WO2006112746A1

WO2006112746A1 - Method and device for splitting hardly-splittable mixtures

Info

Publication number: WO2006112746A1
Application number: PCT/RU2005/000204
Authority: WO
Inventors: Mikhail Jurievich Savinov; Vitaly Leonidovich Bondarenko
Original assignee: Mikhail Jurievich Savinov; Vitaly Leonidovich Bondarenko
Priority date: 2005-04-19
Filing date: 2005-04-19
Publication date: 2006-10-26
Also published as: DE112005003543T5

Abstract

The invention relates to cleaning and splitting isotope and isotopic composition mixtures having a low splitting ratio. The inventive method consists in splitting a mixture by rectification in a column divided into sections which are in series-connected and arranged in a row, in taking a liquid from under a contact space of a preceding section, in supplying said the liquid by means of a flow booster for spraying above the contact space of the next section, in taking a vapour above the contact space of the next section and in supplying said vapour under the contact space of the preceding section. The flow booster is embodied in the form of a vapour lift which is connected to the section contact spaces through hydraulic locks, a liquid evaporation and a vapour condensation in the vapour lift are carried out by supplying a working medium flowing in a low-pressure cycle. A device for carrying out said method is also disclosed. Said invention makes it possible to reduce the metal and power consumption for splitting hardly-splittable mixtures.

Description

METHOD AND DEVICE FOR SEPARATION

DIFFICULT MIXTURES

The invention relates to cryogenic technology, in particular to the purification and separation by distillation of gas mixtures of isotopes and isotopic compounds having a small separation coefficient, and can be used in the chemical industry. A method is known concentration HD compound contained in the electrolytic hydrogen, by low-temperature distillation (see. Fig. 14.4 p. 345 "nick Cppavoch- physico-technical basis kpiogeniki" ed. M. P. Malkova ^g -s ed., Re - slave. and add. - M .: Energoatomizdat, 1985, 432 s). The known method involves the separation of the mixture in a distillation column, obtaining reflux using a high pressure cycle and a low pressure cycle with an intermediate selection of a working fluid low pressure from a high pressure compressor, both cycles being used to obtain reflux directly.

The disadvantages of this method are significant metal and energy consumption in obtaining pure target components from difficult to separate mixtures having a separation coefficient of 1.002-1.1. For example, upon receipt of a neon production isotope with a mass number of 22 with a concentration of 0.995 from gaseous neon, which is a mixture of ²⁰ Ne, ²¹ Ne, ²² Ne isotopes with a separation coefficient of 1.037-1.044, the distillation column will be approximately 100 m high. With such a high distillation column height and, taking into account that the rectification process takes place at a temperature of 27 ÷ 28 K, the dimensions and metal consumption of the equipment determines such high values of heat loss to the environment and, accordingly, the energy intensity of the process, that tion of the known method is practically impossible. At the same time, due to the non-optimal flow rate of the working fluid in the low and high pressure cycles caused by the use of one compressor, an additional energy expenditure appears. However, in a known manner it is impossible to obtain as a production highly volatile component of the mixture.

The aim of the invention is to reduce the metal and energy consumption in the separation of difficult to separate mixtures.

This goal is achieved by the fact that in the method of separation of difficult to separate mixtures, including the separation of mixtures in distillation columns, the generation of heat

