A water curtain purification tower for tobacco moisture removal and a method for realizing automatic water replacement

Abstract

The invention discloses a water curtain purification tower for tobacco dehumidification and a method for realizing automatic water change, which is composed of an upper and lower part through a transverse partition plate, the lower part is a water curtain washing bin, the total air inlet pipe and the total air outlet pipe enter the upper part from the top, the total air inlet pipe is connected to the spray purification channel composed of the upper channel, the middle channel and the lower channel, the lower channel extends into the water curtain washing bin, the middle channel is horizontally provided with a guide plate with an opening downward, and the middle channel is provided with a nozzle; the total air outlet pipe is connected to the left air outlet pipe and the right air outlet pipe connected with the water curtain washing bin, and a nozzle is provided in the left air outlet pipe and the right air outlet pipe; an upper wind shield is provided on the bottom surface of the transverse partition plate, a lower wind shield is provided on the bottom of the water curtain washing bin, and nozzles are provided at equal intervals on the bottom surface of the transverse partition plate; the bottom of the water curtain washing bin is connected to the circulating water tank through a pipeline. The invention has the characteristics of good purification and cooling effect and convenient use and maintenance, and is very suitable for tobacco dehumidification gas purification.

Description

Technical Field

[0001] The invention relates to a smoke purification device, in particular to a tobacco moisture removal water curtain purification tower and a method for realizing automatic water replacement. Background Art

[0002] The existing tobacco dehumidification water curtain purification equipment uses the fan to operate the dust-containing air from the dust source through the pipe and the air inlet into the box. As the airflow flows in the dust collector, a water curtain is formed. The large-particle powder and water vapor are mixed with the water curtain and flow into the circulating water tank along with the water curtain. The ultra-fine dust is absorbed by the sprayed atomized water mist and flows into the circulating water tank. The impurities and water in the circulating water tank are separated by a stainless steel filter barrel and then sprayed into the dust collector through a water pump. This cycle completes the exhaust gas impurity removal.

[0003] The existing equipment mainly has the following problems:

[0004] (1) The impurity removal effect is not good. The air flow speed is too fast, making it difficult to fully purify. A large amount of waste gas carries impurities and steam into the subsequent moisture removal and odor removal system;

[0005] (2) It is easy to cause gas path blockage. After artificial water replenishment, after 1-2 hours of production, the water level in the water tank will increase due to the dissolution of more steam. The excessively high water level will flood the air passage, resulting in a different gas path. First, it will increase the load of the subsequent fan. If this continues for a long time, it will cause damage to the soft connection, and even the fan will become abnormal due to overload; second, the exhaust gas cannot be discharged in time, and the temperature and moisture in the production host equipment are difficult to adjust, which affects the process quality;

[0006] (3) Incomplete cooling. The two water-spraying pipes are difficult to fully spray and cool down. In addition, the pipe space is limited, the material and wind speed are too fast, and the spraying effect cannot be fully achieved, which cannot effectively cool down the environment, bringing great pressure to the subsequent moisture removal and odor removal.

[0007] (4) There are many slightly larger debris such as small leaves brought in, which affect water circulation and pose a risk of blockage. Summary of the invention

[0008] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a tobacco dehumidification water curtain purification tower for improving the impurity removal, dust removal and cooling effect of tobacco dehumidification gas.

[0009] The technical solution of the present invention is:

[0010] A water curtain purification tower for dehumidifying tobacco comprises a tower body, wherein the tower body is composed of an upper and lower part connected by a transverse partition plate, the lower part is a water curtain washing bin, and the bottom of the water curtain washing bin is funnel-shaped. A total air inlet pipe and a total air outlet pipe enter the upper part of the tower body from the top of the upper part, the total air inlet pipe is connected to a spray purification channel, and the spray purification channel is composed of an upper channel, a middle channel and a lower channel connected from top to bottom, the transverse dimension of the middle channel is larger than that of the upper channel and the lower channel, the upper channel and the lower channel are in a trumpet shape at the connection of the middle channel, the lower channel extends from the top of the water curtain washing bin into the middle channel, and a guide plate with an eight-shaped opening downward is transversely arranged near the upper channel of the middle channel, and a group of purification channel nozzles (a total of six groups) are arranged on the side walls on the left and right sides of the middle channel near the upper channel and on both sides of the left and right blades of the eight-shaped guide plate, and these purification channel nozzles are at the same height. The main air outlet duct is connected to the left air outlet duct and the right air outlet duct. The left air outlet duct and the right air outlet duct are respectively located on the left and right sides of the upper half of the tower body and are connected to the water curtain washing chamber through the transverse partition plate. A group of air outlet nozzles are arranged in each of the left and right air outlet ducts. Four upper wind shields are arranged at equal intervals on the bottom surface of the transverse partition plate. The lower part of the upper wind shield is rectangular. A lower wind shield is arranged at the left and right sides of the bottom funnel of the water curtain washing chamber and the offset position of the upper wind shield. The upper part is rectangular and the lower part is provided with water holes. The height of the lower wind shield is higher than the upper wind shield, and a broken line air flow channel is formed in the middle. The bottom funnel of the water curtain washing chamber is connected to the horizontally arranged water outlet pipe, which is connected to the circulating water tank through a check valve and is used to connect the water curtain washing chamber and the circulating water tank to achieve consistent water level. Six groups of washing chamber nozzles are arranged at equal intervals on the bottom surface of the transverse partition plate. The nozzles of the purification channel, the nozzles of the washing bin and the nozzles of the air outlet pipe are connected to the spray pipe, and the spray pipe is connected to the spray water pipe supplied by the water pump and the compressed air pipe at the same time. Three water level detection switches are arranged in the circulating water tank according to the high, medium and low positions. The water level detection switches are used to detect the water level in the circulating water tank and send the water level switch signal to the controller for water replenishment control.

[0011] When the water curtain purification of the present invention is working, the dehumidified gas from the tobacco production host equipment first enters the tower body from the upper end of the water curtain purification tower, and the dehumidified gas first passes through the square blade screen to remove impurities (the blade screen is added here, and it can be used in conjunction with the dehumidification net at the dehumidification outlet of the front-end host equipment, which plays a double insurance role to avoid the damage of the front-end dehumidification net. Large debris such as leaves enter the tower body and cause pipeline blockage. And the three-dimensional structure design of the blade screen in the present invention has better stability and filtering and leakage prevention capabilities than the flat structure dehumidification net of the front-end host equipment). The gas filtered by the blade screen moves downward, and at the guide plate of the middle channel, three groups of dehumidified gas are sprayed and purified by six purification channel nozzles and then merged into the water curtain washing bin. After entering the water curtain washing chamber, the exhaust gas is divided into two paths and moves to the left and right under the action of negative pressure. Under the action of the upper and lower wind shields (four upper wind shields and two lower wind shields), the flow rate of the exhaust gas is reduced, and it moves along a zigzag route. Under the action of the six groups of three-nozzle water vapor mixing nozzles facing downward on the bottom of the horizontal partition plate, the exhaust gas is removed and cooled. Before the exhaust gas from the left and right outlet ducts exit the water curtain washing chamber and merge into the main outlet duct, there is another group (two groups in total) of outlet duct nozzles for impurity removal and cooling. Under the action of the wind shield and the three-nozzle water vapor mixing nozzle, the steam, flavors, and tobacco dust in the exhaust gas will be dissolved in the water curtain washing chamber in large quantities. After passing through the designed tobacco dehumidification water curtain purification tower, the temperature of the exhaust gas is significantly reduced, and the impurities and air volume in the exhaust gas are significantly reduced.

[0012] The internal horizontal plane of the circulating water tank is substantially level with the horizontal plane of the washing chamber of the water curtain purification tower. Under the action of the start signal, the spray motor transports the water in the circulating water tank to the spray pipe, and sprays it through the three-nozzle water vapor mixing nozzle after mixing with the compressed air. The unique three-nozzle nozzle of the designed water vapor mixing nozzle, combined with the action of compressed air, can achieve high-density water vapor full coverage of the area where the dehumidification gas in the enclosed space passes.

[0013] A blade screen is arranged at the air inlet end of the main air inlet pipe. The main air inlet pipe is square, and one side of the square pipe is designed to be open. There are convex grooves inside for setting up and fixing the blade screen.

[0014] The water level is controlled by the water level detection switch and controller inside the circulating water tank. The water level detection switch has three water levels: high water level, middle water level and low water level. When the water level is high, the water is drained to the middle water level; when the water level is low, the water is replenished to the middle water level.

[0015] The nozzle of the present invention adopts a three-nozzle water vapor mixing nozzle, which has three spray ports facing different angles, and the three nozzles are distributed on the hemispherical surface in the form of regular triangles, thereby solving the shortcomings of other nozzles spraying water in a fixed direction for cooling, the water sprayed is in a thin line, the treatment area is limited, and the area involved by the nozzle cannot fully cover the entire space, thereby improving the cleaning and cooling effect of the exhaust gas, and further reducing the smoke, tar, etc. accumulated in the subsequent odor absorption tower. Compressed air is introduced before the soft water spray, the spray atomization effect is optimized, the spray coverage area is increased, the exhaust gas is effectively washed and cooled, and the activated carbon material after cooling can effectively absorb the odor gas.

