Apparatus for removing chlorine ions and formaldehyde from aminotrimethylene phosphonic acid

Abstract

This invention relates to an apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid, comprising a reaction vessel, an absorption tank, and a vacuum pump. The reaction vessel has a first inlet, a stirrer, and a return inlet at the top, and a first outlet at the bottom. The absorption tank has a second air inlet and a third air outlet at the top. An evaporator and a condenser are located between the reaction vessel and the absorption tank. The evaporator has a second inlet, a first air outlet, and a spray mechanism at the top, and a second outlet at the bottom. A steam inlet and a liquid inlet are located on either side of the second outlet. The condenser has a liquid outlet and a second air outlet at the bottom, a first air inlet at the top, and condensate inlets and outlets on opposite sides at the bottom and top. Using this invention not only reduces steam consumption, improves production efficiency, and lowers production costs, but also reduces wastewater treatment volume and electricity consumption, lowering treatment costs and carbon emissions. It is suitable for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid.

Description

Technical Field

[0001] This utility model relates to a device for removing chloride ions and formaldehyde from water treatment agents. Specifically, it is a device for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid. Background Technology

[0002] In the chemical production field, it is well known that the water treatment agent aminotrimethylene phosphoric acid (ATMP) is produced by reacting ammonium chloride, phosphorous acid, and formaldehyde in a reactor. The resulting aminotrimethylene phosphoric acid (ATMP) contains 5-6% chloride and 3-5% formaldehyde. However, the quality requirement for the finished product is a chloride content of less than 1%. Many export orders even require a chloride content of less than or equal to 0.5%. Therefore, the 5-6% chloride content in the resulting aminotrimethylene phosphoric acid (ATMP) is far higher than the required less than 1% chloride content in the finished product. This necessitates further reducing the chloride content to meet the requirement of less than 1%.

[0003] Currently, the method for reducing the chloride content in aminotrimethylene phosphoric acid (ATMP) involves directly introducing steam into the reactor after the reaction to heat the ATMP to 100-140 degrees Celsius. By heating and supplementing with vacuuming, chloride ions and formaldehyde in the ATMP are directly discharged from the reactor along with the gas. While this method can remove chloride ions and formaldehyde from ATMP to achieve the required chloride ion content of less than 1%, achieving this requires, for example, 8-10 hours of steam injection into a 5000-liter reactor, resulting in high steam consumption, low production efficiency, and high production costs. Furthermore, because the heating process directly discharges moisture, chloride ions, and formaldehyde from the ATMP along with the gas, the moisture in the gas is not condensed and collected for reuse, resulting in a significant amount of wastewater. This not only increases wastewater treatment volume and electricity consumption but also raises production costs and carbon emissions. Utility Model Content

[0004] The problem this invention aims to solve is to provide a device for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid. Using this device not only reduces steam consumption, increases production efficiency, and lowers production costs, but also reduces wastewater treatment volume and electricity consumption, thereby lowering treatment costs and carbon emissions.

[0005] The above-mentioned problems to be solved by this utility model are achieved by the following technical solutions:

[0006] This invention relates to an apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid, comprising a reaction vessel, an absorption tank, and a vacuum pump. The reaction vessel has a first inlet, a stirrer, and a return inlet at the top, and a first outlet at the bottom. The absorption tank has a second air inlet and a third air outlet at the top. The third air outlet is connected to the inlet of the vacuum pump via a pipe. The apparatus is characterized by an evaporator and a condenser located between the reaction vessel and the absorption tank. The evaporator has a second inlet, a first air outlet, and a spray mechanism at the top, and a second outlet at the bottom. Steam inlets and liquid inlets are located on the side walls of the second outlet. The condenser has a liquid outlet and a second air outlet at the bottom, a first air inlet at the top, and condensate inlets and outlets on opposite sides of its lower and upper parts, respectively. The first outlet is connected to the second inlet via a first conveying pump and a pipe; the first air outlet is connected to the first air inlet via a pipe; and the second air outlet is connected to the second air inlet via a pipe. The liquid outlet is connected to the liquid inlet via a pipe, the second discharge outlet is connected to the return outlet via a pipe, and the steam inlet is connected to the steam source.

