Continuous desalting and filtering equipment and method

Abstract

The invention provides continuous desalting and filtering equipment and a continuous desalting and filtering method. The continuous desalting and filtering equipment comprises a plurality of filters which are connected in parallel, each filter is provided with a high-temperature salt-containing polymer feed port, a hot water and solvent feed port, a bottom discharge port, a gas feed port and a gas discharge port; the high-temperature salt-containing polymer feed ports are respectively connected with a high-temperature salt-containing polymer main inlet pipeline; the hot water and solvent feed ports are respectively connected with a hot water main inlet pipeline and a solvent main inlet pipeline; a bottom discharge hole is respectively connected with a salt-free polymer and solvent main outlet pipeline and a salt-containing hot water main outlet pipeline; the gas feeding hole is respectively connected with a gas main inlet pipeline and a nitrogen system in sequence; and the gas discharge holes are respectively connected with a gas main outlet pipeline. The continuous desalting and filtering equipment is provided with a plurality of filters, and the three adjacent filters execute different steps, so that continuous desalting and filtering of the high-temperature salt-containing polymer are realized, and the problem of low efficiency of a high-temperature salt-containing polymer filtering procedure is solved.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature salt-containing polymer filtration technology, specifically relating to a continuous desalination filtration device and method. Background Technology

[0002] High-temperature saline polymers include polymers in a purely molten state and polymers dissolved in solvents. Their temperatures range from 170 to 500°C, and their pressures can range from atmospheric pressure to several MPa; the salt content ranges from 5 to 30 wt%, and the viscosity can reach tens of CP. The salt particles in high-temperature saline polymers have diameters ranging from 1 micrometer to several millimeters.

[0003] For example, the polymer in a high-temperature salt-containing polymer is polyphenylene sulfide, and the solvent is methylpyrrolidone; the salt in a high-temperature salt-containing polymer can be a halide, sulfate, phosphate, etc., such as sodium chloride and calcium chloride, which are insoluble in the polymer or polymer system containing solvent.

[0004] Commonly used static equipment for closed-loop separation of solid-containing systems includes cartridge filters and plate filters. While static equipment can withstand high temperatures, cartridge filters are unsuitable for systems with a solid content exceeding 5 wt%, as this necessitates frequent cleaning and replacement of the cartridges. Plate filters suffer from limitations such as limited operating capacity, unsuitability for high temperatures, the need for multiple units to be paralleled to increase processing capacity, cumbersome filter cake cleaning, and environmental pollution. In existing technologies, rotary filters, such as vacuum filters, filter presses, and centrifuges, are commonly used for closed-loop separation of solid-containing systems. However, when using rotary filters to process high-temperature saline polymers, the sealing material cannot withstand temperatures above 170°C, leading to deformation and leakage. Furthermore, the faster the rotary filter rotates, the lower its temperature tolerance. Therefore, existing solid-liquid separation equipment is unsuitable for separating high-temperature saline polymer systems with high temperature, high solid content, and high viscosity. In addition to the aforementioned shortcomings, existing technologies for closed-loop separation of solid-containing systems use intermittent static and dynamic equipment, failing to achieve continuous filtration and resulting in low processing efficiency for the high-temperature saline polymer filtration process.

[0005] Therefore, developing a continuous desalination filtration device capable of continuously filtering high-temperature salt-containing polymers has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art and to provide a continuous desalination filtration device and method.

[0007] One objective of this invention is to provide a continuous desalination filtration device, comprising multiple filters connected in parallel; each of the filters is provided with a high-temperature saline polymer inlet, a hot water and solvent inlet, a bottom outlet, a gas inlet, and a gas outlet; the high-temperature saline polymer inlets are all connected to a total high-temperature saline polymer inlet pipeline; the hot water and solvent inlets are all connected to a total hot water inlet pipeline and a total solvent inlet pipeline; the bottom outlets are all connected to a total non-salt polymer and solvent outlet pipeline and a total saline hot water outlet pipeline; the gas inlets are all sequentially connected to a total gas inlet pipeline and a nitrogen system; and the gas outlets are all connected to the total gas outlet pipeline.

[0008] In a preferred embodiment of the present invention

[0009] A high-temperature saline polymer inlet pipe is provided at the feed inlet of the high-temperature saline polymer. The high-temperature saline polymer inlet pipe is inserted into the side wall of the filter. The inlet end of the high-temperature saline polymer inlet pipe is connected to the main high-temperature saline polymer inlet pipeline, and the outlet end of the high-temperature saline polymer inlet pipe is located inside the filter; and / or

[0010] The hot water and solvent inlets are located on the top surface of the filter; and / or

[0011] The gas inlet is located on the top surface of the filter; and / or

[0012] The gas outlet is located on the top surface of the filter; and / or

[0013] The bottom outlet is located on the bottom surface of the filter;

[0014] Preferably, each filter is provided with a lower filter element, and the horizontal edge of the lower filter element is connected to the side wall of the filter.

[0015] In a preferred embodiment of the present invention

[0016] The hot water and solvent inlet is connected to the hot water and solvent inlet pipeline, which is connected to the main hot water inlet pipeline via the hot water inlet pipeline, and the hot water and solvent inlet pipeline is connected to the main solvent inlet pipeline via the solvent inlet pipeline; and / or

[0017] The bottom outlet is connected to the bottom conveying pipeline, the bottom conveying pipeline is connected to the salt-free polymer and solvent main outlet pipeline through the salt-free polymer and solvent outlet pipeline, and the bottom conveying pipeline is connected to the salt-containing hot water main outlet pipeline through the salt-containing hot water outlet pipeline.

[0018] Preferred,

[0019] Both the hot water inlet pipeline and the solvent inlet pipeline are equipped with shut-off valves; or, a switching valve is provided at the intersection of the hot water inlet pipeline, the solvent inlet pipeline, and the hot water and solvent inlet pipelines; and / or

[0020] Both the salt-free polymer and solvent outlet pipeline and the salt-containing hot water outlet pipeline are equipped with shut-off valves; or, a switching valve is provided at the intersection of the salt-free polymer and solvent outlet pipeline, the salt-containing hot water outlet pipeline, and the bottom conveying pipeline.

[0021] In a preferred embodiment of the present invention

[0022] The high-temperature salt-containing polymer inlet pipe is a straight pipe that is inserted into the filter from the side wall of the filter. The high-temperature salt-containing polymer inlet pipe is divided into an outer inlet pipe and an inner inlet pipe by the side wall of the filter body. The vertical height of the outer inlet pipe is greater than that of the inner inlet pipe.

[0023] Preferably, the angle between the high-temperature salt-containing polymer inlet pipe and the filter axis is no greater than 45°;

[0024] More preferably, the angle between the high-temperature salt-containing polymer inlet pipe and the filter axis is no greater than 30°.

[0025] In a preferred embodiment of the present invention

[0026] The angle between the outlet end face of the high-temperature salt-containing polymer inlet pipe and the horizontal plane is 40-50°, preferably 45°; and / or

[0027] The filter includes a main body, an upper end cap connected to the top surface of the main body, and a lower end cap connected to the bottom surface of the main body; the distance between the outlet end face of the high-temperature salt-containing polymer inlet pipe and the upper end cap is 250–1000 mm, preferably 300–500 mm; and / or

[0028] The upper surface of the lower filter element is provided with a separation medium;

[0029] Preferably, the separation medium is spherical;

[0030] More preferably, the particle size of the separation medium is larger than the inner diameter of the filter pores of the lower filter element.

[0031] In a preferred embodiment of the present invention

[0032] The filter has a first jacket on its outer wall, and the first jacket has a first jacket heat tracing medium inlet and a first jacket heat tracing medium outlet; and / or

[0033] The outer wall of the outer inlet pipe is provided with a second jacket, and the second jacket is provided with a second jacket heat tracing medium inlet and a second jacket heat tracing medium outlet.

[0034] Preferred,

[0035] The vertical height of the first jacket heating medium inlet is less than the vertical height of the first jacket heating medium outlet; and / or

[0036] The vertical height of the inlet of the second jacket heat tracing medium is less than the vertical height of the outlet of the second jacket heat tracing medium.

[0037] In a preferred embodiment of the present invention

[0038] The continuous desalination filtration equipment is also equipped with an upper filter element, the horizontal edge of which is connected to the side wall of the filter; the outlet end face of the high-temperature salt-containing polymer inlet pipe is located below the upper filter element.

[0039] Preferably, both the upper filter element and the lower filter element include a filter screen or a filter cloth;

[0040] More preferably, the filter screen or filter cloth has an inner diameter of 120-40 mesh, preferably 80-40 mesh.

[0041] In a preferred embodiment of the present invention

[0042] The continuous desalination filtration equipment also includes a lower support mesh, the horizontal edge of which is connected to the side wall of the filter; the vertical height of the lower support mesh is lower than the vertical height of the lower filter element; and / or

[0043] The continuous desalination filtration equipment is also equipped with an upper support wire mesh, the horizontal edge of which is connected to the side wall of the filter; the vertical height of the upper support wire mesh is higher than the vertical height of the upper filter element.

[0044] Preferred,

[0045] The aperture of the upper support mesh is not less than the inner diameter of the filter pores of the upper filter element; and / or

[0046] The aperture of the lower support wire mesh is not less than the inner diameter of the filter holes of the lower filter element.

[0047] In a preferred embodiment of the present invention

[0048] The continuous desalination filtration equipment further includes a stirrer, which includes a stirring rod and stirring blades connected to the stirring rod; the stirring rod is inserted into the filter from the side wall of the filter, and the stirring blades are disposed inside the filter;

[0049] Preferably, the stirring blades are positioned at the axial position of the filter;

[0050] More preferably, the acute angle between the stirring rod and the horizontal plane is 0 to 45°;

[0051] Most preferably, the continuous desalination filtration equipment further includes a hot nitrogen inlet pipeline, one end of which is connected to the main hot nitrogen inlet pipeline and the nitrogen system in sequence, and the other end is connected to the bottom outlet through the bottom conveying pipeline; the hot nitrogen inlet pipeline is equipped with a heating device.

