The hydrogen chloride tail gas reclaimer
Technical field
The present invention relates to tail gas recycle treatment facility technical field, especially a kind of hydrogen chloride tail gas reclaimer, be used for absorbing the hydrogen chloride gas in the tail gas that polysilicon production process discharges, the tail gas that will contain hydrogen chloride directly is transformed into the technical equipment of utilizing the byproduct hydrochloric acid that is worth.
Background technology
Produce a large amount of tail gas in the polysilicon production process, contain a large amount of hydrogen chloride in the tail gas, traditional exhaust gas treating method is to neutralize with alkaline solution and tail gas, and the brine waste that this process will produce flood tide needs further to handle, otherwise will cause the serious environmental pollution problem.And traditional exhaust gas treating method also need consume the medicament expense usefulness of great number.How the hydrogen chloride composition in the polysilicon tail gas of discharging is separated or be transformed into useful byproducts, reduce secondary pollution, reduce the production cost of polysilicon enterprise, available resources in the tail gas are reused for the activity in production of enterprise, reduce the discharging of " three wastes " pollution sources, the real new technology that realizes energy-saving and emission-reduction, new equipment.
Existing a kind of hydrochloric acid recovery tower, come absorbing hydrogen chloride gas by the sprayer spray absorption liquid that is provided with in the tower, absorption liquid is selected clear water for use, hydrochloric acid recovery tower bottom has the tail gas import, and hydrochloric acid recovery tower top has the tail gas outlet, and sprayer is arranged on the top of hydrochloric acid recovery tower, the sprayer below has packing layer, hydrochloric acid recovery tower lower end has the circulation fluid case, and the circulation fluid case has liquid outlet, and liquid outlet is communicated with by pipeline and circulating pump with sprayer.Tail gas enters hydrochloric acid recovery tower and upwards mobile by the tail gas import during work, absorption liquid in the circulation fluid case is transported to sprayer by circulating pump, sprayer is distributed to packing layer uniformly to the absorption liquid after atomizing, tail gas is absorbed at packing layer by the absorption liquid of reverse flow, and the tail gas behind the removal hydrogen chloride gas is got rid of from the tail gas outlet at hydrochloric acid recovery tower top.This hydrochloric acid recovery tower is simple in structure, can remove most of hydrogen chloride gas in the tail gas, and operating cost is lower, but still has remaining hydrogen chloride gas in the tail gas, and directly discharging still has harmful effect to environment.
Summary of the invention
The technical problem to be solved in the present invention is: in order to solve deficiency of the prior art, the invention provides a kind of hydrogen chloride tail gas retracting device, have the secondary spray equipment in the hydrogen chloride recovery tower, assimilation effect is better.
The technical solution adopted for the present invention to solve the technical problems is: a kind of hydrogen chloride tail gas retracting device, have at least one hydrochloric acid recovery tower and absorption liquid EGR, the bottom of hydrochloric acid recovery tower offers the tail gas import, the upper end of hydrochloric acid recovery tower offers the tail gas outlet, be provided with the secondary spray equipment of spray absorption liquid in described each hydrochloric acid recovery tower, described secondary spray equipment comprises the sprayer of two upper and lower settings, each sprayer below is respectively equipped with packing layer, the bottom of hydrochloric acid recovery tower has the circulation fluid case of the absorption liquid that reclaims the ejection of secondary spray equipment, and circulation fluid case and secondary spray equipment are by absorption liquid EGR pipeline connection.
For fully absorbing the hydrogen chloride gas in the tail gas, described hydrochloric acid recovery tower quantity is two, be respectively a grade hydrochloric acid recovery tower and the two grade hydrochloric acid recovery towers of series connection successively, pipeline connection is passed through in the tail gas outlet and the tail gas import of two grade hydrochloric acid recovery towers of one grade hydrochloric acid recovery tower, one grade hydrochloric acid recovery tower correspondence is provided with one-level absorption liquid EGR, two grade hydrochloric acid recovery tower correspondences are provided with secondary absorption liquid EGR, are provided with the pressure sensor P of measurement gas pressure in the pipeline between the tail gas outlet of a described grade hydrochloric acid recovery tower and the tail gas import of two grade hydrochloric acid recovery towers.
For guaranteeing that equipment works long hours, reduce the influence that equipment fault brings, described absorption liquid EGR has two and is arranged in parallel standby each other circulating pump, two inlet of circulating pump and circulation fluid case pipeline connection, two outlet of circulating pump and secondary spray equipment pipeline connection, two outlet of circulating pump and import department are respectively equipped with switch electromagnetic valve.
The outlet of described secondary absorption liquid EGR pipeline respectively connects the secondary spray equipment of two grade hydrochloric acid recovery towers and the circulation fluid case of a grade hydrochloric acid recovery tower, pipeline between the secondary spray equipment of the outlet of secondary absorption liquid EGR and two grade hydrochloric acid recovery towers is provided with switch electromagnetic valve, and the pipeline between the circulation fluid case of the outlet of secondary absorption liquid EGR and a grade hydrochloric acid recovery tower is provided with switch electromagnetic valve.
