Freeze-drying and nitrogen-making combined device capable of improving adsorption efficiency

Abstract

The utility model discloses a freeze-drying and nitrogen-making combined device capable of improving adsorption efficiency, which relates to the field of nitrogen-making devices and comprises a refrigerant compressor and the like, a tube pass outlet of an evaporator is communicated with an air suction port of the refrigerant compressor through a gas-liquid separator, an exhaust port of the refrigerant compressor is connected to an inlet of an air-cooled condenser, and the air-cooled condenser is communicated with an air inlet of the air-cooled condenser. An outlet of the air-cooled condenser is sequentially provided with a drying filter and a thermostatic expansion valve and connected to a tube pass inlet of the evaporator, a parallel branch is arranged between the refrigerant compressor and the air-cooled condenser and connected to the tube pass inlet of the evaporator, and a bypass pipeline is arranged between a tube pass outlet of the evaporator and the parallel branch. A tube pass outlet of the precooler is connected with a shell pass inlet of the evaporator, a shell pass outlet of the evaporator is connected to an inlet of the steam-water separator, and an outlet of the steam-water separator is communicated with the shell pass inlet of the precooler. The utility model solves the problems that the nitrogen-making combined device is easily influenced by the temperature change of the external environment, so that the operation of equipment is limited, and the production efficiency is reduced.

Description

Technical Field

[0001] The utility model relates to the field of nitrogen production devices, in particular to a freeze drying and nitrogen production combined device capable of improving adsorption efficiency. Background Art

[0002] Pressure swing adsorption PSA nitrogen generator carbon molecular sieve is a porous material characterized by nanometer-scale pore size, with high specific surface area and chemical stability. Nitrogen molecules are of moderate size, matching the pore size of carbon molecular sieve, and can be selectively separated and purified by pressure swing adsorption technology. The carbon molecular sieve pressure swing adsorber is mainly composed of adsorber, air inlet valve, air outlet valve, transformer and other parts. The adsorber is filled with carbon molecular sieve, and nitrogen and a certain concentration of air are introduced to reduce the pressure in the adsorber to a certain value, so that the carbon molecular sieve adsorbs oxygen, carbon dioxide and other impurity molecules in the air. After a period of time, the pressure is increased, and the nitrogen is desorbed and discharged from the air outlet valve. Through multiple cycles of adsorption and desorption, high-purity nitrogen can be obtained.

[0003] Since the air contains a certain amount of moisture, after passing through the compressor, if it is not strictly purified, it is easily adsorbed by the carbon molecular sieve and difficult to desorb, filling the pore size of the carbon molecular sieve in the nitrogen generator, causing the carbon molecular sieve in the nitrogen generator to be "poisoned" and ineffective. Therefore, a strict air purification device is set before the compressed air enters the adsorption tower of the nitrogen generator, which affects the ability of the nitrogen generator to adsorb O2 and CO2. Therefore, drying and dehydrating the compressed air is an issue that cannot be ignored to improve the adsorption capacity and stability of the carbon molecular sieve of the nitrogen generator. Traditionally, a set of cold dryers is configured in front of the nitrogen generator for dehydration. Due to the large changes in ambient temperature throughout the year, it is too hot in summer and too cold in winter. Traditional cold dryers cannot solve the temperature problem. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a freeze-drying and nitrogen-making combination device with improved adsorption efficiency, which has the advantages of reducing energy consumption, improving adsorption efficiency and reducing environmental interference, and solves the problem that the nitrogen-making combination device in the prior art is easily affected by changes in the external ambient temperature, resulting in limited equipment operation and reduced production efficiency.

[0005] The purpose of the utility model is to achieve the following technical solutions: the freeze-drying and nitrogen-making combined device for improving adsorption efficiency comprises a refrigerant compressor, an air-cooled condenser, a gas-liquid separator, an evaporator, a precooler and a steam-water separator, the tube-side outlet of the evaporator is connected to the air intake port of the refrigerant compressor via the gas-liquid separator, the exhaust port of the refrigerant compressor is connected to the inlet of the air-cooled condenser, a drying filter and a thermal expansion valve are sequentially arranged at the outlet of the air-cooled condenser and connected to the tube-side inlet of the evaporator, a parallel branch is arranged between the refrigerant compressor and the air-cooled condenser and connected to the tube-side inlet of the evaporator, a bypass pipeline is arranged between the tube-side outlet of the evaporator and the parallel branch; an air inlet is arranged at the tube-side inlet of the precooler, the tube-side outlet of the precooler is connected to the shell-side inlet of the evaporator, the shell-side outlet of the evaporator is connected to the steam-water separator inlet, the steam-water separator outlet is connected to the shell-side inlet of the precooler, and an air outlet is arranged at the shell-side outlet of the precooler.

