Dewater the acid solution of filter cloth, device and technique for clean sludge plate frame
Technical field
The present invention relates to filter press technical field, it is specially the acid solution for clean sludge plate frame dehydration filter cloth, device and technique.
Background technology
Filter press is the method that deeply dehydrating sludge is conventional, in filtration procedure, solid particulate and filter cloth hole wall in fluid collide, particle is caught and delay by filter cloth, make it to separate from fluid, reach the object of solid-liquid separation, deeply dehydrating sludge process needs add a large amount of calcium, magnesium, iron, the modified medicament of aluminium class, the small wadding body of part that these medicaments and mud are formed, under strong pressure effect, in space between the hole being very easily deposited between filter cloth yarn and fiber, simultaneously owing to the coagulating agent class medicament of interpolation exists mainly with oxyhydroxide form during the modified flocculation of mud, with air contact process, the carbon dioxide reaction of part calcium hydroxide kind material easily and in air generates carbonate material further, enhance the firmness that between filter cloth hole, stores is combined with filter cloth.
In use after a period of time, filter cloth surface attachment dirt shape thing, occurs hardening, hardening phenomenon filter cloth, and simultaneously along with the prolongation of duration of service, dirt shape thing increases further, filters at diaphragm plate and also piles up between the space of water passage. And water washing effect is poor, seriously affect the filtration efficiency of filter cloth and the normal operation of plate-and-frame filter press.
Filter cloth purging method common at present has heating hot water strong pressure flushing arrangement, high pressure water to add, and chemical agent cleans in conjunction with off-line, the ultrasonic chemical agent that adds cleans, realizes strong acid diluent wash cycles etc. between pipeline and pressure filter by acid proof pump cleaning, existing various purging method have that labour intensity is big, to clean cost height, filter cloth and equipment loss relatively big or other type scavenging solutions to drawbacks such as deeply dehydrating sludge filter cloth to be cleaned suitability are not strong.
The Chinese patent document that publication number is CN203400542U discloses the online soak acid-cleaning system of canvas press cloth in a kind of sludge dewatering work, and this system comprises acid cleaning tank, acid pump is connected as a single entity by pipeline valve and plate-and-frame filter press.System carries oxalic acid and fills and dilute device, by acid pump, pickle solution directly squeezed into pressure filter inside, pressurize is soaked, and compares the method that cleaning pulled down by tradition filter cloth, and the cleaning interval is short, save human cost, but acid cleaning tank only, after diluted acid liquid refluxes after soaking, the operate continuously that multiple plate-and-frame filter press soaks online cannot be realized, in addition the online soak acid-cleaning system of this canvas press cloth also has waste liquid to discharge, and environment can be caused secondary pollution.
Publication number is the washing unit that the Chinese patent document of CN203002072U discloses a kind of canvas press cloth and recycles, and this system comprises plate-and-frame filter press, pressure filter feed valve, pressure filter back-water valve, acid solution clean pipeline, acid solution case. The hydrochloric acid solution of mass concentration 3 ~ 3.5% plays circulation by acid proof pump in the system cleaning pipeline and pressure filter composition, but its concentration of lotion can not regulate, restricted application, adopts hydrochloric acid as scavenging solution, easily cause Chloride residue, bring the secondary pollution of environment.
Summary of the invention
For the problems referred to above, the present invention provides the acid solution of a kind of filter cloth that dewaters for clean sludge plate frame, it can effectively remove dirt shape thing on filter cloth, softening filter cloth, filter cloth damage is little, equipment corrosion is little, acid solution is environmentally friendly simultaneously, it is easy to decompose, present invention also offers the device of the filter cloth that dewaters for clean sludge plate frame simultaneously, its scavenging period is short, cleaning performance is good, can production run continuously, Clean after every can be postponed, reduce running cost, discharge without waste liquid, avoid secondary pollution, in addition, additionally provide the technique of a kind of filter cloth that dewaters for clean sludge plate frame.
