阅读说明：本技术 一种基于热烟气与吸附剂的废水回收工艺及系统 (Waste water recovery process and system based on hot flue gas and adsorbent ) 是由 刘昌豹 李栋 李春虎 于 2021-06-08 设计创作，主要内容包括：一种基于热烟气与吸附剂的废水回收工艺及系统,包括以下步骤：在增湿塔的内部装入高比表面积亲水填料,在除湿塔的内部装入吸附剂,在除湿塔内部的底部设置转动除湿轮,将含盐废水换热升温后从增湿塔的顶部向增湿塔的内部喷淋；将热烟气从增湿塔的侧面注入,热烟气与含盐废水及高比表面积亲水填料在增湿塔内部十字错流接触增湿,进行等温水蒸气相变和冷却回收热烟气中的水分,得到回收水；热烟气与吸附剂在除湿塔内部接触,吸附剂吸收热烟气中的水蒸气,由转动除湿轮吸收-挤压所述吸附剂,得到回收水,解决了传统的废水回收方法存在着因回收工艺复杂和回收能耗较高,从而导致回收效率较低的技术问题,废水回收再利用技术领域。(A waste water recovery process and a system based on hot flue gas and an adsorbent comprise the following steps: filling a high-specific-surface-area hydrophilic filler into the humidifying tower, filling an adsorbent into the dehumidifying tower, arranging a rotary dehumidifying wheel at the bottom of the inside of the dehumidifying tower, and spraying salt-containing wastewater from the top of the humidifying tower to the inside of the humidifying tower after heat exchange and temperature rise; injecting hot flue gas from the side surface of the humidifying tower, contacting the hot flue gas with salt-containing wastewater and a hydrophilic filler with a high specific surface area in a cross-shaped cross flow manner in the humidifying tower for humidifying, carrying out isothermal vapor phase change and cooling to recover moisture in the hot flue gas, and obtaining recovered water; the hot flue gas contacts with the adsorbent in the dehumidification tower, the adsorbent absorbs water vapor in the hot flue gas, and the adsorbent is absorbed and extruded by the rotating dehumidification wheel to obtain recovered water, so that the technical problem that the recovery efficiency is low due to the complex recovery process and high recovery energy consumption in the traditional wastewater recovery method is solved, and the technical field of wastewater recovery and reutilization is realized.)

1. A wastewater recovery process based on hot flue gas and adsorbent is used for carrying out recovery treatment on salt-containing wastewater and hot flue gas, and is characterized by comprising the following steps:

s1, filling a high-specific-surface-area hydrophilic filler into a humidifying tower, filling an adsorbent into the dehumidifying tower, arranging a rotary dehumidifying wheel at the bottom of the dehumidifying tower, heating the salt-containing wastewater, and spraying the salt-containing wastewater into the humidifying tower from the top of the humidifying tower;

s2, injecting the hot flue gas from the side face of the humidifying tower, wherein the hot flue gas, the salt-containing wastewater and the hydrophilic filler with the high specific surface area are in cross-flow contact humidification in the humidifying tower, isothermal water vapor phase change is carried out, and moisture in the hot flue gas is cooled and recovered to obtain recovered water;

s3, the hot flue gas is in contact with the adsorbent in the dehumidification tower, the adsorbent absorbs water vapor in the hot flue gas, and the adsorbent is absorbed and extruded by the rotary dehumidification wheel to obtain recovered water.

2. The process of claim 1, wherein the humidifying tower and the dehumidifying tower are at least two, and the recovered water and the flue gas obtained from the S3 are recycled and treated by repeating the steps S1, S2 and S3.

3. The hot flue gas and adsorbent based wastewater recovery process according to claim 1, wherein the high specific surface area hydrophilic packing is a high specific surface area structured packing net, the diameter of the mesh of the high specific surface area structured packing net is 1mm, and the mesh number is 80-120 meshes; the surface of the high specific surface area regular packing net is coated with Al₂O₃-MnO₂And (c) a complex.

