Summary of the invention
The object of the invention is to the above-mentioned defect for prior art, a kind of sode ash crystallization diafiltration system is provided.
Object of the present invention realizes by following technical measures:
A kind of sode ash crystallization diafiltration system, compared with prior art, its difference is, this sode ash crystallization diafiltration system comprises the sode ash dissolver, crystallization filtration unit and the solids treatment device that connect successively;
Described sode ash dissolver comprises for sode ash and solvent being formed the sode ash dissolving tank of slurry and being used for carrying the slurry transferring pump of slurry;
Described crystallization filtration unit comprises: crystallizer, recycle pump, well heater and washer, described crystallizer, recycle pump and well heater circulate successively and are connected, described washer is connected with described crystallizer, slurry circulates through crystallizer successively, recycle pump, well heater carry out periodic crystallisation and heating to remove chlorion in slurry and potassium ion, the crystallization formed in crystallizer enters in washer carries out recoil washing by cleaning solvent;
Described solids treatment device comprises: a water trap be connected with described washer, the solids recovery tank be connected with water trap, the liquid recovery be connected respectively with water trap and crystallizer.
Preferably, described liquid recovery is connected with described crystallizer by the first transferpump.
Preferably, described crystallization filtration unit also comprises the flasher and condensation water collection tank that are connected with well heater, and described flash tank provides steam for well heater.
Preferably, described water trap is whizzer.
Preferably, the top of described crystallizer is provided with mist eliminator.
Preferably, described sode ash dissolving tank, solids recovery tank and liquid recovery inside are equipped with stirring rake.
Preferably, described sode ash dissolving tank, solids recovery tank and liquid recovery inside are equipped with Fang Xuan mechanism.
Preferably, described sode ash crystallization diafiltration system is also provided with the second transferpump be connected with described solids recovery tank.
Preferably, the porous plate for filtering is provided with in described sode ash dissolving tank.
Sode ash crystallization diafiltration system of the present invention utilizes the difference of the ctystallizing point of sode ash main component sodium sulfate and impurity sodium-chlor, potassium sulfate and Repone K, sode ash is dissolved after forming slurry and carry out repeatedly recrystallization to remove impurity, thus avoid chlorion in impurity and potassium ion to the corrosion of equipment and destruction, reduce dust stratification and the scale formation of alkali recovery furnace; Sode ash crystallization diafiltration system of the present invention is provided with the granularity of washer for crystallization control, for subsequent separation process creates favorable conditions below crystallizer.
Embodiment
In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
Sode ash be concentrated after black liquid to burn in alkali recovery furnace the dust formed.The main component of sode ash is Na
2sO
4, also containing a small amount of NaCl, K in sode ash
2sO
4, KCl.Sode ash is dissolved in after in water, forms mixing solutions (being slurry).Along with the rising Na of temperature
2sO
4, NaCl, K
2sO
4, KCl solubleness also constantly raise, but NaCl, K
2sO
4, KCl ctystallizing point lower, therefore can utilize the difference of ctystallizing point, by mixing solutions (slurry) is heated to certain temperature, then cooling concentration formed crystallization, thus reach remove Cl-and K
+object.
Refer to shown in Fig. 1 to Fig. 4, illustrate the structural representation of the sode ash crystallization diafiltration system 100 of a preferred embodiment of the present invention.The sode ash crystallization diafiltration system 100 that this specification sheets institute accompanying drawings is painted and dependency structure thereof, ratio, size etc., content all only in order to coordinate specification sheets to disclose, understand for person skilled in the art scholar and read, and be not used to limit the enforceable qualifications of the present invention, therefore the not technical essential meaning of tool, the modification of any structure, the change of proportionlity or size, the adjustment of quantity, do not affecting under effect that sode ash crystallization diafiltration system 100 of the present invention can produce and the object that can reach, all should still drop in scope that disclosed technology contents covers.Simultaneously, quote in this specification sheets as " on ", D score, "left", "right", " centre " and " one " etc. term, only clear for the ease of describing, and be not used to limit the enforceable scope of the present invention, the change of its relativeness or adjustment, under changing technology contents without essence, when being also considered as the enforceable category of the present invention.
Present embodiments provide a kind of sode ash crystallization diafiltration system 100, it comprises the sode ash dissolver 10, crystallization filtration unit 20 and the solids treatment device 30 that connect successively.
Wherein, refer to shown in Fig. 2, sode ash dissolver 10 comprises sode ash dissolving tank 101 and slurry transferring pump 102, sode ash dissolving tank 101 is for forming slurry by sode ash and solvent, slurry transferring pump 102 is for carrying slurry in crystallization filtration unit 20, and sode ash dissolving tank 101 inside is equipped with agitator 101a and Fang Xuan mechanism (not shown).The agitator 101a at sode ash dissolving tank 101 top stirs by motor straight tape splicing is dynamic, and power of motor is 4KW, and rotating speed is 1500rpm.The anti-whirlpool device of cell body inside, can make slurry agitation even.Further, porous plate can be set in cell body inside and sode ash dissolving tank be divided into two portions (dissolving stirring area and finished product district), slurry outlet is arranged on finished product district, ensures the slurries quality in finished product district after porous plate filters, thus ensures that equipment below and pipeline do not block.Be provided with inspection door at the top of cell body and bottom, and in cell body inside, cat ladder be housed, serviceman can by inspection and maintenance inside cat ladder to cell body.Sode ash dissolving tank 101 is Verticle atmospheric pressure container, and during normal running, cell body internal temperature is 70 DEG C, and housing and main raw can select 304L.
