A kind of Vacuum Pressure Swing Adsorption oxygen enrichment flow process processed
Technical field
The present invention relates to air separation technology field, particularly a kind of Vacuum Pressure Swing Adsorption (VPSA) separating air and making oxygen enrichment technology.
Background technology
The operation of VPSA oxygen technique comprises two basic steps: air inlet absorption and the desorb of finding time, no matter adopt a few tower flow processs, and each adsorption tower must periodically repeat this two steps.Initial pressure-swing absorption apparatus small scale, generally adopts two tower flow processs, for expansion scale and saving energy consumption, develops again multitower flow process afterwards.Along with the exploitation of new adsorbent and the progress of device manufacturing process, progressively return to two tower flow processs again.When this is because adopts two tower flow processs, in the time that a tower adsorbs, the desorb of can finding time of another one tower, two towers match each other, can within the shortest time, complete necessary operation, make the utilization ratio of adsorbent the highest, and two tower flow processs can realize all pressures between adsorption tower, the yield of oxygen and energy consumption also can reach reasonable level; In addition, two tower flow processs are because technique is simple, and number of devices is few, investment is lower.Although two tower flow processs not as multitower flow process, consider investment and operating cost on energy consumption level, the long-term operating cost of two tower flow processs is minimum.
At present, there are two large difficult points in VPSA oxygen technique on the market, 1. solves the manufacturing issue of major diameter adsorption tower and guarantee the uniformity that in adsorption tower, air-flow distributes; 2. molecular sieve, powder enters vavuum pump, oxygen compressor affects oxygenerator work, even spray sieve.
CN102049170B file discloses a kind of VPSA separating air and making oxygen enrichment flow process, the main adsorption tower group by two groups or more, and vavuum pump, valve and pipeline composition, wherein every group of adsorption tower group is formed by connecting by pipeline and valve by upper and lower two adsorption towers, the lower tower filling activated alumina of adsorption tower group, 13X molecular sieve, the molecular sieve adsorbent that the upper tower filling oxygen nitrogen of adsorption tower group separates.In adsorption tower group, tower bottom is connected vavuum pump with pipeline with valve, and lower tower bottom is connected another vavuum pump with valve by pipeline.CN101700876B file discloses a kind of nitrogen making method by pressure swing adsorption, carries out the nitrogen making method by pressure swing adsorption of all pressing for twice.Above-mentioned two files mainly provide a kind of technical scheme to summarize, and in two large difficult points, are not haveing breakthrough before this, still have the problems such as the interior air-flow skewness of tower, molecular sieve.
Summary of the invention
The object of the invention is to solve above-mentioned VPSA oxygen technique and have two large difficult points, 1. solve the manufacturing issue of major diameter adsorption tower and guarantee the uniformity that in adsorption tower, air-flow distributes; 2. molecular sieve, powder enters vavuum pump, oxygen compressor affects oxygenerator work, even spray sieve.Provide a kind of and guarantee what the interior air-flow of adsorption tower was evenly distributed, prevent the Vacuum Pressure Swing Adsorption method for oxygen enriching of molecular sieve.
Technical problem of the present invention is mainly solved by following technical proposals:
A kind of Vacuum Pressure Swing Adsorption oxygen enrichment flow process processed, outside air is from air inlet process air blast, heat exchanger, then enter the adsorption tower of two alternations, adsorption tower absorbs airborne water by adsorbent, carbon dioxide, nitrogen and hydrocarbon, finished product oxygen enters surge tank, its basic step is absorption, bleed off pressure, vacuum desorption, all press, pressurising, it is characterized in that: described air inlet is located at two adsorption tower tops, for upper air, under give vent to anger, described adsorption tower is Multi-stage airflow distributor adsorption tower, higher level's air distributor is loaded oxygen nitrogen isolated molecule sieve, subordinate's air distributor is loaded activated alumina.Traditional oxygen enrichment flow process processed adopt lower air inlet, on give vent to anger, especially easily by the molecular sieve in upper tower, powder enters vavuum pump, oxygen compressor, even causes spray sieve.