The concrete technical scheme of the present invention is as follows:
The acid solution of a kind of filter cloth that dewaters for clean sludge plate frame, it is characterized in that: the dirty shape thing of attachment on clean sludge plate frame dehydration filter cloth, described acid solution is that acetic acid, oxalic acid, citric acid are dissolved in the acid solution obtained in water by the mass ratio of 3:2:1 ~ 4:3:1, and the acid concentration of described acid solution is less than or equal to 10%.
Further, when the ironic hydroxide mass percent that mud plate frame dewaters in the dirty shape thing on filter cloth is 18 ~ 22%, the mass ratio that the acetic acid in described acid solution, oxalic acid, citric acid press 3:2:1 adds; When the ironic hydroxide mass percent that mud plate frame dewaters in the dirty shape thing on filter cloth is 22% ~ 33%, the mass ratio that the acetic acid in described acid solution, oxalic acid, citric acid press 3:2:1 ~ 4:3:1 adds.
The device of a kind of filter cloth that dewaters for clean sludge plate frame, comprise the acid solution tank connected by pipeline and valve, diluted acid return tank and plate-and-frame filter press, it is provided with acid filling pump between described acid solution tank and plate-and-frame filter press, it is provided with diluted acid reflux pump between described diluted acid return tank and described plate-and-frame filter press, its spy is being: described plate-and-frame filter press is at least provided with two, also comprise and deposit between acid, described deposit to be delivered in described acid solution tank by ortho acid by e Foerderanlage between acid configure acid solution described above, supernatant diluted acid reflux pump it is provided with between described acid solution tank and described diluted acid return tank, the bottom of described diluted acid return tank is provided with scraper, described diluted acid return tank is provided with alkali and adds mouth, described diluted acid return tank is also connected with the modified pond of mud, the modified pond of described mud is connected with described plate-and-frame filter press.
Further, described depositing comprises acetic acid tank, oxalic acid container, citric acid container between acid, the spiral solid doser that described e Foerderanlage comprises the liquid dosing pump being arranged between described acetic acid tank and described acid solution tank, is arranged between described oxalic acid container and described acid solution tank, the spiral solid doser being arranged between described citric acid container and described acid solution tank.
Further, it is provided with oar blade type dilution agitator in described acid solution tank.
Further, it is provided with upflow tube between described acid solution tank and described diluted acid return tank.
Further, described acid solution tank, diluted acid return tank are respectively arranged with acidometer, being provided with pressure controller in described plate-and-frame filter press, described acidometer, liquid dosing pump, spiral solid doser, acid filling pump, diluted acid reflux pump, supernatant diluted acid reflux pump, pressure controller electricly connect with PLC respectively.
The technique of a kind of filter cloth that dewaters for clean sludge plate frame, it is characterised in that, comprise the following steps:
A, pressure detection: when diaphragm type plate-and-frame filter press force controller sense and feed pressure rise to more than 1.0MPa, plate-and-frame filter press stopping work;
B, configuration acid solution: when the ironic hydroxide mass percent that mud plate frame dewaters in the dirty shape thing on filter cloth is 18 ~ 22%, acetic acid, oxalic acid, citric acid are added in acid solution tank by the mass ratio of 3:2:1, water filling in acid solution tank, dilute agitator by oar blade type to stir so that the acid concentration of acid solution is less than or equal to 10% simultaneously;
When mud plate frame dewaters the ironic hydroxide mass percent 22% ~ 33% in the dirty shape thing on filter cloth, acetic acid, oxalic acid, citric acid are added in acid solution tank by the mass ratio of 3:2:1 ~ 4:3:1, water filling in acid solution tank, dilute agitator by oar blade type to stir so that the acid concentration of acid solution is less than or equal to 10% simultaneously;
C, acid filling pickling: after acid solution has configured, by acid filling pump, acid solution in acid solution tank is injected plate-and-frame filter press, pressure in the plate frame of plate-and-frame filter press is kept to be 0.2 ~ 0.6MPa, the dirty shape thing that acid solution is dewatered on filter cloth with mud plate frame in plate-and-frame filter press carries out reaction and cleans filter cloth, and a cleaning interval of pickling, a cleaning interval continue 1.5-2.5 hour;
D, overcurrent precipitate: the plate frame diluted acid on the reacted upper strata in the diaphragm plate frame of plate-and-frame filter press is back in diluted acid reuse tank by diluted acid reflux pump, adding mouth from alkali to make to precipitate with the metal ion acid solution and suspended particle, overcurrent precipitates 10-30 minute consuming time;
E, acid solution reuse: the acid solution of backflow is delivered in acid solution tank through supernatant diluted acid reflux pump after precipitation in diluted acid reuse tank and reuses, it is achieved acid cycle, dynamic cleaning;
F, mud are modified: the precipitated impurities in diluted acid reuse tank is scraped through scraper after 3-5 cleaning interval and carried out modified to mud in the modified pond of mud.