The tail gas that enters for the tail gas import that makes the hydrochloric acid recovery tower is evenly distributed, to improve assimilation effect, the tail gas import department of described hydrochloric acid recovery tower is provided with gas distributor, discharges the hydrochloric acid recovery tower for avoiding acid mist with tail gas, and the tail gas exit of hydrochloric acid recovery tower is provided with demister.
For storing acidity hydrochloric acid up to standard, also have the hydrochloric acid holding vessel, described circulation fluid case is communicated with by hydrochloric acid delivery pump pipeline with the hydrochloric acid holding vessel, is respectively equipped with switch electromagnetic valve on the import of hydrochloric acid delivery pump and the pipeline in exit.When concentration is up to standard, open the hydrochloric acid delivery pump, make hydrochloric acid enter the hydrochloric acid holding vessel and preserve.
For detecting the quality of the absorption liquid in the circulation fluid case in real time, be provided with heat-exchanger rig, liquid level sensor, temperature sensor and concentration of hydrochloric acid sensor in the described circulation fluid case.
For realizing automation control, also has the electric control unit that shows and control heat-exchanger rig, liquid level sensor, temperature sensor, concentration of hydrochloric acid sensor and absorption liquid EGR duty, electric control unit and each circulating pump and switch electromagnetic valve control connection.
The position of optimizing sprayer and packing layer is to improve assimilation effect, and the packing layer distance of described each sprayer and below is 800 ± 100mm.
Because of hydrochloric acid has corrosivity, select the acid-proof corrosion material for use, described hydrogen chloride recovery tower is the fiberglass recovery tower of anti-acid corrosion, described pipeline is a glass reinforced plastic pipe.Glass-reinforced plastic material can be prevented acid corrosion, can also antistatic.
The invention has the beneficial effects as follows, hydrogen chloride tail gas retracting device of the present invention is novel, the hydrochloric acid recovery tower has the secondary spray equipment, absorb the hydrogen chloride better effects if that reclaims in the tail gas, obtain utilizing the salt acid product that is worth, this device is realized electrified control, the automaticity height, and operating cost greatly lowers than original hydrogen chloride tail gas treating column.
Description of drawings
The present invention is further described below in conjunction with drawings and Examples.
Fig. 1 is the structural representation of first embodiment of hydrogen chloride tail gas retracting device of the present invention;
Fig. 2 is the structural representation of second embodiment of hydrogen chloride tail gas retracting device of the present invention.
Among the figure: 1. hydrochloric acid recovery tower, 11. absorption liquid EGRs, 12. sprayers, 13. packing layers, 14. the circulation fluid case, 15. heat-exchanger rigs, 16. hydrochloric acid delivery pumps, 17. gas distributor, 18. demisters, 2. a grade hydrochloric acid recovery tower, 21. one-level absorption liquid EGR, 3. two grade hydrochloric acid recovery towers, 31. secondary absorption liquid EGRs, 4. electric control unit, 5. hydrochloric acid holding vessel, L. liquid level sensor, T. temperature sensor, H. concentration of hydrochloric acid sensor, P. pressure sensor.
The specific embodiment
In conjunction with the accompanying drawings, the present invention is further detailed explanation.These accompanying drawings are the schematic diagram of simplification, basic structure of the present invention only is described in a schematic way, so it only show the formation relevant with the present invention.
Fig. 1 is first embodiment of hydrogen chloride tail gas retracting device of the present invention, have a hydrochloric acid recovery tower 1 and absorption liquid EGR 11, the bottom of hydrochloric acid recovery tower 1 offers the tail gas import, the tail gas import department of hydrochloric acid recovery tower 1 is provided with gas distributor 17, the upper end of hydrochloric acid recovery tower 1 offers the tail gas outlet, the tail gas exit of hydrochloric acid recovery tower 1 is provided with demister 18, be provided with the secondary spray equipment of spray absorption liquid in the hydrochloric acid recovery tower 1, the secondary spray equipment comprises the sprayer 12 of two upper and lower settings, each sprayer 12 below is respectively equipped with packing layer 13, each sprayer 12 is 800 ± 100mm with packing layer 13 distances of below, the bottom of hydrochloric acid recovery tower 1 has the circulation fluid case 14 of the absorption liquid that reclaims the ejection of secondary spray equipment, circulation fluid case 14 passes through absorption liquid EGR 11 pipeline connections with the secondary spray equipment, be provided with heat-exchanger rig 15 in the circulation fluid case 14, liquid level sensor L, temperature sensor T and concentration of hydrochloric acid sensor H also have demonstration and control heat-exchanger rig 15, liquid level sensor L, temperature sensor T, the electric control unit 4 of concentration of hydrochloric acid sensor H and absorption liquid EGR 11 duties.Circulate in the hydrochloric acid recovery tower that absorption liquid EGR 11 does not stop absorption liquid, make watery hydrochloric acid become certain density hydrochloric acid.Electric control unit 4 is controlled each device work automatically according to the duty parameter in the hydrochloric acid recovery tower of gathering, and realizes automation.
