Patent Application
20230227310
The disclosure concerns a system developed for obtaining high purity nitrogen gas and drying the resulting high purity nitrogen gas for use in areas of application. The working method of said system is also in the scope of the disclosure.
High purity nitrogen gas is used in many areas in the industry. High purity nitrogen gas is mostly provided by means of liquid (cryogenic tanks) and pure nitrogen tanks, and in recent years it has been provided by the use of pressure swing adsorption (PSA) type nitrogen generators and subsequently nitrogen purifier units.
The nitrogen needed for the metal industry, electronics industry and applications demanding high technology, which require high purity nitrogen, can be provided cost-effectively with low air consumption (A/N:3 and lower) by using PSA nitrogen generator and subsequently nitrogen purifier unit.
Obtaining high purity nitrogen gas by the nitrogen purifier unit is based on reacting the oxygen molecules contained in the nitrogen gas with the hydrogen molecules on the catalyst surface, obtaining water and thus reducing the oxygen content in the nitrogen gas below 10 ppm.
In the available systems, nitrogen gas with 99.9% and 99.95% purity is reached to 99.999% purity by using nitrogen purifier unit. In these systems, the temperature within the nitrogen purifier unit is in the range of 50-80° C. as a result of the exothermic reaction occurred. The dew point value at the outlet of the nitrogen purifier unit increases up to 25° C.
Since the gas is not dry, providing the nitrogen gas produced directly to the line causes damage to equipment in applications where nitrogen gas is used. Thus, it is required to remove the water resulting from the reaction occurred inside the nitrogen purifier unit. The use of a dryer after the nitrogen purifier unit ensures that the obtained gas is separated from the water/dried before it is supplied to the application area.
An example of the known state of the art is the patent document KR100877511B1. The document relates to a system that produces high purity nitrogen gas to supply high purity nitrogen gas required in an operation, and freely control the supply amount and supply pressure of nitrogen gas as per working conditions. It is stated that this system comprises an air compressor, an air purification unit, a nitrogen generator, a nitrogen purification unit, a pressure booster unit, a pressure tank and a pressure regulator. It is stated that the air purification unit removes impurities and water in compressed air supplied by the air compressor to purify the compressed air; the nitrogen generator separates and discharges nitrogen gas only from the purified compressed air; the nitrogen purification unit reacts nitrogen gas containing oxygen with hydrogen under a platinum catalyst to increase the purity of the nitrogen gas by removing oxygen contained in the nitrogen gas.
Another example of the known state of the art is the utility model CN2526312Y. The document relates to a purifying device for removing oxygen and water from nitrogen. It is stated that the device of the utility model comprises a hydrogen oxygen retort containing a palladium catalyst, a cooler, a filter, and a retort for alternately absorbing water and heating rebirth, which are arranged in order and used for removing oxygen and also a controller which transfers the absorption.
However, these documents do not mention of a dryer unit and purifier unit being under a single unit, and there is no information on obtaining high purity nitrogen gas from nitrogen gas with a purity less than 99.9% and 99.95%.
In the available systems described above with examples, the dryer is used as a separate unit after nitrogen purifier unit, which is unfavorable in terms of both the area occupied and the usage.
Accordingly, there is still a need for a system with a compact structure which is developed for obtaining high purity nitrogen gas from nitrogen gas with a purity less than 99.9% and 99.95% unlike the state of the art.
The disclosure concerns a system developed for obtaining high purity nitrogen gas and drying the resulting high purity nitrogen gas for use in areas of application. The working method of said system is also under the scope of the disclosure.
The disclosure relates to a system that is achieved by combining a nitrogen purifier unit and a dryer unit, and used in nitrogen purification applications.
More specifically, in the disclosure, high purity (minimum 99.999%) nitrogen gas is obtained from nitrogen gas with a 99.5% and 99.9% purity.
An object of the disclosure is to provide a large amount of compressed air savings by obtaining high purity (minimum 99.999%) nitrogen gas particularly from nitrogen gas with a 99.5% purity. While the air/nitrogen ratio is 4 or higher in the present purifier systems, the air/nitrogen ratio is 3 or lower in the system of disclosure.
