Viscose staple fiber post-treatment pickling system and method

Abstract

The invention belongs to the technical field of viscose fiber post-treatment, and particularly relates to a viscose staple fiber post-treatment pickling system and method. The system at least comprises a heat exchanger; a fiber post-treatment pickling device; a pickling water tank; and an acidic water tank. The method at least comprises the following steps: 1) heating acid bath evaporation condensate water, feeding one part into a cut-off water tank, and feeding the other part into a pickling water tank; (2) collecting reflux water of the first leaching unit at the last stage into a pickling water tank, and collecting reflux water of the remaining first leaching units into an acidic water tank; 3) collecting reflux water of each second leaching unit into a pickling water tank; and 4) conveying the water in the pickling water tank to each first leaching unit, and the like. The acid bath evaporation condensate water is used for replacing soft water, and the problems of uneven water supply, equipment failure and the like caused by an original water supply mode are thoroughly solved. Water resources are saved, and the leaching effect of the fiber pickling area is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of viscose fiber post-processing, and in particular relates to a viscose staple fiber post-processing pickling system and method. Background Art

[0002] After being cut, the viscose staple fibers carry acid, salt and other impurities. When entering the post-processing system, they must undergo water washing, desulfurization, bleaching, oiling and other treatments to meet the product index requirements. Pickling is the first leaching area of ​​the post-processing system. The leaching effect of the pickling area is directly related to the reagent consumption and finished product quality of the subsequent fiber treatment effect. In order to save water resources, the process used in the industry is to use a pipeline pump or a steam-spray pump to transport the discharge water from the water washing area behind the pickling area to each leaching unit in the pickling area. Due to insufficient water, a portion of fresh soft water must be added to the pickling area to increase water consumption. The water intake points of each leaching unit in the pickling area are close to each other, so it is easy to "grab water", resulting in insufficient leaching water or no water in some individual leaching units, and a high failure rate of water transportation equipment. Summary of the invention

[0003] In order to solve the deficiencies of the prior art, the present invention provides a viscose staple fiber post-treatment pickling system and method.

[0004] The technical solution provided by the present invention is as follows:

[0005] A viscose staple fiber post-treatment pickling system, comprising at least:

[0006] A heat exchanger having a condensed water inlet and a condensed water outlet, wherein the condensed water inlet is connected to an acid bath evaporation condensed water pipeline;

[0007] A fiber post-treatment pickling device, comprising a plurality of first rinsing units;

[0008] A pickling water tank, wherein the liquid inlet of the pickling water tank is respectively connected to the condensed water outlet of the heat exchanger and the liquid outlet of the last stage of the first rinsing unit, and the liquid outlet of the pickling water tank is respectively connected to the liquid inlet of each of the first rinsing units through a liquid pump;

[0009] and an acidic water tank, wherein the liquid inlet of the acidic water tank is respectively connected to the liquid outlets of the remaining first elution units at each stage, and the liquid outlet of the acidic water tank is connected to the heat and mass inlet of the heat exchanger through a liquid pump.

[0010] The above technical scheme makes full use of the acid bath evaporation condensate with good water quality discharged from the viscose fiber production system, which can replace soft water as the rinsing water for treating the pickling area, improve the water quality and water quantity of fiber pickling, save water resources, and enhance the rinsing effect of the fiber pickling area.

[0011] Furthermore, the viscose staple fiber post-processing pickling system also includes a fiber post-processing soft water washing device, which has a plurality of second washing units; the liquid outlet of each second washing unit is connected to the liquid inlet of the pickling water tank; the liquid inlet of each second washing unit is connected to the flash steam condensate water pipeline, and a spare soft water pipeline is provided.

[0012] Based on the above technical solution, the rinsing water of the second rinsing unit can be further utilized to further save water resources.

[0013] Furthermore, the viscose staple fiber post-processing pickling system also includes a cutting water tank, a liquid pump, a fiber cutting machine and a fiber cooking tank which are connected in sequence, the condensate outlet of the heat exchanger is also connected to the cutting water tank, and the fiber cooking tank is connected to the liquid inlet of the pickling water tank.