For storing acidity hydrochloric acid up to standard, also have hydrochloric acid holding vessel 5, circulation fluid case 14 passes through hydrochloric acid delivery pump 16 pipeline connections with hydrochloric acid holding vessel 5, is respectively equipped with switch valve on the import of hydrochloric acid delivery pump 16 and the pipeline in exit.Entering hydrochloric acid holding vessel 5 after the hydrochloric acid in the circulation fluid case 14 reaches finite concentration preserves.
For guaranteeing that equipment works long hours, reduce the influence that equipment fault brings, absorption liquid EGR 11 has two and is arranged in parallel standby each other circulating pump, two inlet of circulating pump and circulation fluid case 14 pipeline connections, two outlet of circulating pump and secondary spray equipment pipeline connection, two outlet of circulating pump and import department are respectively equipped with switch electromagnetic valve.Electric control unit 4 and each circulating pump and switch electromagnetic valve control connection are realized electrified control.
For preventing hcl corrosion equipment, hydrogen chloride recovery tower 1 and pipeline are the glass-reinforced plastic material of anti-acid corrosion and make.
Below introduce concrete use of the present invention.
Tail gas enters in the tower from the tail gas import of hydrochloric acid recovery tower 1, absorption liquid in the circulation fluid case 14 is transported to the sprayer 12 of two upper and lower settings and sprays absorption liquid downwards under the circulating pump effect of absorption liquid EGR 11, the absorption liquid of bringing into use selects for use clear water to get final product, tail gas evenly makes progress under the gas distributor effect converging in the packing area of mobile and absorption liquid, absorption liquid absorbs hydrogen chloride in tail gas and becomes watery hydrochloric acid later on, get back to circulation fluid case 14 again, circulation repeatedly under the circulating pump effect, the concentration of watery hydrochloric acid constantly raises, after concentration of hydrochloric acid sensor H records concentration of hydrochloric acid and reaches finite concentration, open hydrochloric acid delivery pumps 16 by electrical control control module 4 and the hydrochloric acid in the circulation fluid case 14 are delivered to hydrochloric acid holding vessel 5 preserve.The liquid level of the absorption liquid in the liquid level sensor L monitoring circulation fluid case 14 also adds absorption liquids automatically by electric controller 4, makes that work is sustainable to be carried out.Absorption liquid temperature in the temperature sensor T monitoring circulation fluid case 14 is also passed through 15 work of electric controller 4 control heat-exchanger rigs, and absorption liquid is maintained in the certain temperature range.
Fig. 2 is second embodiment of hydrogen chloride tail gas retracting device of the present invention, the difference of second embodiment and first embodiment is to have two hydrochloric acid recovery towers, be respectively a grade hydrochloric acid recovery tower 2 and the two grade hydrochloric acid recovery towers 3 of series connection successively, pipeline connection is passed through in the tail gas outlet and the tail gas import of two grade hydrochloric acid recovery towers 3 of one grade hydrochloric acid recovery tower 2, one grade hydrochloric acid recovery tower, 2 correspondences are provided with one-level absorption liquid EGR 21, two grade hydrochloric acid recovery towers, 3 correspondences are provided with secondary absorption liquid EGR 31, be provided with the pressure sensor P of measurement gas pressure in the pipeline between the tail gas outlet of one grade hydrochloric acid recovery tower 2 and the tail gas import of two grade hydrochloric acid recovery towers 3, electric control unit 4 is gathered the running parameter of pressure sensor P to control other equipment work.
The outlet of secondary absorption liquid EGR 31 pipeline respectively connects the secondary spray equipment of two grade hydrochloric acid recovery towers 3 and the circulation fluid case 14 of a grade hydrochloric acid recovery tower 2, pipeline between the secondary spray equipment of the outlet of secondary absorption liquid EGR 31 and two grade hydrochloric acid recovery towers 3 is provided with switch electromagnetic valve, and the pipeline between the circulation fluid case 14 of the outlet of secondary absorption liquid EGR 31 and a grade hydrochloric acid recovery tower 2 is provided with switch electromagnetic valve.
Secondary absorption liquid EGR 31 enters a grade hydrochloric acid recovery tower 2 with the absorption liquid shunting part in the two grade hydrochloric acid recovery towers 3.Other structure is similar with first embodiment with operation.
With above-mentioned foundation desirable embodiment of the present invention is enlightenment, and by above-mentioned description, the related work personnel can carry out various change and modification fully in the scope that does not depart from this invention technological thought.The technical scope of this invention is not limited to the content on the specification, must determine its technical scope according to the claim scope.