ι of the carrier in high and low pressure cycles, the placement of equipment in a casing, a distinctive feature is that at least one distillation column is divided into series-connected sections mounted side by side, while the liquid from the previous section is taken from under the contact space of this section and by a flow inducer is fed over the contact space of the subsequent section for irrigation, and steam is taken over the contact space of the subsequent section, which is sent under con the active space of the previous section, while a steam lift with liquid evaporation in the steam lift evaporator in the lower part and steam condensation in the steam lift condenser in the upper part is used as a flow inducer, the steam cavity is communicated with the contact space of the sections through hydraulic locks, liquid evaporation and steam condensation in parlift is carried out by supplying to the evaporator a parlift and a parlit condenser of a working fluid circulating in the low pressure cycle and in the high pressure cycle, and the circulation in the low pressure cycle I carry out using a separate compressor, while the reflux of the low-boiling component is obtained by condensation at the top of the head section of the column, and the heat fluxes in the parlift condensers are controlled by the pressure drop between the condensation cavity of the parlift condenser and the cavity of the contact space in the upper part of the corresponding section, the casing with the equipment evacuate, and heat influx between the casing and the equipment is shielded. A device is known for concentrating an HD compound from electrolytic hydrogen (see Fig. 14.4, p. 345 "Reference book on the physical and technical fundamentals of a cryogenics" under the pedagogue M. P. Malkova, -3 ^~ ed., Revised and additional - M .: Energoatomazot, 1985-432 s). The known device consists of a distillation column connected by lines of apparatuses, valves of high and low pressure cycles, a high pressure compressor. The disadvantages of the known device are significant metal consumption and energy consumption in obtaining the target components from difficult to separate mixtures, the inability to obtain as a production low boiling component of the mixture.

The aim of the invention is to reduce the metal and energy consumption in the separation of difficult to separate mixtures. This goal is achieved by the fact that in the device for the separation of difficult to separate mixtures, including distillation columns connected by pipelines, valves of high and low pressure refrigeration cycles, housed in a casing, a high pressure compressor, the distinctive feature is that at least one distillation column is broken on the head section of the column, the intermediate sections of the column and the section with the cube of the column, the head section of the column and each intermediate section of the column in the lower part under the contact space has nozzles for liquid outlet and steam inlet, the section with the cube of the column and each intermediate section of the column in the upper part over the contact space has nozzles for liquid inlet, steam outlet and a nozzle, nozzles for steam outlet and inlet of different sections connected in series by steam lines, and the nozzles for the outlet and inlet of the liquid of the same sections - liquid lines with additionally installed flow drivers, and the head section of the column at the top hour This additionally contains a column condenser, the cooling medium cavity of which is included in the high and low pressure circulation circuit, the outlet and liquid inlet sections of the sections through the water locks are connected by lines with a parlift, containing a steam lift evaporator in the lower part, and a steam lift condenser in the upper part, and the heating medium cavity of the steam lift evaporator and the cooling medium cavity of the steam lift condenser are connected by lines to the circulation circuits of the low-pressure cycle and the high-pressure cycle, and the low-pressure cycle The control unit is equipped with a separate compressor, while the condensation cavity of each parlift condenser contains a fitting, which together with a fitting in the upper part of the corresponding intermediate section of the column or section with the cube of the column are connected by impulse lines to a pressure comparison device that generates a signal for influencing the heat flux control element in the condenser steamlift, and the casing with the equipment placed is connected by a line with the vacuum pump, and additionally between the casing and the equipment one or more screens.

The inventive method of separation of difficultly separated mixtures can be implemented in the inventive device, schematically shown in the drawing.

The device (installation) contains the head section 1 of the column, several (K) intermediate sections 2-1 ÷ 2-K columns, section 3 with the column cube installed side by side, high pressure cycle, low pressure cycle, block for the supply and preparation of the shared mixture , a vessel 4 with liquid refrigerant and a system of lines (pipelines) 51, 52, 55 ÷ 57, 67 with fittings for supplying liquid refrigerant to the apparatus and for venting steam (gas), a casing 5 with equipment located inside, connected by a line 6 to a vacuum pump 7. Between the casing 5 and the equipment located inside the casing Expected Screen 68.

The head section 1 of the column and the intermediate sections 2-1 ÷ 2-K columns in the lower part under the contact space have nozzles 8 for liquid outlet and nozzles 9 for steam inlet. Section 3 with a column cube and intermediate sections 2-1 ÷ 2-K columns in the upper part above the contact space have nozzles 10 of the liquid inlet, nozzles 1 1 of the steam outlet and fittings 12.

