CN1069296A

CN1069296A - The cyclic cleaning method of calcium dirt and scavenging agent

Info

Publication number: CN1069296A
Application number: CN 91105475
Authority: CN
Inventors: 刘沣
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-08-12
Filing date: 1991-08-12
Publication date: 1993-02-24
Anticipated expiration: 2006-08-12
Also published as: CN1033984C

Abstract

The present invention relates to the removing of calcium dirt, especially the removing method and the scavenging agent of sugar dirt in the sugar industry.

The step of the method for the invention is: one, pretreatment stage; Is that 80-95 ℃, flow velocity are to handle 2-6 hour under the condition of 0-0.5m/s with the preclearing agent in temperature, two, discharge opeing, and the water flushing makes the pH value of wash-down water reduce to 8-9; Three, the treatment stage; Is that 35-45 ℃, flow velocity are under the condition of 0.5-0.8m/s wash cycles 4-8 hour with scavenging agent in temperature; Four, discharge opeing, water flushing make the pH value of wash-down water be 5-7.

Description

The cyclic cleaning method of calcium dirt and scavenging agent

The sugar dirt is a difficult problem of puzzlement sugar manufacturing industry, in order to remove the sugar dirt effectively, people have done number of research projects, " beet sugar industry " sugaring fascicle 1980 the 1st phase 40 pages of publications " trial of ammonium nitrate scale removal " are that the soda ash of employing 8-10% boiled 16 hours, make evaporating pot sugar dirt loose, water is clean with residual alkaline flushing then, adding the 3-4 ammonium nitrate doubly that is about incrustation weight again boiled 16 hours, this kind method is because scavenging period is long, need 32 hours, can not wash the time in (24 hours) at the evaporating pot wheel and finish, in the industrial application of reality, can influence normally carrying out of producing, energy consumption big (steam heating was boiled 32 hours), and be single test only, suitability for industrialized production do not formed.U.S. Pat 3,651,868 to disclose a kind of " removing of calcium dirt " be about remove the calcium dirt from fixed surface, particularly those occur in the bore area of oil well, gas well and the fluid collection device that is attached thereto on the calcium settling, also be related in some industrial equipments with fluid contact surfaces on the removing of dirt layer, as boiler, cooling tower etc., its scavenging process is: a, anhydrous ammonia, carbonic acid gas and water are mixed, form the aqueous solution of volatile salt, ammonia and carbonic acid gas; B, contact with the calcium sulfate of fixed surface, the dirt layer is converted into lime carbonate and ammonium sulfate with above-mentioned solution; C, water or sour water contact with above-mentioned surface with dissolving lime carbonate and ammonium sulfate.The main purpose of this method is to subdue sulphur removal acid calcium adding, and the removal of not mentioned other calcium salt.

In addition, 1981 the 3rd phase 44-46 pages or leaves of " sugarcane sugar industry " sugaring fascicle have been reported " prevention of evaporating pot incrustation and elimination " (being translated from " French sugar industry " the 5th phase in 1977), 1980 the 1st phase 57-59 pages or leaves of " beet sugar industry " sugaring fascicle have been reported " tartar preventing test of French sugar refinery evaporating pot " (being translated from " French sugar industry " the 5th phase in 1977), the main contents of above-mentioned two literary compositions are for adding scale inhibitor-polyelectrolyte such as polyacrylic acid and salt or organophosphate in sugar refining technology, to reach the few incrustation or the purpose of incrustation not.U.S. Pat 4,264,463 have disclosed a kind of " removing the method for caoxalate dirt ", its main purpose is to remove sulfite process, chemical groundwood pulp's method or semichermical pulping, sugarcane or beet sugar process industry, beer to spill the inwall incrustation that fermenting process or grape spill equipment used in fermenting process, whisky still-process or the pulp bleaching process, and its purging method is for caoxalate incrustation with contain a.Al ^{+ 3}Or Fe ^{+ 3}; B. acid radical anion example hydrochloric acid, nitric acid, thionamic acid, formic acid, acetate, propionic acid, oxalic acid, oxyacetic acid, propanedioic acid, oxysuccinic acid, lactic acid, tartrate and lemon aqueous acid generation chemical reaction make dirty dissolved purpose to reach.

The purpose of this invention is to provide a kind of simple, easily row and can be in 20 hours the especially method and the scale remover of sugar mill incrustation of loop cleaning calcium dirt effectively.

The evaporative process of sugar industry mainly is a heat transfer process, in this process, a series of chemistry and physicochemical change have taken place in syrup, and most importantly have a large amount of precipitations to separate out, become the sugar dirt on the METAL HEATING PROCESS face and be attached to, the composition of sugar dirt is partial organic substances and inorganics.And along with the difference of kind, area, growth conditions, geology and geomorphology and the irrigation water of sugarcane and variant, but its major ingredient is carbonate, silicate, vitriol, oxalate and the phosphoric acid salt of calcium, the removing method of calcium dirt of the present invention promptly will be removed above-mentioned incrustation, the steps include:

One, the treatment stage of giving: is that 80-95 ℃, flow velocity are to handle 2-6 hour under the condition of 0-0.5m/s with giving scavenging agent in temperature;

Two, discharge opeing, the water flushing makes the pH value of wash-down water reduce to 8-9;

Three, the treatment stage: is that 35-45 ℃, flow velocity are under the condition of 0.5-0.8m/s wash cycles 4-8 hour with scavenging agent in temperature;

Four, discharge opeing, the water flushing, the pH value that makes wash-down water is 5-7.

