JP2011167602A - Gas generator and system thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas generator with decreased energy loss by using plant air used for a plurality of uses and its system. <P>SOLUTION: The gas generator is characterized in that a prescribed gas is taken out of a gas separation apparatus by supplying plant air at pressure increased by a booster compressor to the gas separation apparatus. The gas generator is a gas generator for taking out a prescribed gas by a pressure increase step of increasing the pressure of plant air by a booster compressor and a separation step of separating the pressure-increased air by a gas separation apparatus. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

Apparatus or system for extracting product gas such as nitrogen or oxygen from air

  The nitrogen gas generator described in Patent Document 1 uses a dedicated air compressor and a dedicated dryer to increase the pressure from atmospheric pressure (0 MPa) to the required pressure (0.93 MPa), and the compressed air is separated into a gas separation device ( (PSA type, membrane type) was connected to supply and nitrogen gas was generated.

  Further, the apparatus for separating air described in Patent Document 2 cools air compressed by an air compressor, further compresses it by a booster compressor, and supplies it to a rectifying column to separate oxygen and nitrogen. It was.

  Patent Document 3 describes a conventional booster compressor.

JP-A-8-57241 JP-A-10-54657 JP 2009-133282 A

  Since the nitrogen gas generator described in Patent Document 1 uses a dedicated air compressor and a dedicated dryer, a large output corresponding to the amount of nitrogen gas generated is required, and energy loss is large.

  In addition, since the apparatus for separating air described in Patent Document 2 uses a dedicated air compressor, cooling is required when supplying compressed air to the booster compressor, resulting in a large energy loss.

  An object of this invention is to supply the gas generator and its system which made energy loss small by using the factory air used for multiple uses.

  In order to solve the above-described problems, a gas generator according to the present invention boosts factory air with a booster compressor, supplies compressed air boosted with the booster compressor to a gas separation device, and supplies a predetermined amount of air from the gas separation device. It is characterized by taking out gas.

  In another aspect, the gas generator according to the present invention is a gas generator that takes out a predetermined gas by a boosting step of boosting factory air with a booster compressor and a separation step of separating the boosted air with a gas separator. A device is provided.

  According to the present invention, by using factory air used for a plurality of purposes, it is possible to generate a predetermined gas with a small energy loss compared to a conventional gas generator.

It is a figure which shows the gas generation system by Example 1 of this invention. It is a figure which shows the gas generation system by Example 2 of this invention.

  FIG. 1 shows a gas generation system according to Embodiment 1 of the present invention.

  The gas generation system shown in FIG. 1 uses factory air 1 to boost the factory air by a booster compressor 2 and supply the compressed air boosted by the booster compressor 2 to an air dryer 3 and a gas separation device 4. The supplied gas is separated and a predetermined gas is taken out. In FIG. 1, a pipe 11 exits from a discharge port of an air tank (buffer tank) 21 for factory air and is connected to a suction port of a booster compressor 2. The pipe 12 exits from the discharge port of the booster compressor 2 and is connected to the air inlet of the air dryer 3. The pipe 13 exits from the air outlet of the air dryer 3 and is connected to the air supply port of the gas separation device 4.

  Here, the factory air 1 refers to compressed air stored in the buffer tank 21 and used for multiple purposes. The factory air 1 is generated by being compressed by a piston-type reciprocating compressor, a scroll-type rotary compressor, a swash plate-type compressor, a screw-type rotary compressor, or the like. Basically, use oil-free air. If it contains oil, it can be handled by installing a filter. Factory air 1 is used for a plurality of uses including the gas generation system in the present invention. Therefore, in the apparatus for separating air described in Patent Document 2, the air is compressed using a dedicated air compressor for compression by the booster compressor. A dedicated compressor for compressing to pressure is not required. Accordingly, the space and cost for installing the dedicated compressor are not required, and thus the space and cost can be reduced as a whole system and apparatus. Since the factory air 1 is stored in a buffer tank 21 that is larger than a tank in a normal compressor, it immediately returns to room temperature even if heat is generated by compression. Therefore, unlike the apparatus for separating air described in Patent Document 2, it is not necessary to cool the compressed air before the factory air is compressed by the booster compressor 2. Accordingly, since the space and cost for installing the cooling device are not required, it is possible to realize space saving and cost reduction as a whole system and device. Moreover, the energy loss required for cooling can be reduced, and the energy saving as the whole apparatus is realizable.