The steam outlet pipes 11 and the steam inlet pipes 9 of different sections are connected in series with the steam lines 72, the liquid outlet pipes 8 and the liquid inlet pipes 10 of the same sections are connected with the liquid lines 13 with additionally installed flow drivers 14-1 (pipes 8 ÷ 11, fitting 12, steam lines 72, liquid lines 13, flow drivers 14-1, are conventionally designated only at the head section 1 of the column and the intermediate section 2-1 of the column).

Pumps or parlifters can be used as flow boosters 14-1. When using the steam lifts, each of which contains a steam lift evaporator 15 in the lower part, in the upper part there is a steam elevator condenser 16 and a traction pipe 73, nozzles of the outlet 8 and the liquid inlet 10 of the sections are connected by a liquid line 13 to the steam through the hydraulic locks 17, 18. The condensation cavity each condenser 16 contains a fitting 19, which together with the fitting 12 are connected by impulse pipelines with a pressure comparing device 20, which generates a signal of influence on the heat flux regulating body 21 in the parlift condenser 16.

The high-pressure cycle consists of pipelines 48, 49, 50, 58 69 connected to the valves of the high-pressure compressor 22, recuperative gas heat exchangers 23, 24 of the immersion heat exchanger 25, and adsorbent 26 cooled by liquid refrigerant boiling under vacuum created by a vacuum pump 27, filter 28, a submersible evaporator-condenser 29 located in the cube of section 3 with the cube of the column, separator 30, condenser 31 of the column located in the upper part of the head section 1 of the column. To start the high and low pressure cycles, the device has a ramp 47 with cylinders filled with a working fluid, connected by line 58 to line 50 at the inlet of the high-pressure compressor 22 and line 69 to line 48 for discharge.

The low-pressure cycle consists of pipelines 49 53, 54, 62 connected with the valves of a low-pressure compressor 32, recuperative gas heat exchangers 33, 34, a submersible heat exchanger 35, an adsorber 36, cooled by liquid refrigerant boiling under vacuum, a filter 37, evaporators 15 parlifts, an evaporator -condenser 38, connected in parallel along the flow of the condensing working fluid, the fluid collector 39. separator 30, connected in parallel on the flow of the boiling working fluid of the condensers 16. Evaporators 15 of the elevator and condenser-evaporator 38 pos COROLLARY line 74 with valve 75 can be connected to a high pressure cycle.

The block for supplying and preparing the mixture to be divided includes a discharge ramp 39 connected with pipelines 64, 65, 66 with valves, and cylinders for the mixture to be separated, a gearbox 40 and compressor 41, recuperative gas heat exchangers 42, 43, immersion heat exchanger 44, adsorber 45, cooled by liquid refrigerant boiling under vacuum, filter 46.

The method of separation of a difficult to separate mixture by the example of separation of a mixture of neon isotopes is as follows.

Before starting the installation, the casing 5, the cavity of the apparatus and pipelines of the high and low pressure cycles, the distillation column sections, the supply and preparation unit for the shared mixture are evacuated, connecting them with lines 6, 59 ÷ 61 with the vacuum pump 7. On the ramp 47, cylinders filled with cleaned the working fluid is neon, and on the discharge ramp 39 there are cylinders with a cleaned separated neon mixture, which is a mixture of neon isotopes, the vessel 4 is filled along line 67 with liquid nitrogen, which is fed through lines 51, 55, 57 to the immersion heat exchangers 25, 35, 44 on cooling the adsorbers 26, 36, 45 and the screen 68. At the same time, from the ramp 47, a working fluid is fed through line 58 to a high pressure cycle. Compressed by a high-pressure compressor 22, the working fluid is liquefied, first sequentially cooled in a recuperative gas heat exchanger 23 due to reverse flows of a cold working fluid and nitrogen vapor, then in a submersible heat exchanger 26 due to liquid nitrogen boiling under vacuum, a regenerative gas heat exchanger 24 due to a reverse steam flow working fluid and, finally, in a submersible evaporator-condenser 29 due to the boiling of liquid neon with a mass number of 22 (in a stationary mode when there is liquid in the cube), and then they are drosellated to the separator 30. The vapor of the working fluid formed during the cross-linking is sent via line 63 to the recuperative gas heat exchanger 22 as a return flow, and the liquid is sent via line 49 to the condenser of the column 31 and the condensers 16 of the elevators. The vapor of the evaporated liquid from the condensers is returned via lines 62, 63 to the separator 30. In the adsorber 26, possible microimpurities are absorbed.