4. The process of claim 1, wherein the adsorbent is selected from the group consisting of collodion, diaper, aerosol, and absorbent sponge.

5. The process of claim 1, wherein the hydrophilic high surface area filler has a surface area of 2500m²/m³Bulk density of 320-650 kg/m³The void ratio is 70-90%, the F factor is 1.5-3.5, the wave pitch is 10-55 mm, and the tooth form angle is 30-80.

6. The process for recovering the wastewater based on the hot flue gas and the adsorbent as claimed in claim 1, wherein the temperature increase of the salt-containing wastewater is realized by using a heat exchanger, and the salt-containing wastewater is sprayed from the top of the humidifying tower to the inside of the humidifying tower after being heated by the heat exchanger.

7. The utility model provides a waste water recovery system based on hot flue gas and adsorbent, includes humidification tower and dehumidification tower, the inside of humidification tower is equipped with the regular packing net of high specific surface area, the top of humidification tower is equipped with the waste water entry, the inside of dehumidification tower is equipped with the adsorbent, the inside bottom of dehumidification tower sets up rotates the dehumidification wheel, the bottom of humidification tower with the bottom of dehumidification tower all is equipped with the recovery water export, humidification tower with the outside of dehumidification tower is equipped with heat exchanger and recovery water storage tank, the heat exchanger with waste water entry intercommunication, the recovery water export with recovery water storage tank intercommunication.

8. The hot flue gas and sorbent-based wastewater recovery system of claim 7, wherein the humidifying tower and the dehumidifying tower are both provided in at least two.

9. The hot flue gas and adsorbent based wastewater recovery system of claim 7, wherein said high specific surface area structured packing mesh is disposed at an inclination of 45 ° inside said humidifying tower.

10. The hot flue gas and adsorbent based wastewater recovery system of claim 7, wherein the surface of the high specific surface area structured packing net is provided with a falling film collecting pipe, and the falling film collecting pipe is made of hydrophobic materials such as polypropylene or polytetrafluoroethylene with a diameter of 3-4 mm.

Technical Field

The application relates to the technical field of waste water recycling, in particular to a waste water recycling process and system based on hot flue gas and an adsorbent.

Background

Water is one of the most important natural resources on the earth, is an indispensable important resource in the life and production of people, and is an important element for promoting the sustainable development of the whole society and economy and promoting the progress of industrial civilization, however, underground water and fresh water which can be directly utilized by people unfortunately are not 0.36 percent of the total amount of the underground water and the fresh water, the total amount of Chinese water is 2.8 billion cubic meters and is listed in the 6 th position of the world, but the average water resource amount of people is only 25 percent of the average level in the world, the united nations are one of 13 countries which are listed as the most poor water in the world, and the average water resource amount of people is lower than 3000 cubic meters and is slightly water deficient according to the internationally recognized standard; the average water resource is moderate water shortage below 2000 cubic meters; the average water resource is less than 1000 cubic meters, and the water is severely deficient; the average water resource is less than 500 cubic meters, which is extremely water-deficient. At present, 16 provinces (districts and cities) in China have the per capita water resource amount (excluding the water passing through the border) lower than the serious water shortage line, and 6 provinces and districts (Ningxia, Hebei, Shandong, Henan, Shanxi and Jiangsu) have the per capita water resource amount lower than 500 cubic meters, and are regions with extreme water shortage. The urban water resource in China is extremely short and has wide related problems, the urban water shortage in China is 60 billion cubic meters every year, the economic loss caused by water shortage is about 2000-4000 billion yuan every year, and the related and affected fields comprise: the serious water shortage problem in industry, agriculture, construction industry, resident life and the like causes the modernized construction process of cities and towns, the increase of GDP and the improvement of the living standard of residents in China to be limited.