Further, also comprising acid solution conditioning: the PH value detecting in acid solution tank when acidometer is more than or equal to 4, PLC control spiral solid doser, liquid dosing pump add ortho acid in acid solution tank and reconfigure acid solution, increase acid concentration.
The acid solution of the filter cloth that dewaters for clean sludge plate frame of the present invention, it is mixed in proportion with citric acid by oxalic acid, acetic acid, oxalic acid, acetic acid and citric acid three kinds of acid are environmentally friendly acid solution, easily decompose, the not easily secondary pollution of boot environment, and filter cloth damage is little, equipment corrosion is little, acetic acid, oxalic acid, citric acid are dissolved in acid solution that water is configured to for cleaning filter cloth by the mass ratio of 3:2:1 ~ 4:3:1, filter cloth can be softened, effectively remove the dirty shape thing on mud plate frame dehydration filter cloth. the device of the filter cloth that dewaters for clean sludge plate frame of the present invention, ortho acid adds configuration dilution in acid solution tank to by e Foerderanlage, three kinds of sour interpolation proportionings can be regulated by e Foerderanlage according to the difference of sludge shale, after cleaning, diluted acid can be back to diluted acid reuse tank by diluted acid reflux pump, add mouth by alkali and throw, to diluted acid reuse tank, a large amount of metal ions and the suspended particle that alkali can precipitate in reuse acid solution, sediment discharge is in the modified pond of mud, containing alkali is oxide-based and mud can be carried out the 2nd step matter by basic metal throw out in throw out, facilitate the modified dehydration of mud, extend the interval time that plate frame cleans simultaneously, and it is low to clean use acid strength, diluted acid enters the modified mud in the modified pond of mud, do not affect recycling sludge, discharge without waste liquid, realize environmental protection to utilize, supernatant liquid is delivered in acid solution tank through supernatant diluted acid reflux pump after precipitation in diluted acid reuse tank and reuses by the acid solution of backflow, realize acid cycle, dynamic cleaning filter cloth, acidometer, liquid dosing pump, spiral solid doser electricly connects with PLC respectively,PLC records total acidity control transporter feeding configuration acid solution in acid acid solution tank according to acidometer, increases acid concentration, completes quantitative, Rapid Cleaning, level of automation height; Acid solution tank is equipped with upflow tube, prevents volumetric expansion that in acid solution dilution, heat release causes and overflow, can by direct for overflowing liquid overflow to diluted acid reuse tank.
Accompanying drawing explanation
Fig. 1 is the structural representation of the device for clean sludge plate frame dehydration filter cloth of the present invention.
Embodiment
Below in conjunction with drawings and Examples, the present invention is further detailed explanation.
The acid solution of a kind of filter cloth that dewaters for clean sludge plate frame of the present invention, the dirty shape thing of attachment on clean sludge plate frame dehydration filter cloth, described acid solution is that acetic acid, oxalic acid, citric acid are dissolved in the acid solution obtained in water by the mass ratio of 3:2:1 ~ 4:3:1, and the acid concentration of acid solution is less than or equal to 10%.