[0052] The second objective of this invention is to provide a continuous desalination filtration method, which is carried out using the continuous desalination filtration equipment described in the first objective of this invention;

[0053] Preferred,

[0054] Each of the filters sequentially performs three steps: preliminary filtration, solvent replacement, hot water salt dissolution, and hot nitrogen purging; wherein, three adjacent filters perform different steps in the sequence.

[0055] More preferably,

[0056] The preliminary filtration process includes the following steps: The high-temperature salt-containing polymer in the main inlet pipeline enters the filter; after the high-temperature salt-containing polymer is fed, the nitrogen system is turned on, and the gas in the main gas inlet pipeline enters the filter, where the high-temperature salt-containing polymer is pressurized into a first salt-free polymer and solvent, and a first sludge cake; when the filter is pressurized to 0.1–10 MPa, the nitrogen system is turned off, and the gas in the filter is discharged through the top main gas outlet pipeline; when the pressure in the filter returns to normal, the first salt-free polymer and solvent enter the salt-free polymer and solvent main outlet pipeline; and / or

[0057] Solvent replacement specifically includes the following steps: Solvent in the main solvent inlet pipeline enters the filter; after solvent feeding is complete, the nitrogen system is turned on, and gas in the main gas inlet pipeline enters the filter, where the first sludge cake is pressurized into a second salt-free polymer and solvent, and a second sludge cake; when the filter is pressurized to 0.1–10 MPa, the nitrogen system is turned off, and the gas in the filter is discharged through the top main gas outlet pipeline; when the pressure in the filter returns to normal, the second salt-free polymer and solvent enter the salt-free polymer and solvent main outlet pipeline; and / or

[0058] The hot water salt dissolution and hot nitrogen purging process includes the following steps: hot water in the main hot water inlet pipeline enters the filter from the top of the filter and is stirred. The second mud cake and hot water form saline hot water, which enters the saline hot water outlet pipeline from the bottom of the filter. After the preset stirring time is reached, the nitrogen system is turned on, and hot nitrogen in the main hot nitrogen inlet pipeline enters the filter. After the preset hot nitrogen purging time is reached, the nitrogen system is turned off.

[0059] The best option,

[0060] In the preliminary filtration, the feed rate of the high-temperature saline polymer accounts for 20-70% of the filter volume, preferably 40-50%; and / or, the feed rate of the high-temperature saline polymer is 0.5-3 m / s, preferably 1.5-2 m / s; and / or, the temperature of the high-temperature saline polymer is 170-500℃, preferably 170-300℃; and / or, the pressure inside the filter is 0.1-10 MPa, preferably 0.4-1.0 MPa; and / or, the pressure filtration time is 1-45 min, preferably 5-15 min; and / or

[0061] In solvent replacement, the solvent feed rate is 50–200 wt% of the high-temperature salt-containing polymer feed rate, preferably 100–150 wt%; and / or, the solvent feed rate is 1–3 m / s, preferably 1.5–2 m / s; and / or, the solvent feed temperature is 170–500 °C, preferably 170–300 °C; and / or, the pressure filtration time is 1–45 min, preferably 5–15 min; and / or, the number of solvent replacements is 1–10 times, preferably 2–4 times; and / or

[0062] In the hot water salt dissolution and hot nitrogen purging process, the hot water feed rate is 20–100 wt% of the high-temperature salt-containing polymer feed rate, preferably 30–50 wt%; and / or, the hot water feed rate is 1–3 m / s, preferably 1.5–2 m / s; and / or, the hot water feed temperature is 50–150 °C, preferably 80–100 °C; and / or, the stirring time is 5–30 min, preferably 5–15 min; and / or, the hot nitrogen temperature is 100–500 °C, preferably 170–300 °C; and / or, the hot nitrogen feed rate is 15–35 m / s, preferably 15–25 m / s; and / or, the hot nitrogen purging time is 2–30 min, preferably 2–10 min.

[0063] Compared with the prior art, the beneficial effects of the present invention are:

[0064] 1. The continuous desalination filtration equipment of the present invention is equipped with multiple filters, with three adjacent filters performing different steps to achieve continuous desalination filtration of high-temperature salt-containing polymers. This solves the problems in the prior art where static and dynamic equipment used for sealed separation of solid-containing systems cannot achieve continuous filtration, and the low efficiency of the high-temperature salt-containing polymer filtration process. Furthermore, each filter can be used to filter and separate high-temperature salt-containing polymer systems (high temperature, high solid content, high viscosity).

[0065] 2. In the continuous desalination filtration method of the present invention, hot water enters from the top of the filter and saline hot water exits from the bottom of the filter. Therefore, the pressure source required for hot water inlet and hot water outlet is relatively small, which can save energy on the one hand and facilitate the one-time emptying of the filter by hot water on the other hand. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the continuous desalination filtration system of the present invention;

[0067] Figure 2 This is a partial structural diagram of the first filter A in the continuous desalination filtration system of the present invention;

[0068] In the figure, 1-stirrer; 21-upper support mesh, 22-lower support mesh; 31-upper filter element, 32-lower filter element; 4-first jacket. Detailed Implementation

[0069] The present invention will now be described in further detail with reference to the accompanying drawings:

[0070] like Figure 1 As shown, the present invention provides a continuous desalination filtration device, including multiple filters, each of which has a lower filter element 32, the horizontal edge of which is connected to the side wall of the filter; each of the multiple filters has a high-temperature salt-containing polymer inlet, a hot water and solvent inlet, a bottom outlet, a gas inlet, and a gas outlet; the high-temperature salt-containing polymer inlet is connected to a total high-temperature salt-containing polymer inlet pipeline; the hot water and solvent inlets are respectively connected to a total hot water inlet pipeline and a total solvent inlet pipeline; the bottom outlets are respectively connected to a total non-salt polymer and solvent outlet pipeline and a total saline hot water outlet pipeline; the gas inlets are sequentially connected to a total gas inlet pipeline and a nitrogen system; and the gas outlets are all connected to the total gas outlet pipeline.

[0071] The following description uses three filters as an example. For ease of description, the three filters are named First Filter A, Second Filter B, and Third Filter C. First Filter A, Second Filter B, and Third Filter C are each provided with a high-temperature saline polymer inlet, referred to as the First High-Temperature Saline Polymer Inlet, Second High-Temperature Saline Polymer Inlet, and Third High-Temperature Saline Polymer Inlet, respectively. Preferably, the three high-temperature saline polymer inlets are respectively located on the side walls of First Filter A, Second Filter B, and Third Filter C. The First High-Temperature Saline Polymer Inlet, Second High-Temperature Saline Polymer Inlet, and Third High-Temperature Saline Polymer Inlet are respectively provided with a First High-Temperature Saline Polymer Inlet Pipeline, a Second High-Temperature Saline Polymer Inlet Pipeline, and a Third High-Temperature Saline Polymer Inlet Pipeline. The other end of each of the First High-Temperature Saline Polymer Inlet Pipeline, Second High-Temperature Saline Polymer Inlet Pipeline, and Third High-Temperature Saline Polymer Inlet Pipeline is connected to the main high-temperature saline polymer inlet pipeline.

[0072] A valve 1-1 is installed on the first high-temperature saline polymer inlet pipeline to control whether the high-temperature saline polymer in the total high-temperature saline polymer inlet pipeline enters the first filter A via the first high-temperature saline polymer inlet pipeline. A valve 1-2 is installed on the second high-temperature saline polymer inlet pipeline to control whether the high-temperature saline polymer in the total high-temperature saline polymer inlet pipeline enters the second filter B via the second high-temperature saline polymer inlet pipeline. A valve 1-3 is installed on the third high-temperature saline polymer inlet pipeline to control whether the high-temperature saline polymer in the total high-temperature saline polymer inlet pipeline enters the third filter C via the third high-temperature saline polymer inlet pipeline.

[0073] In a preferred embodiment of the present invention, a high-temperature saline polymer inlet pipe is provided at the high-temperature saline polymer inlet. The high-temperature saline polymer inlet pipe is connected to the side wall of the filter, and the inlet end of the high-temperature saline polymer inlet pipe is connected to the main high-temperature saline polymer inlet pipeline. The outlet end of the high-temperature saline polymer inlet pipe is located inside the filter and above the lower filter element 32. Specifically, in this embodiment, as... Figure 2 As shown, a first high-temperature salt-containing polymer inlet pipe is provided at the first high-temperature salt-containing polymer inlet. The first high-temperature salt-containing polymer inlet pipe is connected to the side wall of the first filter A. The inlet end of the first high-temperature salt-containing polymer inlet pipe is connected to the high-temperature salt-containing polymer main inlet pipeline. The outlet end of the high-temperature salt-containing polymer inlet pipe is located inside the first filter A and above the lower filter element 32.

[0074] Similarly, a second high-temperature saline polymer inlet pipe is provided at the second high-temperature saline polymer inlet. The second high-temperature saline polymer inlet pipe is connected to the side wall of the second filter B, and the inlet end of the second high-temperature saline polymer inlet pipe is connected to the high-temperature saline polymer main inlet pipeline. The outlet end of the high-temperature saline polymer inlet pipe is located inside the second filter B and above the lower filter element 32. A third high-temperature saline polymer inlet pipe is provided at the third high-temperature saline polymer inlet. The third high-temperature saline polymer inlet pipe is connected to the side wall of the third filter C, and the inlet end of the third high-temperature saline polymer inlet pipe is connected to the high-temperature saline polymer main inlet pipeline. The outlet end of the high-temperature saline polymer inlet pipe is located inside the third filter C and above the lower filter element 32.

[0075] In a preferred embodiment of the present invention, the high-temperature saline polymer inlet pipe is a straight pipe that is inserted into the filter from the side wall of the filter. The high-temperature saline polymer inlet pipe includes an outer inlet pipe and an inner inlet pipe, and the height of the outer inlet pipe in the vertical direction is greater than the height of the inner inlet pipe in the vertical direction. The following description uses a first filter A as an example. The first high-temperature saline polymer inlet pipe is a straight pipe that is inserted into the first filter A from the side wall of the first filter A. A conventional sealing structure is used to seal the insertion point, for example, by using a flange to seal the first high-temperature saline polymer inlet pipe to the side wall of the first filter A. One end of the first high-temperature saline polymer inlet pipe located outside the first filter A is connected to a first high-temperature saline polymer inlet pipeline. Since the first high-temperature saline polymer inlet pipe is divided into two parts by the first filter A, one part located outside the first filter A and the other part located inside the first filter A, for ease of description, they are respectively named the first outer inlet pipe and the first inner inlet pipe. Therefore, the height of the first outer inlet pipe in the vertical direction is greater than the height of the first inner inlet pipe in the vertical direction.