On the other hand, with the continuous expansion of urban scale and the rapid development of industry, the amount of discharged sewage is also increased, the water quality is deteriorated, and the water body is polluted, thereby affecting the sustainable utilization of water resources. Urban areas and industrial pollution sources are characterized by multiple discharge points, various types of discharged sewage, high discharge intensity, strong liquidity and easy pollution to other water resources, and even if local pollution occurs, the pollution range is gradually enlarged due to the liquidity of water. At present, the concentrated treatment of the total discharge of industrial and urban sewage in China accounts for less than half of the total discharge, most of the rest sewage is directly discharged into rivers, the restriction on the discharge of sewage is not large, and a large amount of water resources are deteriorated. Relevant experts in China analyze that the total water demand of 2050 years in China is 8000 hundred million, and at least 2400 hundred million cubic meters is increased than the current water demand, so that the sustainable development of national economy can be guaranteed. Therefore, the water is greatly saved and the reuse rate of the waste water is improved.

The sea water desalination and ocean chemical industry have unique advantages in coastal water-deficient cities and areas, the membrane separation sea water desalination technology still remains an important development direction of sea water desalination at present, but the key technology of sea water desalination still needs to break through, three key cores, namely, energy recovery, high-pressure pump and membrane material technology and equipment, still are made by people and belong to the technology of 'neck clamping', so that the sea water desalination technology in China and Shandong province has high investment, low income and difficult large-scale popularization, and the novel sea water desalination technology for humidifying and dehumidifying by using the novel high-specific surface area hydrophilic material does not need the high-pressure pump and the membrane material, namely, the sea water desalination technology for utilizing waste heat and efficiently separating and condensing gas and liquid can be applied to occasions such as islands, ships, factories and the like.

The humidifying-dehumidifying type wastewater recovery technology is considered to be one of the most promising technologies; at present, most of humidification-dehumidification processes utilize a heat source to enable hot waste water to be in contact with flowing flue gas so as to humidify the flue gas, then wet flue gas is indirectly condensed through cooling water so as to generate fresh water, or hot flue gas and waste water are in contact with water flue gas in a packed tower so as to become saturated water vapor flue gas, then wet flue gas is indirectly condensed through cooling water so as to generate fresh water, and as heat consumption in the humidification-dehumidification processes is huge, Q is KA (T-KA) according to Newton's cooling theorem₀) (Q is a heat transfer amount; k is the heat transfer coefficient; a is the heat transfer area; T-T₀For heat transfer temperature difference), in order to improve the efficiency of mass transfer and heat transfer, the larger the packing area in the packed tower is, the better the packing area is, and the more hydrophilic the packing area is; the design of the packed tower is very important, the Re number and the K are improved as much as possible, and meanwhile, the adsorption material for recovering saturated water vapor in the flue gas is very heavyFirstly, mixing; in view of the above, the invention designs a device for recovering byproduct fresh water from salt-containing wastewater based on a process technology combination method of high specific surface area regular packing, cross flow bed packing mass transfer, heat exchanger and super water absorption developed in the earlier stage, and the device can also be used for high-temperature flue gas 'white smoke' removal and water vapor recovery.

Disclosure of Invention

The application aims to provide a waste water recovery process and a waste water recovery system based on hot flue gas and an adsorbent, and aims to solve the technical problem that the recovery efficiency is low due to the fact that the recovery process is complex and the recovery energy consumption is high in the traditional waste water recovery method.

The first aspect of the embodiment of the application provides a waste water recovery process based on hot flue gas and adsorbent for carrying out recovery treatment on salt-containing waste water and hot flue gas, which comprises the following steps:

s1, filling a high-specific-surface-area hydrophilic filler into a humidifying tower, filling an adsorbent into the dehumidifying tower, arranging a rotary dehumidifying wheel at the bottom of the dehumidifying tower, heating the salt-containing wastewater, and spraying the salt-containing wastewater into the humidifying tower from the top of the humidifying tower;

s2, injecting the hot flue gas from the side face of the humidifying tower, wherein the hot flue gas, the salt-containing wastewater and the hydrophilic filler with the high specific surface area are in cross-flow contact humidification in the humidifying tower, isothermal water vapor phase change is carried out, and moisture in the hot flue gas is cooled and recovered to obtain recovered water;

s3, the hot flue gas is in contact with the adsorbent in the dehumidification tower, the adsorbent absorbs water vapor in the hot flue gas, and the adsorbent is absorbed and extruded by the rotary dehumidification wheel to obtain recovered water.

