Device for recovering solvent and purifying furfuryl propanol in ethyl maltol production

Abstract

The utility model discloses a device for solvent recovery and furfuryl propanol purification in ethyl maltol production. The device comprises a low-temperature evaporator, an addition reagent storage tank, a furfuryl alcohol storage tank, a compressor, an expansion valve, a condenser, a solvent recovery tank, a vacuum pump, a vacuum buffer tank, a high-temperature compressed air supply device and a recovery box. According to the utility model, by controlling the vacuum degree of the low-temperature evaporator and the temperature of a stock solution, toluene and tetrahydrofuran can be effectively promoted to volatilize and condensed and recycled, and a solvent is separated from a furfuryl propanol mixed solution under the conditions of proper temperature and pressure, so that the purity of a furfuryl alcohol intermediate product is favorably improved; and the vacuum control of the low-temperature evaporator, the stock solution feeding speed control, the stock solution temperature control, the filtration of the refrigerant, the regulation and control of the refrigerant amount of the condenser and the like do not need excessive manual intervention, so that the manual operation error is reduced, and the production efficiency and the stability are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a chemical production technical field especially relates to a device of solvent recovery and furfuryl alcohol purification in ethyl maltol production. BACKGROUND

[0002] In the production process of ethyl maltol, furfuryl alcohol mixed solution will be produced after hydrolysis reaction, which contains toluene and tetrahydrofuran and other solvents. The traditional processing mode often has problems such as high energy consumption, low automation degree, difficult to accurately control process parameters when recovering these solvents and purifying furfuryl alcohol intermediate product, resulting in low solvent recovery efficiency, poor product purification effect, and energy cannot be effectively utilized, increasing the production cost and the potential impact on the environment. Therefore, an efficient, energy-saving and automatic control process and the corresponding device are needed to solve the above problems. SUMMARY

[0003] The utility model aims at solving the shortcoming in prior art, and proposes a device of solvent recovery and furfuryl alcohol purification in ethyl maltol production.

[0004] In order to achieve the above object, the utility model adopts the following technical scheme: a device of solvent recovery and furfuryl alcohol purification in ethyl maltol production, including low temperature evaporimeter, addition reagent storage tank, furfuryl alcohol storage tank, compressor, expansion valve, condenser, solvent recovery tank, vacuum pump, vacuum buffer tank, high temperature compressed air providing device and recovery box, the upper wall of low temperature evaporimeter is distributed in left and right and is sequentially provided with feed inlet and steam outlet, the right wall of low temperature evaporimeter is sequentially provided with vacuum connection, refrigerant inlet and discharge port from top to bottom, the left wall of low temperature evaporimeter is provided with refrigerant outlet, the upper and lower ends of condenser are provided with steam inlet and liquid outlet respectively, the left and right side walls of condenser are provided with refrigerant circulation outlet and refrigerant return respectively, expansion valve is arranged between refrigerant outlet and refrigerant return through pipeline, and the expansion valve is provided with filter structure for filtering refrigerant between the expansion valve and refrigerant outlet.

[0005] Further description of the above technical scheme:

[0006] The feed inlet is connected with the outlet end of addition reagent storage tank through feed pump away from one end of low temperature evaporimeter, the steam outlet is connected with steam inlet through pipeline away from one end of low temperature evaporimeter, the compressor is connected between refrigerant circulation outlet and refrigerant inlet through pipeline, the solvent recovery tank is connected at the end of liquid outlet away from condenser through pipeline, the vacuum buffer tank is connected between vacuum pump and vacuum connection through pipeline, and the furfuryl alcohol storage tank is connected with the end of discharge port away from low temperature evaporimeter through pipeline.

[0007] As a further description of the above technical solutions:

[0008] The filter structure comprises a filter, the filter is fixedly connected between the expansion valve and the refrigerant outlet through a pipeline, a third connecting port and a second connecting port are sequentially arranged on the upper wall of the filter in left-right distribution, a fourth connecting port and a first connecting port are sequentially arranged on the lower wall of the filter in left-right distribution, the second connecting port is opposite to the first connecting port in up-down direction, one end of the first connecting port away from the filter is connected with the refrigerant outlet through a pipeline, the second connecting port is connected with the expansion valve through a pipeline, the third connecting port and the fourth connecting port are opposite in up-down direction, one end of the third connecting port away from the filter is connected with the outlet end of the high-temperature compressed air providing device through an air inlet pipe, one end of the fourth connecting port away from the filter is connected with the inlet end of the recovery tank through a collecting pipe, and a control valve is arranged on the outer wall of the air inlet pipe.

