CN105621514A

CN105621514A - Salt-containing wastewater concentration treatment device with air as medium

Info

Publication number: CN105621514A
Application number: CN201610158397.6A
Authority: CN
Inventors: 张锁龙; 戎铖
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2016-03-18
Filing date: 2016-03-18
Publication date: 2016-06-01

Abstract

The invention discloses a novel salt-containing wastewater concentration treatment device with air as a medium. The novel salt-containing wastewater concentration treatment device consists of a packed tower (evaporator), a plate heat exchanger (condenser) and a heating module (low-grade heat energy and solar energy), wherein a humidification and dehumidification method is adopted; flowing air is taken as a vapor carrier to treat salt-containing wastewater in an evaporation concentration manner; air is humidified by the heated salt-containing wastewater in the packed tower, is fed into the plate heat exchanger according to different temperature gradients in the packed tower after a certain amount of vapor is carried, and is condensed and dehumidified, so that fresh water can be produced; condensation latent heat can be recycled to preheat the salt-containing wastewater. (See the structure chart in the drawings of the description) By adopting the novel salt-containing wastewater concentration treatment device disclosed by the invention, the defects that a conventional treatment method is high in energy consumption, up-front cost and later maintenance cost, production scale requirement, and requirement on foundation facilities in a production area can be avoided.

Description

Air is the brine waste concentration device of medium

Technical field:

The present invention relates to and carry out concentrating to high-salt wastewater (total containing salt massfraction be 1%��3.5%) and obtain equipment and the technique thereof of fresh water, belong to the technical field of wastewater treatment, it is possible to be attributed to energy-saving and emission-reduction field.

Background technology

Fresh water belongs to basic natural resources and strategic economic resources, is the control selector of ecotope and the organic component of country's overall national strength. On the earth, only the water source of 3% can be drunk. The whole world about has the population of 25% to can not get enough fresh water, and the country more than 80% faces serious water resources shortage problem. Along with the expansion of world's arid and desertification, exacerbate the seriousness of water resources problems.

In order to tackle fresh water crisis, it is a kind of effective method that brine waste carries out concentration. Brine waste refers to always containing the inorganic salt waste water that salt massfraction is 1%��3.5%, and main source is the high-salt wastewater of seawater, underground shallow layer salt water, Industrial processes generation. Now main concentration method has multistage flash evaporation method, multiple-effect distillation, vapour compression method etc. Above-mentioned several method shortcoming mainly contain following some: 1, being consumed a large amount of electric power and fuel, on the one hand economy is poor, is unfavorable for economizing on resources on the other hand; 2, it is only suitable for scale operation, higher for cost for wastewater treatment on a small scale; 3, production unit drops into relatively big, and safeguards that these equipment needs bigger input; 4, most treatment process all needs just can carry out in area preferably in Infrastructure, is difficult in the area of poor infrastructure carry out. For the shortcoming of above several method, the wet waste water treatment process that dries that increases utilizing air to be medium in recent years obtains certain attention, this kind of method makes both waste water and carrier gas (being generally air) contact with each other, temperature and the humidity of carrier gas is improved with this, its condensation is obtained fresh water thereupon, raw material is concentrated, and condensation latent heat carries out the treatment process of effective recycling, increases the wet wastewater treatment equipment that dries and is generally made up of evaporator room, condensing chamber and heating module.

Packing tower is built with the gas-liquid mass transfer (contact) equipment of a large amount of fillers as alternate contact component taking tower. Waste water adds from tower top, pours on filler through shower nozzle spray, and flows down along filling surface. Gas is sent into from the bottom of tower, is the space that adverse current continues through filler with waste water. Surperficial gas-liquid two-phase at filler closely contacts and carries out mass transfer. Packing tower has that throughput is big, feature little, that liquid holdup is little, turndown ratio is big falls in separation efficiency height, pressure.

Plate-type heat exchanger is a kind of new type high efficient heat exchanger filled by a series of metal film stack with certain bellows-shaped. Form thin rectangular shape passage between various plate, carry out thermal exchange by plate. Plate-type heat exchanger is the ideal equipment that liquid-liquid, liquid-vapour carry out heat exchange. It has heat exchange efficiency height, thermosteresis is little, advantages of compact and light structure, floor space are little, install easy to clean, be widely used, the feature such as long service life. In uniform pressure loss situation, doubly, floor space is 1/3rd of tubular heat exchanger to its ratio of heat transfer coefficient tubular heat exchanger height 3-5, and heat recovery rate can up to more than 90%.

The present invention, using packing tower, plate-type heat exchanger as evaporator room, condensing chamber, selects suitable low grade residual heat, sun power to form sewage treatment equipment as heating module, and selects suitable working parameter according to different operating mode.

Summary of the invention

The present invention is directed to conventional concentration method consumed energy height, production cost input cost big, be unfavorable for small-scale production, need in the Infrastructure problem such as area preferably, utilize the principle increasing wet dehumidification, devise a kind of new concentration instrument and supplies.

The present invention is made up of packing tower (evaporator room), plate-type heat exchanger (condensing chamber), heating module. The technical scheme adopted is the carrier introducing flowing air as water vapour, and is separated with condensing chamber by evaporator room, and their temperature can independently be controlled; Air is increased wet in evaporator room by brine waste, enters in condensing chamber, obtain fresh water through dehumidification by condensation after carrying a certain amount of water vapour, and condensation latent heat is reclaimed by preheating brine waste. Heating module can utilize low grade residual heat and sun power to carry out energy supply. In order to obtain bigger treatment capacity, then several equipment can be carried out series connection combination producing.