  For example, as shown in Patent Document 3, the booster compressor 2 introduces primary compressed air (primary compressed gas) that has been boosted to a pressure higher than atmospheric pressure from an external air supply source (compressed gas supply source). Introduced through the piping, this is further compressed to increase the pressure, and discharged as secondary compressed air (secondary compressed gas) toward the supply destination through the discharge piping. Here, the booster compressor compresses air by, for example, reciprocating a piston by a crank mechanism driven by a drive source. Here, since the booster compressor further compresses the air whose pressure has been increased to a pressure higher than the atmospheric pressure, it has been required to reduce the driving load as compared with a normal compressor that compresses the atmospheric pressure. . As a method for reducing the driving load, for example, there are methods such as a pilot valve, a relief valve, and a stop valve.

  The gas separation device 4 is, for example, a PSA type gas separation device that generates nitrogen gas. In this embodiment, the gas separation device 4 will be described as a gas separation device that generates nitrogen gas by adsorbing oxygen molecules. However, the gas separation device 4 is not limited to nitrogen gas, and is a gas separation device that separates and produces other gases. There may be. The gas separation device 4 has an adsorption tank 23 filled with an adsorbent that adsorbs oxygen molecules. When compressed air generated by a compressor is supplied to the adsorption tank, the pressure in the adsorption tank is increased. As a result, oxygen molecules, which are gas molecules other than nitrogen molecules, are adsorbed, nitrogen molecules are separated, and nitrogen molecules can be extracted. Here, in order to increase the adsorption efficiency of oxygen molecules, it is necessary to increase the compressed air supplied into the adsorption tank. Thereby, the adsorption efficiency of oxygen molecules can be increased, and higher-purity nitrogen gas can be separated and extracted. Then, in the PSA type gas separation device, the separated nitrogen gas is supplied to the nitrogen gas tank 24 through the gas supply pipe. Here, the number of adsorption tanks 23 may be one. However, by providing two or more adsorption tanks as shown in FIG. 1, desorption is performed in another adsorption tank while a certain adsorption tank is being adsorbed. Is possible. That is, by providing a plurality of adsorption tanks 23, nitrogen gas can be efficiently separated.

  The pipe 15 connected to the discharge port of the nitrogen gas tank 24 includes a filter regulator 31 that removes dust and the like and adjusts the gas pressure, a discharge valve 32 that opens and closes the flow path, and a flow rate adjustment valve that adjusts the gas flow rate. 33 is provided.

  A pipe 17 and a pipe 18 are connected to a position of the pipe 16 between the filter regulator 31 and the discharge valve 32. The pipe 17 has an opening / closing valve 34 for opening and closing a flow path in order from the pipe 16 side, A flow rate adjusting valve 35 for adjusting the flow rate and a silencer 36 are provided. The pipe 18 is provided with an open / close valve 37 that opens and closes the flow path, a flow rate adjustment valve 38 that adjusts the flow rate of gas, and an oxygen sensor 39 that detects the oxygen concentration in order from the pipe 16 side.

  The oxygen sensor 39 is communicably connected to the control unit 60 and outputs a detection signal to the control unit 60. The drive solenoid valve 50, the supply valve 51, the exhaust valve 55, the lower pressure equalizing valve 53, the upper pressure equalizing valve 54, the take-off valve 52, the discharge valve 32, and the flow rate adjusting valve 33 are connected to the control unit 60 so as to be communicable. And operates in response to a command from the control unit 60.

(Compressed air separation process)
Here, the separation process of compressed air performed by the gas separation device 4 will be described. The compressed air separation step is configured to sequentially perform the following steps (a) to (d).

  (A) Adsorption process: The compressed air pressurized by the booster compressor 2 and stored in the air tank 22 is introduced into the adsorption tank 23 filled with the adsorbent by opening the supply valve 51, and in the nitrogen tank 24. The step of recirculating the remaining nitrogen gas to the adsorption tank 23 by opening the extraction valve 52 to increase the pressure in the adsorption tank 23 and adsorbing oxygen molecules to the adsorbent using the pressure.