An object of the disclosure is to provide cost savings (air/nitrogen ratio<3) by obtaining high purity (minimum 99.999%) nitrogen gas particularly from nitrogen gas with a 99.5% purity.
Another object of the disclosure is to get a compact system by combining the unit that purifies nitrogen gas, and the dryer unit under a single canopy.
The system of the disclosure mainly comprises a unit that enables the nitrogen gas with a 99.5% and 99.9% purity to have a minimum of 99.999% purity, and a dryer unit that ensures the dew point value to be <3° C. by condensing water formed after the reaction.
The nitrogen gas supplied to the system is provided by a nitrogen generator.
The system of the disclosure comprises, in general;
In an embodiment of the disclosure, the refrigerant type dryer unit comprises a compressor (18) for compressing refrigerant gas.
In an embodiment of the disclosure, the refrigerant type dryer unit comprises a regulator (14) for setting gas pressure.
In an embodiment of the disclosure, the refrigerant type dryer unit comprises a condenser (21) that allows cooling of compressed hot refrigerant gas.
In an embodiment of the disclosure, the refrigerant type dryer unit comprises an eliminator filter dryer (12) for eliminating harmful particles in the refrigerant fluid.
In an embodiment of the disclosure, the refrigerant type dryer unit comprises a thermostatic expansion valve (6) for cooling the fluid by reducing its pressure.
In an embodiment of the disclosure, the refrigerant type dryer unit comprises an exchanger (8) for heating and cooling the gas. More specifically, the exchanger (8) allows drying of the high purity and moist nitrogen at the outlet of the catalyst tank (4) in the system.
In an embodiment of the disclosure, the exchanger (8) comprises a plurality of plates.
In an embodiment of the disclosure, the exchanger (8) comprises an aluminum plate.
In an embodiment of the disclosure, the exchanger (8) has a high heat transfer area.
In an embodiment of the disclosure, the exchanger (8) has a low pressure drop.
In an embodiment of the disclosure, the control unit is a PID control unit.
In an embodiment of the disclosure, there are at least two discharge members. In an embodiment, the discharge member is an egg-shaped discharge (10) member.
In an embodiment of the disclosure, there are at least two egg-shaped discharge (10) members.
In an embodiment of the disclosure, there are two egg-shaped discharge (10) members.
In an embodiment of the disclosure, there is an oxygen analyzer (7) for measuring purity of nitrogen gas.
In an embodiment of the disclosure, there is a dew point analyzer (15) for measuring dryness of nitrogen gas.
In an embodiment of the disclosure, the first cooler (aftercooler) (13) and condenser (21) are contained in a single body.
In an embodiment of the disclosure, the system and all the analyzers, valves and sensors on the system are controlled by the control system panel (17).
In an embodiment of the disclosure, the unit providing nitrogen purification and the dryer unit are contained under a single unit within the system. In other words, the catalyst tank (4) and the dryer unit has a single canopy.
In an embodiment of the disclosure, it comprises a housing (19) surrounding the system. On the housing (19), there is a plurality of openings for the inlet and outlet of nitrogen and hydrogen gas.
In an embodiment, the disclosure comprises a connection cable (20) on the housing (19) that allows driving of energy required for the operation of the system.
In an embodiment of the disclosure, at least two surfaces of the housing (19) have a perforated structure for allowing air inlet and outlet.
In an embodiment of the disclosure, the nitrogen generator is PSA (Pressure Swing
Adsorption).
In an embodiment of the disclosure, the catalyst located in the catalyst tank (4) comprises a metal coating. In an embodiment, the metal is palladium.
The working method of the disclosure is based on mixing 1% hydrogen with nitrogen gas that is produced with 99.5% purity and contains 0.5% oxygen, obtaining water and producing nitrogen with 99.999% purity by removing the obtained water by the dryer unit.
