Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
  • B03C3/017—Combinations of electrostatic separation with other processes, not otherwise provided for
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/007—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by irradiation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/46—Removing components of defined structure
  • B01D53/60—Simultaneously removing sulfur oxides and nitrogen oxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
  • B01J19/081—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing particle radiation or gamma-radiation
  • B01J19/085—Electron beams only
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
  • B03C3/34—Constructional details or accessories or operation thereof
  • B03C3/38—Particle charging or ionising stations, e.g. using electric discharge, radioactive radiation or flames
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
  • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Definitions

• the invention relates to a method according to the preamble of claim 1.
• the primary measures are the use of low-sulfur fuels, the pre-desulfurization of the fuels and the improvement of the combustion plants. However, these primary measures are not sufficient to achieve the prescribed limit values. This can only be achieved through secondary measures for exhaust gas purification, sometimes in combination with primary measures. With secondary measures, the flue gases generated are themselves subjected to the cleaning process.
• the method can be used both for the selective deposition of a
• Pollutant component as well as for the simultaneous separation of several pollutant components, in particular SO x and NO x , are used.
• EBDS processes the flue gas with one pass through the radiation field in a radiation chamber on one or two sides.
• the requirement for the best possible use of the electron radiation used is generally offset by the need for the most effective possible conversion of the harmful gases.
• the latter requires the flue gas to be irradiated as evenly as possible.
• both requirements contradict each other.
• one-sided irradiation because of the decreasing intensity of the radiation along its direction of propagation, a locally highly divergent, overall poor efficiency in the conversion of the pollutants can be achieved (in some cases less than 50%).
• step-wise irradiation was also proposed to improve the degree of separation, but without simultaneously ensuring optimum use of energy and radiation and homogeneous radiation of the flue gas .
• the invention has for its object to provide a method of the type mentioned, in which the above-mentioned disadvantages by suitable process control (steps), by a suitable choice of radiation energy and by mutual adaptation of the radiation field to the shape and dimensions of the flue gas channels and reaction chambers (radiation chambers) can be avoided and an optimal radiation efficiency is ensured, which leads to a reduction in the expenditure on equipment and the primary energy to be used and thus to an optimization of the method.
• the object is achieved by the characterizing method steps of claim 1.
• a step-by-step irradiation is proposed in order to avoid the above-mentioned night silences, in which, according to the inventive concept, the irradiation in succession with partial radiation doses takes place, the desired total radiation dose results as the sum of the partial doses, the flue gas is forcibly mixed between the radiation stages and the radiation chamber assigned to each stage is adapted to the shape of the radiation field and its dimensions are approximately equal to the effective range of the blinded electron radiation in the radiation chamber.
• the gradual irradiation with partial doses which correspond to the total dose required, in conjunction with the forced mixing between the individual stages and the adaptation of the irradiation chamber to the shape and dimensions of the respective irradiation field on the one hand ensures maximum use of the electron radiation in each individual stage without one
• the percentage energy losses in the electron beam window are far lower than bsi low-energy accelerators.
• the window can be made thicker (about 30 ⁇ 10 -3 mm titanium or titanium alloy) without it being mechanical, the transparency impairing support.
• it can also advantageously be designed as a double window, with the cooling medium (inert gas or flue gas-free air) flowing through the intermediate space, so that the jet exit window of the accelerator is not directly exposed to the influences of the flue gas loaded with pollutants and additives (e.g. ammonia) is, which in turn has a positive effect on the operational safety of the system.
• Such a double system consisting of two titanium foils, each 30 ⁇ 10 -3 mm thick, would have been B. at 1000 KeV a transparency of approx. 92%, at 500 KeV of approx. 80%, at 300 KeV however only approx. 55% and at 200 KeV still approx. 35%.
• At least two, but preferably three or more stages should be used in series and form a line, means for turbulent mixing of the radiation material being provided between the stages (e.g. blowers, impellers, Baffles).
• means for turbulent mixing of the radiation material being provided between the stages e.g. blowers, impellers, Baffles.
