CN205252858U - Still original mounting of bivalent mercury conversion zeroth order mercury - Google Patents

Abstract

The utility model provides a still original mounting of bivalent mercury conversion zeroth order mercury for make bivalent mercury conversion zeroth order mercury under the high temperature, including heating pipe and heater strip and temperature control device, the outside series connection pottery porcelain bead of heater strip, the heater strip coils on the heating pipe for to the heating pipe even heating, temperature control device is used for making the temperature all the time 800 DEG C, and the heating pipe outside sets up the insulating tube, and both ends set up sealed lid, can effectually keep inside temperature and make the heating pipe more firm, in a word, the utility model discloses simple structure, the security performance is high, is applicable to the industrial production.

Description

A kind of divalence mercury transforms the reduction apparatus of nonvalent mercury

Technical field

The utility model provides a kind of reduction apparatus, for divalence mercury being converted into zeroth order under high temperatureMercury.

Background technology

Mercury is the metal existing in liquid mode under normal temperature, and its density is large, stable chemical nature,Be insoluble to acid and be not also dissolved in alkali, just can evaporate at normal temperatures, the steam of mercury and the compound of mercuryThere is severe toxicity (chronic) more. Coal-burning power plant is one of main artificial mercury emissions source, accounts for artificial rowPut 1/3rd, and after treatment discharge mercury, mainly exist greatly with the form of mercury vapourIn gas, through accumulation for a long time, mercury can enter in food chain because of bioconcentration, causes mercuryPoisoning. Just because of the hypertoxicity of mercury, so can effectively facilitate the concentration of monitoring mercury to have veryActual meaning.

Monitoring method-UV Absorption method of mercury concentration is taking Beer-Lambert law as basePlinth, utilizes mercury its concentration to be carried out for 253.65nm place has maximum absorption value at wavelengthMonitoring, major advantage is to carry out contactless monitoring, avoids falling because of chemical reactionThe degree of accuracy of low monitoring, and because UV Absorption method is short measuring period, be highly suitable for realityTime on-line monitoring.

The monitoring method of mercury is basis mainly with optics at present, real-time as monitoring material taking mercury atomOn-line monitoring, but Mercury In Coal Combustion Flue Gas have three kinds of forms: nonvalent mercury, divalence mercury andGrain state mercury, the easy loss of divalence mercury and particle mercury, therefore need to all be converted into zero by divalence mercuryValency mercury, to improve the accuracy of monitoring. The usual method that is converted at present nonvalent mercury is also to utilizeDivalence mercury is reduced into nonvalent mercury by former dose, but the performance of reducing agent can be because of under time deferredFall, therefore need to make regular check on replacing, feel trouble very much. Another kind for the treatment of method is to utilize divalence mercuryThe characteristic that can be reduced to nonvalent mercury in the time of high temperature is processed, and this method does not need frequent replacingReducing agent, can long-term stable operation, but need in high-temperature heating device, carry out. General high temperatureThe heater strip of firing equipment is wound directly around on heating tube, and heating tube is heated suddenly, easily cracked.

Utility model content

For the defect of prior art, the utility model provides a kind of divalence mercury to transform the reduction of nonvalent mercuryDevice, it is simple in structure, easy to operate, is applicable to divalence mercury to be converted into nonvalent mercury, so thatAccurately mercury content in monitoring of environmental.

Technical problem described in the utility model is achieved through the following technical solutions:

Divalence mercury transforms a reduction apparatus for nonvalent mercury, comprises heating tube heater strip and throttlingValve, heater strip is coiled on heating tube, and flue-gas passes into heating tube by choke valve, described heatingThe outside series connection of silk ceramic bead, heating tube adopts quartz.

Above-mentioned divalence mercury transforms the reduction apparatus of nonvalent mercury, and described ceramic bead is cylindric, its wallThick is 2mm.

Above-mentioned divalence mercury transforms the reduction apparatus of nonvalent mercury, described heating tube outer setting insulationPipe, the two ends of insulating tube arrange seal cover.