[0009] As a further description of the above technical solutions:

[0010] The upper wall of the filter is fixedly connected with a motor, the motor extends an axis through the upper wall of the filter and into the inside of the filter, one end of the axis of the motor extending into the inside of the filter is fixedly connected with a rotating drum, two groups of through holes are arranged on the inner wall of the rotating drum in up-down direction, the two groups of through holes are opposite to the third connecting port and the second connecting port in up-down direction respectively, a filter screen is clamped in the through holes, and sealing members are arranged on the upper wall and the lower wall of the rotating drum and located at the port portions of the through holes.

[0011] As a further description of the above technical solutions:

[0012] The outer wall of the liquid outlet is provided with a temperature detector for detecting the temperature of the recovered solvent.

[0013] As a further description of the above technical solutions:

[0014] The upper wall of the low-temperature evaporator is provided with a vacuum pressure gauge for detecting the vacuum degree in the low-temperature evaporator, and the left wall of the low-temperature evaporator and located above the refrigerant outlet is provided with a liquid level monitoring device for monitoring the liquid level in the low-temperature evaporator.

[0015] As a further description of the above technical solutions:

[0016] The outer wall of the refrigerant return port is provided with an adjusting valve for controlling the flow of the refrigerant return.

[0017] The utility model has the advantages of:

[0018] 1. Compared with the prior art, the solvent recovery and furfuryl propanol purification device in ethyl maltol production can effectively promote the volatilization and condensation recovery of toluene and tetrahydrofuran by controlling the vacuum degree of the low-temperature evaporator and the temperature of the original solution, improves the recovery rate of the solvent, facilitates repeated use in subsequent production, reduces production cost and environmental impact, separates the solvent from the furfuryl propanol mixed solution under suitable temperature and pressure conditions, helps to improve the purity of the furfuryl alcohol intermediate product, provides high-quality raw materials for subsequent ethyl maltol production, and ensures product quality.

[0019] 2. Compared with the prior art, the solvent recovery and furfuryl propanol purification device in ethyl maltol production realizes automatic control of the whole process, including vacuum control of the low-temperature evaporator, control of the original solution feeding speed, control of the original solution temperature, and control of the condenser refrigerant amount, without excessive manual intervention, reducing human operation errors, and improving production efficiency and stability.

[0020] 3. Compared with the prior art, the solvent recovery and furfuryl propanol purification device in ethyl maltol production uses the working principle of a heating compressor to heat the original solution using a compressor, and the refrigerant can be condensed after passing through an expansion valve and a condenser, realizing the recycling of the same energy in heating and refrigeration, with the advantages of high efficiency, low energy consumption, and meeting the production requirements of energy saving and environmental protection.

[0021] 4. Compared with the prior art, the solvent recovery and furfuryl propanol purification device in ethyl maltol production is provided with a filter between the expansion valve and the low-temperature evaporator, which filters the refrigerant circulating through the filter screen, effectively avoiding the influence of impurities generated during the circulation process on the heat exchange effect, and the motor can drive the rotating drum to switch the use state of the two groups of filter screens, keeping one group in use and the other group in a state of being regenerated and cleaned by high-temperature compressed air, greatly reducing the number of manual maintenance. DETAILED DESCRIPTION

[0022] Figure 1 It is a whole structure schematic view of the solvent recovery and furfuryl propanol purification device in ethyl maltol production.

[0023] Figure 2 It is a low-temperature evaporator structure schematic view of the solvent recovery and furfuryl propanol purification device in ethyl maltol production.

[0024] Figure 3 It is a condenser structure schematic view of the solvent recovery and furfuryl propanol purification device in ethyl maltol production.

[0025] Figure 4The utility model provides a kind of filter, motor connection structure schematic diagram of device of solvent recovery and furfuryl alcohol purification in ethyl maltol production proposed by the utility model.

[0026] Figure 5 The utility model provides a kind of filter internal structure partial section schematic diagram of device of solvent recovery and furfuryl alcohol purification in ethyl maltol production proposed by the utility model.