After the liquid has accumulated in the separator 30, the column condenser 31 and all the condensers 16 of the risers are cooled down, a cooled separable mixture is supplied via line 66 to the column section and a low pressure cycle is started. The separated mixture along the steam lines 72 enters all sections of the column and condenses in the condenser 31 of the column, forming phlegm and initially cooling the contact space. After the cooling of the contact space is completed, the liquid appears at the bottom of the head section 1 of the column and from the pipe 8 through the liquid line 13 is discharged through the hydraulic lock 17 to the vaporizer 15 of the steam lift 14-1, where it partially or completely evaporates due to the condensation of the working fluid compressed and cooled in the low-pressure cycle . Then the vapor-liquid (steam) stream through the traction pipe 73 enters the closed the condenser 16 of the steam lift 14-1, where at the same time the opening of the regulatory body 21 from the separator 30 through line 49 serves the liquid. The vapor part of the flow received in the condenser 16 of the parlift of the stream is condensed, mixed with the liquid part of the stream and flows through the water trap 18 for irrigation to the upper part of the first intermediate section 2-1 of the column. Next, the process of starting the first intermediate section 2-1 of the column proceeds similarly to the process of starting the head section 1 of the column. So, sequentially launching the next intermediate sections of the column and, finally, section 3 with the cube of the column, include the entire installation.

The steam output of the steam lift evaporators 15 is controlled by valves 71 installed on the condensate drain line to the liquid collector 70, which leads to a change in the heat exchange surface due to a change in the level of condensate in the condensation cavity.

The heat flux in the elevator condensers 16 is controlled by changing the heat transfer surface by changing the level of the boiling medium by acting on the regulating bodies 21 depending on the pressure difference between the pressure in the condensation cavity of the elevator condenser, the pulse of which is taken from the nozzle 19, and the pressure in the upper part of the corresponding the intermediate section of the column or section 3 with the cube of the column, the pulse of which is taken from the nozzle 12.

Compressed by a low-pressure compressor 32, the working fluid in the low-pressure cycle through line 53 is fed and subsequently cooled at the beginning in a recuperative gas heat exchanger 33 due to the reverse flows of the cold working fluid and nitrogen vapor, then in the submersible heat exchanger 35 due to boiling under vacuum liquid nitrogen, they are cleaned from possible impurities in the cooled adsorber 36, filtered in the filter 37, cooled in a recuperative gas heat exchanger 34 due to the return flow of steam of the working fluid, is fed to condensation in a submersible evaporator the condenser 38 and the vaporizer 15 evaporators, collect the condensate in the liquid collector 39 and cross into the separator 30. The obtained liquid from the separator 30 is fed through line 49 to the vapor condensers 16 and the condenser 31 of the column for evaporation, and the formed vapors from the apparatus are taken back via line 62 back to the separator 30 and through line 54 through recuperative gas heat exchangers 34, 33 are directed to the inlet of the low pressure compressor 32.