In use after a period of time, filter cloth surface attachment dirt shape thing, occurs hardening, hardening phenomenon filter cloth, and simultaneously along with the prolongation of duration of service, dirt shape thing increases further, filters at diaphragm plate and also piles up between the space of water passage. Filter cloth telogenesis point face attachment dirt shape thing contains calcium carbonate, calcium hydroxide, ironic hydroxide, magnesium hydroxide, magnesium ammonium phosphate (struvite) etc. by analysis. During dirt shape thing forms, change the maximum content for ironic hydroxide. Oxalic acid is better to ironic hydroxide class dirt shape thing elimination effect; Acetic acid is better to calcium carbonate and calcium hydroxide, magnesium hydroxide class dirt shape thing elimination effect, and can soften filter cloth; Citric acid can promote that dirt shape thing dissolves further, especially basic metal class, and has buffering, anti-oxidant, deodorization function, can reduce the damage to filter cloth and equipment.
When dirt shape thing composition mass percent be: calcium carbonate 30 ~ 34.5%, calcium hydroxide 16 ~ 18.9%, magnesium hydroxide 6 ~ 8%, ironic hydroxide 18 ~ 22%, secondary magnesium phosphate 15 ~ 16.6% time, acid solution quality proportioning is selected to be acetic acid: oxalic acid: citric acid 3:2:1, filter cloth can be softened by the acid solution of said ratio configuration, effectively remove the dirty shape thing on mud plate frame dehydration filter cloth, before cleaning, filter cloth is brown, and quality is hard; After cleaning, filter cloth is in white, filter cloth deliquescing, generating portion brown precipitate, a large amount of white precipitate, part reddish-brown precipitation, and when the filter cloth after cleaning uses, charging amount promotes, and mud extraction moisture content of the cake reduces;
When the mass percent of dirt shape thing composition is: calcium carbonate 30 ~ 34.5%, calcium hydroxide 16 ~ 18.9%, magnesium hydroxide 6 ~ 8%, when ironic hydroxide content is 22%-33%, improve the adding proportion of combination acid solution mesoxalic acid, can by acetic acid: oxalic acid: the mass ratio of citric acid brings up to 4:3:1 gradually from 3:2:1, filter cloth can be softened by the acid solution of said ratio configuration, effectively remove the dirty shape thing on mud plate frame dehydration filter cloth, before cleaning, filter cloth is brown, and quality is hard; After cleaning, filter cloth is in white, filter cloth deliquescing, generating portion brown precipitate, a large amount of white precipitate, a large amount of reddish-brown precipitation, and when the filter cloth after cleaning uses, charging amount promotes, and mud extraction moisture content of the cake reduces;
When the mass percent that the ironic hydroxide in dirt shape thing accounts for is greater than 33%, it is necessary to change filter cloth; When the mass percent that the ironic hydroxide in dirt shape thing accounts for is less than 22%, it is not necessary to clean.
See Fig. 1, the device of a kind of filter cloth that dewaters for clean sludge plate frame of the present invention, comprise and deposit between acid 1 by what pipeline and valve connected, acid solution tank 2, diluted acid return tank 3, at least two plate-and-frame filter press 4, deposit between acid 1 to be delivered in acid solution tank 2 by e Foerderanlage by ortho acid to configure acid solution described above, oar blade type dilution agitator 5 it is provided with in acid solution tank 2, deposit between acid 1 and comprise acetic acid tank 6, oxalic acid container 7, citric acid container 8, e Foerderanlage comprises the liquid dosing pump 9 being arranged between acetic acid tank 6 and acid solution tank 2, the spiral solid doser 10a being arranged between oxalic acid container 7 and acid solution tank 2, the spiral solid doser 10b being arranged between citric acid container 8 and acid solution tank, acid filling pump 11 it is provided with between acid solution tank 2 and plate-and-frame filter press 4, supernatant diluted acid reflux pump 12 it is provided with between acid solution tank 2 and diluted acid return tank 3, diluted acid reflux pump 13 it is provided with between diluted acid return tank 3 and plate-and-frame filter press 4, the bottom of diluted acid return tank 3 is provided with scraper 14, diluted acid return tank 3 is provided with alkali and adds mouth 15, diluted acid return tank 3 is also connected with the modified pond 16 of mud, the modified pond 16 of mud is connected with plate-and-frame filter press 4,
Upflow tube 17 it is provided with between acid solution tank 2 and diluted acid return tank 3, acid solution tank 2, diluted acid return tank 3 are respectively arranged with acidometer (not providing in figure), being provided with pressure controller (not providing in figure) in plate-and-frame filter press 4, acidometer, liquid dosing pump 9, spiral solid doser 10a, spiral solid doser 10b, acid filling pump 11, diluted acid reflux pump 13, supernatant diluted acid reflux pump 12, pressure controller (not providing in figure) electricly connect with PLC (not providing in figure) respectively.