[0027] Legend:

[0028] 1, low-temperature evaporator;101, vacuum pressure gauge;102, feed inlet;103, liquid level monitoring device;104, refrigerant inlet;105, steam outlet;106, addition reagent storage tank;107, furfuryl alcohol storage tank;108, refrigerant outlet;109, discharge port;110, vacuum connection port;2, compressor;3, expansion valve;4, condenser;401, liquid outlet;402, temperature detector;403, refrigerant return port;404, refrigerant circulation outlet;405, steam inlet;406, regulating valve;5, solvent recovery tank;6, vacuum pump;7, vacuum buffer tank;8, filter;801, first connecting port;802, second connecting port;803, third connecting port;804, fourth connecting port;805, motor;806, rotating drum;807, communication hole;8071, filter screen;9, air inlet pipe;10, collection pipe;11, control valve. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0030] Refer to Figures 1 to 5The utility model provides a kind of solvent recovery and furfuryl alcohol purification's device in ethyl maltol production: including low temperature evaporator 1, addition reagent storage tank 106, furfuryl alcohol storage tank 107, compressor 2, expansion valve 3, condenser 4, solvent recovery tank 5, vacuum pump 6, vacuum buffer tank 7, high temperature compressed air providing device and recovery tank, the device specific implementation is, using vacuum pump 6 and vacuum buffer tank 7 is extracted to vacuum state in low temperature evaporator 1, reach set vacuum degree range;Then, through the flowmeter commonly seen in market control furfuryl alcohol mixed solution after hydrolysis reaction filtration from addition reagent storage tank 106 into low temperature evaporator 1, compressor 2 is provided with refrigerant, when liquid level in low temperature evaporator 1 reaches set value, compressor 2 is automatically opened, and the high-temperature high-pressure refrigerant gas of discharge is heated to mixed solution, makes it boil, and volatile toluene and tetrahydrofuran enter condenser 4, and after cooling condensation, flow into solvent recovery tank 5, and furfuryl alcohol solution after volatilization purification in low temperature evaporator 1 flows into furfuryl alcohol storage tank 107;Refrigerant is then after expansion valve 3, condenser 4 etc. component, again to compressor 2, so on and so forth, realize the full-automatic control of entire process, reach the purpose of solvent recovery and furfuryl alcohol purification;

[0031] To realize the recycling and purification operation, the upper wall of the low-temperature evaporator 1 is provided with a feed inlet 102 and a steam outlet 105 in sequence from left to right, the right wall of the low-temperature evaporator 1 is provided with a vacuum connection port 110, a refrigerant inlet 104 and a discharge port 109 in sequence from top to bottom, the left wall of the low-temperature evaporator 1 is provided with a refrigerant outlet 108, the upper and lower ends of the condenser 4 are respectively provided with a steam inlet 405 and a liquid outlet 401, the left and right side walls of the condenser 4 are respectively provided with a refrigerant circulation outlet 404 and a refrigerant return port 403, the expansion valve 3 is arranged between the refrigerant outlet 108 and the refrigerant return port 403 through a pipeline, the end of the feed inlet 102 away from the low-temperature evaporator 1 is connected with the outlet end of an additive reagent storage tank 106 through a feed pump, the end of the steam outlet 105 away from the low-temperature evaporator 1 is connected with the steam inlet 405 through a pipeline, the compressor 2 is connected between the refrigerant circulation outlet 404 and the refrigerant inlet 104 through a pipeline, the solvent recovery tank 5 is connected at the end of the liquid outlet 401 away from the condenser 4 through a pipeline, the vacuum buffer tank 7 is connected between the vacuum pump 6 and the vacuum connection port 110 through a pipeline, the furfuryl alcohol storage tank 107 is connected at the end of the discharge port 109 away from the low-temperature evaporator 1 through a pipeline, the furfuryl alcohol solution after hydrolysis reaction and filtration is stored in the additive reagent storage tank 106, and the low-temperature evaporator 1 is used for containing the furfuryl alcohol solution after hydrolysis reaction and filtration; the compressor 2 and the expansion valve 3 are used for driving the refrigerant to circulate between the low-temperature evaporator 1 and the condenser 4; the compressor 2 is used for discharging high-temperature and high-pressure refrigerant gas, the gas is transported into the low-temperature evaporator 1 to heat the furfuryl alcohol solution in the low-temperature evaporator 1, so that the original solution can be boiled in a temperature range of 20-35 DEG C under a specific vacuum condition, and then the toluene and tetrahydrofuran in the original solution are volatilized; in the embodiment, the compressor 2 also has the automatic loading and unloading functions of the common compressor 2 on the market, so as to realize the control of the temperature of the original solution and ensure that the temperature of the original solution is stable when the pressure is stable; the condenser 4 is used for cooling and condensing the toluene and tetrahydrofuran steam volatilized from the low-temperature evaporator 1; the solvent recovery tank 5 is used for recovering the toluene and tetrahydrofuran condensate, and the furfuryl alcohol storage tank 107 is used for storing the furfuryl alcohol solution after purification;