Concrete, while producing oxygen enrichment, adopt circulation step, adsorption tower A upper end air inlet starts absorption by described air blast supercharging, and adsorption tower B is by the vavuum pump beginning desorb of bleeding; Adsorption tower A aerogenesis flows into surge tank, and adsorption tower B continues the desorb of bleeding; Open equalizing valve, two adsorption towers are all pressed, by adsorption tower A to adsorption tower B gas transmission balance; Adsorption tower B starts absorption by described air blast supercharging, and adsorption tower A is by the vavuum pump beginning desorb of bleeding, and adsorption tower B aerogenesis flows into surge tank, and adsorption tower A continues the desorb of bleeding; Open equalizing valve, two adsorption towers are all pressed, by adsorption tower B to adsorption tower A gas transmission balance.Preferably, finished product oxygen enters surge tank again by oxygen compressor.
Further, between described adsorption tower A and adsorption tower B, be provided with ball valve and control valve, after described vavuum pump, be provided with silencer, silencer is provided with sample tap.Sample tap provides tail gas monitoring at any time, for whole technique provides purity sample, and while having problem, can be by described ball valve and control valve conditioning equipment blowback amount, guarantee the high-quality operation of whole technique.
Further, described surge tank is provided with pressure-display device, and the safety valve of controlled pressure, for regulating at any time pressure, improves quality and the efficiency of whole technique.
Further, described surge tank is provided with sewage draining exit, and sewage draining exit is provided with blowoff valve.
The invention has the beneficial effects as follows: traditional oxygen enrichment flow process processed adopt lower air inlet, on give vent to anger, especially easily by the molecular sieve in upper tower, powder enters vavuum pump, oxygen compressor, causes oxygen compressor piston ring scuffing, air valve is not closed completely, even spray sieve.This process using air inlet is located at two adsorption towers top, for upper air, under give vent to anger, adsorption tower is Multi-stage airflow distributor adsorption tower, higher level's air distributor is loaded oxygen nitrogen isolated molecule sieve, subordinate's air distributor is loaded activated alumina.Cause molecular sieve in tower to be not easy sieveization, spray sieve does not occur.Moreover, in an adsorption tower, Multi-stage airflow distributor is set, can impel air-flow to be evenly distributed, improve absorption property, progressively absorb water in air, carbon dioxide, nitrogen and hydrocarbon, oxygen purity is higher.In addition, this technique silencer is provided with sampler, for tail gas at will provides purity sample, guarantees the quality of this technique.
Accompanying drawing explanation
Fig. 1 is schematic flow sheet of the present invention
Fig. 2 is the structural representation of adsorption tower in the present invention
In figure: 1. air inlet, 2. air blast, 3. heat exchanger, 4. surge tank, 5.V1 air valve, 6.V2 air valve, 7.V3 air valve, 8.V4 air valve, 9.V5 air valve, 10.V6 air valve, 11.V7 equalizing valve, 12. adsorption tower A, 13. adsorption tower B, 14. vavuum pumps, 15. silencers, 16. ball valves, 17. control valves, 18. blowoff valves, 19. sewage draining exits, 20. pressure-display devices, 21. safety valves, 22. oxygen compressors.
The specific embodiment
Below by embodiment, and by reference to the accompanying drawings, technical scheme of the present invention is described in further detail.
Embodiment: as Fig. 1, a kind of Vacuum Pressure Swing Adsorption oxygen enrichment flow process processed, outside air is from air inlet 1 process air blast 2, heat exchanger 3, then enter the adsorption tower of two alternations, adsorption tower absorbs airborne water, carbon dioxide, nitrogen and hydrocarbon by adsorbent, finished product oxygen enters surge tank 4, its basic step be adsorb, bleed off pressure, vacuum desorption, all press, pressurising.
