the liquid level and the concentration difference of the salt leg 4, thereby increasing the circulating concentration of COD in the large system and reducing the amount of mother liquor discharged, so as to achieve an increase in the system concentration multiple; during production, the discharge valve 10 on the mother liquor discharge pipe 9 can be opened intermittently or continuously according to actual conditions, and a small amount of high-concentration COD and other impurities can be discharged in combination with flow control, thereby greatly shortening the cleaning cycle of the crystallizer 1.

[0020] In one embodiment, the forced circulation evaporation device for treating high-salinity wastewater of the present invention further includes a second heater 13, which is disposed on the fourth delivery pipe 8 between the second feed pipe 12 and the circulation pump 3. This dual heater arrangement improves the superheat of the single pipe, enhances the fine crystal elimination function, and maximizes evaporation efficiency through clear liquid circulation.

[0021] In one embodiment, a first sight glass 14 and a second sight glass 15 are provided on the side wall of the salt leg 4. The height of the second sight glass 15 is higher than that of the first sight glass 14. The interior of the salt leg 4 can be observed through the first sight glass 14 and the second sight glass 15, so as to facilitate adjustment of the upward flow rate of the material in the salt leg 4.

[0022] In one embodiment, a feed elutriation valve 16 is provided on the first feed pipe 11, and an anti-sedimentation elutriation valve 17 is provided on the third delivery pipe 7. The feed elutriation valve 16 and the anti-sedimentation elutriation valve 17 control the delivery of materials from the salt leg 4.

[0023] In one embodiment, a COD screening and concentration device 18 is provided on the fourth conveying pipe 8 between the circulating discharge port and the second feed pipe 12. The COD screening and concentration device 18 can increase the concentration of COD.

[0024] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A forced circulation evaporation device for treating high-salt wastewater, characterized in that: It includes a crystallizer, a first heater and a circulation pump, the crystallizer is provided with a circulation feed port and a circulation discharge port, the bottom of the crystallizer is provided with a salt leg, the salt leg is provided with an anti-sedimentation port and a mother liquor washing port, one end of the first heater is connected to the outlet end of the circulation pump through a first delivery pipe, the other end of the first heater is connected to the circulation feed port through a second delivery pipe, the second delivery pipe is provided with a third delivery pipe connected to the anti-sedimentation port, the inlet end of the circulation pump is connected to the circulation discharge port through a fourth delivery pipe, the fourth delivery pipe is provided with a mother liquor effluent pipe, the mother liquor effluent pipe is provided with an effluent valve, the mother liquor washing port is connected to the first feed pipe, and the first feed pipe is provided with a second feed pipe connected to the fourth delivery pipe.

2. The forced circulation evaporation device for treating high-salt wastewater according to claim 1, characterized in that: The device further comprises a second heater, which is arranged on the fourth conveying pipe at a position where the second feed pipe and the circulation pump are located.

3. The forced circulation evaporation device for treating high-salt wastewater according to claim 1, characterized in that: A first viewing mirror and a second viewing mirror are provided on the side wall of the salt leg, and the height of the second viewing mirror is higher than that of the first viewing mirror.

4. The forced circulation evaporation device for treating high-salt wastewater according to claim 1, characterized in that: The first feed pipe is provided with a feed elutriation valve, and the third delivery pipe is provided with an anti-sedimentation elutriation valve.

5. The forced circulation evaporation device for treating high-salt wastewater according to claim 1, characterized in that: A COD concentration screening device is provided on the fourth conveying pipe at a position between the circulating discharge port and the second feed pipe.

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