A system for the treatment of dilute solvent prior to evaporation in a lyocell fibre production process

Abstract

The utility model provides a kind of processing system of dilute solvent before evaporation in lyocell fiber production process, including filter unit, anion bed, cation bed, buffer tank, mixed bed and evaporation storage tank arranged in sequence;The mixed bed can remove metal ions and color groups.This processing system increases mixed bed behind anion bed and cation bed, first, it can further purify solvent, at the same time, it can also avoid the risk of increasing solvent colority due to the decline of adsorption effect of previous anion bed and cation bed, and the untimely replacement of anion bed and cation bed under the control of central control system;Since the resin in mixed bed is still composed of anion resin and cation resin, the resin in mixed bed has the functions of decolorization and removal of cations.

Description

Technical Field

[0001] This utility model belongs to the technical field of lyocell fiber production process, and particularly relates to a system for treating dilute solvents before evaporation in the lyocell fiber production process. Background Technology

[0002] In traditional Lyocell solvent purification processes, the color processing capacity of the anion bed often drops significantly before it reaches its rated service life. This leads to an increase in the content of colored ions and metal ions in the dilute solvent entering the evaporation section, which is detrimental to the final color concentration. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a system for treating dilute solvents before evaporation in the production process of lyocell fibers, which can reduce the color of the dilute solvents before evaporation.

[0004] This utility model provides a system for treating dilute solvents before evaporation in the production process of lyocell fiber, comprising a filter unit, an anion bed, a cation bed, a buffer tank, a mixed bed, and an evaporation storage tank arranged in sequence;

[0005] The mixed bed can remove metal ions and colored groups.

[0006] In a specific embodiment of this utility model, the mixed bed includes a mixed bed resin, and the mixed bed resin is of type MB20;

[0007] The mixed bed resin includes a strong cation exchange resin and a strong anion exchange resin.

[0008] In a specific embodiment of this invention, the dilute solvent is N-methylmorpholine oxide.

[0009] In a specific embodiment of this utility model, the resin in the anion bed is of type A180.

[0010] In a specific embodiment of this utility model, the resin in the cation bed is of type C100.

[0011] In a specific embodiment of this utility model, the filtration unit includes a 300-mesh basket filter and a multi-media filter connected in sequence.

[0012] In a specific embodiment of this utility model, the multi-media filter includes a DN2000 multi-media filter, a DN2000 dual-chamber anion and cation exchanger, and a DN2000 dual-chamber mixed resin exchanger connected in series.

[0013] In a specific embodiment of this utility model, the mixed bed is a DN2000 dual-chamber mixed resin exchanger.

[0014] In a specific embodiment of this utility model, the solvent outlet of the cation bed is connected to a buffer tank;

[0015] The buffer tank is connected to the inlet of the mixed bed via a centrifugal pump.

[0016] In a specific embodiment of this utility model, an evaporator connected to the evaporation storage tank is also included.

[0017] This invention provides a system for treating dilute solvents before evaporation in the production of lyocell fibers. The system includes a filter unit, an anion bed, a cation bed, a buffer tank, a mixed bed, and an evaporation tank arranged sequentially. The mixed bed removes metal ions and chromophores. By adding a mixed bed after the anion and cation beds, the system can further purify the solvent and avoid the risk of increased solvent color due to decreased adsorption efficiency of the preceding anion and cation beds, or delayed removal of anion and cation beds from the control system. Since the resin in the mixed bed still consists of anion and cation resins, it possesses decolorizing and cation-removing properties. Attached Figure Description

[0018] Figure 1 A schematic diagram of a dilute solvent treatment system before evaporation in the production process of lyocell fiber provided by this utility model;

[0019] Figure 2 This is a partial structural diagram of the mixed bed in this utility model. Detailed Implementation

[0020] This utility model provides a system for treating dilute solvents before evaporation in the production process of lyocell fiber, comprising a filter unit, an anion bed, a cation bed, a buffer tank, a mixed bed, and an evaporation storage tank arranged in sequence;

[0021] The mixed bed can remove metal ions and colored groups.