The device of a kind of filter cloth that dewaters for clean sludge plate frame of the present invention, solid acid, liquid acid all seal stored in depositing between acid 1, acetic acid tank 2 is equipped with acetic acid, it is connected with acid solution tank 2 by pipeline, by liquid dosing pump 9 quantitatively suction acid solution tank 2, oxalic acid container 7 is equipped with oxalic acid, is quantitatively transferred to acid solution tank 2 by counting heavy spiral solid doser 10a, citric acid container 8 is equipped with citric acid, is quantitatively transferred to acid solution tank 2 by counting heavy spiral solid doser 10b, acid solution tank 2 is equipped with oar blade type dilution agitator 8, it is achieved the dilution of acid solution, with mixing, is equipped with upflow tube 17 in acid solution tank 2, prevents volumetric expansion that in acid solution dilution, heat release causes and overflow, can by direct for overflowing liquid overflow to diluted acid reuse tank 3, in plate-and-frame filter press 4 pressure-filtering process, the pressure controller of plate-and-frame filter press 4 senses that mud enters sample pressure once exceed and specifying limit value 1.0MPa, illustrate that filter cloth permeability can not meet continuation Production requirement, there is fouling in filter cloth, blocking, need to carry out pickling, now pressure signal feeds back in PLC, PLC starts the sour dilution of setting, process realizes three kinds of acid quantitatively add by portfolio ratio, dilution, obtain the sour scavenging solution that total acid concentration is certain, wherein acid solution ratio and concentration can set targetedly according to the fouling character of different mud on plate frame.
After the press filtration of a plate-and-frame filter press 4 terminates, modified mud injects another plate-and-frame filter press 4 and carries out press filtration, within batch press filtration interval time, this platen frame enters acid soak wash procedure, acid filling pump 11 by the acid solution just diluted from acid solution tank 2 low pressure injection plate frame, when there is certain pressure reduction 0.3-0.6MPa in plate frame, keep pressure reduction on the one hand for ensureing the stopping property of room, plate-and-frame filter press chamber, avoid the liquid entering plate frame to overflow; On the other hand under pressure, the dirty shape thing chemical reaction on acid solution and filter cloth surface is more violent, ensure cleaning performance, by diluted acid reflux pump 13 by plate frame diluted acid suction diluted acid reuse tank 3, stop in diluted acid reuse tank 3 after precipitating by supernatant diluted acid reflux pump 12 suction acid solution tank 2, realize acid cycle, dynamic cleaning plate frame. Filter cloth cleans acid solution and reaches the effect removing dirt shape thing mainly through the effect of acid, along with the carrying out of acid solution with dirt shape thing reaction, wherein in acid solution, effective ion consumes during the course gradually, and loses cleaning performance, and whether acid solution also has the change apparent feedback of cleaning performance by pH value. Acidometer measures total acidity in acid solution tank 2, reduces obvious if cleaning acid concentration, and PH value is greater than 4, then without cleaning performance, then again start configuration acid solution process, increase acid concentration, complete quantitative, Rapid Cleaning, acidometer measures total acidity in diluted acid reuse tank 3, before and after cleaning, acid concentration difference is tending towards in certain limit, it is believed that filter cloth cleaning, and acid filling pump 11 stops work, acid solution in plate frame is found time by diluted acid reflux pump 13, completes the cleaning of plate frame filter cloth.