[0007] The evaporator is a falling film evaporator, which includes a cylindrical outer shell. This cylindrical outer shell is a jacketed shell, and inside it are columnar graphite blocks with vertical through holes evenly distributed on them. The steam inlet is connected to the inner cavity of the jacketed shell.

[0008] A further improvement of this invention is that the outlet of the vacuum pump is connected to the second air inlet of the absorption tank via a second delivery pump and a pipeline.

[0009] A further improvement of this utility model is that the bottom side of the absorption tank has a drain outlet.

[0010] A further improvement of this utility model is that the top of the evaporator has a temperature measuring port, and a thermometer is installed inside the temperature measuring port.

[0011] A further improvement of this utility model is that a sampling port and a valve are provided on the pipe between the second discharge port and the return port.

[0012] The vacuum pump is any one of a water jet vacuum pump, a valve plate vacuum pump, a screw vacuum pump, and a water circulation vacuum pump.

[0013] A further improvement of this utility model is that the vacuum pump is a corrosion-resistant vacuum pump.

[0014] An evaporator and a condenser are located between the reactor and the absorption tank. The evaporator has a second feed inlet, a first gas outlet, and a spray mechanism at the top, and a second discharge outlet at the bottom. Steam inlets and liquid inlets are located on the side walls of the second discharge outlet. The condenser has a liquid outlet and a second gas outlet at the bottom, a first gas inlet at the top, and condensate inlets and outlets on opposite sides of its lower and upper parts. The first discharge outlet is connected to the second feed inlet via a first delivery pump and a pipeline; the first gas outlet is connected to the first gas inlet via a pipeline; and the second gas outlet is connected to the second gas inlet via a pipeline. The liquid outlet is connected to the liquid inlet via a pipeline; the second discharge outlet is connected to the return port via a pipeline; and the steam inlet is connected to a steam source. During operation, while steam is supplied to the lower part of the evaporator and deionized water is sprayed into the evaporator by the spray mechanism, aminotrimethylene phosphoric acid (ATMP), which has undergone reaction in the reactor, is fed into the upper part of the evaporator via the first delivery pump, pipeline, and second feed inlet. Aminotrimethylene phosphoric acid (ATMP) entering the evaporator evaporates, and the moisture, chloride ions, and formaldehyde contained within are sent along with the steam from the top of the evaporator through pipes and the first inlet into the condenser. The evaporated ATMP then flows back into the reactor through the second outlet and pipes. The gas entering the condenser is condensed into liquid and sent to the bottom of the evaporator through the liquid outlet, pipes, and inlet, where it flows back into the reactor along with the evaporated ATMP. Meanwhile, the chloride ions and formaldehyde entering the condenser are absorbed into the absorption tank by a vacuum pump. This process removes a large amount of chloride ions and formaldehyde from the ATMP.

[0015] Because this invention features a steam inlet on the lower side wall of the evaporator, steam is directly supplied to the evaporator for heating during operation. Through multiple experiments, taking a 5000-liter reactor as an example, it only takes about 4 hours to reduce the chloride ion content in aminotrimethylene phosphoric acid (ATMP) to below 1%. Compared to the prior art, which requires 8-10 hours of steam heating to reduce the chloride ion content in ATMP to below 1%, this not only reduces steam consumption, improves production efficiency, and lowers production costs, but also reduces wastewater treatment volume and electricity consumption, thus lowering treatment costs and carbon emissions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the device for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to this invention. Detailed Implementation

[0017] like Figure 1 As shown, the device for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to this invention includes a reaction vessel 1, an evaporator 2, a condenser 3, an absorption tank 4, and a vacuum pump 5.

[0018] The reactor 1 is provided with a first feed inlet 11, a stirrer 12, and a return outlet 13 at the top, and a first discharge outlet 15 at the bottom.