[0014] Furthermore, the cutting water tank is connected to the top of the cutting knife of the fiber cutting machine through a liquid pump; the water outlet of the acidic water tank is also connected to the hopper of the cutting knife of the fiber cutting machine through a liquid pump.

[0015] Based on the above technical solution, the acid bath evaporation condensate with good water quality discharged from the viscose fiber production system can be further utilized as cutting water for the fiber cutting machine, thereby further saving water resources.

[0016] The present invention also provides a viscose staple fiber post-treatment pickling method, which uses the viscose staple fiber post-treatment pickling system, comprising the following steps:

[0017] 1) After the acid bath evaporated condensed water is heated through the heat exchanger, it is divided into two parts, one part is sent to the cut-off water tank, and the other part is sent to the pickling water tank;

[0018] 2) collecting the return water of the last stage of the first rinsing unit of the fiber post-treatment pickling device into the pickling water tank, and collecting the return water of the remaining first rinsing units into the acidic water tank;

[0019] 3) collecting the return water of each second rinsing unit of the fiber post-treatment soft water rinsing device into the acid washing water tank;

[0020] 4) transporting the water in the pickling water tank to each first rinsing unit of the fiber post-treatment pickling device;

[0021] 5) The water from the cutting water tank is transported to the top of the cutting knife of the fiber cutting machine; the water from the acid water tank is transported to the hopper below the cutting knife of the fiber cutting machine;

[0022] 6) The water transported to the top and bottom of the cutting knife is mixed, and the cut fibers are sent to the fiber cooking tank. The cooked water flows back to the acid water tank, and the cut fibers enter the pickling area along the conveyor chain network;

[0023] 7) The excess water in the acid water tank is cooled by a heat exchanger and then discharged to the next treatment process.

[0024] Based on the above technical solution:

[0025] The acid bath evaporation condensate with good water quality discharged from the viscose fiber production system can be fully utilized to replace soft water as the rinse water for the pickling area;

[0026] The acid bath evaporation condensate with good water quality discharged from the viscose fiber production system can be fully utilized to replace soft water and used as cutting water for the fiber cutting machine;

[0027] The rinse water of the second rinse unit can be utilized.

[0028] The above technical solution improves the water quality and water quantity of fiber pickling, saves water resources, and enhances the elution effect of the fiber pickling area.

[0029] Specifically, the flash evaporation system converts the excess water in the acid bath into secondary steam, which then passes through the condensation system to become condensed water, which is acidic. The acid bath evaporates the condensed water: the water volume is 120-140m 3 / h, pH is 1-3, conductivity is 200-600us / cm, turbidity is 0.8-2ntu, COD is 100-300mg / L, initial water temperature is 50-60℃, and the water temperature after heating is 75-80℃.

[0030] The above technical solution can be applied to the viscose staple fiber production system with a production capacity of 120,000-130,000 tons / year.

[0031] Specifically, the return water of the last stage first elution unit: the water volume is 35-45m 3 / h, pH is 1-1.8, conductivity is 5000-8000us / cm, turbidity is 15-25ntu, COD is 300-800mg / L, and water temperature is 70-75℃.

[0032] Specifically, the return water of the other first elution units: the water volume is 110-130m 3 / h, pH is 0.3-1.2, conductivity is 20000-50000us / cm, turbidity is 40-80ntu, COD is 1200-5000mg / L, and water temperature is 80-90℃.

[0033] The pickling process of the post-processing system is the first rinsing area for the staple fibers to enter the post-processing equipment, which is divided into several rinsing units according to the production capacity. The above technical solution can be applied to the pickling area with a production capacity of 120,000-130,000 tons / year, which is divided into 4 rinsing units. Among them, the return water quality of the last rinsing unit is better, so it is recycled into the pickling water tank and reused as fiber rinsing water in the pickling area. The water quality of the first three rinsing units is poor, and they are recycled into the acidic water tank as the rinsing water for the cut fibers.