Diluted acid enters diluted acid reuse tank 3 precipitated impurities, after cleaning 3-5 cleaning interval, starts scraper 14 bottom diluted acid reuse tank 3, and mud slag returns to the modified pond 15 of mud and processes, and it is modified that mud can be carried out the first step by contained diluted acid. Repeatedly containing a large amount of metal ions and suspended particle in the reuse acid solution of clean plate frame, acid residual concentration keeps lower level simultaneously, by alkali, alkali is added mouth 18 add, precipitation removes these materials, it is linked into the modified pond 15 of mud again by scraper 14, contained alkali is oxide-based and mud can be carried out the 2nd step matter by basic metal throw out, facilitates the modified dehydration of mud, extends the interval time that plate frame cleans simultaneously.Three kinds of acid are environmentally friendly acid solution, easily decompose, and it is low to clean use acid strength, and diluted acid enters the modified mud in the modified pond of mud, does not affect recycling sludge, discharges without waste liquid, it is achieved environmental protection utilizes.
The technique of a kind of filter cloth that dewaters for clean sludge plate frame, it is characterised in that, comprise the following steps:
A, pressure detection: when diaphragm type plate-and-frame filter press pressure controller sense and feed pressure rise to more than 1.0MPa, plate-and-frame filter press stopping work.
B, configuration acid solution: when the ironic hydroxide mass percent that mud plate frame dewaters in the dirty shape thing on filter cloth is 18 ~ 22%, acetic acid, oxalic acid, citric acid are added in acid solution tank by the mass ratio of 3:2:1, water filling in acid solution tank, dilute agitator by oar blade type to stir so that the acid concentration of acid solution is less than or equal to 10% simultaneously;
When mud plate frame dewaters the ironic hydroxide mass percent 22% ~ 33% in the dirty shape thing on filter cloth, acetic acid, oxalic acid, citric acid are added in acid solution tank by the mass ratio of 3:2:1 ~ 4:3:1, water filling in acid solution tank, dilute agitator by oar blade type to stir so that the acid concentration of acid solution is less than or equal to 10% simultaneously;
C, acid filling pickling: after acid solution has configured, by acid filling pump, acid solution in acid solution tank is injected plate-and-frame filter press, pressure in the plate frame of plate-and-frame filter press is kept to be 0.2 ~ 0.6MPa, the dirty shape thing that acid solution is dewatered on filter cloth with mud plate frame in plate-and-frame filter press carries out reaction and cleans filter cloth, and a cleaning interval of pickling, a cleaning interval continue 1.5-2.5 hour;
D, overcurrent precipitate: the plate frame diluted acid on the reacted upper strata in the diaphragm plate frame of plate-and-frame filter press is back in diluted acid reuse tank by diluted acid reflux pump, adding mouth from alkali to make to precipitate with the metal ion acid solution and suspended particle, overcurrent precipitates 10-30 minute consuming time.
E, acid solution reuse: the acid solution of backflow is delivered in acid solution tank through supernatant diluted acid reflux pump after precipitation in diluted acid reuse tank and reuses, it is achieved acid cycle, dynamic cleaning.
F, acid solution are nursed one's health: the PH value detected in acid solution tank when acidometer is more than or equal to 4, and PLC control spiral solid doser, liquid dosing pump add ortho acid in acid solution tank and reconfigure acid solution, increase acid concentration.
G, mud are modified: the precipitated impurities in diluted acid reuse tank is scraped through scraper after 3-5 cleaning interval and carried out modified to mud in the modified pond of mud.
