System for obtaining process air through deep purification

Abstract

The utility model relates to a system for obtaining process air through deep purification. The system comprises an air compressor, a deoiling and dehydrating device, a buffer tank and a drying device which are sequentially connected in series. The deoiling and dehydrating device is used for reducing the temperature of the compressed air and condensing moisture in the air; the drying device comprises a drying bed assembly and a drying machine assembly which are arranged in series. An air inlet and an air outlet are formed in the top of the buffer tank, the air inlet is used for introducing compressed air generated by the air compressor, and factory air is discharged from the air outlet; an immersion pipe is arranged in the buffer tank, extends to the bottom of the buffer tank from the top, then extends to the top of the buffer tank from the bottom of the buffer tank, and is used for cooling the gas. Compared with the prior art, through the pre-arranged physical dehydration device, the dehydration load of the drying machine and the drying bed is reduced, the regeneration period of the drying bed is prolonged, the dew point temperature of process air can be reduced to-85 DEG C, and meanwhile the air using requirements of factories for different water contents can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of process air purification, and in particular to a system for deep purification of process air. Background Art

[0002] Plant air and instrument air are two common air sources used in factories, powering diaphragm pumps, instruments, control valves, and other components. Plant air is the air produced at the outlet of an air compressor, with a dew point temperature controlled at -20°C. To protect instrumentation, instrument air has a relatively low moisture content, typically controlled at around -40°C. Instrument air is obtained by subjecting plant air to certain treatments. Due to process requirements, some production processes require the use of oxygen in oxidation reactions, but oxygen is relatively expensive. Therefore, instrument air is deeply dehydrated to reduce its moisture content and obtain process air for subsequent process flow.

[0003] Currently, there are many methods for drying process and instrument air, including chemical methods, adsorption methods, and freeze-drying. Freeze-drying is suitable for dehumidifying high-temperature, high-humidity air. While it has a high dehumidification capacity, it consumes too much energy and can result in suboptimal dehumidification dew points. Solid adsorption dehumidification can reduce the air dew point to below -60°C, but requires regeneration heat.

[0004] Therefore, there is an urgent need to develop a system that can deeply purify and obtain process air, which can further purify the instrument air so that the dew point temperature drops to -85 to -90°C, so that it can be used in the process production process to achieve the purpose of replacing pure oxygen. Utility Model Content

[0005] The purpose of this utility model is to overcome the above-mentioned shortcomings of the existing technology and provide a device for deep purification of process air. Through the pre-installed physical dehydration device, the dehydration load of the dryer and drying bed is reduced, the regeneration cycle of the drying bed is extended, and the dew point temperature of the process air is reduced to -85°C. At the same time, it can meet the factory's air demand for different moisture contents.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] The utility model provides a system for deep purification of process air, comprising an air compressor, a deoiling and dehydrating device, a buffer tank and a drying device connected in series;

[0008] The deoiling and dehydrating device includes a plate heat exchanger and a physical dehydrator, and is used to reduce the temperature of the compressed air generated by the air compressor and condense the moisture in the compressed air;

[0009] The drying device includes a drying bed assembly and a dryer assembly arranged in series;

[0010] The top of the buffer tank is provided with an air inlet and an air outlet, the air inlet is used to allow the compressed air generated by the air compressor to enter, and the air outlet is used to discharge the factory air;

[0011] An immersion pipe is provided inside the buffer tank, and the immersion pipe extends from the top to the bottom of the buffer tank, and then extends from the bottom to the top of the tank, for cooling the compressed air.

[0012] Furthermore, the heat exchanger is a plate heat exchanger, and circulating water is used as the cooling medium.

[0013] Furthermore, a drain valve is provided at the bottom of the buffer tank, and the drain valve is used to discharge condensed water in the compressed air.

[0014] Furthermore, the dryer assembly includes a heatless regeneration dryer and a micro-thermal regeneration dryer, the drying bed assembly includes a first drying bed and a second drying bed, and the heatless regeneration dryer, the first drying bed, the second drying bed and the micro-thermal regeneration dryer are connected in series in sequence.

[0015] Furthermore, the heatless regeneration dryer is filled with 4A or 5A molecular sieve to reduce the dew point of the factory air to -40°C.