[0034] Specifically, the flash steam condensate water entering each second rinsing unit of the fiber post-treatment soft water rinsing device has the following indicators: pH 6.5-7.5, conductivity 50-150 us / cm, turbidity 0-0.5 ntu, and COD 0-50 mg / L.

[0035] Specifically, the soft water indicators of each second washing unit of the fiber post-treatment soft water washing device are as follows: pH 7-8.5, conductivity 200-400us / cm, turbidity 0-0.5ntu, and COD 0-50mg / L.

[0036] The fiber post-treatment soft water washing device can use the steam condensate from the flash evaporation system. The flash evaporation system needs to use fresh steam to provide heat energy during the evaporation of the acid bath, and the fresh steam eventually becomes condensate. During the operation of the flash evaporation system, the steam has a separate channel and does not contact other media, so the water quality of the steam condensate is close to soft water.

[0037] In addition, in order to prevent the flash system from malfunctioning and insufficient water supply for steam condensation, and to ensure the normal operation of the soft water washing area, a soft water supply pipeline is provided.

[0038] Specifically, the indicators of the return water of each second rinsing unit of the fiber post-treatment soft water rinsing device are: pH 7-8.5, conductivity 1500-5000us / cm, turbidity 5-20ntu, COD 1200-5000mg / L, and water temperature 60-75°C.

[0039] The soft water washing area is the last washing area of ​​the post-treatment system. The above technical solution is applicable to a production capacity of 120,000-130,000 tons / year, and its soft water washing area is divided into two washing units.

[0040] The water quality in the soft water washing area is better and can be recycled into the pickling water tank and reused as fiber washing water in the pickling area.

[0041] Specifically, the pressure of the water from the cutting water tank delivered to the top of the cutting blade of the fiber cutting machine is 5-6 bar.

[0042] Before the viscose fiber is cut, it exists in the form of tow. The 5-6 bar water above the cutting knife of the cutting machine surrounds the tow in a ring shape, forming a straight line into the cutting knife to cut the fiber into the hopper. The water in the acid water tank is transported to the hopper as flushing water to flush the short fibers into the fiber cooking tank.

[0043] Specifically, the temperature of the fiber cooking tank is 98-100°C.

[0044] Specifically, the water returning to the acid water tank is equivalent to the sum of the return water of the cut-off water, rinse water, and the first three units of the pickling area. The water temperature after mixing is 88-95°C.

[0045] Specifically, the external drainage of the acidic water tank is cooled to 55-60°C by the heat exchanger and enters the next treatment process.

[0046] The flushing water is to be continuously delivered to the cutter hopper, and the entry of the cut water and the return water from the first three units of the pickling area will cause the acid water tank to gradually increase, so a part of the water must be discharged to maintain the liquid level balance. In order to recover the heat of the discharged water, it is used as the heat source for the evaporated condensed water in the acid bath evaporation system in step 1), and the temperature is reduced to 50-60℃ and discharged to the next treatment process.

[0047] The present invention uses the condensed water evaporated from the acid bath to replace the soft water, which is used not only as the cutting water of the fiber cutting machine but also as the rinsing water in the pickling area, thereby improving the water quality and water quantity of the fiber pickling, and completely changing the problems of uneven water supply and equipment failure caused by the original water supply method, saving water resources and enhancing the rinsing effect of the fiber pickling area. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a structural schematic diagram of the viscose staple fiber post-treatment pickling system provided by the present invention.

[0049] Attached Figure 1 The structures represented by the labels are listed below:

[0050] 1. Heat exchanger, 2. Fiber post-treatment pickling device, 21. First rinsing unit, 3. Pickling water tank, 4. Acidic water tank, 5. Fiber post-treatment soft water rinsing device, 51. Second rinsing unit; 6. Cutting water tank, 7. Fiber cutting machine, 8. Fiber cooking tank. DETAILED DESCRIPTION

[0051] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0052] Unless otherwise specified, the test methods used in the embodiments of the present invention are conventional methods; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0053] Example 1

[0054] like Figure 1 As shown, the viscose staple fiber post-processing pickling system includes: a heat exchanger 1, a fiber post-processing pickling device 2, a pickling water tank 3 and an acidic water tank 4.