In one embodiment, the humidifying tower and the dehumidifying tower are at least two, and the recovered water and the flue gas obtained from the S3 are recycled by repeating the steps S1, S2 and S3.

In one embodiment, the high specific surface area hydrophilic filler is a high specific surface area structured filler net, the diameter of the mesh wire of the high specific surface area structured filler net is 1mm, and the mesh number is 80-120 meshes(ii) a The surface of the high specific surface area regular packing net is coated with Al₂O₃-MnO₂And (c) a complex.

In one embodiment, the adsorbent is collodion, diaper, aerosol or absorbent sponge.

In one embodiment, the high specific surface area hydrophilic filler has a specific surface area of 2500m²/m³Bulk density of 320-650 kg/m³The void ratio is 70-90%, the F factor is 1.5-3.5, the wave pitch is 10-55 mm, and the tooth form angle is 30-80.

In one embodiment, the temperature of the salt-containing wastewater is raised by a heat exchanger, and the salt-containing wastewater is heated by the heat exchanger and then is sprayed from the top of the humidifying tower to the inside of the humidifying tower.

A second aspect of the embodiment of the application provides a waste water recovery system based on hot flue gas and adsorbent, including humidification tower and dehumidification tower, the inside of humidification tower is equipped with the regular packing net of high specific surface area, the top of humidification tower is equipped with the waste water entry, the inside of dehumidification tower is equipped with the adsorbent, the inside bottom of dehumidification tower sets up and rotates the dehumidification wheel, the bottom of humidification tower with the bottom of dehumidification tower all is equipped with the export of recovery water, humidification tower with the outside of dehumidification tower is equipped with heat exchanger and recovery water storage tank, the heat exchanger with waste water entry intercommunication, the export of recovery water with recovery water storage tank intercommunication.

In one embodiment, the humidifying tower and the dehumidifying tower are provided in at least two.

In one embodiment, the high specific surface area structured packing mesh is disposed at an inclination of 45 ° inside the humidified column.

In one embodiment, the surface of the high specific surface area structured packing net is provided with a falling film collecting pipe, and the falling film collecting pipe is made of hydrophobic materials such as polypropylene or polytetrafluoroethylene with the diameter of 3-4 mm.

Compared with the traditional humidifying-dehumidifying method, the waste water recycling process and system based on hot flue gas and adsorbent provided by the invention have the remarkable characteristic that the ratio table of the hydrophilic regular packing isThe area is as high as 2500m²/m³The surface is coated with a hydrophilic agent, so that the porosity is high, the hydrophilic wettability is good, the pressure drop is small, the flux is large, the service life is long, and the mass transfer and heat transfer are fast; the flue gas containing saturated steam contacts with low-temperature wastewater to raise temperature and humidify, and an isothermal steam phase change capture steam inclined plate designed by the hydrophilic high-specific surface area structured packing precursor net is designed, so that the recycled fresh water is increased, and the efficiency of a humidifying tower is increased; the flue gas from each humidifying tower absorbs water vapor in the flue gas through cloth made of high water absorption materials with the same width, the water vapor is absorbed, squeezed and dehumidified and fresh water is recovered through a rotating stainless steel mesh double-wheel, and the wastewater enters a first-effect humidifying tower for temperature rise and humidification after passing through a heat exchanger, so that the wastewater recovery rate is further improved; and the recovered water enters a recovered water storage tank after being collected. The humidifying tower is made of acrylic or PPR, so that the manufacturing cost of the humidifying tower is reduced, and meanwhile, the humidifying tower is resistant to wastewater corrosion and can observe the operation condition in the tower; the hot flue gas and the wastewater are in cross-flow contact, so that the pressure loss of flue gas operation is reduced, and an induced draft fan is not required to be additionally arranged; the heat exchanger is arranged outside the humidifying tower, so that the maintenance and the adjustment of the area of the heat exchange module are facilitated; an adsorbent made of a high water absorption material and a rotary dehumidifying wheel are arranged in the closed space of the dehumidifying tower, and a motor is waterproof; the technical invention can obviously reduce the manufacturing cost of the humidifying tower and the recycling and operating cost of the wastewater, and the recovery rate of the salt-containing wastewater can reach 70-80%.