Traditional soaking technology adopt 15% hydrochloric acid clean, acid strength height, environment also can be caused secondary pollution by hydrochloric acid, the technique employing acetic acid of the filter cloth that dewaters for clean sludge plate frame of the present invention, oxalic acid, citric acid is mixed in proportion configuration, the acid concentration of acid solution is less than or equal to 10%, acid solution consumption is few, save acid solution, traditional soaking technology adopt 15% hydrochloric acid carry out cleaning to equipment and filter cloth corrosion height, the acid solution for the technique of clean sludge plate frame dehydration filter cloth of the present invention is not obvious to equipment corrosion, especially the aging change of filter cloth is slow, filter cloth life cycle postpones, the work-ing life of 10% can be postponed, pressure in the plate frame of plate-and-frame filter press is kept to be 0.2 ~ 0.6MPa during pickling, require that 0.75MPa is more energy-conservation compared with traditional soaking technology, acid solution cleans one-period 1.5-2.5 hour consuming time, require more to save the time for 6-8 hour compared with traditional soaking technology, and 2 hours mud press filtration batch used times, do not affect continuous production, in traditional soaking technology, acid solution residual concentration height after immersion, due to metal salinity impurities accumulation in acid solution after prolonged and repeated use, need to be processed, cause waste, in the technique of the present invention, the plate frame diluted acid on the reacted upper strata in the diaphragm plate frame of plate-and-frame filter press is back in diluted acid reuse tank, add mouth from alkali to make to precipitate with the metal ion acid solution and suspended particle, directly throw out can be used for mud after Reusability modified, realize Appropriate application, supernatant liquid is delivered in acid solution tank through supernatant diluted acid reflux pump after precipitation in diluted acid reuse tank and reuses by the acid solution of backflow, discharge without waste liquid, realize environmental protection to utilize, adopting traditional soaking technology usually monthly to be cleaned once, the technique for clean sludge plate frame dehydration filter cloth of the present invention can postpone Clean after every, cleaned once every 1.5 months,After adopting the technique for clean sludge plate frame dehydration filter cloth of the present invention to clean, the charging amount of plate-and-frame filter press promotes 16%-17%, and mud extraction moisture content of the cake reduces 3%-5%.
Specific embodiment 1: certain deeply dehydrating sludge project, has diaphragm type plate-and-frame filter press two, plate-and-frame filter press filter plate size 2m*2m, filter plate 115 pieces. Using after for some time, filter cloth occurs that dirt shape thing is obvious, and filter cloth hardens hardening phenomenon, and feed pressure rapidly increases to more than 1.0MPa and sample size obviously reduces, and illustrates that this platen frame filter cloth needs to clean. Dirt shape thing composition quality per-cent is after testing: calcium carbonate 32.5%, calcium hydroxide 17.9%, magnesium hydroxide 6.5%, ironic hydroxide 21.6%, secondary magnesium phosphate 14.2%, 7.3% composition are not clear. PLC starts joins acid process, and acid solution tank injects acetic acid 0.3t(acetic acid content >=99.5% through e Foerderanlage), oxalic acid 0.2t(oxalic acid content >=99%), citric acid 0.1t(citric acid content >=99%), after thin up, obtain solution 18m3,Before soaking, acid solution pH value is 1.38; After this press filtration terminates, modified mud is squeezed into another plate-and-frame filter press and is ensured normal production, this TV station plate-and-frame filter press stop cleaning filter cloth, acid solution squeezes into plate-and-frame filter press by acid filling pump, pressure about 0.3Mpa in holding frame, by crossing, plate cleaning acid solution is back to diluted acid reuse tank to diluted acid reflux pump, overcurrent precipitation about 10min, supernatant liquor returns acid solution tank, realizing dynamic pickling, pickling about 2h completes filter cloth and cleans, and the dirty shape thing between water passage on filter cloth and filter press filter board disappears, loosens, filter cloth recovers resilient flexible, and after soaking, acid solution pH value is 3.54; Impurity is regularly precipitated removal by diluted acid reuse tank, is generally 3 ~ 5 cleaning intervaies, and impurity liquid is used for the modified dehydration of mud, can significantly reduce moisture content of the cake. Dirt settling between filter cloth surface and lining cloth is removed further, and simultaneously between fiber cloth and remain acid solution between transport pipe and be rinsed totally, charging amount promotes 16.5%, mud extraction moisture content of the cake reduction by 3.5%.