[0032] To improve the condensing effect, the outer wall of the liquid outlet 401 is provided with a temperature detector 402 for detecting the temperature of the recovered solvent, the temperature detector 402 is used for detecting the temperature of the toluene and tetrahydrofuran condensate, according to the temperature change, the refrigerant flow is adjusted through an adjusting valve 406 to accurately control the amount of refrigerant entering the condenser 4, so as to ensure good condensing effect;

[0033] To realize automatic control, the upper wall of the low-temperature evaporator 1 is provided with a vacuum pressure gauge 101 for detecting the vacuum degree in the low-temperature evaporator 1, and the vacuum pressure gauge 101 is used for detecting the vacuum degree in the low-temperature evaporator 1 after being pumped by the vacuum pump 6.

[0034] In order to realize automatic control, a liquid level monitoring device 103 for monitoring the liquid level inside the low-temperature evaporator 1 is arranged on the left wall of the low-temperature evaporator 1 above the refrigerant outlet 108; the liquid level monitoring device 103 is used to monitor the liquid volume of the mixed solution drawn from the additive reagent storage tank 106 into the low-temperature evaporator 1 by the feed pump, and the start of the compressor 2 is controlled according to the signal of the liquid level monitoring device 103;

[0035] In order to control the condensing effect, an adjusting valve 406 for controlling the flow of refrigerant return is arranged on the outer wall of the refrigerant return port 403; the adjusting valve 406 is used to adjust the amount of refrigerant entering the condenser 4;

[0036] In order to filter the impurities generated in the refrigerant circulation process, a filter structure for filtering the refrigerant is arranged between the expansion valve 3 and the refrigerant outlet 108, the filter structure comprising a filter 8 fixedly connected between the expansion valve 3 and the refrigerant outlet 108 by a pipeline, the upper wall of the filter 8 being arranged with a third connecting port 803 and a second connecting port 802 in turn from left to right, the lower wall of the filter 8 being arranged with a fourth connecting port 804 and a first connecting port 801 in turn from left to right, the second connecting port 802 being opposite to the first connecting port 801, the first connecting port 801 being connected with the refrigerant outlet 108 through a pipeline at the end away from the filter 8, the second connecting port 802 being connected with the expansion valve 3 through a pipeline, the third connecting port 803 and the fourth connecting port 804 being opposite to each other, the third connecting port 803 being connected with the outlet end of the high-temperature compressed air providing device through an air inlet pipe 9 at the end away from the filter 8, the fourth connecting port 804 being connected with the inlet end of the recovery tank through a collection pipe 10 at the end away from the filter 8, the control valve 11 being arranged on the outer wall of the air inlet pipe 9, the motor 805 being fixedly connected to the upper wall of the filter 8 at the central position in the top view projection, the motor 805 extending shaft penetrating through the upper wall of the filter 8 and extending into the inside of the filter 8, the motor 805 extending shaft being fixedly connected with the rotating drum 806 at the end extending into the inside of the filter 8, the inner wall of the rotating drum 806 being arranged with two groups of through communication holes 807, the two groups of communication holes 807 being opposite to each other in the vertical direction, the filter screen 8071 being clamped in the communication hole 807, the sealing element being arranged on the upper and lower sides of the rotating drum 806 at the port part of the communication hole 807, the refrigerant entering the expansion valve 3 from the low-temperature evaporator 1 passing through the group of filter screens 8071 aligned with the second connecting port 802 in the vertical direction, the impurities in the refrigerant being fully filtered through the filter screen 8071, after the refrigerant circulates for a certain number of times, the motor 805 drives the rotating drum 806 to rotate one hundred and eighty degrees along the shaft center of the motor 805, the positions of the two groups of filter screens 8071 being exchanged, the filter screen 8071 in the idle state entering the filtering state, the filter screen 8071 in the filtering state being regenerated by opening the control valve 11 and blowing the high-temperature compressed air provided by the high-temperature compressed air providing device to realize reverse blowing and drying, the impurities blown away from the filter screen 8071 by the high-temperature compressed air being collected by the recovery tank, the two groups of communication holes 807 and the inner side upper wall and inner side lower wall of the filter 8 being sealed by the sealing elements.