[0022] The present invention provides a system for treating dilute solvents before evaporation during the production of lyocell fibers, including a filtration unit. The filtration unit comprises a 300-mesh basket filter and a multi-media filter connected in sequence.

[0023] The multi-media filter consists of a DN2000 multi-media filter, a DN2000 dual-chamber cation and anion exchanger, and a DN2000 dual-chamber mixed resin exchanger connected in series. A 300-mesh basket filter is connected to the DN2000 multi-media filter, and the DN2000 dual-chamber mixed resin exchanger is connected to the anion bed.

[0024] In this invention, the dilute solvent in the tank farm dilute solvent unit is transported to the filtration unit via pipeline; specifically, the tank farm dilute solvent unit is connected to the 300-mesh basket filter of the filtration unit.

[0025] The present invention provides a system for treating dilute solvents before evaporation during the production of lyocell fibers, comprising an anion bed connected to a filtration unit. The resin in the anion bed is of type A180.

[0026] The present invention provides a system for treating dilute solvents before evaporation in the production process of lyocell fibers, comprising a cation bed connected to an anion bed. The resin in the cation bed is of type C100.

[0027] The present invention provides a system for treating dilute solvents before evaporation in the production process of lyocell fibers, including a buffer tank connected to the cation bed; the solvent outlet of the cation bed is connected to the buffer tank; the buffer tank serves as a buffer to prevent flow interruption.

[0028] The present invention provides a dilute solvent treatment system for the production process of lyocell fiber before evaporation, comprising a mixed bed connected to a buffer tank; the mixed bed is capable of removing metal ions and colored groups; the metal ions include Mg 2+ Ca 2+ Fe 3+ Na + and K + The chromophores include phenolic groups, quinone groups, etc. The bed is a DN2000 dual-chamber mixed resin exchanger. See also... Figure 2 The mixed bed is provided with a liquid distribution zone, an anion exchange resin zone and a cation exchange resin zone from top to bottom; the mixed bed includes a mixed bed resin, the mixed bed resin being of type MB20; the mixed bed resin includes a strong cation exchange resin and a strong anion exchange resin, and has the function of decolorizing and removing cations (metal ions).

[0029] In existing technologies, the color processing capacity of the anion bed often drops significantly before it reaches its rated service life, leading to an increase in the content of colored ions and metal ions in the dilute solvent entering the evaporation section, which is detrimental to the final color concentration. In this invention, the solvent outlet of a single cation bed is connected to a solvent buffer tank; the solvent buffer tank is directly connected to the solvent inlet of the mixed bed via a centrifugal pump. Specifically, the solvent from the DN100 304 pipeline of a single cation bed enters a 100m... 3 The solvent buffer tank is then directly connected to the solvent inlet of the mixed bed via a centrifugal pump.

[0030] This invention, by employing a mixed bed, can reduce the color of the solvent before evaporation and also avoid the situation where the adsorption effect of the anion bed and cation bed decreases, resulting in untimely feedback from laboratory tests.

[0031] The present invention provides a system for treating dilute solvents before evaporation in the production process of lyocell fibers, including an evaporation tank connected to the mixed bed; the evaporation tank is a solvent storage tank into which the N-methylmorpholine oxide (NMMO) solvent purified by the mixed bed is collected, and then directly enters the evaporation system.

[0032] In this invention, the mixed bed is configured as 2 in use and 2 in standby, which can be adjusted to a 3 in use and 1 in standby configuration, thereby reducing the flow rate of NMMP and increasing the residence time of the dilute solvent in the mixed bed.

[0033] The solvent color after passing through the mixed bed in the processing system provided by this utility model is less than 100, which meets the requirement of a color of less than 300 as a primary parameter index for dilute solvents.