[0016] Furthermore, the micro-heat regeneration dryer is filled with activated alumina.

[0017] Furthermore, the first drying bed is filled with one of 13X, 4A, and 5A molecular sieves.

[0018] Furthermore, the second drying bed is filled with activated alumina.

[0019] Furthermore, two factory air outlets are provided on the air outlet of the buffer tank. The first factory air outlet is used to discharge the factory air cooled by the buffer tank, and the second factory air outlet is used to transport the factory air to the drying device for further purification.

[0020] Furthermore, two instrument air outlets are provided on the outlet pipes of the first drying bed and the second drying bed. The first instrument air outlet is used to discharge part of the instrument air, and the second instrument air outlet is used to transport the instrument air to the micro-heat regeneration dryer for further purification. The instrument air is the instrument driving gas with a water content of 5 to 30 ppm.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] The utility model reduces the dehydration load of the dryer and the drying bed through a pre-installed physical dehydration device, prolongs the regeneration cycle of the drying bed, and reduces the regeneration cost. In addition, the utility model can reduce the dew point temperature of the process air to -85°C, and at the same time can meet the factory's demand for air with different moisture contents, with low operating costs and long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the structure of a system for deep purification and acquisition of process air.

[0024] Description of the markings in the figure:

[0025] 1-air compressor, 2-plate heat exchanger, 3-physical dehydrator, 4-buffer tank, 5-heatless regeneration dryer, 6-first drying bed, 7-second drying bed, 8-micro-heat regeneration dryer. DETAILED DESCRIPTION

[0026] The specific implementation methods of the present invention are described in detail below through examples. These examples are implemented on the premise of the scheme described in the present invention, and provide detailed implementation methods and specific operating processes, but the protection scope of the present invention is not limited to the following examples.

[0027] The present invention is further described below with reference to the accompanying drawings and specific embodiments. Any features, such as component models, material names, connection structures, preparation methods, materials, structures, or composition ratios, that are not explicitly described in this technical solution are considered to be common technical features disclosed in the prior art.

[0028] Example 1

[0029] This embodiment provides a system for deep purification of process air, such as Figure 1 As shown, it includes an air compressor 1, a plate heat exchanger 2, a physical dehydrator 3, a buffer tank 4, a heatless regeneration dryer 5, a first drying bed 6, a second drying bed 7 and a micro-heat regeneration dryer 8 connected in series.

[0030] Plate heat exchanger 2 and physical dehydrator 3 are used to lower the temperature of the compressed air, facilitating condensation of moisture in the gas and thereby reducing the water content of the compressed air. Plate heat exchanger 2 uses circulating water as its cooling medium. The physical dehydrator is a compressed air oil-water separator, model SAYF-20.

[0031] The top of the buffer tank 4 is provided with an air inlet and an air outlet. The air inlet is used to allow the compressed air generated by the air compressor to enter, and the air outlet is used to discharge the factory air. The inside of the buffer tank 4 is provided with an immersion pipe, which extends from the top to the bottom of the buffer tank 4, and then extends from the bottom to the top of the tank, for cooling the gas. The bottom of the buffer tank 4 is provided with a steam trap, which is used to discharge the condensed moisture in the gas. The air outlet of the buffer tank 4 is also provided with a factory air inlet. The air outlet of the buffer tank 4 is provided with two factory air outlets. The first factory air outlet is used to discharge the factory air cooled by the buffer tank 1, and the second factory air outlet is used to transport the factory air to the drying device for further purification.

[0032] The heatless regeneration dryer 5 is filled with 5A molecular sieve to reduce the dew point of the factory air to -40°C; the micro-heat regeneration dryer is filled with activated alumina.

[0033] The outlet pipes of the first and second drying beds 6 and 7 are equipped with two instrument air outlets. The first outlet is used to discharge a portion of the instrument air, while the second outlet is used to convey the instrument air to the micro-heat regeneration dryer 8 for further purification. The instrument air serves as the instrument drive gas and has a water content of 5-30 ppm. The first drying bed 6 is filled with 5A molecular sieve, while the second drying bed 7 is filled with gamma-crystalline alumina. The regeneration time of the first and second drying beds 6 and 7 is 10 months, reducing regeneration costs.