[0037] Working principle: the device embodiment is, using vacuum pump 6 and vacuum buffer tank 7 to be extracted to vacuum state in low temperature evaporator 1, reach the set vacuum degree range;Then, through the common flow meter control hydrolysis reaction after filtering furfuryl alcohol mixed solution from addition reagent storage tank 106 into low temperature evaporator 1, compressor 2 is provided with refrigerant, when the liquid level in low temperature evaporator 1 reaches the set value, compressor 2 is automatically started, the high temperature and high pressure refrigerant gas discharged is heated to make the mixed solution boil, the volatilized toluene and tetrahydrofuran enter the condenser 4, and after cooling and condensation, flow into the solvent recovery tank 5, the furfuryl alcohol solution after volatilization and purification in low temperature evaporator 1 flows into furfuryl alcohol storage tank 107;The refrigerant is recycled to compressor 2 again after passing through expansion valve 3, condenser 4 and other components, so as to realize the whole process of automatic control, achieve the purpose of solvent recovery and furfuryl alcohol purification;

[0038] The hydrolysis reaction after filtering furfuryl alcohol mixed solution is stored in addition reagent storage tank 106, and low temperature evaporator 1 is used to contain the hydrolysis reaction after filtering furfuryl alcohol mixed solution;Compressor 2 and expansion valve 3 are used to drive the refrigerant to circulate between low temperature evaporator 1 and condenser 4;The function of compressor 2 is to discharge high temperature and high pressure refrigerant gas, which is transported to low temperature evaporator 1 to heat the furfuryl alcohol mixed solution in it, so that the original liquid can boil in the temperature range of 20-35℃ under specific vacuum conditions, thereby promoting the volatilization of toluene and tetrahydrofuran in the original liquid;In this embodiment, compressor 2 also has the automatic loading and unloading function of common compressor 2 on the market, so as to realize the control of the temperature of the original liquid and ensure that the temperature of the original liquid is stable when the pressure is stable;Condenser 4 is used to cool and condense the toluene and tetrahydrofuran vapor volatilized from low temperature evaporator 1;Solvent recovery tank 5 is used to recover toluene and tetrahydrofuran condensate, and furfuryl alcohol storage tank 107 is used to store the purified furfuryl alcohol solution;Temperature detector 402 is used to detect the temperature of toluene and tetrahydrofuran condensate, and according to the temperature change, the refrigerant flow is adjusted through adjusting valve 406 to accurately control the amount of refrigerant entering the condenser 4, so as to ensure good condensation effect;Vacuum pressure gauge 101 is used to detect the vacuum degree of low temperature evaporator 1 after being pumped by vacuum pump 6;Liquid level monitoring device 103 is used to monitor the liquid volume of the mixed solution extracted from addition reagent storage tank 106 to low temperature evaporator 1 by feed pump, and the start of compressor 2 is controlled according to the signal of liquid level monitoring device 103;Adjusting valve 406 is used to adjust the amount of refrigerant entering the condenser 4;

[0039] The refrigerant passes through the inside of the filter screen 8071 which is aligned with the second connecting port 802 before entering the expansion valve 3 from the low-temperature evaporator 1, and the impurities in the refrigerant are filtered sufficiently by the filter screen 8071, when the refrigerant circulates for a certain number of times, the motor 805 drives the rotating drum 806 to rotate 180 degrees along the axis of the motor 805, and the positions of the two filter screens 8071 are exchanged, the filter screen 8071 which is in the idle state before enters the filtering state, and the filter screen 8071 which is in the filtering state before enters the reverse blowing and drying by the high-temperature compressed air provided by the device after the opening control valve 11 is opened, so as to obtain regeneration and facilitate subsequent reuse, and the impurities blown away from the filter screen 8071 by the high-temperature compressed air are collected by the recovery tank.