[0055] The heat exchanger 1 has a condensate inlet and a condensate outlet, and the condensate inlet is connected to the acid bath evaporation condensate pipeline. The fiber post-treatment pickling device 2 includes four first rinsing units 21. The liquid inlet of the pickling water tank 3 is respectively connected to the condensate outlet of the heat exchanger 1 and the liquid outlet of the last first rinsing unit 21, and the liquid outlet of the pickling water tank 3 is respectively connected to the liquid inlet of each first rinsing unit 21 through a liquid pump. The liquid inlet of the acidic water tank 4 is respectively connected to the liquid outlet of the remaining first rinsing units 21, and the liquid outlet of the acidic water tank 4 is connected to the heat and mass inlet of the heat exchanger 1 through a liquid pump. In other embodiments, the number of first rinsing units 21 can be adjusted according to production capacity.

[0056] The above technical solution makes full use of the acid bath evaporation condensate with good water quality discharged from the viscose fiber production system to replace soft water as the rinse water for treating the pickling area.

[0057] Example 2

[0058] On the basis of Example 1, Figure 1 As shown, the viscose staple fiber post-treatment pickling system also includes a fiber post-treatment soft water rinsing device 5, which has two second rinsing units 51; the liquid outlet of each second rinsing unit 51 is connected to the liquid inlet of the pickling water tank 3. The liquid inlet of each second rinsing unit 51 is connected to the flash steam condensate water pipeline, and a spare soft water pipeline can be set. In other embodiments, the number of second rinsing units 51 can be adjusted according to production capacity. This technical solution utilizes the rinsing water of the second rinsing unit to further save water resources.

[0059] Example 3

[0060] On the basis of Example 2, Figure 1 As shown, the viscose staple fiber post-treatment pickling system also includes a cut water tank 6, a liquid pump, a fiber cutter 7 and a fiber cooking tank 8 which are connected in sequence. The condensed water outlet of the heat exchanger 1 is also connected to the cut water tank 6, and the fiber cooking tank 8 is connected to the liquid inlet of the pickling water tank 3. The cut water tank 6 is connected to the top of the cutter blade of the fiber cutter 7 through the liquid pump; the water outlet of the acid water tank 4 is also connected to the hopper of the cutter blade of the fiber cutter 7 through the liquid pump. This technical solution uses the acid bath evaporated condensed water with good water quality discharged from the viscose fiber production system as the cut water of the fiber cutter, which further saves water resources.

[0061] Example 4

[0062] A viscose staple fiber post-treatment pickling method, specifically using the viscose staple fiber post-treatment pickling system of Example 3, comprises the following steps:

[0063] 1) After the acid bath evaporated condensed water is heated through the heat exchanger 1, it is divided into two parts, one part is sent to the cut-off water tank 6, and the other part is sent to the pickling water tank 3;

[0064] 2) collecting the return water of the last stage of the first rinsing unit 21 of the fiber post-treatment pickling device 2 into the pickling water tank 3, and collecting the return water of the remaining first rinsing unit 21 into the acidic water tank 4;

[0065] 3) collecting the return water of each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 into the acid washing water tank 3;

[0066] 4) transporting the water in the pickling water tank 3 to each first rinsing unit 21 of the fiber post-treatment pickling device 2;

[0067] 5) The water from the cutting water tank 6 is transported to the top of the cutting blade of the fiber cutting machine 7; the water from the acidic water tank 4 is transported to the hopper below the cutting blade of the fiber cutting machine 7;

[0068] 6) The water transported to the top and bottom of the cutting blade is mixed, and the cut fibers are sent to the fiber cooking tank 8. The cooked water flows back to the acid water tank 4, and the cut fibers enter the pickling area along the conveyor chain network;

[0069] 7) The excess water in the acidic water tank 4 is cooled by the heat exchanger 1 and then discharged to the next treatment process.