[0006] As a further technical solution, a high and low pressure switch is provided on the bypass pipeline.

[0007] As a further technical solution, a sensor for sensing the temperature of the refrigerant is arranged in the evaporator, and the sensor controls the thermal expansion valve through a signal to automatically adjust the opening of the thermal expansion valve.

[0008] As a further technical solution, a high-pressure switch and a hot gas bypass valve are sequentially arranged on the parallel branch, and the hot gas bypass valve is used to provide a load to the evaporator when the thermal expansion valve is automatically closed.

[0009] As a further technical solution, a sight glass is provided on the pipeline between the filter drier and the thermal expansion valve.

[0010] As a further technical solution, the steam-water separator is connected to a drainer via a ball valve.

[0011] As a further technical solution, the air outlet conveys room temperature air to the nitrogen generator adsorption tower through an outlet pipeline.

[0012] As a further technical solution, a branch is also arranged on the connecting pipeline between the steam-water separator and the precooler, and is connected in parallel with the outlet pipeline, so that the low-temperature air is mixed with the normal-temperature air and then transported to the nitrogen generator adsorption tower. A regulating valve and a flow control valve are sequentially arranged on the branch to adjust the mixing ratio of the low-temperature air and the normal-temperature air according to the ambient temperature.

[0013] The beneficial effects of the utility model are:

[0014] 1. A temperature sensor is installed in the evaporator. When the load in the nitrogen production assembly increases, the refrigerant temperature in the evaporator rises. The thermal expansion valve is automatically adjusted through the signal transmission of the sensor on the thermal expansion valve until a new balance is reached, thereby reducing the energy consumption in the nitrogen production process. When the load is too small and the evaporation temperature drops, the thermal expansion valve automatically closes the valve, and the hot gas bypass valve automatically provides a load to the evaporator to keep the evaporation temperature stable and prevent ice blockage in the evaporator.

[0015] 2. A branch is also set on the connecting pipeline between the steam-water separator and the precooler. Through the regulating valve and the flow control valve, the mixing ratio of low-temperature air and normal-temperature air can be adjusted according to the ambient temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is a schematic diagram of the connection structure between the utility model and the adsorption tower of the nitrogen generator.

[0018] Explanation of the reference numerals in the accompanying drawings: refrigerant compressor 1, hot gas bypass valve 2, air-cooled condenser 3, drying filter 4, sight glass 5, thermal expansion valve 6, high and low pressure switches 7, gas-liquid separator 8, evaporator 9, precooler 10, steam-water separator 11, ball valve 12, drainer 13, high pressure switch 14, air inlet 15, air outlet 16, nitrogen generator adsorption tower 17, regulating valve V1, flow control valve Z1. DETAILED DESCRIPTION

[0019] The utility model will be described in detail below with reference to the accompanying drawings:

[0020] Example: As attached Figure 1 , 2 As shown, the freeze-drying and nitrogen-making combined device for improving adsorption efficiency includes a refrigerant compressor 1, a hot gas bypass valve 2, an air-cooled condenser 3, a drying filter 4, a sight glass 5, a thermal expansion valve 6, a high-low pressure switch 7, a gas-liquid separator 8, an evaporator 9, a precooler 10, a steam-water separator 11, a ball valve 12, a drainer 13, a high-pressure switch 14, an air inlet 15, an air outlet 16, a nitrogen generator adsorption tower 17, a regulating valve V1 and a flow control valve Z1.