  (B) Extraction step: Continuing from the adsorption step, compressed air is continuously introduced from the air tank 22 into the adsorption tank 23, and at the same time, nitrogen gas separated and generated by the adsorbent is taken out from the adsorption tank 23 and stored in the nitrogen tank 24. Process.

  (C) Pressure equalization step: By opening and closing the lower pressure equalization valve 53 and the upper pressure equalization valve 54, pressure equalization after the end of the take-out step is achieved, and the adsorption efficiency of the next adsorption step is increased to generate higher purity nitrogen gas. Process.

  (D) Regeneration process: By opening the exhaust valve 55 in the adsorption tank 23 after completion of the pressure equalization process, the air is released through the pipe 14 and the exhaust silencer 56 to desorb oxygen molecules adsorbed on the adsorbent. The process of regenerating the adsorbent. In this regeneration step, the supply valve 51, the lower pressure equalizing valve 53, the upper pressure equalizing valve 54, and the take-off valve 52 related to the adsorption tank 23 other than the exhaust valve 55 are closed.

  The controller 60 switches the steps (a) to (d) to the adsorption tank 23 based on a preset time or pressure conditions such as the air tank 22, the adsorption tank 23, and the nitrogen tank 24. This is performed by controlling the opening and closing of the supply valve 51, the exhaust valve 55, the lower pressure equalizing valve 53, the upper pressure equalizing valve 54 and the take-out valve 52 which are arranged. In addition, switching between the steps (a) to (d) is repeated for each adsorption tank 23 so that the processes in each adsorption tank 23 are executed in cooperation, that is, the adsorption process is performed in one adsorption tank 23. Then, after the extraction process is completed and the regeneration process is completed in the other adsorption tank 23, the control unit 60 controls to perform the pressure equalization process.

  In addition, the (c) pressure equalization process is unnecessary when the number of adsorption tanks 23 is one.

  Here, in the conventional nitrogen gas generator described in Patent Document 1, in order to obtain the discharge pressure of the generated nitrogen gas, the pressure is increased from the atmospheric pressure (0 MPa) to the necessary pressure (0.93 MPa), and the gas separation device Therefore, a compressor with a high output with a pressure and an air volume corresponding to the amount of nitrogen gas generated was necessary. On the other hand, as described above, the gas generator in the present embodiment generates nitrogen gas through the boosting step of boosting the factory air-1 in the booster compressor 2 and the separation step of separating the pressurized compressed air by the gas separation device 4. I'm taking it out.

  In the present embodiment, the PSA type gas separation device has been described as the gas separation device 4, but the ASU type separation device that separates expectations based on the difference in boiling point after the raw material air is pressurized and liquefied is liquefied. You may apply as The PSA gas separation device can increase the adsorption efficiency by increasing the pressure of the gas to be supplied. Therefore, the PSA gas separation device can utilize the advantages of the present embodiment, which can efficiently obtain high-pressure compressed air, by using the factory air 1 and the booster compressor 2 as compared with the ASU type gas separation device.

<About energy reduction in this embodiment>
Here, the atmospheric pressure is increased to the pressure of factory air 1 (0.5 MPa), and the booster compressor 2 further increases the pressure to 1 MPa. With respect to the energy reduction effect of the system in this embodiment, the pressure is increased from atmospheric pressure to 1 MPa by a dedicated compressor. This will be described in comparison with a conventional system for boosting pressure.

The theoretical adiabatic aerodynamic power when the atmospheric pressure (0 MPa) 600 L / min is increased to 1 MPa by a dedicated compressor as in the prior art is as follows.

Next, in this example, the theoretical adiabatic aerodynamic power when the pressure of the atmosphere (0 MPa) 600 L / min is increased to the pressure of the factory air 1 (0.5 MPa) is as follows.

  In this embodiment, the factory air 1 obtained by boosting the atmosphere is used to boost the air necessary for gas generation by a booster compressor and supply it to the PSA type gas separation device.

  Here, in the system in the present embodiment, the factory air 1 is naturally cooled in a pipe or a tank, and the temperature is cooled to about room temperature (20 ° C.).

Here, the temperature of the factory air to be used is 20 ° C., and the actual air volume per minute in the suction state at 0.5 MPa is as follows.

Here, the theoretical adiabatic air power when the factory air 1 (0.5 MPa) 108 L / min cooled to 20 ° C. is increased to 1 MPa is as follows.

