Ultrasonic integrated calcium and magnesium removal-saline water recovery device

Abstract

The utility model relates to an ultrasonic integrated calcium and magnesium removal-saline water recovery device. The device comprises a calcium removal unit, a magnesium removal unit and a saline water recovery unit which are connected in sequence, wherein each unit comprises a stirring paddle type or ultrasonic mixer and a filter. The wastewater is pumped to a calcium removal unit by a booster pump and reacts with additional sodium carbonate to generate calcium carbonate precipitate, and calcium removal is completed after solid-liquid separation; the filtrate enters a magnesium removal unit and reacts with additional sodium hydroxide to generate magnesium hydroxide precipitate, and magnesium removal is completed after solid-liquid separation; the filtrate enters a saline water recovery unit to react with additional hydrochloric acid, redundant sodium carbonate and sodium hydroxide are consumed and converted into sodium chloride, and the sodium chloride enters a saline water collection tank for standby application after being filtered. The whole set of equipment provided by the utility model has a series of advantages of small occupied area, high automation degree, low equipment investment, low operation and maintenance cost and the like, is simple in process and good in effect when being used for treating wastewater, and can recycle water resources and save the purchase of industrial salt at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment equipment, in particular to an ultrasonic integrated calcium and magnesium removal-brine water recovery device. Background Art

[0002] At present, it is difficult to treat industrial wastewater. The large investment in equipment and high operation and maintenance costs have always been a major problem that plagues industrial enterprises. In the process of industrial wastewater treatment, there is a resin softening and regeneration process, during which the resin must be regenerated with industrial salt (sodium chloride). The concentrated brine produced by backwashing the resin contains a large amount of calcium, magnesium ions and industrial salts. These components will not only corrode and damage metal pipes, but also cause serious damage to the environment once discharged to the outside world. If they penetrate into the soil, they will cause soil compaction.

[0003] For this type of waste liquid, the common treatment process at this stage is evaporation and crystallization. However, this treatment method not only consumes a lot of energy, but also has high equipment costs and operating costs. It is estimated that the various costs of treating one ton of the above concentrated brine will cost at least 1 million yuan. In addition, the operating cost of this treatment process is also very high, and it produces a lot of solid waste, which is very difficult to treat. Utility Model Content

[0004] The purpose of the utility model is to overcome the above-mentioned problems existing in the prior art and to provide an ultrasonic integrated calcium and magnesium removal-brine recovery device, which includes a calcium removal unit, a magnesium removal unit and a brine recovery unit. The three units are connected by pipelines, and the wastewater passes through the calcium removal unit and the magnesium removal unit in turn and then enters the brine recovery unit, thereby successively completing the removal and separation of calcium and magnesium in the wastewater and the recovery of brine.

[0005] Furthermore, the decalcification unit includes a No. 1 mixer and a No. 1 filter. The No. 1 mixer is connected to the No. 1 filter via a pipeline, and the No. 1 filter is connected to the magnesium removal unit via a pipeline.

[0006] Furthermore, the mixer No. 1 includes a tank body, a stirring paddle or an ultrasonic transducer, and a sodium carbonate dosing device, wherein the stirring paddle or the ultrasonic transducer is fixed inside the tank body, and the sodium carbonate dosing device is arranged on the top or side wall of the tank body. Both the stirring paddle and the ultrasonic transducer can complete the mixing of materials, preferably the ultrasonic transducer. This is because ultrasound has the effects and characteristics of cavitation, activation, heating and temperature rise, and can accelerate the full play of the external agent in each link, shorten the processing time of each link, thereby improving production efficiency and reducing costs.

[0007] Furthermore, the magnesium removal unit includes a No. 2 mixer and a No. 2 filter. The No. 2 mixer is connected to the decalcification unit and the No. 2 filter through pipelines, and the No. 2 filter is connected to the brine recovery unit through a pipeline.

[0008] Furthermore, the second mixer includes a tank body, a stirring paddle or an ultrasonic transducer, and a sodium hydroxide dosing device. The stirring paddle or the ultrasonic transducer is fixed inside the tank body, and the sodium hydroxide dosing device is arranged on the top or side wall of the tank body.