[0070] Effect Example 1

[0071] The method of Example 4 is applied to a viscose staple fiber production system with a production capacity of about 125,000 tons / year.

[0072] Acid bath evaporation condensate: water volume is 120m 3 / h, pH is 1, conductivity is 600us / cm, turbidity is 2ntu, COD is 300mg / L, initial water temperature is 60℃, and the water temperature after heating is 80℃.

[0073] The return water of the last stage first elution unit 21: the water volume is 35m 3 / h, pH is 1, conductivity is 8000us / cm, turbidity is 25ntu, COD is 800mg / L, water temperature is 75℃. The return water of the remaining first elution unit 21: water volume is 110m 3 / h, pH is 0.3, conductivity is 50000us / cm, turbidity is 80ntu, COD is 5000mg / L, and water temperature is 90℃.

[0074] The indicators of the flash steam condensate water entering each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 are as follows: pH is 6.5, conductivity is 150 us / cm, turbidity is 0.5 ntu, and COD is 50 mg / L.

[0075] The indicators of the return water of each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 are as follows: pH is 7, conductivity is 5000us / cm, turbidity is 20ntu, COD is 5000mg / L, and water temperature is 75°C.

[0076] As a backup, the soft water indicators of each second washing unit 51 of the fiber post-treatment soft water washing device 5 are as follows: pH is 7, conductivity is 400us / cm, turbidity is 0.5ntu, and COD is 50mg / L.

[0077] The amount of fresh water used in the fiber post-treatment pickling device is increased from the existing 40m 3 / h, reduced to 10m 3 / h.

[0078] The amount of fresh water used by the fiber post-treatment soft water washing device is increased from the existing 80m 3 / h, reduced to 40m 3 / h.

[0079] The amount of desulfurizer used in the post-treatment system is reduced by 0.65kg / t fiber.

[0080] Bleaching agent reduces 0.45kg / t fiber.

[0081] Effect Example 2

[0082] The method of Example 4 is applied to a viscose staple fiber production system with a production capacity of about 125,000 tons / year.

[0083] Acid bath evaporation condensate: water volume is about 140m 3 / h, pH is 3, conductivity is 200us / cm, turbidity is 0.8ntu, COD is 100mg / L, initial water temperature is 50℃, and the water temperature after heating is 75℃.

[0084] The return water of the last stage first elution unit 21: the water volume is 45m 3 / h, pH is 1, conductivity is 5000us / cm, turbidity is 15ntu, COD is 300mg / L, water temperature is 70℃. The return water of the remaining first elution unit 21: water volume is 130m 3 / h, pH is 0.3, conductivity is 20000us / cm, turbidity is 40ntu, COD is 1200mg / L, and water temperature is 80℃.

[0085] The indicators of the flash steam condensate water entering each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 are as follows: pH is 7.5, conductivity is 150 us / cm, turbidity is 0.1 ntu, and COD is 10 mg / L.

[0086] The indicators of the return water of each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 are as follows: pH is 8.5, conductivity is 1500us / cm, turbidity is 5ntu, COD is 1200mg / L, and water temperature is 60°C.

[0087] As a backup, the soft water indicators of each second washing unit 51 of the fiber post-treatment soft water washing device 5 are as follows: pH is 8.5, conductivity is 200us / cm, turbidity is 0.15ntu, and COD is 15mg / L.

[0088] The amount of fresh water used in the fiber post-treatment pickling device is increased from the existing 40m 3 / h, reduce to 0m 3 / h.

[0089] The amount of fresh water used by the fiber post-treatment soft water washing device is increased from the existing 80m 3 / h, reduced to 30m 3 / h.