[0021] Reference Figure 1The tube-side outlet of the evaporator 9 is connected to the air intake port of the refrigerant compressor 1 through the gas-liquid separator 8, and the exhaust port of the refrigerant compressor 1 is connected to the inlet of the air-cooled condenser 3. The outlet of the air-cooled condenser 3 is provided with a drying filter 4 and a thermal expansion valve 6 in sequence and connected to the tube-side inlet of the evaporator 9. A parallel branch is provided between the refrigerant compressor 1 and the air-cooled condenser 3 and connected to the tube-side inlet of the evaporator 9. A bypass pipeline is provided between the tube-side outlet of the evaporator 9 and the parallel branch; an air inlet 15 is provided at the tube-side inlet of the precooler 10, and the tube-side outlet of the precooler 10 is connected to the shell-side inlet of the evaporator 9. The shell-side outlet of the evaporator 9 is connected to the inlet of the steam-water separator 11. The outlet of the steam-water separator 11 is connected to the shell-side inlet of the precooler 10, and an air outlet 16 is provided at the shell-side outlet of the precooler 10. Figure 2 As shown, the air outlet 16 delivers the normal temperature air to the nitrogen generator adsorption tower 17 through the outlet pipeline. A branch is also arranged on the connecting pipeline between the steam-water separator 11 and the precooler 10, and is connected in parallel with the outlet pipeline, and the low temperature air is mixed with the normal temperature air and then delivered to the nitrogen generator adsorption tower 17. The regulating valve V1 and the flow control valve Z1 are arranged in sequence on the branch to adjust the mixing ratio of the low temperature air and the normal temperature air according to the ambient temperature.

[0022] Furthermore, a high-low pressure switch 7 is provided on the bypass line. A sensor is provided in the evaporator 9, which can sense the refrigerant temperature in real time. At the same time, the sensor controls the thermal expansion valve 6 through a signal to automatically adjust the opening of the thermal expansion valve 6. A high-pressure switch 14 and a hot gas bypass valve 2 are provided in sequence on the parallel branch, and the hot gas bypass valve 2 can provide a load to the evaporator 9 when the thermal expansion valve 6 is automatically closed.

[0023] Preferably, a sight glass 5 is provided on the pipeline between the drying filter 4 and the thermal expansion valve 6. A drainer 13 is connected to the steam-water separator 11 via a ball valve 12.

[0024] The compressed air enters the precooler 10 from the air inlet 15, exchanges heat with the dried and cooled compressed air from the evaporator 9, lowers the saturation temperature of the compressed air, removes some moisture, and then enters the evaporator 9 to cool the compressed air to a pressure dew point of about 1.7°C. The moisture and some impurities are condensed here, separated by the steam-water separator 11, and the moisture and impurities sink to the bottom and are discharged from the dryer through the ball valve 12 and the drainer 13.

[0025] Refrigeration process flow: low-temperature liquid refrigerant flows into the evaporator 9 through the pipe, absorbs a large amount of heat and evaporates into gas. The gaseous refrigerant enters the gas separator 8 from the outlet of the evaporator 9, and enters the air intake of the refrigerant compressor 1 after the trace amount of liquid refrigerant is completely gasified in it. The refrigerant compressor 1 compresses the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gas. Through the automatic adjustment of the hot gas bypass valve 2, a small part of the gas directly enters the evaporator 9, while most of the gas enters the air-cooled condenser 3 for condensation and cooling. The high-pressure and low-temperature liquid refrigerant coming out of the condenser passes through the drying filter 4 and the sight glass 5 and enters the thermal expansion valve 6 to be throttled and depressurized, and becomes a low-pressure liquid and enters the evaporator 9 through the pipe, cooling the compressed air that has entered the evaporator 9 through the shell. The function of the drying filter 4 is to remove trace moisture and pollutants in the refrigerant. In this way, the cycle repeats over and over again.

[0026] When the load of the cold dryer increases, the temperature of the refrigerant in the evaporator 9 increases, and the thermal expansion valve 6 is automatically adjusted through the signal transmission of the thermal expansion valve sensor until a new balance is reached.

[0027] When the load of the cold dryer is too small and the evaporation temperature drops, the thermal expansion valve 6 automatically closes the valve, and the hot gas bypass valve 2 automatically provides a load to the evaporator 9 to keep the evaporation temperature stable, prevent the evaporator from being blocked by ice, and ensure the suction volume of the compressor so that the cold dryer can work normally.