Drawings

FIG. 1 is a schematic flow diagram of a hot flue gas and sorbent-based wastewater recovery process according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a wastewater recovery system based on hot flue gas and an adsorbent according to an embodiment of the present application.

The symbols in the drawings illustrate that:

1. a first humidifying tower; 2. a first dehumidification tower; 3. a structured packing net with high specific surface area; 4. a wastewater inlet; 5. an adsorbent; 6. rotating the dehumidifying wheel; 7. a first recovered water outlet; 8. a second recovered water outlet; 9. a heat exchanger; 10. a reclaimed water storage tank; 11. a second humidification tower; 12. a second dehumidification tower; 13. a waste water pump; 14. and (4) a chimney.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The traditional humidifying-dehumidifying type salt-containing wastewater recovery process usually adopts random packing and metal or ceramic regular packing; generally, these structured packings have a maximum specific surface area of not more than 700m²/m³Surface hydrophilic modification is not intentionally made; according to the mass transfer theory, Q ═ k_da(C₀-C_t) I.e. in the concentration difference (C)₀-C_t) Under certain conditions, the mass transfer rate and the mass transfer coefficient k_dProportional to the specific surface area a per unit volume of the filler, that is, the higher the specific surface area of the filler, the faster the mass transfer rate; on the other hand, the mass transfer coefficient k_dThe Re number is related to the Re number of the fluid and the thickness of a Plant boundary layer, and is closely related to the hydrophilicity (liquid holdup) of the surface of the filler, when the filler has strong hydrophilicity, the liquid holdup of the surface of the filler is large, the mass transfer is fast, and the high Re number can not cause the occurrence of flooding, so that the operation is deteriorated; meanwhile, the traditional filler has no hydrophilic function, so that the gas-liquid mass transfer rate of hot flue gas and spray wastewater on the surface of the filler only depends on the mass transfer rate and the gas-liquid equilibrium theorem.

Referring to fig. 1, a schematic flow chart of a wastewater recycling process based on hot flue gas and adsorbent according to an embodiment of the present application is shown, and for convenience of illustration, only the relevant portions of the present application are shown, which is detailed as follows:

in one embodiment, the first aspect of the present application provides a wastewater recovery process based on hot flue gas and adsorbent, for performing recovery treatment on saline wastewater and hot flue gas, comprising the following steps:

and S1, filling a high-specific-surface-area hydrophilic filler into the humidifying tower, filling an adsorbent into the dehumidifying tower, arranging a rotary dehumidifying wheel at the bottom inside the dehumidifying tower, and spraying the salt-containing wastewater into the humidifying tower from the top of the humidifying tower after the salt-containing wastewater is heated.