[0090] The amount of desulfurizer used in the post-treatment system is reduced by 0.75kg / t fiber.

[0091] Bleaching agent reduces 0.55kg / t fiber.

[0092] Effect Example 3

[0093] The method of Example 4 is applied to a viscose staple fiber production system with a production capacity of about 125,000 tons / year.

[0094] Acid bath evaporation condensate: water volume is about 130m 3 / h, pH is 1.3, conductivity is 300us / cm, turbidity is 1.2ntu, COD is 200mg / L, initial water temperature is 58℃, and the water temperature after heating is 78℃.

[0095] The return water of the last stage first elution unit 21: the water volume is 40m 3 / h, pH 1.2, conductivity 7000us / cm, turbidity 20ntu, COD 600mg / L, water temperature 73℃. The remaining return water of the first elution unit 21: water volume 120m 3 / h, pH is 1.0, conductivity is 40000us / cm, turbidity is 65ntu, COD is 3500mg / L, and water temperature is 86℃.

[0096] The indicators of the flash steam condensate water entering each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 are as follows: pH is 7, conductivity is 110 us / cm, turbidity is 0.3 ntu, and COD is 40 mg / L.

[0097] The indicators of the return water of each second rinsing unit 51 of the fiber post-treatment soft water rinsing device 5 are as follows: pH is 8.0, conductivity is 4000us / cm, turbidity is 18ntu, COD is 4000mg / L, and water temperature is 65°C.

[0098] As a backup, the soft water indicators of each second washing unit 51 of the fiber post-treatment soft water washing device 5 are as follows: pH 8, conductivity 300us / cm, turbidity 0.35ntu, COD 40mg / L.

[0099] The amount of fresh water used in the fiber post-treatment pickling device is increased from the existing 40m 3 / h, reduced to 5m 3 / h.

[0100] The amount of fresh water used by the fiber post-treatment soft water washing device is increased from the existing 80m 3 / h, reduced to 35m 3 / h.

[0101] The amount of desulfurizer used in the post-treatment system is reduced by 0.7kg / t fiber.

[0102] Bleaching agent reduces 0.5kg / t fiber.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A viscose staple fiber post-treatment pickling system, characterized in that: At least: A heat exchanger (1) having a condensed water inlet and a condensed water outlet, wherein the condensed water inlet is connected to an acid bath evaporation condensed water pipeline; A fiber post-treatment pickling device (2), comprising a plurality of first rinsing units (21); A pickling water tank (3), wherein the liquid inlet of the pickling water tank (3) is respectively connected to the condensed water outlet of the heat exchanger (1) and the liquid outlet of the first elution unit (21) at the last stage, and the liquid outlet of the pickling water tank (3) is respectively connected to the liquid inlet of each of the first elution units (21) through a liquid pump; and an acidic water tank (4), wherein the liquid inlet of the acidic water tank (4) is respectively connected to the liquid outlets of the remaining stages of the first elution units (21), and the liquid outlet of the acidic water tank (4) is connected to the heat and mass inlet of the heat exchanger (1) via a liquid pump.

2. The viscose staple fiber post-treatment pickling system according to claim 1, characterized in that: The viscose staple fiber post-treatment pickling system also includes a fiber post-treatment soft water rinsing device (5), which has a plurality of second rinsing units (51); the liquid outlet of each second rinsing unit (51) is connected to the liquid inlet of the pickling water tank (3); the liquid inlet of each second rinsing unit (51) is connected to the flash steam condensate water pipeline, and a spare soft water pipeline is provided.

3. The viscose staple fiber post-treatment pickling system according to claim 2, characterized in that: The viscose staple fiber post-processing pickling system also includes a cutting water tank (6), a liquid pump, a fiber cutting machine (7) and a fiber cooking tank (8) which are connected in sequence, the condensate outlet of the heat exchanger (1) is also connected to the cutting water tank (6), and the fiber cooking tank (8) is connected to the liquid inlet of the pickling water tank (3).