[0028] The working process of this utility model:

[0029] The low-temperature liquid refrigerant (through the pipe side) flows into the evaporator 9, and is evaporated into gas. The gaseous refrigerant enters the gas-liquid separator 8 from the outlet of the evaporator 9, and enters the air intake of the refrigerant compressor 1 after the trace amount of liquid refrigerant is completely gasified in it. The refrigerant compressor 1 compresses the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gas. Through the automatic adjustment of the hot gas bypass valve 2, a small part of the gas directly enters the evaporator 9, while most of the gas enters the condenser 3 for condensation and cooling. The high-pressure and low-temperature liquid refrigerant coming out of the condenser passes through the drying filter 4 and the sight glass 5 and enters the thermal expansion valve 6 to be throttled and reduced in pressure, and becomes a low-pressure liquid (through the pipe side) and enters the evaporator 9 to cool the compressed air that has entered the evaporator 9 (through the shell side).

[0030] The compressed air coming out of the evaporator is at a very low temperature and can be divided into two parts (such as Figure 2 As shown), one part is heat exchanged through the precooler 10, and the other part is mixed with the relatively high temperature gas from the precooler 10 through the regulating valve V1. The size of the valve V1 / Z1 can be adjusted according to the ambient temperature, so that the high temperature problem can be solved and the problem of too low temperature can be solved at the same time.

[0031] It is understandable that, for those skilled in the art, any equivalent replacement or change to the technical solution and the concept of the utility model should fall within the protection scope of the claims attached to the utility model.

Claims

1. A freeze drying and nitrogen production combined device for improving adsorption efficiency, characterized in that: The invention comprises a refrigerant compressor (1), an air-cooled condenser (3), a gas-liquid separator (8), an evaporator (9), a precooler (10) and a steam-water separator (11), wherein the pipe-side outlet of the evaporator (9) is connected to the air intake of the refrigerant compressor (1) via the gas-liquid separator (8), the exhaust port of the refrigerant compressor (1) is connected to the inlet of the air-cooled condenser (3), the outlet of the air-cooled condenser (3) is provided with a drying filter (4) and a thermal expansion valve (6) in sequence and connected to the pipe-side inlet of the evaporator (9), the refrigerant compressor (1) and the air-cooled condenser (3) are connected to the pipe-side outlet of the evaporator (9), and the refrigerant compressor (1) and the air-cooled condenser (3) are connected to the pipe-side outlet of the evaporator (9). (3) is provided with a parallel branch connected to the tube side inlet of the evaporator (9), and a bypass pipeline is provided between the tube side outlet of the evaporator (9) and the parallel branch; an air inlet (15) is provided at the tube side inlet of the precooler (10), the tube side outlet of the precooler (10) is connected to the shell side inlet of the evaporator (9), the shell side outlet of the evaporator (9) is connected to the inlet of the steam-water separator (11), the outlet of the steam-water separator (11) is communicated with the shell side inlet of the precooler (10), and an air outlet (16) is provided at the shell side outlet of the precooler (10); The air outlet (16) transports normal temperature air to a nitrogen generator adsorption tower (17) through an outlet pipeline; a branch line is also provided on the connecting pipeline between the steam-water separator (11) and the precooler (10), and is connected in parallel with the outlet pipeline, and is used to mix low-temperature air with the normal temperature air and then transport them to the nitrogen generator adsorption tower (17); a regulating valve (V1) and a flow control valve (Z1) are sequentially provided on the branch line, and are used to adjust the mixing ratio of the low-temperature air and the normal temperature air according to the ambient temperature.

2. The freeze-drying and nitrogen-generating combined device for improving adsorption efficiency according to claim 1, characterized in that: The bypass pipeline is provided with a high and low pressure switch (7).

3. The freeze-drying and nitrogen-generating combined device for improving adsorption efficiency according to claim 1, characterized in that: A sensor for sensing the temperature of the refrigerant is arranged in the evaporator (9), and the sensor controls the thermal expansion valve (6) through a signal to automatically adjust the opening of the thermal expansion valve (6).

4. The freeze-drying and nitrogen-generating combined device for improving adsorption efficiency according to claim 3, characterized in that: The parallel branch is provided with a high-pressure switch (14) and a hot gas bypass valve (2) in sequence, and the hot gas bypass valve (2) is used to provide a load to the evaporator (9) when the thermal expansion valve (6) is automatically closed.

5. The freeze-drying and nitrogen-generating combined device for improving adsorption efficiency according to claim 1, characterized in that: A sight glass (5) is provided on the pipeline between the drying filter (4) and the thermal expansion valve (6).

6. The freeze-drying and nitrogen-generating combined device for improving adsorption efficiency according to claim 1, characterized in that: The steam-water separator (11) is connected to a drainer (13) via a ball valve (12).

Images