Specifically, the humidifying tower and the dehumidifying tower are at least two, high specific surface area hydrophilic fillers are filled in the humidifying tower and the dehumidifying tower, the high specific surface area hydrophilic fillers are high specific surface area regular filler nets, the high specific surface area regular filler nets are arranged in the humidifying tower and the dehumidifying tower in an inclined manner of 45 degrees, the length of the high specific surface area regular filler nets is 300mm, the widths of the high specific surface area regular filler nets are the same as those of the humidifying tower and the dehumidifying tower, the diameters of net wires of the high specific surface area regular filler nets are 1mm, the mesh number is 80-120 meshes, and the surfaces of the high specific surface area regular filler nets are coated with Al₂O₃-MnO₂The composite is provided with a falling film collecting pipe and a condensed fresh water pipe, and the specific surface area of the hydrophilic filler with high specific surface area is 2500m²/m³Bulk density of 320-650 kg/m³The void ratio is 70-90%, the F factor is 1.5-3.5, the wave pitch is 10-55 mm, and the tooth form angle is 30-80; an adsorbent is filled in the dehumidification tower, and the adsorbent is made of super absorbent materials such as collodion, water-absorbent mop, diaper, aerosol or water-absorbent sponge; after the temperature of the salt-containing wastewater with the temperature of 20-30 ℃ is raised to 30-40 ℃ by a heat exchanger, pumping the salt-containing wastewater into the top of the humidifying tower by a wastewater pump and spraying the salt-containing wastewater into the humidifying tower.

S2, injecting hot flue gas from the side face of the humidifying tower, enabling the hot flue gas, the saline wastewater and the hydrophilic filler with the high specific surface area to be in cross-flow contact and humidifying in the humidifying tower, carrying out isothermal steam phase change, cooling and recovering moisture in the hot flue gas to obtain recovered water, and cooling the recovered water.

Specifically, hot flue gas is generally waste flue gas discharged by a factory, hot flue gas at 70-130 ℃ is injected into a humidifying tower from the side surface of the humidifying tower, the hot flue gas in cross-flow contact humidifying with a hydrophilic regular catalytic packing with a high specific surface area in the humidifying tower, isothermal water vapor phase change and cooling are carried out on the net surface of a regular packing net with the high specific surface area to recover moisture in the hot flue gas, fresh water recovered water is obtained, the recovered moisture falls into a free falling body and enters a cooling water storage tower, and the recovered water is cooled in the cooling water storage tower.

S3, the hot flue gas is contacted with the adsorbent in the dehumidification tower, the adsorbent absorbs the water vapor in the hot flue gas, and the adsorbent is absorbed and extruded by the rotary dehumidification wheel to obtain the recovered water.

Specifically, the hot flue gas is contacted with the adsorbent in the dehumidification tower, the adsorbent absorbs water vapor carried in the hot flue gas, and the water vapor is absorbed and extruded by the rotary dehumidification wheel to recover the water, so as to obtain recovered water, a cycle is completed (called as a first effect), then the second effect is carried out, the obtained recovered water and the flue gas are recycled and treated in steps S1, S2 and S3, and multiple effects can be carried out by analogy until the temperature of the flue gas is reduced to 30 ℃ and the flue gas is discharged through a chimney; the key of the process technology is as follows: the humidifying tower of each effect is characterized in that the water temperature is increased to 15-20 ℃, the bottom of the dehumidifying tower is connected with a liquid-sealed water recoverer, a water receiving pipe is inserted into the bottom of a recovered water storage tank to play a role of liquid sealing, and finally fresh water is uniformly collected into a recovered water tank.

In this example, the humidifying-dehumidifying tower is designed to have 3 effects, the temperature of hot flue gas is 100 deg.C, the temperature of each effect is reduced by 15 deg.C, the flue gas is discharged into chimney when the temperature is 25 deg.C, and the flow rate of hot flue gas is 4000Nm³H, the tower feeding linear speed is about 1.1 m/s; the temperature of the salt-containing wastewater is 20 ℃, and the flow of the treated wastewater is 20m³The method comprises the following steps that firstly, normal-temperature water can be injected into a recovered water storage tank when the system is started, and then the temperature of cooling recovered water is maintained not to exceed 25 ℃; after 1 week of operation, the operating cost (electricity consumption) and the wastewater recovery rate were measured, and the results are shown in Table 1.

Table 1 hot flue gas and high specific surface area hydrophilic structured packing humidifying tower and high water absorbent material wastewater recovery process parameters

Therefore, the ton cost of wastewater recovery is low, and the investment cost is low due to the normal-pressure operation of the humidifying tower and the plastic manufacturing.