• a variant of the mixing consists in the fact that the media are guided during the irradiation in such a way that gas volumes which are exposed to a relatively high radiation dose during the first irradiation are passed through in areas under the radiation source where they have a low radiation exposure are exposed, while at the same time gas volumes which are exposed to a relatively low radiation dose during the first irradiation are carried out with further irradiation in areas under the radiation source in which they are exposed to a high radiation exposure. Mixing of the partial volumes can take place simultaneously between the individual irradiation processes.
• One embodiment of the invention is that the first radiation with a partial dose of 60% to 100% and the second irradiation with a partial dose of 10% to 30% and vice versa.
• the method can be carried out analogously if the radiation channel of each of the n stages into the
• Segments a 1 , a 2 ... a n is divided and each partial volume as it passes through the n stages from a. To a 2 . , , transferred to a.
• the method according to the inventive concept is also not limited to the use of ammonia as absorbent, which is known per se.
• Other substances of a similar type would also be conceivable, in particular if the required radiation dose can be reduced thereby and / or other reaction products are to be obtained.
• the dose can also be reduced by adding reaction-accelerating additives and / or water additives and / or additional electric fields within the radiation chambers. In conjunction with the measures mentioned above, this further increases the efficiency and economy of the process.
• FIGS. 1 to 8 show exemplary embodiments of systems for carrying out the method according to the invention.
• the same reference numerals are used in the individual figures for the corresponding components.
• the system shown in FIG. 1 has three electron radiation devices 1 connected in series, each of which emits a partial radiation dose.
• the partial doses result in the sum total effect of the desired total radiation dose, which, for. B. could also be supplied by five individual electron irradiation devices.
• a mixing device 2 which mixes the irradiated flue gas mixture, is arranged after each electron irradiation device. Before the flue gas enters the first radiation stage, it is in a collecting device 3 from Fly ash cleaned and enriched in an additional device 4 with, for example, ammonia in a preferably stochiometric ratio to sulfur dioxide (SO 2 ) and nitrogen oxide (NO x ).
• a device 5 serves to regulate the temperature of the mixture from which the reaction products (ammonium sulfate / nitrate) are withdrawn in a collecting device 7 after passage through the electron irradiation and mixing devices 1 and 2, respectively, before being drawn off into the chimney denoted by 6. This is powdery failure.
• the fly ash is caught in the collecting device 3, the addition of the additives by means of the additional device 4, the mixing in the mixing device 2 and the temperature control using the device 5 again at the entrance of the process line.
• the separation of the reaction products is carried out decentrally after each irradiation and mixing stage 1 or 2 by decentralized devices 7.
• the fly ash is caught at the beginning of the process line.
• the powdery failures are precipitated at the end of the process line.
• additives e.g. B. of ammonia or possibly other substances, the temperature control and the radiation are decentralized gradually.
• FIG. 4 Another variant is shown in FIG. 4.
• the fly ash is caught (centrally) at the entrance of the process line, while the other process steps are modular and each include additional addition, temperature control, radiation part and separation of the powdery failures.
• Mixing (2) takes place between the module components. It is practically a combination of the systems from FIGS. 2 and 3.
• the necessary auxiliary and measuring means of course.
• FIGS. 1 to 4 show systems for carrying out the method according to the invention, as are primarily used for the simultaneous deposition of SO x and NO x . It goes without saying that when using the dsr in the exemplary embodiments shown in FIGS. 1 to 4 for the selective separation of NO x before or after a flue gas desulfurization system, the chimneys labeled 6 or the collecting devices labeled 3 for fly ash can be dispensed with, since these generally are connected upstream or downstream of the desulfurization plants.
• FIG. 5 shows a special design proposal for a simultaneous system based on the inventive concept for a power plant block 100 MW el , the electrical supply devices being designated by (5).
• the required beam power of 2.6 MW could e.g. are realized with three 800 KV / 1000 KW radiation systems, each of which has five radiation heads with an output of 800 KV / 250 mA.
• the five radiation heads of each partial system can be connected in series in the sense of the inventive concept, mixing between the stages so that they form a partial line for 1/3 of the amount of flue gas, ie 120,000 m 3 / h.