[0034] To further illustrate this utility model, the following detailed description, in conjunction with embodiments, of a system for treating dilute solvents before evaporation in the production process of lyocell fibers provided by this utility model, should not be construed as limiting the scope of protection of this utility model.

[0035] Example 1

[0036] use Figure 1 The processing system shown controls the flow rate of solvent NMMO through a 300-mesh basket filter and a multi-media filter to 80 m / s. 3 / h, the flow rate through the anal bed is 50m³ / h. 3 / h, the flow rate through the cation bed is 70m³ / h. 3 / h, after buffering by the buffer tank, the flow rate through the mixed bed is 80m³ / h. 3 / h, the color of the dilute solvent before final evaporation is 95.

[0037] Example 2

[0038] The flow rate of solvent NMMO through a 300-mesh basket filter and a multi-media filter was controlled at 80 m / s. 3 / h, the flow rate through the anal bed is 50m³ / h. 3 / h, the flow rate through the cation bed is 70m³ / h. 3 / h, after buffering by the buffer tank, the flow rate through the mixed bed is 75m³ / h. 3 / h, reducing the solvent flow rate in the mixed bed and increasing the residence time of the dilute solvent in the mixed bed, so that the color of the dilute solvent before evaporation is 90.

[0039] Example 3

[0040] The flow rate of solvent NMMO through a 300-mesh basket filter and a multi-media filter was controlled at 80 m / s. 3 / h, the flow rate through the anal bed is 50m³ / h. 3 / h, the flow rate through the cation bed is 70m³ / h. 3 / h, after buffering by the buffer tank, the flow rate through the mixed bed is 73m³ / h.3 / h, reducing the solvent flow rate in the mixed bed and increasing the residence time of the dilute solvent in the mixed bed, the final color of the dilute solvent before evaporation is 88.

[0041] As can be seen from the above embodiments, this utility model provides a treatment system for dilute solvents before evaporation in the production process of lyocell fibers, including a filter unit, an anion bed, a cation bed, a buffer tank, a mixed bed, and an evaporation storage tank arranged in sequence; the mixed bed can remove metal ions and chromophores. The addition of a mixed bed after the anion and cation beds in this treatment system can further purify the solvent and also avoid the risk of increased solvent color due to decreased adsorption efficiency of the preceding anion and cation beds, or untimely removal of the anion and cation beds from the control system; since the resin in the mixed bed is still composed of anion and cation resins, the mixed bed resin has the function of decolorization and removal of cations.

[0042] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A system for treating dilute solvents before evaporation during the production of lyocell fibers, characterized in that, It includes a filter unit, anion bed, cation bed, buffer tank, mixed bed and evaporation storage tank arranged in sequence; The mixed bed can remove metal ions and colored groups.

2. The processing system according to claim 1, characterized in that, The mixed bed includes a mixed bed resin, and the mixed bed resin is of type MB20. The mixed bed resin includes a strong cation exchange resin and a strong anion exchange resin.

3. The processing system according to claim 1, characterized in that, The dilute solvent is N-methylmorpholine oxide.

4. The processing system according to claim 1, characterized in that, The resin used in the anion bed is type A180.

5. The processing system according to claim 1, characterized in that, The resin in the cation exchange bed is of type C100.

6. The processing system according to claim 1, characterized in that, The filtration unit includes a 300-mesh basket filter and a multi-media filter connected in sequence.

7. The processing system according to claim 6, characterized in that, The multi-media filter includes a DN2000 multi-media filter, a DN2000 dual-chamber anion and cation exchanger, and a DN2000 dual-chamber mixed resin exchanger connected in series.

8. The processing system according to claim 1, characterized in that, The mixed bed is a DN2000 dual-chamber mixed resin exchanger.

9. The processing system according to claim 1, characterized in that, The solvent outlet of the cation exchange bed is connected to a buffer tank; The buffer tank is connected to the inlet of the mixed bed via a centrifugal pump.

10. The processing system according to claim 1, characterized in that, It also includes an evaporator connected to the evaporation tank.

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