[0076] In a preferred embodiment of the present invention, the angle between the high-temperature salt-containing polymer inlet pipe and the axis of the filter is greater than 0°, preferably not greater than 45°, and more preferably greater than 0° and less than or equal to 30°. The following description uses the first filter A as an example. The angle between the first high-temperature salt-containing polymer inlet pipe and the axis of the first filter A is greater than 0°, preferably not greater than 45°, and more preferably greater than 0° and less than or equal to 30°. This ensures that the high-temperature salt-containing polymer smoothly enters the first filter A along the slope, thereby preventing solid accumulation dead zones within the first filter A.

[0077] In a preferred embodiment of the present invention, the angle between the outlet end face of the high-temperature salt-containing polymer inlet pipe and the horizontal plane is 40-50°, preferably 45°. The following description uses the first filter A as an example. The acute angle between the outlet end face of the first high-temperature salt-containing polymer inlet pipe and the horizontal plane is 40-50°, preferably 45°, to maximize the cross-sectional area of ​​the outlet end face of the first high-temperature salt-containing polymer inlet pipe, further facilitating the smooth entry of the high-temperature salt-containing polymer into the first filter A and preventing blockage of the outlet of the first high-temperature salt-containing polymer inlet pipe.

[0078] The filter includes a main body, an upper end cap connected to the top surface of the main body, and a lower end cap connected to the bottom surface of the main body. In another preferred embodiment of the invention, the distance between the outlet end face of the high-temperature salt-containing polymer inlet pipe and the upper end cap is 250–1000 mm, preferably 300–500 mm. The following description uses a first filter A as an example. The first filter A includes a main body, an upper end cap connected to the top surface of the main body, and a lower end cap connected to the bottom surface of the main body. The distance between the outlet end face of the first high-temperature salt-containing polymer inlet pipe and the upper end cap of the first filter A is 250–1000 mm, preferably 300–500 mm.

[0079] In a preferred embodiment of the present invention, such as Figure 2 As shown, the outer wall of the external inlet pipe is provided with a second jacket. The jacket has a second jacket heating medium inlet and a second jacket heating medium outlet to maintain the high-temperature salt-containing polymer in the high-temperature salt-containing polymer inlet pipe within a preset temperature range, preventing the high-temperature salt-containing polymer from cooling and precipitating due to ambient temperature, thus avoiding blockage of the high-temperature salt-containing polymer inlet pipe. Preferably, the vertical height of the second jacket heating medium outlet is greater than the vertical height of the second jacket heating medium inlet. More preferably, each filter is provided with a second jacket.

[0080] In a preferred embodiment of the present invention, the hot water and solvent inlet is located on the top surface of the filter. Preferably, the hot water and solvent inlet is connected to a hot water and solvent inlet pipeline, which is connected to the main hot water inlet pipeline via the hot water inlet pipeline, and the hot water and solvent inlet pipeline is connected to the main solvent inlet pipeline via the solvent inlet pipeline. Specifically, in this embodiment, the tops of the first filter A, the second filter B, and the third filter C are all provided with hot water and solvent inlets, referred to as the first hot water and solvent inlet, the second hot water and solvent inlet, and the third hot water and solvent inlet, respectively. The first hot water and solvent inlet, the second hot water and solvent inlet, and the third hot water and solvent inlet are respectively provided with the first hot water and solvent inlet pipeline, the second hot water and solvent inlet pipeline, and the third hot water and solvent inlet pipeline.

[0081] The other ends of the first hot water and solvent inlet pipelines are connected to the first hot water inlet pipeline and the first solvent inlet pipeline, respectively. The other end of the first hot water inlet pipeline is connected to the main hot water inlet pipeline. The other end of the first solvent inlet pipeline is connected to the main solvent inlet pipeline. Similarly, the other ends of the second hot water and solvent inlet pipelines are also connected to the second hot water inlet pipeline and the second solvent inlet pipeline, respectively. The other end of the second hot water inlet pipeline is connected to the main hot water inlet pipeline. The other end of the third hot water and solvent inlet pipelines are connected to the third hot water inlet pipeline and the third solvent inlet pipeline, respectively. The other end of the third hot water inlet pipeline is connected to the main hot water inlet pipeline. The other end of the third solvent inlet pipeline is connected to the main solvent inlet pipeline. In some cases, a solvent feed pump can be installed on the main solvent inlet pipeline to achieve the required solvent feed rate, and a hot water feed pump can be installed on the main hot water inlet pipeline to achieve the required solvent feed rate.

[0082] In one specific embodiment of the present invention, both the hot water inlet pipeline and the solvent inlet pipeline are equipped with shut-off valves. Specifically, in this embodiment, a valve 3-1 is provided on the first solvent inlet pipeline to control whether the solvent in the total solvent inlet pipeline passes through the first solvent inlet pipeline, the first hot water inlet pipeline, and the solvent inlet pipeline before finally entering the first filter A. A valve 3-2 is provided on the second solvent inlet pipeline to control whether the solvent in the total solvent inlet pipeline passes through the second solvent inlet pipeline, the second hot water inlet pipeline, and the solvent inlet pipeline before finally entering the second filter B. A valve 3-3 is provided on the third solvent inlet pipeline to control whether the solvent in the total solvent inlet pipeline passes through the third solvent inlet pipeline, the third hot water inlet pipeline, and the solvent inlet pipeline before finally entering the third filter C.

[0083] A valve 4-1 is installed on the first hot water inlet pipeline to control whether the hot water in the main hot water inlet pipeline enters the first hot water and solvent inlet pipelines via the first hot water inlet pipeline, and finally enters the first filter A. A valve 4-2 is installed on the second hot water inlet pipeline to control whether the hot water in the main hot water inlet pipeline enters the second hot water and solvent inlet pipelines via the second hot water inlet pipeline, and finally enters the second filter B. A valve 4-3 is installed on the third hot water inlet pipeline to control whether the hot water in the main hot water inlet pipeline enters the third hot water and solvent inlet pipelines via the third hot water inlet pipeline, and finally enters the third filter C.

[0084] In another specific embodiment of the present invention, a switching valve (such as a three-way valve) is provided at the intersection of the hot water inlet pipeline, the solvent inlet pipeline, and the hot water and solvent inlet pipeline to control the connection between the hot water and solvent inlet pipeline and the hot water inlet pipeline, or the connection between the hot water and solvent inlet pipeline and the solvent inlet pipeline. Specifically, in this embodiment, a first top three-way valve is provided at the intersection of the first hot water inlet pipeline, the first solvent inlet pipeline, and the first hot water and solvent inlet pipeline; a second top three-way valve is provided at the intersection of the second hot water inlet pipeline, the second solvent inlet pipeline, and the second hot water and solvent inlet pipeline; and a third top three-way valve is provided at the intersection of the third hot water inlet pipeline, the third solvent inlet pipeline, and the third hot water and solvent inlet pipeline.

[0085] In a preferred embodiment of the present invention, the gas inlet is located on the top surface of the filter. Specifically, in this embodiment, the top of the first filter A, the second filter B, and the third filter C are respectively provided with a first top gas inlet, a second top gas inlet, and a third top gas inlet. The first top gas inlet, the second top gas inlet, and the third top gas inlet are respectively provided with a first top gas inlet pipeline, a second top gas inlet pipeline, and a third top gas inlet pipeline. All three top gas inlet pipelines are connected to a main top gas inlet pipeline. Preferably, the main top gas inlet pipeline is connected to a nitrogen system.

[0086] On the first top gas inlet pipeline, a first top gas valve 8-1 and a first top gas delivery pump are installed to control whether the gas in the main top gas inlet pipeline enters the first filter A through the first top gas inlet pipeline. On the second top gas inlet pipeline, a second top gas valve 8-2 and a second top gas delivery pump are installed to control whether the gas in the main top gas inlet pipeline enters the second filter B through the second top gas inlet pipeline. On the third top gas inlet pipeline, a third top gas valve 8-3 and a third top gas delivery pump are installed to control whether the gas in the main top gas inlet pipeline enters the third filter C through the third top gas inlet pipeline.

[0087] In a preferred embodiment of the present invention, the gas outlet is located on the top surface of the filter. Specifically, in this embodiment, the tops of the first filter A, the second filter B, and the third filter C are respectively provided with a first top gas outlet, a second top gas outlet, and a third top gas outlet. The first top gas outlet, the second top gas outlet, and the third top gas outlet are respectively provided with a first top gas outlet pipeline, a second top gas outlet pipeline, and a third top gas outlet pipeline. The first top gas outlet pipeline, the second top gas outlet pipeline, and the third top gas outlet pipeline are all connected to the main top gas outlet pipeline.

[0088] A valve 6-1 is installed on the first top gas outlet pipeline to control whether the gas in the first filter A passes through the first top gas outlet and the first top gas outlet pipeline before finally entering the main top gas outlet pipeline. Similarly, a valve 6-2 is installed on the second top gas outlet pipeline to control whether the gas in the second filter B passes through the second top gas outlet and the second top gas outlet pipeline before finally entering the main top gas outlet pipeline. A valve 6-3 is installed on the third top gas outlet pipeline to control whether the gas in the third filter C passes through the third top gas outlet and the third top gas outlet pipeline before finally entering the main top gas outlet pipeline.

[0089] In a preferred embodiment of the present invention, the bottom outlet is located on the bottom surface of the filter. Specifically, in this embodiment, the bottom of the first filter A, the second filter B, and the third filter C are all provided with bottom feed ports, referred to as the first bottom feed port, the second bottom feed port, and the third bottom feed port, respectively. The first bottom feed port, the second bottom feed port, and the third bottom feed port are respectively provided with a first bottom feed pipeline, a second bottom feed pipeline, and a third bottom feed pipeline.