The system of the disclosure is operated by placing it in a housing (19). The working principle of the system of disclosure is as follows. Low purity (99.5%) nitrogen gas from the nitrogen generator is provided to the nitrogen purifier unit by means of the nitrogen inlet port (5). Nitrogen gas enters the catalyst tank (4) filled with primarily palladium catalyst in the nitrogen purifier unit. Hydrogen gas set to a desired flow rate by the hydrogen flowmeter (3) is sent into the said catalyst tank (4) to react it with oxygen in the nitrogen gas. Moist nitrogen gas at high temperature exiting from the catalyst tank (4) is cooled by passing it through the first cooler (aftercooler) (13) in the dryer unit. Then the gas is sent to the water separator (11) to separate the liquid water. The nitrogen gas from the water separator (11) is sent to the exchanger (8) comprising a thin aluminum plate to be dried in order to obtain dry nitrogen (<3° C. PdP).
The refrigerant compressor (18) in the dryer unit compresses the cooler in gas form with a higher pressure. The compressed hot gas is sent to the condenser (21) and it is cooled. The resulting refrigerant fluid is passed through an eliminator filter dryer (12) to protect the expansion valve (6) by eliminating harmful particles. After the filtering process, the fluid is transmitted to the thermostatic expansion valve (6) and cooled by reducing its pressure. Then the fluid is transferred to the nitrogen-gas exchanger (8), it turns from liquid to gas form by condensing the water contained in pure nitrogen. The cooling cycle is completed by sending the refrigerant from the nitrogen-gas exchanger (8) to the refrigerant compressor (18) and proceeds as a continuous cycle.
By means of the dryer unit, heat is removed from pure nitrogen, and by cooling it to the desired dew point, high purity (99.999%) dry nitrogen gas is obtained.
In the operations for purifying 99.5% purity nitrogen gas, the temperature in the nitrogen purifier unit within the system of the disclosure may increase up to approximately 80° C. as a result of the reaction. The nitrogen purifier unit allows for a smooth nitrogen (min 99.999% purity) production up to a maximum temperature of 150° C. The dew point value at the outlet of this unit is above 25° C.
Additionally, if the purity within the system decreases down to 99.2%, the flow rate of hydrogen is set by the PID control unit on the system.
In summary, the disclosure is, in general, a system for obtaining high purity nitrogen gas, wherein it comprises a nitrogen inlet port (5) for the inlet of nitrogen gas from the nitrogen generator which provides connection with and is connected to a nitrogen generator, a catalyst tank (4) with at least one catalyst, allowing the removal of oxygen molecules in the nitrogen gas, a hydrogen inlet port (1) for the inlet of hydrogen gas into the said catalyst tank (4), at least one solenoid valve (2) for controlling the flow of hydrogen gas entering the catalyst tank (4), and closing the hydrogen gas inlet to the system, a hydrogen flow meter (3) for monitoring the flow of hydrogen gas, at least one proportional valve that allows the passage of hydrogen gas at the correct flow rate, a PID control unit for setting the flow rate of hydrogen and controlling the temperature, a first cooler (aftercooler) (13) allowing the condensation of water therein by cooling the nitrogen gas, a water separator (11) for separating the liquid water formed in the gas, at least one discharge member and at least one discharge port (16) for discharging the water separated by the water separator (11), a refrigerant type dryer unit, at least one temperature sensor for controlling the temperature, a control system panel (17) for controlling the system and a nitrogen outlet port (9) for the outlet of nitrogen gas from the system.
The working method of the system is also under the scope of the disclosure.
In summary, the working method of the disclosure comprises the steps of
By means of the disclosure, contrary to the present systems in the state of art, savings in terms of air and cost are provided by obtaining high purity gas from low purity (e.g. 99.5%) nitrogen gas, and also a complex structure is provided by combining the unit purifying nitrogen gas and the dryer unit under a single canopy. Therefore, thanks to the disclosure, an efficient system is created in terms of nitrogen purity and usage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020/08714 | Jun 2020 | TR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/TR2020/050953 | 10/16/2020 | WO |