Here, the energy (1) required for boosting in the conventional system is compared with the energy (2) + (3) required for boosting in this embodiment. In contrast to 3.33 kW in the conventional system, the system in this embodiment is 3.04 kW, which can reduce energy by about 9%.
<About the downsizing of the dryer in this embodiment>
Next, regarding the downsizing of the dryer of the system in the present embodiment in which the atmosphere is increased to the pressure of factory air 1 (0.5 Mpa) and further increased to 1 MPa by the booster compressor 2, the atmospheric pressure is reduced to 1 MPa from the atmospheric pressure by a dedicated compressor. This will be described in comparison with a conventional system that boosts the pressure up to.

(I) Saturated moisture First, since the system in this embodiment uses factory air 1 (0.5 MPa, temperature 20 ° C.) cooled to room temperature, the intake air of the booster compressor has a pressure of 0.5 MPa and a temperature of 20 It becomes ℃. From the saturated water vapor amount table, since the saturated moisture at a temperature of 20 ° C. and a pressure of 0.1013 MPa is 17.3 g / m 3, the saturated moisture at a temperature of 20 ° C. and a pressure of 0.5 MPa is
(Equation 5)
17.3 / (0.5 + 0.1013) · 9.8 = 2.9 g / m 3 (4)
That is, in this example, the factory air 1 having a temperature of 20 ° C. and a pressure of 0.5 MPa is compressed by a booster compressor, so that the air whose saturated moisture has decreased from 17.3 g / m 3 to 2.9 g / m 3 is used. It is compressed by a booster compressor. That is, the system in the present embodiment can reduce the saturated moisture of the intake air as compared with the conventional system. Therefore, in the system in the present embodiment, the dryer for removing moisture in the compressed air supplied to the gas separation device 4 can be reduced in size as compared with the conventional system.

温度２０℃，圧力０．５ＭＰａから１ＭＰａに昇圧した場合の吐出ガスの絶対温度は

ブースタ圧縮機で昇圧することで、２３１℃の温度差が得られ、ドライヤ入気温度の低減が可能となる。これによりドライヤにて冷却のエネルギーが低減可能となる。・・・（5） (II) Inlet temperature Next, the absolute temperature of the discharge gas when the pressure is increased from 20 ° C. and the pressure from 0 MPa to 1 MPa is as follows:

The absolute temperature of the discharge gas when the temperature is raised from 20 ° C and pressure from 0.5 MPa to 1 MPa is

By increasing the pressure with the booster compressor, a temperature difference of 231 ° C. is obtained, and the dryer inlet temperature can be reduced. As a result, the cooling energy can be reduced by the dryer. ···(Five)

The amount of heat calculated from the above temperature difference is

Therefore, the energy is reduced by 2.7 kW. ... (6)
(4) Since the humidity of the intake air of the booster compressor is lower than that of (5) and (6) and the temperature of the discharge air of the booster compressor is low, the dryer used in this system can be downsized.

  Therefore, by configuring the nitrogen gas generator as in this embodiment, the following effects can be obtained as compared with the conventional nitrogen gas generator.

  First, since the factory air 1 produced efficiently and in large quantities is boosted by the booster compressor 2, the compression ratio of the compressed air before and after compression can be made smaller than the conventional gas generator that boosts pressure from the atmospheric pressure. High efficiency and nitrogen gas can be obtained with less energy. In addition, since a dedicated compressor for raising the pressure of the factory air 1 only to obtain nitrogen gas is not required, space saving and cost reduction can be realized as a whole apparatus. Further, since the booster compressor 2 having a smaller output than the compressor used in the conventional gas generator is used, the installation area of the supply device can be reduced. Moreover, since the factory air 1 cooled to room temperature is used, the generated heat can be suppressed lower than when the pressure is increased from the atmospheric pressure, and the environmental temperature change at the installation location can be suppressed small. Further, since the factory air 1 cooled to room temperature is used, the moisture content of the suction air is smaller than that when the pressure is increased from the atmospheric pressure. Therefore, when the dehumidification is performed using the dryer, the size of the dryer can be measured.

  A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The nitrogen gas supply system in this embodiment is a system in which a booster compressor, a dryer, and a gas separation system are housed in a single casing. In addition, you may comprise separately from a compressor, a dryer, and PSA.