Referring to fig. 2, a schematic structural diagram of a wastewater recycling system based on hot flue gas and adsorbent according to an embodiment of the present application is shown, and for convenience of illustration, only the relevant portions of the system are shown, which is detailed as follows:

the second aspect of the embodiment of the application provides a waste water recovery system based on hot flue gas and adsorbent, including humidification tower and dehumidification tower, the inside of humidification tower is equipped with the regular packing net 3 of high specific surface area, the top of humidification tower is equipped with waste water entry 4, the inside of dehumidification tower is equipped with adsorbent 5, the inside bottom of dehumidification tower sets up rotates dehumidification wheel 6, the bottom of humidification tower is equipped with first recovered water export 7, the bottom of dehumidification tower is equipped with second recovered water export 8, the outside of humidification tower and dehumidification tower is equipped with heat exchanger 9 and recovered water storage tank 10, heat exchanger 9 and waste water entry 4 intercommunication, first recovered water export 7 and second recovered water export 8 all communicate with recovered water storage tank 10.

Specifically, the humidifying tower and the dehumidifying tower are at least two, two groups of humidifying and dehumidifying towers are arranged in the drawing of the embodiment, namely a first humidifying tower 1, a first dehumidifying tower 2, a second humidifying tower 11 and a second dehumidifying tower 12, the humidifying towers are made of acrylic, polypropylene (PPR) or plastics, the strong corrosion resistance of the acrylic, the polypropylene (PPR) or the plastics is utilized, the manufacturing cost is saved, and when the humidifying towers are made of acrylic, the gas-liquid contact mass transfer and heat transfer operation conditions in the towers can be observed due to the transparency of the acrylic; the humidifying tower is designed as a rectangular tower, and the size is as follows: the length, width and height are 1000, 1200 and 1000, so that the linear velocity of hot flue gas entering the humidifying tower is reduced, the pressure drop is reduced, and the flue gas after temperature reduction and dehumidification is directly discharged through a chimney without arranging an induced draft fan.

The humidifying tower is characterized in that the humidifying tower is internally provided with a high specific surface area regular packing net 3, the high specific surface area regular packing net 3 is arranged in the humidifying tower in an inclined manner of 45 degrees, the length of the high specific surface area regular packing net 3 is 300mm, the width of the high specific surface area regular packing net 3 is the same as that of the humidifying tower and the dehumidifying tower, the diameter of a net wire of the high specific surface area regular packing net 3 is 1mm, the net mesh number is 80-120 meshes, and the surface of the high specific surface area regular packing net 3 is coated with Al₂O₃-MnO₂The surface of the high specific surface area regular packing net 3 is provided with falling film collecting pipes which are diameter3-4mm hollow pipe made of hydrophobic materials such as polypropylene or polytetrafluoroethylene, the outer wall of the hollow pipe is provided with a groove for facilitating falling film flow of water drops, meanwhile, the hydrophobicity of the falling film collecting pipe is better, the water drops are in a laminar flow fluid state on the surface, the heat exchanger 9 is arranged outside and is convenient to maintain, the falling film collecting pipe is connected with a low-temperature water pipe of the heat exchanger 9 and can play a role of slight cooling and liquid sealing, and the temperature of the collected recovered water is 3-10 ℃ lower than that of the flue gas, so that partial phase change water and condensed water can be recovered through the design of the falling film collecting pipe, the fresh water spraying amount of the humidifying tower is reduced, and meanwhile, the steam phase change heat is transferred to the hot flue gas again, so that the temperature of the hot flue gas is not reduced basically, but the recovered water amount is increased; the high specific surface area regular packing net 3 has a hard surface and a permeability function, when hot smoke containing saturated water vapor passes through, water vapor fog beads can rotate around the surface of the net wire in a laminar flow state to be condensed, and under the combined action of phase change at the same temperature and low-temperature condensation, water is collected and then enters the humidifying tower.