[0019] The evaporator 2 is a falling film evaporator, which includes a cylindrical outer shell. This cylindrical outer shell is a jacketed shell, and columnar graphite blocks 28 are installed inside it. The columnar graphite blocks 28 are evenly distributed with vertical through holes. The number of columnar graphite blocks 28 can be determined as needed, and can be one, two, or more. In this embodiment, there are three columnar graphite blocks 28, which are stacked vertically along the inner cavity of the cylindrical outer shell. They have the same number of vertical through holes and correspond one-to-one. The top of the evaporator 2 is provided with a second feed port 21, a first air outlet 23, and a spray mechanism 22, and the bottom is provided with a second discharge port 26. Steam inlets 27 and liquid inlets 25 are respectively machined on the side walls on both sides of the second discharge port 26. The steam inlets 27 and liquid inlets 25 are located on opposite sides of the bottom of the cylindrical outer shell. Among them, the upper part of the cylindrical shell opposite the steam inlet 27 is machined with a steam outlet 271, which is connected to a water supply valve through a pipe.

[0020] The condenser 3 has a jacketed outer shell with a liquid outlet 34 and a second air outlet 32 ​​machined at its bottom and a first air inlet 31 machined at its top. The liquid outlet 34, the second air outlet 32, and the first air inlet 31 are all connected to the inner cavity of the condenser 3. The condensate inlet 33 and condensate outlet 35 on the lower and upper side walls of the condenser 3 are also connected to the inner cavity of its jacketed outer shell. A refrigeration unit for cooling the refrigerant is connected between the condensate inlet 33 and the condensate outlet 35.

[0021] The absorption tank 4 has a second air inlet 41 and a third air outlet 42 machined on its top, and a water outlet 43 machined on one side of its bottom. The third air outlet 42 is connected to the inlet 51 of the vacuum pump 5 through a pipe.

[0022] The first discharge port 15 of the reactor 1 is connected to the second inlet 21 of the evaporator 2 via a first transfer pump 16 and a pipeline. The first outlet 23 of the evaporator 2 is connected to the first inlet 31 at the top of the condenser 3 via a pipeline. The second outlet 32 ​​at the bottom of the condenser 3 is connected to the second inlet 41 at the absorption tank 4 via a pipeline. The third outlet 42 of the absorption tank 4 is connected to the inlet of the vacuum pump 5 via a pipeline. The outlet of the vacuum pump 5 is connected to the second inlet 41 at the top of the absorption tank 4 via a second transfer pump 7 and a pipeline. The liquid outlet 34 of the condenser 3 is connected to the liquid inlet 25 of the evaporator 2 via a pipeline. The second discharge port 26 of the evaporator 2 is connected to the return port 13 of the reactor 1 via a pipeline. The steam inlet 27 of the evaporator 2 is connected to the outlet of the steam source (boiler) and the inner cavity of the jacketed shell via pipelines.

[0023] The absorption tank 4 can be a single unit or multiple units as needed, with the specific number determined according to requirements. If there are two absorption tanks 4, the third outlet 42 of the first absorption tank 4 is connected to the second inlet 41 of the second absorption tank 4, the second inlet 41 of the first absorption tank 4 is connected to the second outlet 32 ​​of the condenser 3, and the third outlet 42 of the second absorption tank 4 is connected to the inlet of the vacuum pump 5 via a pipe. The drain outlet 52 of the vacuum pump 5 is connected to the second inlet 41 of the first absorption tank 4 via a second delivery pump 7.

[0024] To facilitate the measurement of the temperature inside the evaporator 2, a temperature measuring port is machined on the top of the evaporator 2, and a thermometer 24 is installed inside the temperature measuring port.

[0025] To facilitate real-time monitoring of chloride ion and formaldehyde content in the material at the bottom of evaporator 2, a sampling port 29 is machined on the pipe between the second discharge port 26 and the return port 13, and a valve 291 is installed at the sampling port 29.

[0026] The vacuum pump 5 is any one of a water jet vacuum pump, a valve plate vacuum pump, a screw vacuum pump, and a water circulation vacuum pump. In this embodiment, the vacuum pump is a water jet vacuum pump.

[0027] Both the first delivery pump 16 and the second delivery pump 7 are corrosion-resistant delivery pumps. The vacuum pump 5 is a corrosion-resistant vacuum pump.

[0028] The pipe and valve 291 are respectively a corrosion-resistant pipe and a corrosion-resistant valve.