Scavenging agent of the present invention comprises and gives scavenging agent and scavenging agent that giving scavenging agent is NaOH0.8-1%, Na ₂CO ₃0.5-1%, X0.2-0.6%(X=Na ₃PO ₄, Na ₂HPO ₄, NaH ₂PO ₄In at least a), scavenging agent is HCl0.05-1%, Y0.3-0.5%(Y=HF, H ₂SiF ₆In any one), inhibiter 0.3-0.5%, tensio-active agent 0.5-1%, additive 1-2%(weight percent).

Mainly be to make to give scavenging agent and the reaction of sugar dirt treatment stage of of the present invention giving, make the sugar dirt loose, peel off with the metallic surface then, reaction mechanism is as follows:

The a large amount of lime carbonate that occur above are can discharging of particulate from waste liquid, if formation precipitates and is attached on the sugared dirt, clean the treatment stage of awaiting.The phosphoric acid salt that gives in the scavenging agent both can be participated in reaction, and the effect that makes metal surface phosphating is arranged again, and equipment is not corroded.Purpose treatment stage of giving mainly is the acid non-soluble substance of removing in the incrustation (being mainly silicon class thing), it is cellular that dirt is become, the carrying out of the chemical reaction the treatment stage of being convenient to, in this stage, can circulate, send into steam by steam drum and make and give scavenging agent and in vaporizer, seethe with excitement, reach convection current operation (or molecular motion is accelerated in the heating back) by its boiling.

Treating processes mechanism is as follows:

From following formula as can be seen, a large amount of iron have participated in reaction, that is to say except that rusty stain etc. is eliminated, the metal of container is also reacted, promptly produced corrosion, so added inhibiter in scavenging agent of the present invention, its inhibiter can be dike is got in the oil by product quinoline, pyridine, tetrahydroglyoxaline etc.Promoting agent surface in the scavenging agent of the present invention is an aniorfic surfactant, and as OP15, Sodium dodecylbenzene sulfonate etc., additive is NH ₄F, NH ₄NO ₃, NH ₄Cl.

The cyclic cleaning method of calcium dirt of the present invention and scavenging agent are applicable to the sugar industry evaporation equipment; the papermaking evaporation equipment; heat exchanger in drinks fermentation equipment and the light industry; the method of the invention is owing to adopted wash cycles; whole technology is accomplished in the short period of time; and energy consumption is low (needs comparatively high temps treatment stage of only giving; and the time is short); extraordinary economic benefit is arranged in industrial application; and in scavenging agent, adopted inhibiter; corrosion inhibition rate is up to more than 99%; also promptly the etching problem in whole acid cleaning process can be ignored; equipment after the cleaning is black oxide film protection layer, makes newborn dirt be difficult for adhering to, deposition; in scavenging agent, adopted tensio-active agent, obstinate incrustation can successfully be eliminated.

Accompanying drawing is the method for the invention wash cycles piping plan.

Among the figure: 1-evaporating pot 2-circulation groove 3-recycle pump 4-sampling valve 5-temperature measuring valve 6-pressure valve 7-liquid adding bottle

Embodiment: in evaporating pot, add entry to normal evaporation liquid level, add NaOH, Na ₂CO ₃, Na ₂HPO ₄, make its concentration be respectively 0.5%, 0.6%, 0.2%, send into steam by steam drum and boiled 4 hours, open hand-hole, the mud that hand sweeping is peeled off is carried out in effluent discharge, and particularly the settling in the U type circle is used 2kg/cm ²Service water flushing, make about solution ph=7, add water to normal evaporation liquid level in the evaporating pot again, add HCl, HF, pyridine, OP ₁₅, NH ₄NO ₃Make its concentration be respectively 0.1%, 0.3%, 0.4%, 0.7%, 1%, connect pipeline by shown in the accompanying drawing, temperature is controlled at 40-45 ℃, and flow velocity is 0.5m/s, and wash cycles has been dissolved (about 6 hours) until incrustation, opens into hand hole, uses 2kg/cm ²Water flushing pipe and container, the dirty piece that will accumulate the particularly waste liquid in the U type circle are removed totally, and wash-down water PH is about 7, can split out the cleaning pipeline, make the equipment operation of putting into production.

For the special sugar dirt of part, still have some soda acid insolubless to be the bull pine shape and be attached on the inside pipe wall, at this moment, availablely manually disclose brush once, water flushing again can reach satisfied cleaning performance.

Claims

1, a kind of cyclic cleaning method of calcium dirt, comprise the treatment stage of giving, the water flushing, the treatment stage, water flushing, it is characterized in that: the treatment stage of giving system to adopt and to give scavenging agent be that 80-95 ℃, flow velocity are to handle 2-6 hour under the condition of 0-0.5m/s in temperature, the treatment stage to adopt scavenging agent be that 35-45 ℃, flow velocity are under the condition of 0.5-0.8m/s wash cycles 4-8 hour in temperature.

2, a kind of calcium dirt scavenging agent comprises and gives scavenging agent and scavenging agent, it is characterized in that giving scavenging agent and is: NaOH0.8-1%, Na ₂CO ₃0.5-1%, X0.2-0.6%(X=Na ₃PO ₄, Na ₂HOP ₄, NaH ₂PO ₄In at least a), scavenging agent is: HC10.05-1%, Y0.3-0.5%(Y=HF, H ₂SiF ₆In any one), inhibiter 0.3-0.5%, tensio-active agent 0.5-1%, additive 1-2%(weight percent).

3,, it is characterized in that the telogenesis promoting agent is OP15, Sodium dodecylbenzene sulfonate according to the described scavenging agent of claim 2.

4,, it is characterized in that additive is NH according to the described scavenging agent of claim 2 ₄F, NH ₄NO ₃, NH ₄Cl.