After the temperature of the salt-containing wastewater is raised by a heat exchanger 8, the salt-containing wastewater is pumped into the first humidifying tower 1 from a wastewater inlet 4 by a wastewater pump 13, the salt-containing wastewater and hot flue gas entering from the side surface cross flow contact humidifying in the cross flow of a high specific surface area regular packing net 3 in the first humidifying tower 1, isothermal water vapor phase change and cooling are carried out on the net surface of the high specific surface area regular packing net 3 to recover moisture in the flue gas to obtain recovered water, the recovered water enters a recovered water storage tank 10 through a first recovered water outlet 6, the hot flue gas discharged from the first humidifying tower 1 enters the first dehumidifying tower 2, the recovered water is contacted with an adsorbent in the first dehumidifying tower 2, the adsorbent 5 absorbs the water vapor carried in the hot flue gas and is absorbed and extruded by a rotating dehumidifying wheel 6 to recover the moisture to obtain recovered water, the rotating dehumidifying wheel 6 is made of a stainless steel mesh so that the absorbed and extruded recovered water naturally falls down from the mesh, the bottom of the dehumidification tower is connected with a liquid-sealed water recoverer, a water receiving pipe is inserted into the bottom of the recovery water tank to play a role of liquid sealing, finally, fresh water is uniformly collected into the recovery water storage tank 10 to complete a recovery treatment cycle (namely a first effect), and then the fresh water enters a second effect, namely the second humidification tower 11 and the second dehumidification tower 12 repeat the cyclic treatment of the steps S1, S2 and S3, and the like, so that multiple effects can be realized until the temperature of the flue gas is reduced to 30 ℃ and the flue gas is discharged through a chimney 14.

In conclusion, compared with the traditional humidifying-dehumidifying method, the waste water recovery process and the waste water recovery system based on the hot flue gas and the adsorbent provided by the invention have the remarkable characteristic that the specific surface area of the hydrophilic regular packing is as high as 2500m²/m³The surface is coated with a hydrophilic agent, so that the porosity is high, the hydrophilic wettability is good, the pressure drop is small, the flux is large, the service life is long, and the mass transfer and heat transfer are fast; the flue gas containing saturated steam contacts with low-temperature wastewater to raise temperature and humidify, and an isothermal steam phase change capture steam inclined plate designed by the hydrophilic high-specific surface area structured packing precursor net is designed, so that the recycled fresh water is increased, and the efficiency of a humidifying tower is increased; the flue gas from each humidifying tower absorbs water vapor in the flue gas through cloth made of high water absorption materials with the same width, the water vapor is absorbed, squeezed and dehumidified and fresh water is recovered through a rotating stainless steel mesh double-wheel, and the wastewater enters a first-effect humidifying tower for temperature rise and humidification after passing through a heat exchanger, so that the wastewater recovery rate is further improved; and the recovered water enters a recovered water storage tank after being collected. The humidifying tower is made of acrylic or PPR, so that the manufacturing cost of the humidifying tower is reduced, and meanwhile, the humidifying tower is resistant to wastewater corrosion and can observe the operation condition in the tower; the hot flue gas and the wastewater are in cross-flow contact, so that the pressure loss of flue gas operation is reduced, and an induced draft fan is not required to be additionally arranged; the heat exchanger is arranged outside the humidifying tower, so that the maintenance and the adjustment of the area of the heat exchange module are facilitated; an adsorbent made of a high water absorption material and a rotary dehumidifying wheel are arranged in the closed space of the dehumidifying tower, and a motor is waterproof; the technical invention can obviously reduce the manufacturing cost of the humidifying tower and the recycling and operating cost of the wastewater, and the recovery rate of the salt-containing wastewater can reach 70-80%.

Various embodiments are described herein for various devices, circuits, apparatuses, systems, and/or methods. Numerous specific details are set forth in order to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. However, it will be understood by those skilled in the art that the embodiments may be practiced without such specific details. In other instances, well-known operations, components and elements have been described in detail so as not to obscure the embodiments in the description. It will be appreciated by those of ordinary skill in the art that the embodiments herein and shown are non-limiting examples, and thus, it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.