[0090] The first bottom conveying pipeline is connected to the first hot nitrogen inlet pipeline, the first salt-free polymer and solvent outlet pipeline, and the first saline hot water outlet pipeline, respectively. The second bottom conveying pipeline is connected to the second hot nitrogen inlet pipeline, the second salt-free polymer and solvent outlet pipeline, and the second saline hot water outlet pipeline, respectively. The other end of the third bottom conveying pipeline is connected to the third hot nitrogen inlet pipeline, the third salt-free polymer and solvent outlet pipeline, and the third saline hot water outlet pipeline, respectively.

[0091] The other end of the first hot nitrogen inlet pipeline is connected to the main hot nitrogen inlet pipeline; the other end of the first salt-free polymer and solvent outlet pipeline is connected to the main salt-free polymer and solvent outlet pipeline; the other end of the first saline hot water outlet pipeline is connected to the main saline hot water outlet pipeline. The other end of the second hot nitrogen inlet pipeline is connected to the main hot nitrogen inlet pipeline; the other end of the second salt-free polymer and solvent outlet pipeline is connected to the main salt-free polymer and solvent outlet pipeline; the other end of the second saline hot water outlet pipeline is connected to the main saline hot water outlet pipeline. The other end of the third hot nitrogen inlet pipeline is connected to the main hot nitrogen inlet pipeline. The other end of the third salt-free polymer and solvent outlet pipeline is connected to the main salt-free polymer and solvent outlet pipeline; the other end of the third saline hot water outlet pipeline is connected to the main saline hot water outlet pipeline.

[0092] A valve 7-1 is installed on the first hot nitrogen inlet pipeline to control whether the hot nitrogen in the total hot nitrogen inlet pipeline flows through the first hot nitrogen inlet pipeline, the first bottom conveying pipeline, and the first bottom conveying port before finally entering the first filter A. Similarly, a valve 7-2 is installed on the second hot nitrogen inlet pipeline to control whether the hot nitrogen in the total hot nitrogen inlet pipeline flows through the second hot nitrogen inlet pipeline, the second bottom conveying pipeline, and the second bottom conveying port before finally entering the second filter B. A valve 7-3 is installed on the third hot nitrogen inlet pipeline to control whether the hot nitrogen in the total hot nitrogen inlet pipeline flows through the third hot nitrogen inlet pipeline, the third bottom conveying pipeline, and the third bottom conveying port before finally entering the third filter C.

[0093] In one specific embodiment of the present invention, both the salt-free polymer and solvent outlet pipeline and the saline hot water outlet pipeline are equipped with shut-off valves. Specifically, in this embodiment, a valve 2-1 is provided on the first salt-free polymer and solvent outlet pipeline to control whether the salt-free polymer and solvent in the first filter A enters the total salt-free polymer and solvent outlet pipeline via the first bottom feed port, the first bottom feed pipeline, and the first salt-free polymer and solvent outlet pipeline. A valve 2-2 is provided on the second salt-free polymer and solvent outlet pipeline to control whether the salt-free polymer and solvent in the second filter B enters the total salt-free polymer and solvent outlet pipeline via the second bottom feed port, the second bottom feed pipeline, and the second salt-free polymer and solvent outlet pipeline. A valve 2-3 is provided on the third salt-free polymer and solvent outlet pipeline to control whether the salt-free polymer and solvent in the third filter C enters the total salt-free polymer and solvent outlet pipeline via the third bottom feed port, the third bottom feed pipeline, and the third salt-free polymer and solvent outlet pipeline. In some cases, a first salt-free polymer and solvent discharge pump may be installed on the first salt-free polymer and solvent outlet pipeline.

[0094] A valve 5-1 is installed on the first saline hot water outlet pipeline to control whether the saline hot water in the first filter A flows through the first bottom feed port, the first bottom feed pipeline, and the first saline hot water outlet pipeline before finally entering the main saline hot water outlet pipeline. Similarly, a valve 5-2 is installed on the second saline hot water outlet pipeline to control whether the saline hot water in the second filter B flows through the second bottom feed port, the second bottom feed pipeline, and the second saline hot water outlet pipeline before finally entering the main saline hot water outlet pipeline. A valve 5-3 is installed on the third saline hot water outlet pipeline to control whether the saline hot water in the third filter C flows through the third bottom feed port, the third bottom feed pipeline, and the third saline hot water outlet pipeline before finally entering the main saline hot water outlet pipeline. In some cases, a saline hot water discharge pump can be installed on the main saline hot water outlet pipeline.

[0095] In another specific embodiment of the present invention, a switching valve (such as a three-way valve) is provided at the intersection of the salt-free polymer and solvent outlet pipeline, the saline hot water outlet pipeline, and the bottom conveying pipeline to connect the bottom conveying pipeline with the salt-free polymer and solvent outlet pipeline, or to connect the bottom conveying pipeline with the saline hot water outlet pipeline. Specifically, in this embodiment, a first bottom three-way valve is provided at the intersection of the first salt-free polymer and solvent outlet pipeline, the first saline hot water outlet pipeline, and the first bottom conveying pipeline; a second bottom three-way valve is provided at the intersection of the second salt-free polymer and solvent outlet pipeline, the second saline hot water outlet pipeline, and the second bottom conveying pipeline; and a third bottom three-way valve is provided at the intersection of the third salt-free polymer and solvent outlet pipeline, the third saline hot water outlet pipeline, and the third bottom conveying pipeline.

[0096] In a preferred embodiment of the present invention, such as Figure 2 As shown, the outer wall of the filter is provided with a first jacket 4 to heat the material inside the filter to a preset temperature. The first jacket 4 is respectively provided with a first jacket heating medium inlet and a first jacket heating medium outlet. Preferably, the vertical height of the first jacket heating medium inlet is less than the vertical height of the first jacket heating medium outlet. More preferably, each filter is provided with a first jacket 4.

[0097] In a preferred embodiment of the present invention, the upper surface of the lower filter element 32 is covered with a separation medium, which can be any one of ceramic, stainless steel, or alloy. This prevents high-temperature salt-containing polymers from bridging or agglomerating into lumps, and also maintains a certain porosity for the solid material. Preferably, the separation medium is spherical; more preferably, the particle size of the separation medium is larger than the inner diameter of the filter pores of the filter screen or filter cloth to avoid loss of the separation medium. The selection of the separation medium is illustrated below. For example, selecting a separation medium for filter cakes prone to bridging can prevent bridging and clumping. The separation medium is recommended to be spherical particles with a particle size of a few micrometers to a few centimeters, preferably tens of micrometers to a few millimeters.

[0098] In a preferred embodiment of the present invention, such as Figure 2 As shown, the continuous desalination filtration equipment further includes an upper filter element 31, which is disposed inside the filter, and the horizontal edge of the upper filter element 31 is connected to the side wall of the filter; the outlet end face of the high-temperature salt-containing polymer inlet pipe is located below the upper filter element 31. The first filter A is used as an example for illustration. Figure 1 As shown, the upper filter element 31 is disposed within the first filter A, and the horizontal edge of the upper filter element 31 is connected to the side wall of the first filter A; the outlet end face of the first high-temperature salt-containing polymer inlet pipe is located below the upper filter element 31. The space between the upper filter element 31 and the lower filter element 32 is the separation filtration chamber. Preferably, the upper filter element 31 and the lower filter element 32 include a filter screen or filter cloth. The inner diameter of the filter pores of the filter screen or filter cloth is 80-40 mesh, preferably 120-40 mesh.

[0099] In a preferred embodiment of the invention, such as Figure 2 As shown, the continuous desalination filtration equipment further includes a lower support mesh 22, which is disposed inside the filter. The horizontal edge of the lower support mesh 22 is connected to the side wall of the filter. The vertical height of the lower support mesh 22 is lower than the vertical height of the lower filter element 32, and it is used to trap salt in a solid state. Each filter is provided with a lower support mesh 22. Specifically, in this embodiment, the three lower support meshes 22 are respectively connected to the side walls of the first filter A, the second filter B, and the third filter C. Preferably, the aperture of the lower support mesh 22 is not greater than the inner diameter of the filter holes of the lower filter element 32.

[0100] In a preferred embodiment of the invention, such as Figure 2As shown, the continuous desalination filtration equipment further includes an upper support mesh 21, which is disposed inside the filter. The horizontal edge of the upper support mesh 21 is connected to the side wall of the filter. The vertical height of the upper support mesh 21 is higher than that of the upper filter element 31, and it is used to trap and separate the medium. Each filter is provided with an upper support mesh 21. Specifically, in this embodiment, the three upper support meshes 21 are respectively connected to the side walls of the first filter A, the second filter B, and the third filter C. Preferably, the aperture of the upper support mesh 21 is not larger than the inner diameter of the filter holes of the upper filter element 31.

[0101] In a preferred embodiment of the present invention, the continuous desalination filtration device further includes a stirrer 1, the stirrer 1 including a stirring rod and stirring blades connected to the stirring rod; the stirring rod is inserted into the filter from the side wall of the filter, and the stirring blades are disposed inside the filter. Specifically, in this embodiment, the first filter A, the second filter B, and the third filter C are all equipped with a stirrer 1 (e.g., Figure 1 (As shown). Preferably, the stirring blade is positioned along the axis of the filter; more preferably, the acute angle between the stirring rod and the horizontal plane is 0–45°.