Wherein, refer to as indicated at 3, crystallization filtration unit 20 comprises: crystallizer 201, recycle pump 202, well heater 203, washer 204, flasher (not shown), condensation water collection tank 205, mist eliminator (not shown), described crystallizer 201, recycle pump 202 circulates successively with well heater 203 and is connected, washer 204 is connected with the bottom of crystallizer 203, slurry circulates through crystallizer 201 successively, recycle pump 202, well heater 203 carries out periodic crystallisation and heating to remove chlorion in slurry and potassium ion, the crystallization formed in crystallizer 203 enters in washer 204 carries out recoil washing by cleaning solvent, flash tank provides the steam needed for heating for well heater 203, the water of condensation got rid of from well heater 203 collected by condensation water collection tank 205, the top of crystallizer is located at by mist eliminator.
Particularly, the selective freezing of sodium sulfate is carried out in one-level pump circulation crystallizer 201, and this crystallizer 201 is mixing suspension graded product tripping devices with one way outer pipe type well heater 203.In crystallization filtration unit 20, slurry keeps certain concentration, and the heat exchanger being pumped into well heater 203 from the evaporator room of crystallizer 201 is recycled to the evaporator room of crystallizer 201, is realized the pump circulation of slurry by an axial flow circulating pump 202.Steam needed for evaporating, concentrating and crystallizing or energy is provided by tubular heater 203.Vapor condensation provides the energy needed for moisture evaporation.Water of condensation is then sent to alkali recovery furnace.Along with the evaporation of moisture, sodium sulfate crystallizes out from size circulations liquid, and in size circulations liquid, the concentration of chlorion and potassium ion also can be more and more higher simultaneously.Crystallization (main component the is sodium sulfate) density formed in crystallizer 201 is greater than the size circulations liquid of surrounding, crystallization overcomes the frictional force of liquid under the effect of gravity and buoyancy, produce downward motion, enter in washer 204, in washer 204, recoil passes into cleaning solvent (such as, slurry is preferably adopted as recoil cleaning solvent) in the present embodiment, it is contrary with the direction that crystalline particle falls that cleaning solvent rinses direction, by designing the sectional dimension of crystallizer 201 and adjusting the amount of feeding of recoil cleaning solvent, the granularity of crystallization is controlled, namely large, first heavy ingot is removed from crystallizer 201, slurry as cleaning solvent can carry out crystallization in crystallizer 201, as supplementing size circulations liquid.In addition, the problem that the concentration for chlorion and potassium ion in size circulations liquid also can be more and more higher, is removed chlorine, potassium ion by the mode of discharge section size circulations liquid from whole system 100.The wave-shaped plate demister arranged in crystallizer 201 top gas exit, can effectively except carrying secretly in devaporation.Well heater 203 adopts low-pressure steam to heat slurry, makes slurry outlet temperature remain on 104 DEG C, and well heater 203 is preferably designed for single tube journey, monoshell journey counterflow configuration form, steam walks shell side, slurries walk tube side, and wherein, tube side and tube sheet material adopt super austenitic stainless steel S31254; Tube bank is by diameter 38.1mm, wall thickness 0.7mm, titanium (Gr2) the pipe composition of overall length 8000mm, diameter of the housing is 1650mm, and case material is Q345R, be 2050mm at steam-in place diameter of the housing, and steam-in adopts expander structure, can pass through dilatation step-down like this, reduce the impact of steam exchange heat pipe, in the work-ing life of increase equipment, spring supporting considered by interchanger.
Wherein, refer to shown in Fig. 4, solids treatment device 30 comprises: water trap 301, solids recovery tank 302, liquid recovery 303, first transferpump 304 and the second transferpump 305.Water trap 301 is connected with washer 204, and solids recovery tank 302 is connected with water trap 301, and liquid recovery 303 is connected respectively with water trap 301 and crystallizer 201.Liquid recovery 303 is connected with crystallizer 201 by the first transferpump 304.Second transferpump 305 is connected 302 and connects with solids recovery tank.
Particularly, the sulfate crystal that isolated granularity is larger from washer 204 contains micro-moisture owing to have passed through the recoil of cleaning solvent, because recoil cleaning solvent is slurry, causing may containing micro-chlorion and potassium ion in moisture, therefore, water trap 301 is adopted to carry out dehydration to remove chlorion and the potassium ion of these trace to it, water trap 301 is preferably whizzer, through water trap 301 process after crystallization enter in solids recovery tank 302 carry out dissolvings formation lysate mix with night, enter in alkali recovery furnace after concentrated and burn away.The liquid component removed in water trap 301 mainly slurry, again can be delivered in crystallizer 201 and carry out crystallization.Solids recovery tank and liquid recovery inside are equipped with stirring rake and Fang Xuan mechanism.
The sode ash crystallization diafiltration system of the embodiment of the present invention utilizes the difference of the ctystallizing point of sode ash main component sodium sulfate and impurity sodium-chlor, potassium sulfate and Repone K, sode ash is dissolved after forming slurry and carry out repeatedly recrystallization to remove impurity, thus avoid chlorion in impurity and potassium ion to the corrosion of equipment and destruction, reduce dust stratification and the scale formation of alkali recovery furnace; The sode ash crystallization diafiltration system of the embodiment of the present invention is provided with the granularity of washer for crystallization control, for subsequent separation process creates favorable conditions below crystallizer.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.