The present invention is different from traditional salt-containing waste water treatment method, production cost and the treatment scale of the main flow treatment processs such as conventional treatment process such as multistage flash evaporation method, multiple-effect distillation, vapour compression method are closely related, relatively be applicable to large-scale treating processes, but these technology and be not suitable for process engineering on a small scale. And the input of purchase of equipment is relatively big in advance, and later maintenance cost is also higher. For the enterprise that some industrial scales are less, utilizing electric energy to carry out processing cost higher, particularly those have the enterprise enriching low grade residual heat, the treatment unit that urgent needs are compact simplified. Increasing the wet desalination techniques that dries and overcome an above difficult problem ingeniously, apparatus structure is simple, and does not consume fossil energy, is easy to operation and maintenance, although output is not as good as traditional method, but can carry out series connection production and supply.

Accompanying drawing explanation

Fig. 1 is the structural representation of the brine waste concentration device of the present invention.

Number in the figure illustrates: 1-fresh water pond for recovering, 2,3,4-plate-type heat exchanger, 5-heating module, 6-packing tower, 7-shower nozzle, 8-gas blower, 9-concentrated solution outlet, 10-feed reservoir, 11-pump, 12,13-water vapour pipeline, 14,15-fluid pipeline.

Embodiment

During the device start of the present invention, water pump 11, by brine waste suction system from feed reservoir 10, leads to heating module 5 via plate-type heat exchanger 2,3,4. Raw material flows to packing tower 6 after being heated to 70��90 DEG C by heating module 5, evenly is spilt by shower nozzle 7 and forms water smoke to inner-tower filling material; Now have in tower by tower pucking blower fan 8 blow into normal temperature air. High temperature feedstock water smoke fully contacts generation mass-and heat-transfer with air on filler, and absorption of air moisture is saturated gradually by unsaturated state, and the temperature of air is in constantly uphill process simultaneously, and wettability power is also in continuous enhancing. Raw material moisture constantly evaporates and scatters and disappears and concentration rising, reaches concentrated object, is finally discharged outside tower. The air of moist high temperature enters plate-type heat exchanger 2,3,4 by the different gradient segmentations of temperature, and carries out pre-warmed raw material and carries out heat exchange, becomes liquid water, heated by the raw material waste water of normal temperature simultaneously after steam coagulation. The wet air that in tower, temperature is higher temperature after higher level's interchanger is consistent with subordinate interchanger inlet temperature and mixes, with ingress of subordinate water vapour, the heat transfer process participating in next interchanger through pipeline 13, utilizes the condensation latent heat of water vapour to greatest extent. Flow process like this, until final product obtains concentrated solution and fresh water. Water vapour produces certain negative pressure in liquefaction process simultaneously, accelerates raw materials evaporate in packing tower 6.

Claims

1. air is the wet dehumidification brine waste concentration device of increasing of medium, appliance arrangement comprises: 1-fresh water pond for recovering, 2,3,4-plate-type heat exchanger, 5-heating module, 6-packing tower, 7-shower nozzle, 8-gas blower, 9-concentrated solution outlet, 10-feed reservoir, 11-pump, 12,13-water vapour pipeline, 14,15-fluid pipeline. Water pump 11, by brine waste suction system from feed reservoir 10, leads to heating module 5 via plate-type heat exchanger 2,3,4. Raw material flows to packing tower 6 after being heated to 70��90 DEG C by heating module 5, evenly is spilt by shower nozzle 7 and forms water smoke to inner-tower filling material; Now have in tower by tower pucking blower fan 8 blow into normal temperature air. High temperature feedstock water smoke fully contacts generation mass-and heat-transfer with air on filler, and absorption of air moisture is saturated gradually by unsaturated state, and the temperature of air is in constantly uphill process simultaneously, and water-retaining capacity is also in continuous enhancing. Raw material moisture constantly evaporates and scatters and disappears and concentration rising, reaches concentrated object, is finally discharged outside tower. The air of moist high temperature enters plate-type heat exchanger 2,3,4 by the different gradient segmentations of temperature, and carries out pre-warmed raw material and carries out heat exchange, becomes liquid water, heated by the raw material waste water of normal temperature simultaneously after steam coagulation. The wet air that in tower, temperature is higher temperature after higher level's interchanger is consistent with subordinate interchanger inlet temperature and mixes, with ingress of subordinate water vapour, the heat transfer process participating in next interchanger through pipeline 13, utilizes the condensation latent heat of water vapour to greatest extent. Flow process like this, until final product obtains concentrated solution and fresh water. Water vapour produces certain negative pressure in liquefaction process simultaneously, accelerates raw materials evaporate in packing tower 6.

2. require according to right 1 that increasing wet dehumidification brine waste concentration device is characterized in that: it is multistage derivation structure (being generally three grades) that the water vapour on packing tower 6 derives structure, utilize this kind of structure can greatly utilize the heat in tower, and then improve the utilization of water vapor condensation latent heat.

3. require according to right 1 that increasing wet dehumidification brine waste concentration device is characterized in that: the carrier gas medium using the air of normal temperature and pressure as water vapour, these medium wide material sources, during plant running, physicochemical property are reliable and stable.