• the three sub-lines can then either be operated in series or in parallel (as shown in FIG. 5), each sub-line optionally being operated independently of the others or being shut down. This enables individual adaptation to the load being driven. First of all, only one line is used; Only when the capacity of one line is insufficient with thorough mixing is it intended to gradually use the other.
• the five radiation heads of each partial system can be connected in series in the sense of the inventive concept, mixing between the stages and forming a partial line for 1/3 of the amount of belly gas, ie 120,000 m 3 / h.
• the three sub-lines can then either be operated in series or in parallel (as shown in FIG. 5), each sub-line optionally being operated independently of the others or being shut down. This enables individual adaptation to the load being driven.
• the series is primarily used; Only when the throughput of the purified abdominal gas is not sufficient with sufficient mixing is it intended to carry out the parallel operation.
• FIG. 8 The structural design of one of the three sub-lines described in FIG. 8 is shown by way of example in FIG. 6.
• the radiation system is housed in separate trees 9a and 9b, the abdominal gas channel 10 with the radiation chambers (11) and the intermixing stages (2) lying in the actual radiation chamber (9b) below the earth's surface, so that a minimum of structural radiation protection is required here .
• the belly gases to be treated are supplied and discharged - also for reasons of radiation protection - from the above-standard flue gas ducts arranged above labyrinth-shaped ducts (12) with the thickness required for the radiation shielding.
• a collection device for fly ash and dust (3) and a device for adding additives, for example H 2 O, NH 3 , (4) and a temperature control device (5) are connected upstream of the radiation stage in the flue gas supply duct.
• the resulting reaction products for example ammonium sulfate / nitrate, are withdrawn from the belly gas in the collecting device (7). It goes without saying that the collecting device (3) can be omitted if the belly gas supplied has previously been cleaned of fly ash and dust.
• the radiation system consists, for example, of five stages, each with a radiation head (1) more common Type (with scanner) and a central electrical supply unit (8) (e.g. a high-voltage cascade generator).
• the individual radiation heads (1) are flanged equidistantly in a star shape to the supply unit (8) via T-shaped flanges (13).
• Their outer jackets form a common pressure vessel, which is at earth potential, which is filled with compressed gas (eg 6 atü sulfur hexafluoride) for better insulation, cooling and safe contact of the high-voltage components.
• the concentric arrangement of the (high-voltage) supply unit and the radiation heads enables a space-saving, functional and maintenance-friendly construction of the system.
• the setting, control and regulation of the electrical parameters is carried out centrally and uniformly for the system.
• FIG. 7a The basic structure of one of the five radiation stages of the partial line described in FIG. 6 is shown in FIG. 7a and the associated side view 7b.
• the radiation head (1) here consists of an evacuated, multi-stage accelerator tube (14) with an electron gun (15) arranged at a negative high-voltage potential (against earth).
• the electrons are generated in it and accelerated under the influence of the applied DC voltage of preferably 600 to 1000 kV to the corresponding energy (600 to 1000 keV).
• the high-voltage poles (16) of the individual accelerator tubes are connected to the high-voltage pole of the supply unit (8), not shown, by concentric feeders (17) lying inside the flange-like connections (13) insulated with compressed gas.
• the electron beams (18) generated in the electron gun (15) and accelerated in the accelerator tube (14) are by means of a deflection magnet (19) fanned out in the scanner (20).
• the fanned out electron beams (18a) then pass through a thin window (21), which is largely transparent to electron beams, preferably from a 15-30 m ⁇ thick film of titanium or a titanium alloy, into the intermediate space (22) and after penetrating an adjacent second window (23 ) approximately the same transparency into the radiation chamber (11) integrated in the abdominal gas channel.
• the double window is cooled in the intermediate space (22) between the two windows (21) and (23) by a gas stream (24), preferably an inert gas or a flue gas-free air stream, in which the heat generated by partial absorption of the electrons in the window material is dissipated.
• a gas stream preferably an inert gas or a flue gas-free air stream, in which the heat generated by partial absorption of the electrons in the window material is dissipated.