[0009] Furthermore, the brine recovery unit includes a No. 3 mixer, a No. 3 filter, and a brine collection tank. The No. 3 mixer is connected to the magnesium removal unit and the No. 3 filter through pipelines, and the No. 3 filter is connected to the brine collection tank through a pipeline.

[0010] Furthermore, the third mixer includes a tank body, a stirring paddle or an ultrasonic transducer, and a hydrochloric acid dosing device. The stirring paddle or the ultrasonic transducer is fixed inside the tank body, and the hydrochloric acid dosing device is arranged on the top or side wall of the tank body.

[0011] Furthermore, the ultrasonic transducers are all pulsed, and their structures can refer to our earlier patent achievement CN2015559822U.

[0012] Furthermore, the device also includes a booster pump, which is connected to the decalcification unit through a pipeline. The main function of the booster pump is to transport wastewater into the decalcification unit, the magnesium removal unit and the brine recovery unit for corresponding treatment.

[0013] Furthermore, the device also includes an electric control unit, which is electrically connected to the decalcification unit, the magnesium removal unit, and the brine recovery unit and controls the operation states of the respective switches. The electric control unit includes electrical devices such as a controller (such as a microcomputer), a sensor, a flow meter, and a switch (such as a solenoid valve, a relay).

[0014] The utility model aims at the current situation that wastewater containing calcium, magnesium and industrial salt (such as resin regeneration brine) is difficult to treat, has high cost and complicated process, and provides a novel complete set of treatment equipment. Through the chemical reactions of calcium precipitation and magnesium precipitation occurring in the calcium removal unit and the magnesium removal unit, calcium and magnesium in the wastewater are precipitated, separated and removed in sequence effectively and at low cost, during which not only other impurities are not introduced, but also the added reagents and the original substances in the wastewater can be converted into sodium chloride and recycled, and basically no waste liquid or waste residue is generated.

[0015] The order of the magnesium removal unit and the calcium removal unit in the utility model cannot be interchanged, because: first, the magnesium content in the wastewater is low and the calcium content is high. If the magnesium is removed first and then the calcium is removed, the wastewater treatment cost will be much higher; secondly, an instrument for testing the pH value is added at the beginning of the magnesium removal link, and an instrument for testing the pH value is also added in the last link. The amount of hydrochloric acid solution and the speed of addition need to be set by the pH value, so that the final solution is not alkaline (adjusted to neutral), so as to avoid the output sodium chloride solution from adversely affecting the resin in the subsequent resin softening link. The comparative experimental results show that if the positions of the calcium removal unit and the magnesium removal unit are interchanged, the cost of the reagent alone will increase by 35%, because the calcium content in the wastewater is much greater than the magnesium content, and the price of sodium hydroxide used for magnesium precipitation is higher than the price of sodium carbonate used for calcium precipitation.

[0016] Compared with the existing evaporation crystallization process, the beneficial effects of the utility model are embodied in the following aspects:

[0017] (1) The production and operation costs of the entire set of equipment are low. It not only occupies a small area but also has a high degree of automation in operation, which greatly reduces equipment investment costs and operation and maintenance costs;

[0018] (2) The equipment can be operated in an integrated manner, the wastewater treatment process is relatively simple, water resources can be recycled, and the purchase of industrial salt is saved;

[0019] (3) The equipment can separate calcium and magnesium from wastewater and convert them into calcium carbonate and magnesium hydroxide with high economic value. The recovered sodium chloride solution has high purity and can be used directly or further processed into other chemical raw materials, with good comprehensive benefits;

[0020] (4) The problem of treating wastewater from resin softening and regeneration is solved. The entire process produces almost no wastewater, waste residue, or waste gas, and does not require high temperature or high pressure reaction conditions. It has a series of advantages such as energy saving and environmental protection;

[0021] (5) High degree of automation, intelligent online monitoring of the calcium and magnesium content and pH value of the circulating water, and automatic real-time adjustment of the ultrasonic transducer's operating time, power, and dosage of the reagent based on the data, thereby achieving better treatment effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the ultrasonic integrated calcium and magnesium removal-brine recovery device of the utility model.