  According to the system of the present embodiment, control can be performed with a single substrate, and since it is not necessary to provide a housing for soundproofing for each apparatus, space saving can be realized. In the present embodiment, the factory air supplied to the booster compressor is supplied from outside the casing. Here, when PSA is used, oxygen gas increases around the PSA, and nitrogen gas decreases. When the proportion of nitrogen gas in the compressed air supplied to the PSA decreases, the efficiency of supplying nitrogen gas by the PSA decreases. However, the nitrogen gas supply system is housed in a single housing as in this embodiment, and the factory air supplied from outside the housing is used to reduce the nitrogen gas supply efficiency even when used for a long time. The nitrogen gas can be separated and supplied without causing it.

  In this embodiment, any compressor capable of boosting air, such as a piston-type reciprocating compressor, a scroll-type rotary compressor, a swash plate-type compressor, or a screw-type compressor, may be used.

  Further, the gas separation device of the present embodiment may be either a PSA type or a membrane type, and a configuration having a plurality of tanks of a pair or more is also possible. Furthermore, it is also possible to connect a plurality of booster compressor and gas separation system systems in parallel to increase the discharge amount of the product gas as required.

  Further, in this embodiment, an example in which the entire system is stored in one package has been described. However, the package may have multiple tanks and may be packaged separately for each device, or after packaging each, May be combined into one package.

  Further, the gas to be separated is not limited to nitrogen gas but may be other gas such as oxygen.

  Moreover, when factory air contains an oil component or a booster compressor is an oil supply type, it is good also as a structure which installs a filter etc. in the upstream of a gas separation apparatus, and removes an oil component. Needless to say, if the oil content of the factory air sucked into the booster compressor has been removed in advance, the booster compressor can select an oil-free type compressor that does not use oil for lubrication. Installation of an oil filter can be omitted in this system, and space saving and low cost are possible.

1: factory air, 2: booster compressor, 3: air dryer, 4: gas separation device,
11: piping, 12: piping, 13: piping, 14: piping, 15: piping, 16: piping, 17: piping, 18: piping,
21: factory air tank, 22: booster compressor air tank, 23: adsorption tank, 24: nitrogen gas tank,
31: Filter regulator, 32: Nitrogen gas discharge valve, 33: Flow rate adjusting valve, 34: Open / close valve, 35: Flow rate adjusting valve, 36: Silencer, 37: Open / close valve, 38: Flow rate adjusting valve, 39: Oxygen sensor,
50: Drive solenoid valve, 51: Supply valve, 52: Extraction valve, 53: Lower pressure equalization valve, 54: Upper pressure equalization valve, 55: Exhaust valve, 56: Exhaust silencer, 60: Control unit

Claims (10)

  A gas generator that boosts factory air with a booster compressor, supplies the compressed air boosted with the booster compressor to a gas separator, and takes out a predetermined gas separated by the gas separator.   The gas separation device introduces air compressed by the booster compressor to the adsorption tank, pressurizes the adsorption tank, and adsorbs molecules of gas other than the predetermined gas to the adsorbent of the adsorption tank. The gas generator according to claim 1, wherein the gas generator is a PSA type gas separator that separates and extracts the predetermined gas.   The gas generator according to claim 2, wherein the gas separation device has a plurality of adsorption tanks.   The gas generator according to claim 1, further comprising an air dryer between a discharge port of the booster compressor and an air supply port of the gas separation device.   The gas generator according to claim 1, wherein the factory air is compressed air stored in a buffer tank and used for a plurality of purposes.   A gas generation system in which the gas generation device according to claim 1 is housed in one casing. A boosting process for boosting factory air with a booster compressor;
A gas generator for extracting a predetermined gas by a separation step of separating the pressurized air by a gas separation device. In the separation step,
Of the air compressed by the booster compressor, an adsorption step for adsorbing molecules of gas other than the predetermined gas in an adsorption tank;
An extraction step of taking out the predetermined gas from the adsorption tank;
A regeneration step for desorbing molecules adsorbed in the adsorption tank;
The gas generator according to claim 7, wherein:   The gas generator according to claim 8, wherein in the separation step, a pressure equalization step of equalizing a plurality of adsorption tanks is performed after the extraction step.   The gas generator according to claim 7, wherein the field air is compressed air stored in a buffer tank and used for a plurality of purposes.

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