• Devices (25) can be provided on the window (23) which closes the radiation chamber (11) and has no (significant) pressure difference in order to clean and / or renew it continuously or discontinuously during operation and / or during breaks .
• Such devices (25) can e.g. consist of running or reversing winders and unwinders with a scraper.
• a flue gas-free air flow can be returned to the entrance of the radiation chamber (11) after passing through the intermediate space (22), so that the reaction products, in particular ozone, generated by interaction with the electron radiation intensify the direct electron beam effect in the belly gas.
• the window (23) closing the radiation chamber (11) can be cleaned and / or renewed,
• the energy losses in the double window system can be kept small (for example under 15%) with the electron energies under consideration (600 to 1000 keV) and - Mechanically more sensitive windows with high loss rates, such as those used as single windows with web support, some with water cooling for electron beams with energies less than 500 keV, can be avoided. This also results in the service life, operational safety and efficiency of the device.
• the high-energy electron beams that enter the radiation chamber (11) after passing through the double-window system interact with the flue gas and its pollutants and additives at the same time and gradually lose their energy.
• the energy distribution in the resulting three-dimensional radiation field characterized by its isodose distribution (27), is determined by the geometry (in FIG. 10, for example, by fanning out) of the primary electron radiation, its energy-dependent range of fiesta B R when it emerges from the double-window system and the likewise energy-dependent scattering. While the remaining range B R increases with increasing energy of the (primary) electron radiation, the scattering decreases with increasing energy. Accordingly, different field distributions (isodoses) of the type sketched in FIG. 10 result with different primary electron energies (acceleration voltages).
• the shape and size of the radiation chamber (11) are dimensioned so that, on the one hand, as large a part of the radiation field as possible can be used for irradiating the flue gas, but on the other hand the abdominal gas channel and the radiation chamber (11) should not be made unnecessarily large, that it encloses the radiation field spatially as completely as possible, but preferably at least the 5% isodose characteristic curve, while at the same time an interaction with the temperature control device (5) temperature-regulates the wall of the radiation chamber (11) in accordance with the most favorable reaction temperature of the abdominal gas. In this way, a high utilization of the electron radiation radiated into the radiation chamber is achieved with an inhomogeneous dose distribution in the fusing gas flowing through.
• a homogenization of the dose distribution in the flue gas is achieved according to the inventive concept in that several such irradiation stages are operated in series to form a (partial) line, the flue gas flowing through being mixed between the stages, and the target radiation dose of the (partial) line is balanced the (multiple folds) effect of the individual stages.
• FIG. 8 gives examples a, b and c.
• the illustrations in principle represent a section along the line E - F of FIG. 6. For the sake of simplicity, however, only three (of the five irradiation heads (1) shown in FIG. 6) are shown.
• the flue gas to be irradiated (26) flows from the left side of the picture through the additional and temperature control device (4, 5) through the labyrinthine channel (12) into the radiation zone located underground with the three radiation chambers (11) and passes through another labyrinthine channel section (12) in the collecting device (7) and from there (into the chimney, not shown).
• the flue gas is mixed in two mixing stages between the three radiation chambers.
• Example 8a the mixing stages consist of (rotating) fans
• example 8b the mixing is carried out by a (turbulence-generating) design of the abdominal gas channel between the radiation chambers (1), e.g. achieved by multiply kinked channel sections (29).
• elements (30) determining the flow and / or flow direction, e.g. special grids or lamella inserts, intended for thorough mixing.

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• 1986
  • 1986-06-20 DE DE19863620673 patent/DE3620673A1/de not_active Ceased
  • 1986-09-20 WO PCT/EP1986/000549 patent/WO1987002597A1/de not_active Ceased
  • 1986-09-20 EP EP86905294A patent/EP0244429A1/de not_active Withdrawn
  • 1986-10-22 ES ES8602718A patent/ES2003146A6/es not_active Expired
• 1987
  • 1987-06-09 DK DK294687A patent/DK294687A/da not_active Application Discontinuation
  • 1987-06-22 FI FI872757A patent/FI872757A0/fi not_active Application Discontinuation

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