[0102] This invention also provides a continuous desalination filtration method, using the aforementioned continuous desalination filtration equipment; preferably, the multiple filters sequentially perform three steps: preliminary filtration, solvent replacement, hot water salt dissolution, and hot nitrogen purging; wherein, three adjacent filters perform different steps. Before describing the continuous desalination filtration, the filtration method is illustrated using the first filter A as an example. Before starting filtration, it is necessary to check all valves of the continuous desalination filtration equipment to ensure that they are all closed before proceeding with the following filtration separation steps. The filtration separation method using the first filter A specifically includes the following steps:

[0103] S1: Preliminary Filtering

[0104] Open valve 1-1. The high-temperature saline polymer (material to be separated) in the main inlet pipeline of the high-temperature saline polymer enters the first hot water and solvent inlet pipeline through the first high-temperature saline polymer inlet pipeline, and finally enters the separation and filtration chamber of the first filter A. After the high-temperature saline polymer feeding is completed, close valve 1-1, and the high-temperature saline polymer in the main inlet pipeline will no longer enter the first filter A. Preferably, the feed amount of the high-temperature saline polymer accounts for 20-70% of the volume of the first filter A, more preferably 40-50%; and / or, the feed rate of the high-temperature saline polymer is 0.5-3 m / s, more preferably 1.5-2 m / s; and / or, the temperature of the high-temperature saline polymer is 170-500℃, more preferably 170-300℃.

[0105] After the high-temperature salt-containing polymer is fed, valve 1-1 is closed, the nitrogen system is started, and the first top gas valve 8-1 and the first top gas delivery pump are opened. The gas in the top gas main inlet pipeline enters the first filter A through the first top gas inlet pipeline, making the pressure of the first filter A 0.1-10 MPa, preferably 0.4-1.0 MPa. Under the action of nitrogen, the liquid polymer and solvent (hereinafter referred to as "first salt-free polymer and solvent") enter the lower part of the first filter A through the lower filter element 32, while the solid salt is trapped on the upper surface of the lower filter element 32 in the form of a sludge cake. It should be noted that the sludge cake still contains a certain amount of polymer and solvent at this time, and for ease of description, it is called the first sludge cake. That is, under the action of nitrogen, the high-temperature salt-containing polymer is separated into two parts: one part is the polymer and solvent located in the lower part of the first filter A, and the other part is the first sludge cake (still containing a certain amount of polymer and solvent) located on the upper surface of the lower filter element 32.

[0106] After the first filter A is pressurized to 0.1–10 MPa, the nitrogen system, the first top gas valve 8-1, and the first top gas delivery pump are shut off, and the gas in the top gas inlet pipeline no longer enters the first filter A. Simultaneously, valve 6-1 is opened, and the gas in the first filter A enters the top gas outlet pipeline via the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, valve 6-1 is closed and valve 2-1 is opened. The first salt-free polymer and solvent located at the bottom of the first filter A enter through the first bottom feed port, the first bottom feed pipeline, the first salt-free polymer and solvent outlet pipeline, and finally into the salt-free polymer and solvent outlet pipeline. After a period of pressure filtration, indicating that all the first salt-free polymer and solvent in the first filter A has been removed, valve 2-1 is closed. The pressure filtration time is 1–45 minutes, preferably 5–15 minutes.

[0107] It should be noted that, under the action of the separation medium, the high-temperature salt-containing polymer in the separation filter chamber of the first filter A will not bridge or accumulate into lumps, and the first filter cake will maintain a certain porosity, thereby achieving a better separation effect.

[0108] S2: Solvent displacement

[0109] After initial filtration, the solvent and polymer in the first sludge cake are replaced with a solvent. It should be noted that the "solvent" used here is preferably the same as the solvent in the high-temperature salt-containing polymer of the material to be separated.

[0110] After the preset pressure filtration time is reached in the above preliminary filtration, valve 2-1 is closed and valve 3-1 is opened. The solvent in the total solvent inlet pipeline enters the first filter A through the first solvent inlet pipeline, the first hot water pipeline, and the solvent inlet pipeline. Preferably, the solvent feed rate is 50-200 wt% of the high-temperature salt-containing polymer feed rate, more preferably 100-150 wt%; and / or, the solvent feed rate is 1-3 m / s, more preferably 1.5-2 m / s; and / or, the solvent feed temperature is 170-500°C, more preferably 170-300°C.

[0111] After the solvent is fed, valve 3-1 is closed, the nitrogen system is started, and the first top gas valve 8-1 and the first top gas delivery pump are opened. The gas in the top gas main inlet pipeline enters the first filter A through the first top gas inlet pipeline, making the pressure of the first filter A 0.1-10 MPa, preferably 0.4-1.0 MPa. Under the action of nitrogen and solvent, the remaining polymer and solvent in the first cake enter the lower part of the first filter A through the lower filter element 32, while the second cake, from which the polymer and solvent have been removed, is trapped on the upper surface of the lower filter element 32. It should be noted that the second cake here contains almost no polymer and solvent. That is, under the action of solvent, the first cake is separated into two parts: one part is the polymer and solvent located in the lower part of the first filter A (hereinafter referred to as "second salt-free polymer and solvent"), and the other part is the second cake (almost no polymer and solvent) located on the upper surface of the lower filter element 32.

[0112] After the first filter A is pressurized to 0.1–10 MPa, the nitrogen system is shut off, along with the first top gas valve 8-1 and the first top gas delivery pump. Gas from the top gas inlet pipeline no longer enters the first filter A. Simultaneously, valve 6-1 is opened, allowing gas from the first filter A to enter the top gas outlet pipeline via the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, valve 6-1 is closed and valve 2-1 is opened. The second salt-free polymer and solvent located at the bottom of the first filter A enter through the first bottom feed port, the first bottom feed pipeline, the first salt-free polymer and solvent outlet pipeline, and finally into the salt-free polymer and solvent outlet pipeline. After a period of pressure filtration, it indicates that all the second salt-free polymer and solvent in the first filter A has been removed. The pressure filtration time is 1–45 minutes, preferably 5–15 minutes.

[0113] It should be noted that, under the action of the separation medium, the polymer and solvent in the first filter cake will not bridge or accumulate into lumps, and the retained second filter cake will maintain a certain porosity, thereby achieving a better separation effect.

[0114] S3: Salt dissolved in hot water

[0115] After the preset filtration time is reached during the solvent replacement process described above, valve 2-1 is closed and valves 4-1, 5-1, and the agitator are opened. The hot water in the main hot water inlet pipeline enters the first hot water and solvent inlet pipelines via the first hot water inlet pipeline, and finally enters the separation and filtration chamber of the first filter A. Preferably, the hot water feed rate is 20-100 wt% of the high-temperature salt-containing polymer feed rate, more preferably 30-50 wt%; and / or, the hot water feed rate is 1-3 m / s, more preferably 1.5-2 m / s; and / or, the hot water feed temperature is 50-150°C, more preferably 80-100°C. Under the action of hot water and agitation, the second sludge cake dissolves in the hot water, forming salt-containing hot water (containing a small amount of solvent). Since valve 5-1 is in the open state, the salt-containing hot water enters the main salt-containing hot water outlet pipeline via the first bottom feed port, the first bottom feed pipeline, and the first salt-containing hot water outlet pipeline.

[0116] When the preset stirring time is reached, it indicates that the second filter cake has been completely converted into saline hot water and exited the first filter A. At this point, the stirrer, valve 4-1, and valve 5-1 are closed. Preferably, the stirring time is 5–30 minutes, more preferably 5–15 minutes. After closing valve 4-1, the hot water in the main hot water inlet pipe no longer enters the first filter A; after closing valve 5-15, the remaining hot water and a small amount of solvent in the first filter A no longer exit the first filter A.

[0117] S4: Hot nitrogen purging

[0118] The nitrogen system is started and valves 7-1 and 6-1 are opened. The hot nitrogen in the main hot nitrogen inlet pipeline flows through the first hot nitrogen inlet pipeline, the first bottom conveying pipeline, and the first bottom conveying port, finally entering the first filter A. Preferably, the temperature of the hot nitrogen is 100–500℃, more preferably 170–300℃; and / or, the feed rate of the hot nitrogen is 15–35 m / s, more preferably 15–25 m / s. It should be noted that a heating device, preferably an electric heater, is provided at the main hot nitrogen inlet pipeline.

[0119] Under the action of hot nitrogen, the residual hot water and solvent in the first filter A are evaporated into gas and move to the upper part of the first filter A, forming a mixed gas of water, solvent and nitrogen. This mixed gas is discharged through the first gas outlet pipeline and the top gas main outlet pipeline. When the purging time reaches the preset purging time, it means that all the residual hot water and solvent in the first filter A has been evaporated into gas. The nitrogen system is then shut off and valves 7-1 and 6-1 are closed, and the gas in the hot nitrogen main inlet pipeline no longer enters the first filter A. At this time, the first filter A can be used for the filtration of the next batch of high-temperature salt-containing polymer. Preferably, the hot nitrogen purging time is 2 to 30 minutes, more preferably 2 to 10 minutes.

[0120] The continuous desalination filtration method will now be described in detail, and the specific steps of the continuous desalination filtration method are as follows:

[0121] (1) Open valve 1-1, and the high-temperature salt-containing polymer (material to be separated) in the high-temperature salt-containing polymer inlet pipeline enters the first filter A. After the high-temperature salt-containing polymer is fed, close valve 1-1. Start the nitrogen system and open the first top gas valve 8-1 and the first top gas delivery pump, and the gas in the top gas inlet pipeline enters the first filter A. When the pressure in the first filter A reaches the preset range, close the nitrogen system and close the first top gas valve 8-1 and the first top gas delivery pump. The high-temperature salt-containing polymer in the first filter is separated into the first salt-free polymer and solvent and the first sludge cake. Open valve 6-1, and the gas in the first filter A enters the top gas outlet pipeline through the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, close valve 6-1 and open valve 2-1, and the first salt-free polymer and solvent are transferred to the salt-free polymer and solvent outlet pipeline. Close valve 2-1, and the preliminary filtration of the first filter A is completed.

[0122] (2) Open valve 1-2, and the high-temperature salt-containing polymer (material to be separated) in the high-temperature salt-containing polymer inlet pipeline enters the second filter B. After the high-temperature salt-containing polymer feeding is completed, close valve 1-2. Start the nitrogen system and open the second top gas valve 8-2 and the second top gas delivery pump, and the gas in the top gas inlet pipeline enters the second filter B. When the pressure in the second filter B reaches the preset range, close the nitrogen system and close the second top gas valve 8-2 and the second top gas delivery pump. The high-temperature salt-containing polymer in the second filter is separated into the first salt-free polymer and solvent and the first sludge cake. Open valve 6-2, and the gas in the second filter B enters the top gas outlet pipeline through the second top gas outlet pipeline. When the pressure in the second filter B returns to normal, close valve 6-2 and open valve 2-2, and the first salt-free polymer and solvent are transferred to the salt-free polymer and solvent outlet pipeline. Close valve 2-2, and the preliminary filtration of the second filter B is completed.

