Vacuum device for Lyocell fiber spinning small test line

Abstract

The utility model relates to the technical field of vacuum devices, and particularly discloses a vacuum device for a Lyocell fiber spinning small test line, which comprises a wiped film evaporator, a condenser, a first vacuum pump, a second vacuum pump and a bypass valve, the wiped film evaporator is connected with the condenser through a first pipeline, the condenser is connected with the first vacuum pump through a second pipeline, and the bypass valve is connected with the second vacuum pump through a third pipeline. The first vacuum pump is connected with the second vacuum pump through a third pipeline, the condenser is connected with the second vacuum pump through a fourth pipeline, and a bypass valve is installed on the fourth pipeline. The water ring vacuum pump is firstly used as a backing pump of the Roots vacuum pump to operate, the pressure in the system is pumped to the allowable discharge pressure required by starting of the Roots vacuum pump, then the Roots vacuum pump is started, and the vacuum degree of the system is further improved by utilizing the advantages of rapid air pumping and high air pumping rate of the Roots vacuum pump, so that the system is more stable in operation. When a vacuum condition is provided for a small-scale experiment glue making device for Lyocell fiber spinning, sealing oil is not used, so that the problem of water vapor pollution is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of vacuum devices, and in particular relates to a vacuum device for a Lyocell fiber spinning pilot line. Background Art

[0002] In the Lyocell fiber spinning pilot plant, the vacuum pump plays a crucial role. It provides the necessary vacuum for the wiped film evaporator, ensuring that the entire evaporation process can proceed smoothly under negative pressure. This environment is crucial for fiber spinning experiments because it helps to precisely control the texture and properties of the fiber.

[0003] To meet this demand, rotary vane vacuum pumps have traditionally been used. The working principle of a rotary vane vacuum pump is quite ingenious. It utilizes the tiny gap between the vanes and the pump chamber to extract the gas through rotation, thereby achieving a vacuum effect. The advantage of this pump is its relatively simple structure and relatively high extraction efficiency.

[0004] However, rotary vane vacuum pumps also have a significant drawback. As oil-sealed mechanical vacuum pumps, they require internal vacuum pump oil to maintain a seal. However, during the exhaust process of the wiped-film evaporator, some water vapor is inevitably entrained. Once this water vapor enters the vacuum pump, it reacts with the pump oil, causing it to emulsify and deteriorate. This not only affects the proper functioning of the vacuum pump and reduces its extraction efficiency, but can also pollute the experimental environment. Consequently, we must confront a practical problem: frequent oil replacement increases experimental maintenance costs and can easily introduce new sources of contamination due to improper replacement procedures. Utility Model Content

[0005] The purpose of the utility model is to provide a vacuum device for a Lyocell fiber spinning pilot line to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A vacuum device for a Lyocell fiber spinning pilot line, comprising:

[0008] A wiped film evaporator, a condenser, a vacuum pump 1, a vacuum pump 2 and a bypass valve, wherein the wiped film evaporator is connected to the condenser via a pipe 1, the condenser is connected to the vacuum pump 1 via a pipe 2, the vacuum pump 1 is connected to the vacuum pump 2 via a pipe 3, the condenser is connected to the vacuum pump 2 via a pipe 4, and the bypass valve is installed on the pipe 4.

[0009] Preferably, the air inlet of the vacuum pump one is connected to the exhaust port of the condenser, the exhaust port of the vacuum pump one is connected to the air inlet of the vacuum pump two, and the air inlet of the vacuum pump two is also connected to the exhaust port of the condenser, so that part of the gas enters the vacuum pump two through the vacuum pump one, and the other part of the gas enters the vacuum pump two through the pipe four.

[0010] Preferably, the vacuum pump 1 is configured as a Roots vacuum pump.

[0011] Preferably, the second vacuum pump is configured as a water ring vacuum pump.

[0012] Preferably, the pumping rate of the water ring vacuum pump is greater than the pumping rate of the Roots vacuum pump.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The utility model provides a water ring vacuum pump which first operates as a fore pump of a Roots vacuum pump, pumps the pressure in the system to the allowable discharge pressure required for starting the Roots vacuum pump, and then starts the Roots vacuum pump, utilizing the advantages of rapid air pumping and high air pumping rate to further improve the vacuum degree of the system. While providing vacuum conditions for a small-scale experimental glue-making device for Lyocell fiber spinning, the problem of water vapor contamination is overcome because no sealing oil is used. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0016] In the figure: 1. Wiped film evaporator; 2. Condenser; 3. Roots vacuum pump; 4. Water ring vacuum pump; 5. Bypass valve. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0018] Example:

[0019] See also Figure 1 As shown, a vacuum device for a Lyocell fiber spinning pilot line comprises:

[0020] Wiped film evaporator 1, condenser 2, vacuum pump 1, vacuum pump 2 and bypass valve 5. The wiped film evaporator 1 is connected to the condenser 2 through pipe 1, the condenser 2 is connected to the vacuum pump 1 through pipe 2, the vacuum pump 1 is connected to the vacuum pump 2 through pipe 3, the condenser 2 is connected to the vacuum pump 2 through pipe 4, and a bypass valve 5 is installed on pipe 4.