[0023] Figure 2 It is a schematic diagram of the integrated calcium and magnesium removal-brine recovery device of the utility model.

[0024] Among them, 1-boosting pump, 2-ultrasonic transducer, 3-No. 1 ultrasonic mixer, 4-No. 2 ultrasonic mixer, 5-No. 3 ultrasonic mixer, 6-No. 1 filter, 7-No. 2 filter, 8-No. 3 filter, 9-sodium carbonate dosing device, 10-sodium hydroxide dosing device, 11-hydrochloric acid dosing device, 12-brine collection tank, 13-electronic control unit. DETAILED DESCRIPTION

[0025] In order to enable ordinary technicians in the field to fully understand the technical solutions and beneficial effects of the utility model, further description is given below in conjunction with specific embodiments and drawings.

[0026] like Figure 1 The ultrasonic integrated calcium and magnesium removal and brine recovery device shown in the figure includes, from left to right, a booster pump 1, a calcium removal unit A, a magnesium removal unit B, and a brine recovery unit C, which are connected by pipelines. The calcium removal unit A, the magnesium removal unit B, and the brine recovery unit C have similar structures and each includes a tank (respectively, ultrasonic mixers No. 1 to No. 3, corresponding to Figure 1 3-5), a filter (filters 1 to 3, corresponding to Figure 1 6-8), and the two adjacent tanks and filters are connected by pipelines. An ultrasonic transducer 2 and an automatic dosing device are arranged on the top of each tank, which are divided into a sodium carbonate dosing device 9, a sodium hydroxide dosing device 10, and a hydrochloric acid dosing device 11 according to the different dosing agents. The third filter 8 of the brine recovery unit is connected to the brine collection tank 12 through a pipeline.

[0027] like Figure 2 As shown, in another embodiment of the present invention, part or all of the ultrasonic transducer 2 is replaced by a stirring paddle. Compared with ultrasound, the stirring paddle is less effective, but the cost is also low, and for some customers, it is the best choice because of its high cost performance.

[0028] The operation process and principle of the device are as follows:

[0029] (1) Calcium removal: The wastewater containing calcium, magnesium and industrial salt is pumped by the booster pump 1 to the first ultrasonic mixer 3 of the magnesium removal unit A, and an excess of sodium carbonate is added through the sodium carbonate dosing device 9. The ultrasonic transducer 2 is turned on to allow the materials to be fully mixed and the following reactions occur:

[0030] CaCl 2 +Na 2 CO 3 =CaCO 3 ↓+2NaCl

[0031] The solid-liquid mixture obtained by the reaction is transported to the first filter 6 for filtration, the solid is collected and dried to obtain calcium carbonate, and the filtrate is further transported to the magnesium removal unit B for further treatment.

[0032] (2) Magnesium removal: The filtrate after calcium removal enters the second ultrasonic mixer 4 of the magnesium removal unit B, and excess sodium hydroxide is added through the sodium hydroxide dosing device 10. The ultrasonic transducer 2 is turned on to allow the materials to be fully mixed and the following reactions occur:

[0033] MgCl 2 +2NaOH=Mg(OH) 2 ↓+2NaCl

[0034] The solid-liquid mixture obtained by the reaction is transported to the second filter 7 for filtration, the solid is collected and dried to obtain magnesium hydroxide, and the filtrate is continuously transported to the brine recovery unit C for further treatment.

[0035] (3) Brine recovery: The filtrate after magnesium removal enters the No. 3 ultrasonic mixer 5 of the brine recovery unit C, and an appropriate amount of hydrochloric acid solution is added through the hydrochloric acid dosing device 11. The ultrasonic transducer 2 is turned on to allow the materials to be fully mixed and the following reactions occur:

[0036] Na 2 CO 3 + 2HCl = 2NaCl + CO 2 ↑+H 2 O

[0037] When there are no more bubbles in the No. 3 ultrasonic mixer 5, the addition of the hydrochloric acid solution is stopped, and then the mixture is transported to the No. 3 filter 8 for filtration, and the obtained filtrate is transported to the brine collection tank 12 for standby use.