[0029] During operation, while steam is introduced into the lower part of evaporator 2, deionized water is sprayed into evaporator 2 by spray mechanism 22, and cooling water is introduced into the jacketed shell of condenser 3 through condensate inlet 33, aminotrimethylene phosphoric acid (ATMP) reacted in reactor 1 is sent into the upper part of evaporator 2 through first transfer pump 16, pipeline, and second feed inlet 21. After evaporation, the water, chloride ions, and formaldehyde in aminotrimethylene phosphoric acid (ATMP) entering evaporator 2 are sent into condenser 3 from the top of evaporator 2 through pipeline and first air inlet 31 under the action of vacuum pump 5, while the evaporated aminotrimethylene phosphoric acid (ATMP) enters the bottom of evaporator 2. After the evaporated gas enters condenser 3, it condenses into liquid and is sent to the bottom of evaporator 2 through liquid outlet 34, pipeline, and liquid inlet 25, where it flows back into reactor 1 together with the evaporated aminotrimethylene phosphoric acid (ATMP). The chloride ions and formaldehyde that enter the condenser 3 are absorbed into the absorption tank 4 by the vacuum pump 5, thereby removing a large amount of chloride ions and formaldehyde from the aminotrimethylene phosphoric acid.

Claims

1. An apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid, comprising a reaction vessel (1), an absorption tank (4), and a vacuum pump (5); the reaction vessel (1) has a first feed inlet (11), a stirrer (12), and a return inlet (13) at the top, and a first discharge outlet (15) at the bottom; the absorption tank (4) has a second air inlet (41) and a third air outlet (42) at the top; the third air outlet (42) is connected to the inlet (51) of the vacuum pump (5) via a pipe; characterized in that: An evaporator (2) and a condenser (3) are located between the reactor (1) and the absorption tank (4); the evaporator (2) has a second feed inlet (21), a first gas outlet (23) and a spray mechanism (22) at the top, and a second discharge outlet (26) at the bottom; the side walls on both sides of the second discharge outlet (26) have a steam inlet (27) and a liquid inlet (25) respectively; the condenser (3) has a liquid outlet (34) and a second gas outlet (32) at the bottom, and a first gas inlet (31) at the top, with the lower and upper sides of the condenser having separate outlets. It has a condensate inlet (33) and a condensate outlet (35); the first discharge port (15) is connected to the second feed port (21) via the first delivery pump (16) and a pipeline; the first air outlet (23) is connected to the first air inlet (31) via a pipeline; the second air outlet (32) is connected to the second air inlet (41) via a pipeline; the liquid outlet (34) is connected to the liquid inlet (25) via a pipeline; the second discharge port (26) is connected to the return port (13) via a pipeline; and the steam inlet (27) is connected to the steam source.

2. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to claim 1, characterized in that: The evaporator (2) is a falling film evaporator, which contains a cylindrical shell. The cylindrical shell is a jacketed shell, and there are columnar graphite blocks (28) inside. Vertical through holes are evenly distributed on the columnar graphite blocks (28). The steam inlet (27) is connected to the inner cavity of the jacketed shell.

3. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to claim 1, characterized in that: The outlet of the vacuum pump (5) is connected to the second air inlet (41) of the absorption tank (4) via a second delivery pump (7) and a pipe.

4. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to claim 1, characterized in that: The absorption tank (4) has a drain outlet (43) on one side of its bottom.

5. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to claim 1, characterized in that: The evaporator (2) has a temperature measuring port at the top, and a thermometer (24) is inside the temperature measuring port.

6. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to claim 1, characterized in that: There is a sampling port (29) and a valve (291) on the pipe between the second discharge port (26) and the return port (13).

7. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to claim 1, characterized in that: The vacuum pump (5) is any one of a water jet vacuum pump, a valve plate vacuum pump, a screw vacuum pump, and a water circulation vacuum pump.

8. The apparatus for removing chloride ions and formaldehyde from aminotrimethylene phosphoric acid according to any one of claims 1 to 7, wherein the vacuum pump (5) is a corrosion-resistant vacuum pump.

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