[0123] During the initial filtration process in the second filter B, the first filter A can complete solvent replacement. Open valve 3-1, and the solvent in the main solvent inlet line enters the first filter A. After solvent feeding is complete, close valve 3-1. Start the nitrogen system and open the first top gas valve 8-1 and the first top gas delivery pump, allowing gas from the main top gas inlet line to enter the first filter A. When the pressure inside the first filter A reaches the preset range, close the nitrogen system and shut off the first top gas valve 8-1 and the first top gas delivery pump. The first cake in the first filter A is separated into a second salt-free polymer and solvent, and a second cake. Open valve 6-1, and the gas in the first filter A enters the main top gas outlet line via the first top gas outlet line. When the pressure inside the first filter A returns to normal, close valve 6-1 and open valve 2-1. After all the second salt-free polymer and solvent have exited the first filter A, close valve 2-1, completing the solvent replacement of the first filter A.

[0124] (3) Open valves 1-3, and the high-temperature salt-containing polymer (material to be separated) in the high-temperature salt-containing polymer inlet pipeline enters the third filter C. After the high-temperature salt-containing polymer feeding is completed, close valves 1-3. Start the nitrogen system and open the third top gas valve 8-3 and the third top gas delivery pump, and the gas in the top gas inlet pipeline enters the third filter C. When the pressure in the third filter C reaches the preset range, close the nitrogen system and close the third top gas valve 8-3 and the third top gas delivery pump. The high-temperature salt-containing polymer in the third filter is separated into the first salt-free polymer and solvent and the first sludge cake. Open valve 6-3, and the gas in the third filter C enters the top gas outlet pipeline through the third top gas outlet pipeline. When the pressure in the third filter C returns to normal, close valve 6-3 and open valve 2-3, and the first salt-free polymer and solvent are transferred to the salt-free polymer and solvent outlet pipeline. Close valve 2-3, and the preliminary filtration of the third filter C is completed.

[0125] During the initial filtration process in the third filter C, the first filter A completes hot water salt dissolution and hot nitrogen purging. Open valves 4-1 and 5-1 and the agitator, allowing hot water from the main hot water inlet line to enter the first filter A. The hot water and the second sludge cake form saline hot water, which is then transferred to the saline hot water outlet line. Close valves 4-1 and 5-1 and the agitator, completing the hot water salt dissolution in the first filter A. Start the nitrogen system and open valves 7-1 and 6-1, allowing gas from the main hot nitrogen inlet line to enter the first filter A. The evaporated hot water and solvent, along with the nitrogen, are transferred to the main nitrogen outlet line. Close the nitrogen system and close valves 7-1 and 6-1, completing the hot nitrogen purging of the first filter A.

[0126] During the initial filtration process in the third filter C, the second filter B can complete solvent replacement. Open valve 3-2, and the solvent in the main solvent inlet line enters the second filter B. After solvent feeding is complete, close valve 3-2. Start the nitrogen system and open the second top gas valve 8-2 and the second top gas delivery pump, allowing gas from the main top gas inlet line to enter the second filter B. When the pressure inside the second filter B reaches the preset range, close the nitrogen system and shut off the second top gas valve 8-2 and the second top gas delivery pump. The first cake in the second filter B is separated into a second salt-free polymer and solvent, and a second cake. Open valve 6-2, and the gas in the second filter B enters the main top gas outlet line via the second top gas outlet line. When the pressure inside the second filter B returns to normal, close valve 6-2 and open valve 2-2. After all the second salt-free polymer and solvent have exited the second filter B, close valve 2-2, completing the solvent replacement of the second filter B.

[0127] (4) Open valve 1-1, and the high-temperature salt-containing polymer (material to be separated) in the high-temperature salt-containing polymer inlet pipeline enters the first filter A. After the high-temperature salt-containing polymer is fed, close valve 1-1. Start the nitrogen system and open the first top gas valve 8-1 and the first top gas delivery pump, and the gas in the top gas inlet pipeline enters the first filter A. When the pressure in the first filter A reaches the preset range, close the nitrogen system and close the first top gas valve 8-1 and the first top gas delivery pump. The high-temperature salt-containing polymer in the first filter is separated into the first salt-free polymer and solvent and the first sludge cake. Open valve 6-1, and the gas in the first filter A enters the top gas outlet pipeline through the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, close valve 6-1 and open valve 2-1, and the first salt-free polymer and solvent are transferred to the salt-free polymer and solvent outlet pipeline. Close valve 2-1, and the preliminary filtration of the first filter A is completed.

[0128] During the initial filtration process in the first filter A, the second filter B completes hot water salt dissolution and hot nitrogen purging. Open valves 4-2 and 5-2 and the agitator, allowing hot water from the main hot water inlet line to enter the second filter B. The hot water and the second sludge cake form saline hot water, which is then transferred to the saline hot water outlet line. Close valves 4-2 and 5-2 and the agitator; hot water salt dissolution in the second filter B is complete. Start the nitrogen system and open valves 7-2 and 6-2, allowing gas from the main hot nitrogen inlet line to enter the second filter B. The evaporated hot water and solvent, along with the nitrogen, are transferred to the main nitrogen outlet line. Close the nitrogen system and close valves 7-2 and 6-2; hot nitrogen purging of the second filter B is complete.

[0129] During the initial filtration process in the first filter A, the third filter C completes solvent replacement. Open valve 3-3, allowing solvent from the main solvent inlet line to enter the third filter C. After solvent feeding is complete, close valve 3-3. Start the nitrogen system and open the third top gas valve 8-3 and the third top gas delivery pump, allowing gas from the main top gas inlet line to enter the third filter C. When the pressure inside the third filter C reaches the preset range, close the nitrogen system and shut off the third top gas valve 8-3 and the third top gas delivery pump. The first cake in the third filter C is separated into a second salt-free polymer, solvent, and the second cake. Open valve 6-3, allowing gas from the third filter C to enter the main top gas outlet line via the third top gas outlet line. When the pressure inside the third filter C returns to normal, close valve 6-3 and open valve 2-3. After all the second salt-free polymer has exited the third filter C, close valve 2-3, completing the solvent replacement in the third filter C.

[0130] (5) Open valve 3-1, and the solvent in the solvent inlet pipeline enters the first filter A. After the solvent feeding is completed, close valve 3-1. Start the nitrogen system and open the first top gas valve 8-1 and the first top gas delivery pump, and the gas in the top gas inlet pipeline enters the first filter A. When the pressure in the first filter A reaches the preset range, close the nitrogen system and close the first top gas valve 8-1 and the first top gas delivery pump. The first sludge cake in the first filter A is separated into the second salt-free polymer and solvent and the second sludge cake. Open valve 6-1, and the gas in the first filter A enters the top gas outlet pipeline through the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, close valve 6-1 and open valve 2-1. After all the second salt-free polymer and solvent have been transferred out of the first filter A, close valve 2-1, and the solvent replacement of the first filter A is completed.

[0131] During solvent replacement in the first filter A, the second filter B performs preliminary filtration. Valve 1-2 is opened, allowing the high-temperature saline polymer (material to be separated) from the high-temperature saline polymer inlet pipeline to enter the second filter B. After the high-temperature saline polymer feeding is complete, valve 1-2 is closed. The nitrogen system is started, and the second top gas valve 8-2 and the second top gas delivery pump are opened, allowing gas from the top gas inlet pipeline to enter the second filter B. When the pressure in the second filter B reaches the preset range, the nitrogen system is closed, and the second top gas valve 8-2 and the second top gas delivery pump are shut off. The high-temperature saline polymer in the second filter is separated into a first salt-free polymer, solvent, and a first sludge cake. Valve 6-2 is opened, allowing gas from the second filter B to enter the top gas outlet pipeline via the second top gas outlet pipeline. When the pressure in the second filter B returns to normal, valve 6-2 is closed, and valve 2-2 is opened, transferring the first salt-free polymer and solvent to the salt-free polymer and solvent outlet pipeline. Valve 2-2 is then closed, completing the preliminary filtration of the second filter B.

[0132] During solvent replacement in the first filter A, the third filter C completes hot water salt dissolution and hot nitrogen purging. Open valves 4-3 and 5-3 and the agitator; hot water from the main hot water inlet line enters the third filter C. The hot water and the second sludge cake form saline hot water, which is then transferred to the saline hot water outlet line. Close valves 4-3 and 5-3 and the agitator; hot water salt dissolution in the third filter C is complete. Start the nitrogen system and open valves 7-3 and 6-3; gas from the main hot nitrogen inlet line enters the third filter C. The evaporated hot water and solvent, along with the nitrogen, are transferred to the main nitrogen outlet line. Close the nitrogen system and close valves 7-3 and 6-3; hot nitrogen purging of the third filter C is complete.

[0133] (6) By continuing to repeat the above steps, each of the first filter A, the second filter B, and the third filter C will perform different steps to achieve continuous desalination filtration of high-temperature salt-containing polymers.

[0134] Example 1

[0135] 1. The first filter A performs preliminary filtration.

[0136] Open valve 1-1, and the high-temperature salt-containing polymer (in this embodiment, the "high-temperature salt-containing polymer" is high-temperature salt-containing polyphenylene sulfide, which has a temperature of 240 degrees Celsius and contains 18 wt% sodium chloride, 60 wt% methylpyrrolidone, and 14 wt% polyphenylene sulfide) in the high-temperature salt-containing polymer inlet pipeline enters the first filter A. The feed rate of the high-temperature salt-containing polymer is 0.5 m / s. After the high-temperature saline polymer is fed (the feed volume of the high-temperature saline polymer accounts for 40% of the filter volume), close valve 1-1. Start the nitrogen system and open the first top gas valve 8-1 and the first top gas delivery pump. The gas in the top gas main inlet pipeline enters the first filter A. When the pressure in the first filter A reaches 0.4 MPa, close the nitrogen system and close the first top gas valve 8-1 and the first top gas delivery pump. The high-temperature saline polymer in the first filter is filtered into the first salt-free polymer, solvent, and first sludge cake. The filtration time is 5 minutes. Open valve 6-1, and the gas in the first filter A enters the top gas main outlet pipeline through the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, close valve 6-1 and open valve 2-1. The first salt-free polymer and solvent are transferred to the salt-free polymer and solvent main outlet pipeline. Close valve 2-1. The preliminary filtration of the first filter A is completed.