[0038] Example 1

[0039] The calcium content in the wastewater to be treated is about 12000 mg / L, and the magnesium content is about 2000 mg / L. The relevant process parameters for treatment using the above device are as follows: the mass ratio of sodium carbonate added to the wastewater in the calcium removal unit A = 1:1.2, the ultrasonic power is 1000W, the reaction temperature is 30°C, and the reaction time is about 5s; the mass ratio of sodium hydroxide added to the magnesium removal unit B to the wastewater (filtrate) obtained by magnesium removal = 1:1.2, the ultrasonic power is 500W, the reaction temperature is 30°C, and the reaction time is about 5s; the mass ratio of hydrochloric acid (mass concentration 5%) added to the brine recovery unit C to the wastewater (filtrate) obtained by calcium and magnesium removal = 0.1:100, the ultrasonic power is 1000W, the reaction temperature is 30°C, and the reaction time is about 5s.

[0040] Treatment results: 12 kg / ton wastewater of calcium carbonate with a purity of about 96% and 1.2 kg / ton wastewater of magnesium hydroxide with a purity of about 96% were finally obtained. The mass concentrations of calcium, magnesium and sodium chloride in the brine collection pool were 0.01%, 0.005% and 4% respectively.

[0041] The above results indicate that the complete set of equipment provided by the utility model can indeed effectively treat wastewater, separate high-purity and high-value calcium carbonate and magnesium hydroxide therefrom, and recover a relatively high-purity aqueous sodium chloride solution.

Claims

1. An ultrasonic integrated calcium and magnesium removal-brine recovery device, characterized in that: The device comprises a decalcification unit, a magnesium removal unit and a salt water recovery unit. The decalcification unit and the magnesium removal unit, as well as the magnesium removal unit and the salt water recovery unit are all connected through pipelines. Wastewater flows through the decalcification unit and the magnesium removal unit and enters the salt water recovery unit. The decalcification unit comprises a No. 1 mixer and a No. 1 filter. The No. 1 mixer is connected to the No. 1 filter through a pipeline. The No. 1 filter is connected to the magnesium removal unit through a pipeline. The No. 1 mixer comprises a tank body, a stirring paddle or an ultrasonic transducer, and a sodium carbonate dosing device. The stirring paddle or the ultrasonic transducer is fixed inside the tank body, and the sodium carbonate dosing device is arranged on the top or side wall of the tank body. The magnesium removal unit comprises a No. 2 mixer and a No. 2 filter. The No. 2 mixer is respectively connected to the decalcification unit and the salt water recovery unit through pipelines. The first mixer is connected to a first filter and a second filter, the second filter is connected to the brine recovery unit through a pipeline, the second mixer comprises a tank body, a stirring paddle or an ultrasonic transducer, and a sodium hydroxide dosing device, the stirring paddle or the ultrasonic transducer is fixed inside the tank body, and the sodium hydroxide dosing device is arranged on the top or side wall of the tank body; the brine recovery unit comprises a third mixer, a third filter, and a brine collection tank, the third mixer is connected to the magnesium removal unit and the third filter through pipelines respectively, the third filter is connected to the brine collection tank through a pipeline, the third mixer comprises a tank body, a stirring paddle or an ultrasonic transducer, and a hydrochloric acid dosing device, the stirring paddle or the ultrasonic transducer is fixed inside the tank body, and the hydrochloric acid dosing device is arranged on the top or side wall of the tank body.

2. The device according to claim 1, characterized in that: The ultrasonic transducer is of pulse type.

3. The device according to claim 1, characterized in that: The device also includes a booster pump, which is connected to the decalcification unit through a pipeline.

4. The device according to claim 1, characterized in that: The device also includes an electric control unit, which is electrically connected to the decalcification unit, the magnesium removal unit, and the brine recovery unit to control the operation thereof.

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