[0034] The specific operation process is as follows: compressed air is generated by air compressor 1, passes through plate heat exchanger 2 and physical dehydrator 3, and most of the water and oil in the compressed air is removed. The air then enters buffer tank 4, and factory air is introduced into the top of buffer tank 4. After passing through heatless regeneration dryer 5, the dew point temperature drops to -40°C and the oil content drops to 1ppm. The air then enters the first drying bed 6, where the dew point temperature drops to -70°C. Instrument air is introduced into the pipeline and mixed. After passing through the second drying bed 7 and the micro-heat regeneration dryer, the dew point temperature drops to -85°C, thus producing process air. This process air is then introduced into the reactor to participate in the subsequent chemical reaction.

[0035] Plant air, which is the air from the compressor outlet, is not dehydrated. Instrument air is plant air that has undergone preliminary dehydration and is used as instrument drive air. Its water content is generally between 5 and 30 ppm. Process air is instrument air that has been further dehydrated to a water content below 1 ppm and is used for process chemical reactions.

[0036] The above description of the embodiments is intended to facilitate understanding and use of the utility model by those skilled in the art. Those skilled in the art will readily be able to make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the utility model is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of this utility model without departing from the scope of this utility model should be within the scope of protection of this utility model.

Claims

1. A system for deep purification of process air, characterized in that: It comprises an air compressor (1), a deoiling and dehydrating device, a buffer tank (4) and a drying device which are sequentially connected in series; The deoiling and dehydrating device comprises a plate heat exchanger (2) and a physical dehydrator (3), and is used to reduce the temperature of the compressed air generated by the air compressor (1) and condense the moisture in the compressed air; The drying device includes a drying bed assembly and a dryer assembly arranged in series; The top of the buffer tank (4) is provided with an air inlet and an air outlet, the air inlet is used to allow the compressed air generated by the air compressor to enter, and the air outlet is used to discharge the factory air; An immersion pipe is provided inside the buffer tank (4), and the immersion pipe extends from the top to the bottom of the buffer tank (4), and then extends from the bottom to the top of the tank, for cooling the compressed air.

2. A system for deep purification and acquisition of process air according to claim 1, characterized in that: The heat exchanger adopts a plate heat exchanger (2), and uses circulating water as the cooling medium.

3. The system for deep purification and acquisition of process air according to claim 1, characterized in that: The bottom of the buffer tank (4) is provided with a drain valve, and the drain valve is used to discharge the condensed water in the compressed air.

4. The system for deep purification and acquisition of process air according to claim 1, characterized in that: The dryer assembly comprises a heatless regeneration dryer (5) and a micro-heat regeneration dryer, the drying bed assembly comprises a first drying bed (6) and a second drying bed (7), and the heatless regeneration dryer (5), the first drying bed (6), the second drying bed (7) and the micro-heat regeneration dryer (8) are sequentially connected in series.

5. The system for deep purification and acquisition of process air according to claim 4, characterized in that: The heatless regeneration dryer (5) is filled with 4A or 5A molecular sieve.

6. The system for deep purification and acquisition of process air according to claim 4, characterized in that: The micro-heat regeneration dryer (8) is filled with activated alumina.

7. The system for deep purification and acquisition of process air according to claim 4, characterized in that: The first drying bed (6) is filled with one of 13X, 4A and 5A molecular sieves.

8. The system for deep purification and acquisition of process air according to claim 4, characterized in that: The second drying bed (7) is filled with activated alumina.

9. The system for deep purification and acquisition of process air according to claim 1, characterized in that: The buffer tank (4) is provided with two factory air outlets on its air outlet, the first factory air outlet being used to discharge the factory air cooled by the buffer tank (4), and the second factory air outlet being used to transport the factory air to a drying device for further purification.

10. The system for deep purification and acquisition of process air according to claim 4, characterized in that: Two instrument air outlets are provided on the outlet pipes of the first drying bed (6) and the second drying bed (7). The first instrument air outlet is used to discharge part of the instrument air, and the second instrument air outlet is used to transport the instrument air to the micro-heat regeneration dryer (8) for further purification. The instrument air is instrument driving air with a water content of 5 to 30 ppm.

Images