[0137] 2. The second filter B performs preliminary filtration, and the first filter A performs solvent replacement.

[0138] 2.1 The second filter B performs preliminary filtration.

[0139] Open valves 1-2. The high-temperature salt-containing polymer (in this embodiment, the "high-temperature salt-containing polymer" is high-temperature salt-containing polyphenylene sulfide, with a temperature of 240 degrees Celsius and containing 18 wt% sodium chloride, 60 wt% methylpyrrolidone, and 14 wt% polyphenylene sulfide) from the high-temperature salt-containing polymer inlet pipeline enters the second filter B at a feed rate of 0.5 m / s. After the high-temperature salt-containing polymer feed is complete (the feed amount of the high-temperature salt-containing polymer accounts for 40% of the filter volume), close valves 1-2. Start the nitrogen system and open the second top gas valve 8-2 and the second top gas delivery pump. Gas from the top gas inlet pipeline enters the second filter B. When the pressure in the second filter B reaches 0.4 MPa, close the nitrogen system and close the second top gas valve 8-2 and the second top gas delivery pump. The high-temperature salt-containing polymer in the second filter is separated into a first salt-free polymer, solvent, and a first sludge cake. The filtration time is 5 minutes. Open valve 6-2, and the gas in the second filter B enters the main top gas outlet pipeline through the second top gas outlet pipeline. When the pressure in the second filter B returns to normal, close valve 6-2 and open valve 2-2, and the first salt-free polymer and solvent are transferred to the salt-free polymer and solvent main outlet pipeline. Close valve 2-2, and the preliminary filtration of the second filter B is completed.

[0140] 2.2 Solvent replacement is performed in the first filter A.

[0141] Open valve 3-1, allowing the solvent in the solvent inlet pipeline to enter the first filter A. In this embodiment, the solvent is methylpyrrolidone (99wt%), the solvent feed rate is 1.5 m / s, and the solvent feed temperature is 240°C. After the solvent feed is complete (the solvent feed rate is 100wt% of the high-temperature salt-containing polymer feed rate), close valve 3-1. Start the nitrogen system and open the first top gas valve 8-1 and the first top gas delivery pump, allowing the gas in the top gas inlet pipeline to enter the first filter A. When the pressure in the first filter A reaches 0.4 MPa, close the nitrogen system and close the first top gas valve 8-1 and the first top gas delivery pump. The first sludge cake in the first filter A is pressurized into a second salt-free polymer and solvent, and a second sludge cake, with a pressurization time of 5 minutes. Open valve 6-1, allowing the gas in the first filter A to enter the top gas outlet pipeline via the first top gas outlet pipeline. When the pressure in the first filter A returns to normal, close valve 6-1 and open valve 2-1. After all the second salt-free polymer and solvent have been transferred out of the first filter A, close valve 2-1. The solvent replacement of the first filter A is now complete. Solvent replacement needs to be performed three times to replace the polymer and solvent mixture in the first sludge cake with solvent.

[0142] 3. The third filter C performs preliminary filtration, the second filter B performs solvent replacement, and the first filter A performs hot water salt dissolution and hot nitrogen purging.

[0143] 3.1 The third filter C performs preliminary filtration.

[0144] Open valves 1-3. The high-temperature salt-containing polymer (in this embodiment, the "high-temperature salt-containing polymer" is high-temperature salt-containing polyphenylene sulfide, with a temperature of 240 degrees Celsius and containing 18 wt% sodium chloride, 60 wt% methylpyrrolidone, and 14 wt% polyphenylene sulfide) from the high-temperature salt-containing polymer inlet pipeline enters the third filter C at a feed rate of 0.5 m / s. After the high-temperature salt-containing polymer feed is complete (the feed amount of the high-temperature salt-containing polymer accounts for 40% of the filter volume), close valves 1-3. Start the nitrogen system and open the third top gas valve 8-3 and the third top gas delivery pump. The gas in the top gas inlet pipeline enters the third filter C. When the pressure in the third filter C reaches 0.4 MPa, close the nitrogen system and close the third top gas valve 8-3 and the third top gas delivery pump. The high-temperature salt-containing polymer in the third filter is separated into a first salt-free polymer, solvent, and a first sludge cake. The filtration time is 5 minutes. Open valve 6-3, and the gas in the third filter C enters the top gas outlet pipeline through the third top gas outlet pipeline. When the pressure in the third filter C returns to normal, close valve 6-3 and open valve 2-3. The first salt-free polymer and solvent are transferred to the salt-free polymer and solvent outlet pipeline. Close valve 2-3, and the preliminary filtration of the third filter C is completed.

[0145] 3.2 Solvent replacement is performed using the second filter B.

[0146] Open valve 3-2, allowing the solvent in the total solvent inlet pipeline to enter the second filter B. In this embodiment, the solvent is methylpyrrolidone (99wt%), the solvent feed rate is 1.5 m / s, and the solvent feed temperature is 240°C. After the solvent feed is complete (the solvent feed rate is 100wt% of the high-temperature salt-containing polymer feed rate), close valve 3-2. Start the nitrogen system and open the second top gas valve 8-2 and the second top gas delivery pump, allowing the gas in the total top gas inlet pipeline to enter the second filter B. When the pressure in the second filter B reaches 0.4 MPa, close the nitrogen system and close the second top gas valve 8-2 and the second top gas delivery pump. The first sludge cake in the second filter B is separated into the second salt-free polymer and solvent, and the second sludge cake, with a filtration time of 5 minutes. Open valve 6-2, allowing the gas in the second filter B to enter the total top gas outlet pipeline via the second top gas outlet pipeline. When the pressure in the second filter B returns to normal, close valve 6-2 and open valve 2-2. After all the second salt-free polymer and solvent have been transferred out of the second filter B, close valve 2-2. The solvent replacement of the second filter B is now complete. Solvent replacement needs to be performed three times to replace the polymer and solvent mixture in the first sludge cake with solvent.

[0147] 3.3 The first filter A is subjected to hot water salt dissolution and hot nitrogen purging.

[0148] Open valves 4-1 and 5-1 and the agitator. Hot water from the main hot water inlet pipeline enters the first filter A. In this embodiment, the hot water temperature is 80 degrees Celsius, the hot water feed rate is 50 wt% of the high-temperature salt-containing polymer feed rate, and the hot water feed rate is 1.5 m / s. The stirring time is 5 minutes. The hot water and the second mud cake form saline hot water and are transferred to the saline hot water outlet pipeline. Close valves 4-1 and 5-1 and the agitator. The hot water salt dissolution in the first filter A is complete. Start the nitrogen system and open valves 7-1 and 6-1. Gas from the main hot nitrogen inlet pipeline enters the first filter A. In this embodiment, the hot nitrogen temperature is 200 degrees Celsius, and the hot nitrogen feed rate is 20 m / s. The hot nitrogen purging time is 5 minutes. The evaporated hot water and solvent, along with the nitrogen gas, are transferred to the main nitrogen outlet pipeline. Close the nitrogen system and close valves 7-1 and 6-1. The hot nitrogen purging of the first filter A is complete.

[0149] 4. The first filter A performs preliminary filtration, the second filter B performs hot water salt dissolution and hot nitrogen purging, and the third filter C performs solvent replacement.

[0150] It should be noted that the steps of "hot water salt dissolution and hot nitrogen purging of the second filter B" and "solvent replacement of the third filter C" are basically the same as described above, the only difference being the control of different valves. Since the continuous desalination filtration method has been described in detail above, it will not be repeated here. By continuing to cycle the above steps, each of the first filter A, the second filter B, and the third filter C can perform different steps to achieve continuous desalination filtration of high-temperature salt-containing polymers.

[0151] Comparative Example 1

[0152] This comparative example is basically the same as Example 1, except that: the original saline hot water outlet pipeline is used as the new hot water inlet pipeline, and a hot water feed pump is added to the new hot water inlet pipeline; the original hot water inlet pipeline is used as the new saline hot water outlet pipeline. Therefore, the original first saline hot water outlet pipeline is used as the new first hot water inlet pipeline, the original second saline hot water outlet pipeline is used as the new second hot water inlet pipeline, the original third saline hot water outlet pipeline is used as the new third hot water inlet pipeline, the original first hot water inlet pipeline is used as the new first saline hot water outlet pipeline, the original second hot water inlet pipeline is used as the new second saline hot water outlet pipeline, and the original third hot water inlet pipeline is used as the new third saline hot water outlet pipeline.

[0153] Comparing Example 1 and Comparative Example 1, it can be seen that in Example 1, the vertical height of the hot water inlet pipeline is greater than that of the filter, so the hot water feed does not require pumping and can enter the filter under gravity. In Comparative Example 1, the vertical height of the new hot water inlet pipeline is less than that of the filter, so a hot water feed pump is required. Similarly, in Example 1, the vertical height of the saline hot water outlet pipeline is less than that of the filter, so the saline hot water in the filter can enter the saline hot water outlet pipeline without pumping and can enter under gravity. In Comparative Example 1, the vertical height of the new saline hot water outlet pipeline is greater than that of the filter, so the saline hot water in the filter needs to be pushed out by nitrogen gas to enter the new saline hot water outlet pipeline. Because the hot water in Comparative Example 1 enters from the bottom and exits from the top, it needs to overcome a greater static pressure head to discharge the saline hot water containing dissolved salt from the top of the filter. In addition, it will cause a large amount of hot water to remain in the filter, which will eventually need to be drained from the bottom of the filter.