Concrete, while producing oxygen enrichment, adopt circulation step, open V3 air valve 7, outside air through air blast 2, heat exchanger 3, then starts absorption by described air blast 2 superchargings by molecular sieve, activated alumina from adsorption tower A12 upper end air inlet from air inlet 1, opens V2 air valve 6 simultaneously, vavuum pump 14 is started working, and adsorption tower B13 is by the vavuum pump 14 beginning desorb of bleeding; Open V5 air valve 9, adsorption tower A12 aerogenesis, by oxygen compressor 22, flows into surge tank 4, and adsorption tower B13 continues the desorb of bleeding simultaneously; Open 11, two adsorption towers of V7 equalizing valve and start all to press, by adsorption tower A12 to adsorption tower B13 gas transmission balance; Close V3 air valve 7, close V7 equalizing valve 11, open V4 air valve 8, outside air is from air inlet 1 process air blast 2, heat exchanger 3, then start absorption by described air blast 2 superchargings by molecular sieve, activated alumina from adsorption tower B13, close V2 air valve 6, open V1 air valve 5, vavuum pump 14 is started working, and adsorption tower A12, by the vavuum pump 14 beginning desorb of bleeding, closes V5 air valve 9, open V6 air valve 10, adsorption tower B13 aerogenesis, by oxygen compressor 22, flows into surge tank 4, and adsorption tower A12 continues the desorb of bleeding simultaneously; Open 11, two adsorption towers of V7 equalizing valve open as all press, by adsorption tower B13 to adsorption tower A12 gas transmission balance.
Between described adsorption tower A12 and adsorption tower B13, be provided with ball valve 16 and control valve 17, after described vavuum pump 14, be provided with silencer 15, silencer 15 is provided with sample tap.Sample tap provides tail gas monitoring at any time, for whole technique provides purity sample, and while having problem, can be by described ball valve 16 and control valve 17 conditioning equipment blowback amounts, guarantee the high-quality operation of whole technique.
Described surge tank 4 is provided with pressure-display device 20, and the safety valve 21 of controlled pressure, for regulating at any time pressure, improves quality and the efficiency of whole technique.
Described surge tank 4 is provided with sewage draining exit 19, and sewage draining exit 19 is provided with blowoff valve 18.
As Fig. 2, tower cylinder is provided with two groups of distributors, fully purifying gas of two groups of distributors described in adsorption tower.First order distributor is provided with dress sieve mouth, puts sieve mouthful, provides convenience for changing adsorbent.Described first order distributor is provided with first order air-flow distribution layer, and described second level distributor is provided with second level air-flow distribution layer.Two-stage distributes and arranges, and distribution of gas is more even, and absorption property is more powerful.
Operation principle of the present invention is:
Control system adopts PLC control system air valve to switch Automatic Control, whole employing circulation step, and adsorption tower A upper end air inlet starts absorption by described air blast supercharging, and adsorption tower B is by the vavuum pump beginning desorb of bleeding; Adsorption tower A aerogenesis flows into surge tank, and adsorption tower B continues the desorb of bleeding; Open equalizing valve, two adsorption towers are all pressed, by adsorption tower A to adsorption tower B gas transmission balance; Adsorption tower B starts absorption by described air blast supercharging, and adsorption tower A is by the vavuum pump beginning desorb of bleeding, and adsorption tower B aerogenesis flows into surge tank, and adsorption tower A continues the desorb of bleeding; Open equalizing valve, two adsorption towers are all pressed, by adsorption tower B to adsorption tower A gas transmission balance.
The present embodiment is the embodiment of example of the present invention; for those skilled in the art; the invention discloses on the basis of application process and principle; be easy to make various types of improvement or distortion; and be not limited only to the described structure of the above-mentioned specific embodiment of the present invention, therefore previously described mode is preferred version, and does not have restrictive meaning; every equivalence of doing according to the present invention changes and revises, all in the scope protection domain of the claims in the present invention book.