[0021] refer to Figure 1 As shown, the air inlet of vacuum pump one is connected to the exhaust port of condenser 2, the exhaust port of vacuum pump one is connected to the air inlet of vacuum pump two, and the air inlet of vacuum pump two is also connected to the exhaust port of condenser 2, so that part of the gas enters vacuum pump two through vacuum pump one, and the other part of the gas enters vacuum pump two through pipe four.

[0022] refer to Figure 1 As shown, the vacuum pump 1 is set to be a Roots vacuum pump 3.

[0023] refer to Figure 1 As shown, the vacuum pump 2 is set as a water ring vacuum pump 4. When it is working, the water ring vacuum pump 4 should be started first to reduce the pressure in the system to the allowable discharge pressure required for starting the Rhodes vacuum pump 3, and then the Rhodes vacuum pump 3 should be started.

[0024] refer to Figure 1 As shown, the pumping rate of the water ring vacuum pump 4 is greater than the pumping rate of the Roots vacuum pump 3.

[0025] Furthermore, the ultimate pressure that the water ring vacuum pump 4 can reach should be lower than the allowable discharge pressure required for starting the Roots vacuum pump 3 .

[0026] The gas extracted from the wiped film evaporator 1 is mainly composed of water vapor and some non-condensable gases (such as air). These gases first enter the condenser to remove water vapor, leaving only non-condensable gases and a small amount of water vapor to enter the vacuum system, thereby reducing the workload of the vacuum system.

[0027] The vacuum system consists of a Roots vacuum pump 3 and a water ring vacuum pump 4. When working, the water ring vacuum pump 4 should be started first, and then the Roots vacuum pump 3 should be started. At this time, the inlet and exhaust pressure difference of the Roots vacuum pump 3 is large, and the bypass valve 5 opens automatically. Part of the pumped gas enters the water ring vacuum pump 4 through the bypass valve 5, and the other part of the gas also enters the water ring vacuum pump 4 through the pump under the action of the Roots vacuum pump 3. Obviously, the pumping rate increases, and the pre-vacuum of the Roots vacuum pump 3 can be reached soon. At this time, the inlet and exhaust pressure difference of the Roots vacuum pump 3 will decrease, and the bypass valve can be automatically closed.

[0028] In this system, the water ring vacuum pump 4 first operates as the fore pump of the Roots vacuum pump 3, pumping the pressure in the system to the allowable discharge pressure required for starting the Roots vacuum pump 3. Then, the Roots vacuum pump 3 is started to take advantage of its fast pumping and high pumping rate to further improve the vacuum degree of the system.

[0029] It can be seen from this that not only the pumping rate of the water ring vacuum pump 4 should match that of the Roots vacuum pump 3, but also the ultimate pressure it can reach should be less than the allowable discharge pressure required for starting the Roots vacuum pump 3.

[0030] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vacuum device for a Lyocell fiber spinning pilot line, characterized in that: include: A scraped film evaporator (1), a condenser (2), a vacuum pump 1, a vacuum pump 2 and a bypass valve (5), wherein the scraped film evaporator (1) is connected to the condenser (2) via a pipe 1, the condenser (2) is connected to the vacuum pump 1 via a pipe 2, the vacuum pump 1 is connected to the vacuum pump 2 via a pipe 3, the condenser (2) is connected to the vacuum pump 2 via a pipe 4, and the bypass valve (5) is installed on the pipe 4.

2. The vacuum device for a Lyocell fiber spinning pilot line according to claim 1, characterized in that: The air inlet of the vacuum pump 1 is connected to the exhaust port of the condenser (2), the exhaust port of the vacuum pump 1 is connected to the air inlet of the vacuum pump 2, and the air inlet of the vacuum pump 2 is also connected to the exhaust port of the condenser (2).

3. The vacuum device for a Lyocell fiber spinning pilot line according to claim 2, characterized in that: The vacuum pump 1 is configured as a Roots vacuum pump (3).

4. The vacuum device for a Lyocell fiber spinning pilot line according to claim 3, characterized in that: The second vacuum pump is configured as a water ring vacuum pump (4).

5. The vacuum device for a Lyocell fiber spinning pilot line according to claim 4, characterized in that: The pumping rate of the water ring vacuum pump (4) is greater than the pumping rate of the Roots vacuum pump (3).

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