[0040] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. An apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol, characterized in that: The system includes a low-temperature evaporator (1), an addition reagent storage tank (106), a furfuryl alcohol storage tank (107), a compressor (2), an expansion valve (3), a condenser (4), a solvent recovery tank (5), a vacuum pump (6), a vacuum buffer tank (7), a high-temperature compressed air supply device, and a recovery box. The upper wall of the low-temperature evaporator (1) is provided with a feed inlet (102) and a steam outlet (105) arranged sequentially from left to right. The right wall of the low-temperature evaporator (1) is provided with a vacuum connection port (110), a refrigerant inlet (104), and a discharge port (105) arranged sequentially from top to bottom. 09), the low-temperature evaporator (1) has a refrigerant outlet (108) on its left wall, the condenser (4) has a steam inlet (405) and a liquid outlet (401) at its upper and lower ends respectively, the condenser (4) has a refrigerant circulation outlet (404) and a refrigerant return outlet (403) on its left and right side walls respectively, the expansion valve (3) is installed between the refrigerant outlet (108) and the refrigerant return outlet (403) through a pipe, and a filter structure for filtering the refrigerant is provided between the expansion valve (3) and the refrigerant outlet (108).

2. The apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol according to claim 1, characterized in that: The end of the feed inlet (102) away from the low-temperature evaporator (1) is connected to the outlet of the addition reagent storage tank (106) via a feed pump. The end of the steam outlet (105) away from the low-temperature evaporator (1) is connected to the steam inlet (405) via a pipe. The compressor (2) is connected between the refrigerant circulation outlet (404) and the refrigerant inlet (104) via a pipe. The solvent recovery tank (5) is connected to the end of the liquid outlet (401) away from the condenser (4) via a pipe. The vacuum buffer tank (7) is connected between the vacuum pump (6) and the vacuum connection port (110) via a pipe. The furfuryl alcohol storage tank (107) is connected to the end of the discharge port (109) away from the low-temperature evaporator (1) via a pipe.

3. The apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol according to claim 1, characterized in that: The filtration structure includes a filter (8), which is fixedly connected between the expansion valve (3) and the refrigerant outlet (108) via a pipe. The upper wall of the filter (8) has a third connection port (803) and a second connection port (802) arranged sequentially from left to right. The lower wall of the filter (8) has a fourth connection port (804) and a first connection port (801) arranged sequentially from left to right. The second connection port (802) and the first connection port (801) are vertically opposite each other, and the first connection port (801) is located away from the filter (8). One end is connected to the refrigerant outlet (108) through a pipe, the second connection port (802) is connected to the expansion valve (3) through a pipe, the third connection port (803) and the fourth connection port (804) are opposite each other, the end of the third connection port (803) away from the filter (8) is connected to the outlet end of the high temperature compressed air supply device through the air inlet pipe (9), the end of the fourth connection port (804) away from the filter (8) is connected to the inlet end of the recovery box through the collection pipe (10), and a control valve (11) is provided on the outer wall of the air inlet pipe (9).

4. The apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol according to claim 3, characterized in that: A motor (805) is fixedly connected to the upper wall of the filter (8) at the center of the top view projection. The extension shaft of the motor (805) passes through the upper wall of the filter (8) and extends into the interior of the filter (8). A rotating drum (806) is fixedly connected to one end of the extension shaft of the motor (805) that extends into the interior of the filter (8). Two sets of vertically penetrating connecting holes (807) are provided on the inner wall of the rotating drum (806). The two sets of connecting holes (807) are respectively vertically opposite to the third connecting port (803) and the second connecting port (802). A filter screen (8071) is snapped into the connecting hole (807). Sealing elements are provided on both the upper and lower sides of the rotating drum (806) at the opening of the connecting hole (807).

5. The apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol according to claim 1, characterized in that: A temperature detector (402) for detecting the temperature of the recycled solvent is provided on the outer wall of the liquid outlet (401).

6. The apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol according to claim 1, characterized in that: The upper wall of the low-temperature evaporator (1) is provided with a vacuum pressure gauge (101) for detecting the vacuum level inside the low-temperature evaporator (1), and the left wall of the low-temperature evaporator (1) and above the refrigerant outlet (108) is provided with a liquid level monitoring device (103) for monitoring the liquid level inside the low-temperature evaporator (1).

7. The apparatus for solvent recovery and furfuryl propanol purification in the production of ethyl maltol according to claim 1, characterized in that: The outer wall of the refrigerant return port (403) is provided with a regulating valve (406) for controlling the refrigerant return flow rate.

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