[0154] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0155] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0156] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A continuous desalination filtration device, characterized in that, The system includes multiple filters connected in parallel; each filter is equipped with a high-temperature saline polymer inlet, a hot water and solvent inlet, a bottom outlet, a gas inlet, and a gas outlet; the high-temperature saline polymer inlets are all connected to the main high-temperature saline polymer inlet pipeline; the hot water and solvent inlets are all connected to the main hot water inlet pipeline and the main solvent inlet pipeline; the bottom outlets are all connected to the main non-salt polymer and solvent outlet pipeline and the main saline hot water outlet pipeline; the gas inlets are all connected sequentially to the main gas inlet pipeline and the nitrogen system; and the gas outlets are all connected to the main gas outlet pipeline.

2. The continuous desalination filtration equipment according to claim 1, characterized in that, A high-temperature saline polymer inlet pipe is provided at the feed inlet of the high-temperature saline polymer. The high-temperature saline polymer inlet pipe is inserted into the side wall of the filter. The inlet end of the high-temperature saline polymer inlet pipe is connected to the main high-temperature saline polymer inlet pipeline, and the outlet end of the high-temperature saline polymer inlet pipe is located inside the filter; and / or The hot water and solvent inlets are located on the top surface of the filter; and / or The gas inlet is located on the top surface of the filter; and / or The gas outlet is located on the top surface of the filter; and / or The bottom outlet is located on the bottom surface of the filter; Preferably, each filter is provided with a lower filter element, and the horizontal edge of the lower filter element is connected to the side wall of the filter.

3. The continuous desalination filtration equipment according to claim 1, characterized in that, The hot water and solvent inlet is connected to the hot water and solvent inlet pipeline, which is connected to the main hot water inlet pipeline via the hot water inlet pipeline, and the hot water and solvent inlet pipeline is connected to the main solvent inlet pipeline via the solvent inlet pipeline; and / or The bottom outlet is connected to the bottom conveying pipeline, the bottom conveying pipeline is connected to the salt-free polymer and solvent main outlet pipeline through the salt-free polymer and solvent outlet pipeline, and the bottom conveying pipeline is connected to the salt-containing hot water main outlet pipeline through the salt-containing hot water outlet pipeline. Preferred, Both the hot water inlet pipeline and the solvent inlet pipeline are equipped with shut-off valves; or, a switching valve is provided at the intersection of the hot water inlet pipeline, the solvent inlet pipeline, and the hot water and solvent inlet pipelines; and / or Both the salt-free polymer and solvent outlet pipeline and the salt-containing hot water outlet pipeline are equipped with shut-off valves; or, a switching valve is provided at the intersection of the salt-free polymer and solvent outlet pipeline, the salt-containing hot water outlet pipeline, and the bottom conveying pipeline.

4. The continuous desalination filtration equipment according to claim 2, characterized in that, The high-temperature salt-containing polymer inlet pipe is a straight pipe that is inserted into the filter from the side wall of the filter. The high-temperature salt-containing polymer inlet pipe is divided into an outer inlet pipe and an inner inlet pipe by the side wall of the filter body. The vertical height of the outer inlet pipe is greater than that of the inner inlet pipe. Preferably, the angle between the high-temperature salt-containing polymer inlet pipe and the filter axis is no greater than 45°; More preferably, the angle between the high-temperature salt-containing polymer inlet pipe and the filter axis is no greater than 30°.

5. The continuous desalination filtration equipment according to claim 2, characterized in that, The angle between the outlet end face of the high-temperature salt-containing polymer inlet pipe and the horizontal plane is 40-50°, preferably 45°; and / or The filter includes a main body, an upper end cap connected to the top surface of the main body, and a lower end cap connected to the bottom surface of the main body; the distance between the outlet end face of the high-temperature salt-containing polymer inlet pipe and the upper end cap is 250–1000 mm, preferably 300–500 mm; and / or The upper surface of the lower filter element is provided with a separation medium; Preferably, the separation medium is spherical; More preferably, the particle size of the separation medium is larger than the inner diameter of the filter pores of the lower filter element.

6. The continuous desalination filtration equipment according to claim 4, characterized in that, The filter has a first jacket on its outer wall, and the first jacket has a first jacket heat tracing medium inlet and a first jacket heat tracing medium outlet; and / or The outer wall of the outer inlet pipe is provided with a second jacket, and the second jacket is provided with a second jacket heat tracing medium inlet and a second jacket heat tracing medium outlet. Preferred, The vertical height of the first jacket heating medium inlet is less than the vertical height of the first jacket heating medium outlet; and / or The vertical height of the inlet of the second jacket heat tracing medium is less than the vertical height of the outlet of the second jacket heat tracing medium.

7. The continuous desalination filtration equipment according to claim 2, characterized in that, The continuous desalination filtration equipment is also equipped with an upper filter element, the horizontal edge of which is connected to the side wall of the filter; the outlet end face of the high-temperature salt-containing polymer inlet pipe is located below the upper filter element. Preferably, both the upper filter element and the lower filter element include a filter screen or a filter cloth; More preferably, the filter screen or filter cloth has an inner diameter of 120-40 mesh, preferably 80-40 mesh.

8. The continuous desalination filtration equipment according to claim 7, characterized in that, The continuous desalination filtration equipment also includes a lower support mesh, the horizontal edge of which is connected to the side wall of the filter; the vertical height of the lower support mesh is lower than the vertical height of the lower filter element; and / or The continuous desalination filtration equipment is also equipped with an upper support wire mesh, the horizontal edge of which is connected to the side wall of the filter; the vertical height of the upper support wire mesh is higher than the vertical height of the upper filter element. Preferred, The aperture of the upper support mesh is not less than the inner diameter of the filter pores of the upper filter element; and / or The aperture of the lower support wire mesh is not less than the inner diameter of the filter holes of the lower filter element.

9. The continuous desalination filtration equipment according to claim 1, characterized in that, The continuous desalination filtration equipment further includes a stirrer, which includes a stirring rod and stirring blades connected to the stirring rod; the stirring rod is inserted into the filter from the side wall of the filter, and the stirring blades are disposed inside the filter; Preferably, the stirring blades are positioned at the axial position of the filter; More preferably, the acute angle between the stirring rod and the horizontal plane is 0 to 45°; Most preferably, the continuous desalination filtration equipment further includes a hot nitrogen inlet pipeline, one end of which is connected in sequence to the hot nitrogen main inlet pipeline and the nitrogen system, and the other end is connected to the bottom outlet through the bottom conveying pipeline; The hot nitrogen inlet pipeline is equipped with a heating device.

10. A continuous desalination filtration method, characterized in that, The continuous desalination filtration equipment according to any one of claims 1 to 9 is used; Preferred, Each of the filters sequentially performs three steps: preliminary filtration, solvent replacement, hot water salt dissolution, and hot nitrogen purging; wherein, three adjacent filters perform different steps in the sequence. More preferably, The preliminary filtration process includes the following steps: The high-temperature salt-containing polymer in the main inlet pipeline enters the filter; after the high-temperature salt-containing polymer is fed, the nitrogen system is turned on, and the gas in the main gas inlet pipeline enters the filter, where the high-temperature salt-containing polymer is pressurized into a first salt-free polymer and solvent, and a first sludge cake; when the filter is pressurized to 0.1–10 MPa, the nitrogen system is turned off, and the gas in the filter is discharged through the top main gas outlet pipeline; when the pressure in the filter returns to normal, the first salt-free polymer and solvent enter the salt-free polymer and solvent main outlet pipeline; and / or Solvent replacement specifically includes the following steps: Solvent in the main solvent inlet pipeline enters the filter; after solvent feeding is complete, the nitrogen system is turned on, and gas in the main gas inlet pipeline enters the filter, where the first sludge cake is pressurized into a second salt-free polymer and solvent, and a second sludge cake; when the filter is pressurized to 0.1–10 MPa, the nitrogen system is turned off, and the gas in the filter is discharged through the top main gas outlet pipeline; when the pressure in the filter returns to normal, the second salt-free polymer and solvent enter the salt-free polymer and solvent main outlet pipeline; and / or The hot water salt dissolution and hot nitrogen purging process includes the following steps: hot water in the main hot water inlet pipeline enters the filter from the top of the filter and is stirred. The second mud cake and hot water form saline hot water, which enters the saline hot water outlet pipeline from the bottom of the filter. After the preset stirring time is reached, the nitrogen system is turned on, and hot nitrogen in the main hot nitrogen inlet pipeline enters the filter. After the preset hot nitrogen purging time is reached, the nitrogen system is turned off. The best option, In the preliminary filtration, the feed rate of the high-temperature saline polymer accounts for 20-70% of the filter volume, preferably 40-50%; and / or, the feed rate of the high-temperature saline polymer is 0.5-3 m / s, preferably 1.5-2 m / s; and / or, the temperature of the high-temperature saline polymer is 170-500℃, preferably 170-300℃; and / or, the pressure inside the filter is 0.1-10 MPa, preferably 0.4-1.0 MPa; and / or, the pressure filtration time is 1-45 min, preferably 5-15 min; and / or In solvent replacement, the solvent feed rate is 50–200 wt% of the high-temperature salt-containing polymer feed rate, preferably 100–150 wt%; and / or, the solvent feed rate is 1–3 m / s, preferably 1.5–2 m / s; and / or, the solvent feed temperature is 170–500 °C, preferably 170–300 °C; and / or, the pressure filtration time is 1–45 min, preferably 5–15 min; and / or, the number of solvent replacements is 1–10 times, preferably 2–4 times; and / or In the hot water salt dissolution and hot nitrogen purging process, the hot water feed rate is 20–100 wt% of the high-temperature salt-containing polymer feed rate, preferably 30–50 wt%; and / or, the hot water feed rate is 1–3 m / s, preferably 1.5–2 m / s; and / or, the hot water feed temperature is 50–150 °C, preferably 80–100 °C; and / or, the stirring time is 5–30 min, preferably 5–15 min; and / or, the hot nitrogen temperature is 100–500 °C, preferably 170–300 °C; and / or, the hot nitrogen feed rate is 15–35 m / s, preferably 15–25 m / s; and / or, the hot nitrogen purging time is 2–30 min, preferably 2–10 min.

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