Above-mentioned divalence mercury transforms the reduction apparatus of nonvalent mercury, and described heating tube two ends arrange respectively methodBlue assembly, flange assembly is made up of right flange and left flange, and on described right flange, arrange and take part,Make right flange can cover closely left flange, between right flange and left flange, sealing gasket is setCircle, right flange outer setting choke valve.

Above-mentioned divalence mercury transforms the reduction apparatus of nonvalent mercury, and described heating tube bottom arranges base,Insulation cotton pad is set between heating tube and base.

Above-mentioned divalence mercury transforms the reduction apparatus of nonvalent mercury, and described heater strip connects temperature controllerWith A.C. contactor, between heater strip and heating tube, thermocouple is set.

The utlity model has following advantage:

The utility model is closely coiling heater strip in heating tube outside, and heater strip is used for heatingPipe heats, and the outside series connection of heater strip arranges ceramic bead, can effectively avoid heater strip temperature rapidBecome and cause breaking of heating tube, and can play the effect to heating tube insulation; Heating tube with addThermocouple is set between heated filament, and the temperature signal detecting by thermocouple is controlled by temperature controllerA.C. contactor processed, and then control heater strip and whether switch on, carry out realization response temperature maintenance oneFixed object. Heating tube outer setting insulating tube, two ends arrange seal cover, can effectively keepInner temperature, improves heat utilization rate.

Brief description of the drawings

Fig. 1 is the utility model structural representation;

Fig. 2 is the local enlarged diagram of the utility model quartz ampoule;

Fig. 3 is the absorption cross-section figure after fitting of a polynomial;

Absorbance figure when Fig. 4 is certain a moment;

Fig. 5 adds high-temperature service to contrast spectrum with the absorption that does not increase temperature equipment.

In figure, each label is expressed as: 1, right flange, 2, heating tube, 3, ac contactorDevice, 4, temperature controller, 5, thermocouple, 6, insulating tube, 7, ceramic bead, 8, heatingSilk, 9, seal cover, 10, base, 11, insulation cotton pad, 12, seal washer, 13, jointStream valve, 14, left flange.

Detailed description of the invention

Consult accompanying drawing 1,2, the utility model comprises heating tube 2, heater strip 8 and throttlingValve 13, because quartzy fusing point is more than 1500, and hardness is high, fragility is good, resistance toizationCorrosive nature is good, little to the suction-operated of mercury, so heating tube 2 adopts quartz ampoule,The divalence mercury containing in flue-gas is converted into nonvalent mercury in heating tube 2. Described heater strip8 outside series connection ceramic beads 7, heater strip 8 is coiled on heating tube 2, and in the time of coilingMake heater strip 8 compress ceramic bead 7, ceramic bead 7 compresses heating tube 2. Like this, heatingThe heat that silk 8 produces can pass to heating tube 2 by ceramic bead, avoids heater strip 8 temperatureThe cataclysm of degree causes breaking of heating tube 2. But the utility model is in tandem on heater stripAfter ceramic bead, inevitably can make heat transfer efficiency reduce, for this reason, this practicality is newType has taked a series of measure to solve this contradiction. The one, ceramic bead adopts aluminium oxide to doFor main component is made, because aluminium oxide thermal conductivity factor is 20W/m.K, thermal expansion systemNumber is 7.2 × 10^-6M/m.K, density is more than or equal to 3.6g/cm3, itself do not put aside heat,Thermal conductivity is high, has good thermal conductivity and heat-resisting quantity; The 2nd, the utility model is meticulousThe shape of design ceramic bead, being shaped as that the utility model adopts is cylindrical, columniformEnd face center is provided with projection, and bottom center is provided with groove, in the time being wound around heating tube 2, protrudingRise and insert in groove, make ceramic bead 7 more firm in the time of series connection: the 3rd, optimize its size,Because ceramic bead 7 also has heat insulation and insulation effect simultaneously, so the utility model needsBetween heat transfer, insulation and heat insulation three, try to achieve balance. The utility model adopts thickness to beThe ceramic bead 7 of 2mm, by adopting the ceramic bead 7 of different-thickness to 20 groups of quartz heatingsPipe 2 is heated to time and the Thermal-shock Damage test of 800 DEG C of needs, and experimental data is as follows:

The breakage of the time of table 1 quartz heating-pipe to 800 DEG C needs and Thermal-shock Damage testRate

Found through experiments, the thickness of ceramic bead is less, and heating reaches more than 800 DEG C instituteThe time needing is shorter, but the breakage rate of its Thermal-shock Damage test is higher simultaneously, works as ceramic beadThickness while reaching 2mm, heating reaches more than 800 DEG C and needs 20 minutes, and thermal shockThe breakage rate of damage test is 0, when the thickness of ceramic bead is greater than after 2mm, although thermal shockThe breakage rate of damage test is 0, but more than being heated to 800 DEG C, the required times obviously increaseMany, therefore adopt the ceramic bead 7 of 2mm thickness to transfer heat within the shortest timeHeating tube 2, and be difficult for heating tube to form and damage.

The utility model high-temperature region nominal operation temperature is 1400 DEG C, the overall length of heater strip 8Degree is 4m, and heating power is about 1400W, and heating formula is:

Q＝W*t

(1)

Wherein Q is the heat producing, the rated power that W is work, and t is the heat time.

Heater strip 8 connects temperature controller 4 and A.C. contactor 3, heater strip 8 and heating tube 2 itBetween thermocouple 5 is set, in the time that temperature is greater than 800 degrees Celsius, A.C. contactor 3 disconnects, therebyCut off heater strip 8, stop heating. When temperature is during lower than 800 degrees Celsius, A.C. contactor 3 closesClose, connect heater strip 8 and heat; Described temperature controller 4 can be used for regulating to be controlled in heating tube 2Temperature and on display screen, show in real time Current Temperatures.

Described heating tube 2 outer setting insulating tubes 6, the two ends of insulating tube 6 arrange seal cover 9, protectTemperature pipe 6 adopts carborundum tube, and insulating tube 6 plays insulation and firm effect to heating tube 2, closeCapping 9 is further incubated heating tube 2.

Described heating tube 2 two ends arrange flange assembly, flange assembly outer setting choke valve 13,Flange assembly is made up of right flange 1 and left flange 14, on described right flange 1, arranges and takes part, makes the right sideFlange 1 can cover left flange 1 closely, between right flange 1 and left flange 14, sealing gasket is setCircle 12. Heating tube 2 bottoms arrange base 10, between heating tube 2 and base 10, insulation cotton pad are set11, insulation cotton pad 11 prevents that the heating tube 2 of high temperature from contacting the base 10 of low temperature and cracked.

The course of work of the present utility model is as described below:

In the utility model, choke valve 13 is all in the shape of unlatching in the whole process of experimentState, at mobile environment of the interior manufacture of insulating tube 2, prevents that localized hyperthermia's high pressure from causingHeating tube 2 is cracked. Open after two ends choke valve 13, first logical nitrogen, opened and adds after one minuteThermoelectric generator, is 800 DEG C by the Temperature Setting of temperature controller 4 in advance, in the time reaching predetermined value,Heating power supply disconnect, now pass into divalence mercury vapour, treat temperature control panel temperature show lower than800 DEG C time, A.C. contactor 3 is automatically closed, and heating wire works continues heating, makes heatingPipe internal temperature reaches 800 degrees Celsius all the time, so circulation, and the gas after heating is along with gas circuitEnter in optical monitoring system, mercury concentration is carried out to analysis to measure.