4. The viscose staple fiber post-treatment pickling system according to claim 3, characterized in that: The cutting water tank (6) is connected to the upper side of the cutting blade of the fiber cutting machine (7) through a liquid pump; The water outlet of the acidic water tank (4) is also connected to the hopper of the cutting blade of the fiber cutting machine (7) through a liquid pump.

5. A viscose staple fiber post-treatment pickling method, using the viscose staple fiber post-treatment pickling system according to claim 4, characterized in that: The following steps are involved: 1) After the acid bath evaporated condensate is heated through a heat exchanger (1), it is divided into two parts, one part is sent to a cut-off water tank (6), and the other part is sent to a pickling water tank (3); 2) collecting the return water of the last stage of the first rinsing unit (21) of the fiber post-treatment pickling device (2) into the pickling water tank (3), and collecting the return water of the remaining first rinsing unit (21) into the acidic water tank (4); 3) collecting the return water of each second rinsing unit (51) of the fiber post-treatment soft water rinsing device (5) into the acid washing water tank (3); 4) transporting the water in the pickling water tank (3) to each first rinsing unit (21) of the fiber post-treatment pickling device (2); 5) conveying the water output from the cutting water tank (6) to the top of the cutting blade of the fiber cutting machine (7); conveying the water output from the acidic water tank (4) to the hopper below the cutting blade of the fiber cutting machine (7); 6) The water transported to the top and bottom of the cutting blade is mixed, and the cut fibers are sent to the fiber cooking tank (8). The cooked water flows back to the acid water tank (4), and the cut fibers enter the pickling area along the conveying chain net; 7) Excess water in the acid water tank (4) is cooled by the heat exchanger (1) and then discharged to the next treatment process.

6. The post-treatment pickling method of viscose staple fibers according to claim 5, characterized in that: The acid bath evaporates condensed water: the water volume is 120-140m 3 / h, pH is 1-3, conductivity is 200-600us / cm, turbidity is 0.8-2ntu, COD is 100-300mg / L, initial water temperature is 50-60℃, and the water temperature after heating is 75-80℃.

7. The post-treatment pickling method for viscose staple fibers according to claim 5, characterized in that: The return water of the last stage first elution unit (21): the water volume is 35-45m 3 / h, pH is 1-1.8, conductivity is 5000-8000us / cm, turbidity is 15-25ntu, COD is 300-800mg / L, water temperature is 70-75℃; The return water of the remaining first rinsing unit (21): the water volume is 110-130m 3 / h, pH is 0.3-1.2, conductivity is 20000-50000us / cm, turbidity is 40-80ntu, COD is 1200-5000mg / L, and water temperature is 80-90℃.

8. The post-treatment pickling method for viscose staple fibers according to claim 5, characterized in that: The flash steam condensate water entering each second rinsing unit (51) of the fiber post-treatment soft water rinsing device (5) has the following indicators: pH 6.5-7.5, conductivity 50-150 us / cm, turbidity 0-0.5 ntu, COD 0-50 mg / L; The soft water indicators of each second washing unit (51) of the fiber post-treatment soft water washing device (5) are as follows: pH 7-8.5, conductivity 200-400us / cm, turbidity 0-0.5ntu, COD 0-50mg / L; The indicators of the return water of each second rinsing unit (51) of the fiber post-treatment soft water rinsing device (5) are: pH 7-8.5, conductivity 1500-5000us / cm, turbidity 5-20ntu, COD 1200-5000mg / L, and water temperature 60-75°C.

9. The viscose staple fiber post-treatment pickling method according to claim 5, characterized in that: The pressure of the water from the cutting water tank (6) delivered to the cutting blade of the fiber cutting machine (7) is 5-6 bar; The temperature of the fiber cooking tank (8) is 98-100°C.

10. The post-treatment pickling method of viscose staple fibers according to any one of claims 5 to 9, characterized in that: The external drainage of the acidic water tank (4) is cooled to 55-60°C by the heat exchanger (1) and enters the next treatment process.

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