The stream of the separated mixture is first fed through line 66 directly from the discharge ramp 39, cooling it in recuperative gas heat exchangers 42 and 43 due to the return production flows of the light component ²⁰ Ne, ²¹ Ne of the separated mixture, taken out through line 65 from under the cover of the condenser 31 of the column, and the production stream of the heavy component ²² Ne of the separated mixture discharged along line 64 from the section cube 3 with a cube of columns. After the recuperative gas heat exchanger 42, the flow of the separated mixture is cooled in the submersible heat exchanger 44 by boiling under vacuum of nitrogen, it is cleaned of possible microimpurities in the adsorber 45 and filtered in the filter 46. When the pressure in the supply ramp 39 decreases, the booster compressor 41 and the flow are switched on the separated mixture along line 69 is fed to line 66. The prepared separated mixture is directed to the intermediate section of the column, which, when the device is in operation, has a vapor composition close to that of the divided mixture.

The proposed invention allows to reduce the metal and energy consumption during the separation of difficultly separated mixtures, and also to obtain, in addition to the production stream of the heavy component of the mixture, the production stream of the light component.

Claims

CLAIM

1. The method of separation of difficult to separate mixtures, including the separation of mixtures in distillation columns, the generation of coolant in high and low pressure cycles, the placement of equipment in a casing, characterized in that at least one distillation column is divided into series-connected sections mounted side by side, with this liquid is taken from the previous section from under the contact space of this section and by means of a flow stimulator serves over the contact space of the subsequent section for irrigation, moreover, steam is taken over the contact space of the subsequent section, which is sent under the contact space of the previous section, while a steam lift with vaporization of liquid in the steam lift evaporator in the lower part and steam condensation in the steam lift condenser in the upper part, and a steam lift cavity are used as a flow inducer communicate with the contact space of the sections through a water trap, the evaporation of the liquid and the condensation of steam in the parlift is carried out by supplying a steam lift to the vaporizer and a vaporizer condenser of the working fluid, circulating it in the low and high pressure cycle, and the circulation in the low pressure cycle is carried out using a separate compressor, while the reflux of the low-boiling component is obtained at the top of the head section of the column by condensation, and the heat fluxes in the condenser of the elevators are regulated by the pressure drop between the condensation cavity a steam lift condenser and a cavity of contact space in the upper part of the corresponding section.

2. The method according to claim 1, characterized in that the casing with the equipment is evacuated, and the heat flows between the casing and the equipment are shielded.

3. A device for the separation of difficult to separate mixtures, including distillation columns, piped apparatuses, fittings of high and low pressure cycles located in the casing, a high pressure compressor, characterized in that at least one distillation column is divided into the head section of the column, intermediate sections of the column and the section with the cube of the column, the head section of the column and each intermediate section of the column in the lower part under the contact space have nozzles for liquid outlet and steam inlet, The section with the cube of the column and each intermediate section of the column in the upper part above the contact space have liquid inlet, steam outlet and nozzles, steam outlet and inlet pipes of different sections are connected in series by steam lines, and liquid outlet and inlet pipes of the same sections are connected with liquid lines with additionally installed flow drivers, and the head section of the column in the upper part contains a column condenser, the cooling medium cavity of which is included in the circulation circuit of high and low pressure cycles.

4. The device according to p. 3, characterized in that the nozzles for the outlet and inlet of the liquid sections through the hydraulic locks are connected by liquid lines to a parlift containing a parlift evaporator in the lower part and a parlift condenser in the upper part, and the cavity of the heating medium of the parlift evaporator and the cavity of the condenser cooling medium the steam lifts are connected by lines to the circulation circuits of the low pressure cycle and the high pressure cycle, the low pressure cycle being equipped with a separate compressor, and the condensation cavity of each condenser The airlift contains a fitting, which together with a fitting in the upper part of the corresponding intermediate section of the column or section with the cube of the column is connected by impulse lines to a pressure comparison device that generates an impact signal on the heat flow regulating organ in the steam lift condenser.

5. The device according to p. 3 or p. 4, characterized in that the casing with the equipment placed is connected by a line with the vacuum pump, and one or more screens are additionally installed between the casing and the equipment.