It is to adopt DOAS that the utility model is monitored the mercury vapour restoring.DOAS is according to Lambert-Beer law, and its expression formula is as follows:

$I\left(\mathrm{\λ}\right)=I_0\left(\mathrm{\λ}\right)\×\exp \{-L\×\left(\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\σ}}_i\right(\mathrm{\λ})\×c_i+{\mathrm{\ϵ}}_{Mie}(\mathrm{\λ})+{\mathrm{\ϵ}}_{Ray}(\mathrm{\λ}\left)\right)\}---\left(2\right)$

Wherein I₀(λ) be the original light intensity of light source, I (λ) is the light intensity after decaying, σ_i(λ) be i kindGAS ABSORPTION cross section, c_iBe i kind gas concentration, L is for absorbing light path, ε_Mie(λ) be Mie scattering,ε_Ray(λ) be Rayleigh scattering. Rayleigh scattering and Mie scattering are because smoke components is too multipleAssorted causing, in DOAS, absorption cross-section can be divided into fast changing unit andSlow changing unit.

Differential absorption cross-section is with the fast part changing of wavelength, is mainly inhaled by gas molecule featureReceipts cause, and can obtain initial spectrum by simulation:

σ_i(λ)＝σ_i0(λ)+σ′_i(λ)(3)

Wherein σ_i0(λ) be with the fast changing unit of wavelength, mainly by Mie scattering and Rayleigh scattering andMolecule causes for the slow variation absorption of light, σ_i(λ) be differential absorption cross-section, mainly by gasBody characterization of molecules causes.

D'(λ)＝L*Σ_i＝1σ_i(λ)*c_iλ(4)

Wherein D'(λ) be difference absorbance.

Mercury vapour absorption cross-section figure is carried out to fitting of a polynomial and isolate fast changing unit, obtainThe absorption cross-section of mercury vapour and absorbance change curve, respectively as shown in Figure 3, Figure 4.

The control temperature that in this example, temperature controller 4 arranges is 820 DEG C, and mercury vapour concentration existsWhile not adding this high-temperature service and increase temperature absorption spectra after equipment as shown in Figure 5, as seen for addingEnter after this utility model, the absorption line of mercury significantly declines, and this shows that this equipment can be wellTransform divalence mercury and be converted into nonvalent mercury, utilize dense under this condition that DOAS calculatesDegree is 2.414ng/ml.

In Fig. 5, find while not adding this high-temperature service, also have a small amount of mercury to absorb, may be byIn following two reasons: have the absorption of mercury in (1) complete equipment, suddenly can in the time of variations in temperatureThere is the absorption of mercury; (2) produce divalence mercury because various environmental factors can be mixed a small amount of nonvalent mercurySteam.

Claims (6)

1. the reduction apparatus of a divalence mercury conversion nonvalent mercury, comprise heating tube (2), heater strip (8) and choke valve (13), heater strip (8) is coiled on heating tube (2), flue-gas passes into heating tube (2) by choke valve (13), it is characterized in that, described heater strip (8) outside series connection ceramic bead (7), heating tube (2) adopts quartz.

2. divalence mercury according to claim 1 transforms the reduction apparatus of nonvalent mercury, it is characterized in that, described ceramic bead (7) is cylindric, and its wall thickness is 2mm.

3. divalence mercury according to claim 2 transforms the reduction apparatus of nonvalent mercury, it is characterized in that, and described heating tube (2) outer setting insulating tube (6), the two ends of insulating tube (6) arrange seal cover (9).

4. divalence mercury according to claim 3 transforms the reduction apparatus of nonvalent mercury, it is characterized in that, described heating tube (2) two ends arrange respectively flange assembly, flange assembly is made up of right flange (1) and left flange (14), the upper setting of described right flange (1) taken part, make right flange (1) can cover closely left flange (1), between right flange (1) and left flange (14), seal washer (12) is set, right flange (1) outer setting choke valve (13).

5. divalence mercury according to claim 4 transforms the reduction apparatus of nonvalent mercury, it is characterized in that, described heating tube (2) bottom arranges base (10), and insulation cotton pad (11) is set between heating tube (2) and base (10).

6. divalence mercury according to claim 5 transforms the reduction apparatus of nonvalent mercury, it is characterized in that, described heater strip (8) connects temperature controller (4) and A.C. contactor (3), between heater strip (8) and heating tube (2), thermocouple (5) is set.