Specific embodiment 2: certain deeply dehydrating sludge project, has diaphragm type plate-and-frame filter press two, plate-and-frame filter press filter plate size 1.5m*1.5m, filter plate 110 pieces. Using after for some time, filter cloth occurs that dirt shape thing is obvious, and filter cloth hardens hardening phenomenon, and feed pressure rapidly increases to more than 1.0MPa and sample size obviously reduces, and illustrates that this platen frame filter cloth needs to clean. After testing dirt shape thing composition quality per-cent be calcium carbonate 30.8%, calcium hydroxide 16.6%, magnesium hydroxide 6.4%, ironic hydroxide 23.8%, secondary magnesium phosphate 12.5%, 9.9% composition fail to understand. PLC starts joins acid process, and acid solution tank injects acetic acid 0.4t(acetic acid content >=99.5% through e Foerderanlage), oxalic acid 0.28t(oxalic acid content >=99%), citric acid 0.12t(citric acid content >=99%), after thin up, obtain solution 18m3, acid solution pH value is 1.56. After this press filtration terminates; modified mud is squeezed into another plate-and-frame filter press and is ensured normal production; this TV station plate-and-frame filter press stop cleaning filter cloth; acid solution squeezes into plate-and-frame filter press by acid filling pump; pressure about 0.3Mpa in holding frame; by crossing, plate cleaning acid solution is back to diluted acid reuse tank to diluted acid reflux pump; overcurrent precipitation about 10min; supernatant liquor returns acid solution tank; realizing dynamic pickling, pickling about 2h completes filter cloth and cleans, and the dirty shape thing between water passage on filter cloth and filter press filter board disappears, loosens; filter cloth recovers resilient flexible, and now cleaning acid solution pH value is 3.86.Impurity is regularly precipitated removal by diluted acid reuse tank, is generally 3 ~ 5 cleaning intervaies, and impurity liquid is used for the modified dehydration of mud, can significantly reduce moisture content of the cake. Dirt settling between filter cloth surface and lining cloth is removed further, and simultaneously between fiber cloth and remain acid solution between transport pipe and be rinsed totally, charging amount promotes 17%, mud extraction moisture content of the cake reduction by 4.1%.
Specific embodiment 3: certain deeply dehydrating sludge project, has diaphragm type plate-and-frame filter press two, plate-and-frame filter press filter plate size 1.5m*1.5m, filter plate 110 pieces. Using after for some time, filter cloth occurs that dirt shape thing is obvious, and filter cloth hardens hardening phenomenon, and feed pressure rapidly increases to more than 1.0MPa and sample size obviously reduces, and illustrates that this platen frame filter cloth needs to clean. After testing dirt shape thing composition be calcium carbonate 31.6%, calcium hydroxide 17.1%, magnesium hydroxide 6.8%, ironic hydroxide 22.8%, secondary magnesium phosphate 13.5%, 8.2% composition fail to understand. PLC starts joins acid process, and acid solution tank injects acetic acid 0.32t(acetic acid content >=99.5% through e Foerderanlage), oxalic acid 0.24t(oxalic acid content >=99%), citric acid 0.08t(citric acid content >=99%), after thin up, obtain solution 18m3, acid solution pH value is 1.24. After this press filtration terminates; modified mud is squeezed into another plate-and-frame filter press and is ensured normal production; this TV station plate-and-frame filter press stop cleaning filter cloth; acid solution squeezes into plate-and-frame filter press by acid filling pump; pressure about 0.3Mpa in holding frame; by crossing, plate cleaning acid solution is back to diluted acid reuse tank to diluted acid reflux pump; overcurrent precipitation about 10min; supernatant liquor returns acid solution tank; realizing dynamic pickling, pickling about 2h completes filter cloth and cleans, and the dirty shape thing between water passage on filter cloth and filter press filter board disappears, loosens; filter cloth recovers resilient flexible, and now cleaning acid solution pH value is 3.64. Impurity is regularly precipitated removal by diluted acid reuse tank, is generally 3 ~ 5 cleaning intervaies, and impurity liquid is used for the modified dehydration of mud, can significantly reduce moisture content of the cake. Dirt settling between filter cloth surface and lining cloth is removed further, and simultaneously between fiber cloth and remain acid solution between transport pipe and be rinsed totally, charging amount promotes 16.8%, mud extraction moisture content of the cake reduction by 3.4%.