[0016] As an example, Figure 3 As shown, the three-nozzle water vapor mixing nozzle is installed on the soft water metal pipeline, and the compressed air pipeline is connected to the three-nozzle water vapor mixing nozzle through a metal pipe. The compressed air is controlled by a pneumatic valve to switch, and the dehumidification fan start signal is connected. When the spray tower starts working, the compressed air and the spray motor are turned on and run at the same time. Among them, the compressed air channel and the softened water channel enter the nozzle from the rear of the three-nozzle water vapor mixing nozzle, mix in the mixing chamber in front of the three-nozzle water vapor mixing nozzle, and spray out through the three scattering nozzles on the head, thereby achieving the purpose of atomization and wide-angle scattering.

[0017] The present invention also provides a method for realizing automatic water replacement of a water curtain purification tower, comprising:

[0018] (1) The equipment operates when receiving a start signal of the exhaust fan, and particulate matter and steam in the exhaust gas are dissolved therein. Water is changed when one of the two conditions is met: first, when the water level detection switch (81) detects a high water level, water is directly discharged to the middle water level. When the water level detection switch (81) can detect a low water level but cannot detect a middle water level, water discharge is immediately stopped. Second, when the water change requirement is satisfied after calculation by the water change algorithm, water is first discharged to the low water level when the water change algorithm calculation is satisfied. At this time, the water level detection switch (81) detects a low water level and immediately stops draining water, and opens the water replenishment solenoid valve to automatically replenish water until the water level detection switch (81) detects a middle water level.

[0019] (2) The water replacement algorithm is calculated as follows: When to replace the water, the influencing factors are the processing air volume and the circulating water temperature; the temperature is transferred to the air through thermal radiation, and the processing air volume is converted by the frequency of the dehumidification fan. According to previous work data, the water level storage capacity in the water curtain purification tower of the present invention is 3.0 cubic meters, and the dehumidification fan frequency operating range is 20-50Hz, which is relatively stable;

[0020] (2.1) When the exhaust fan frequency is set to [35, 50 Hz], the water change instruction START = {the time TIME for processing the exhaust air reaches the threshold} OR {the temperature T of the circulating water tank reaches the limit}; that is, after the last water change is completed, the program timer starts to count again, but the water level detection switch (81) detects that the drainage caused by the high water level is not reset to zero and recalculated. When the time TIME for processing the exhaust air reaches the threshold or the temperature T of the circulating water tank reaches the limit, as long as any one of these two conditions is met, the water is changed; where:

[0021] The threshold of the time TIME in minutes for processing the dehumidification wind = {(50 - fan setting frequency)³ * 60 / 10³ + 150}. In this formula: at a higher frequency, the motor frequency and power are in a cubic relationship, and the power and the processed air volume are in a linear relationship. Therefore, the cubic value of the frequency is combined with the correction value to obtain the threshold of the time TIME for processing the dehumidification wind when the frequency is in the range of 35 to 50. When the drainage interval reaches this threshold, drainage is carried out;

[0022] The temperature limit T of the circulating water tank (8) in °C = {60 °C + (65 °C-60 °C) * [(fan setting frequency - 35 Hz) / (50 Hz-35 Hz)]}, where: when the fan frequency is higher, more exhaust air is processed per unit time, and the steam dissolves and enters the water tank, causing the water tank temperature to rise to a greater extent; when the frequency increases within the range of 35 to 50, the circulating water tank temperature limit T increases within the range of 60 °C to 65 °C, and the two are positively correlated. When the circulating water tank temperature reaches the temperature limit T calculated by the formula, drainage is carried out;

[0023] (2.2) When the frequency of the dehumidification fan is set to [20, 35 Hz), the water change instruction START = {the time TIME for processing the dehumidification wind reaches the threshold} OR {the temperature T of the circulating water tank reaches the limit}, that is: after the last water change is completed, the program timer starts to count again, but the water level detection switch (81) detects that the drainage caused by the high water level is not reset to zero and recalculated. When the time TIME for processing the dehumidification wind reaches the threshold or the temperature T of the circulating water tank reaches the limit, as long as any one of these two conditions is met, the water is changed; where:

[0024] The threshold of the time TIME in minutes for processing the dehumidification wind = {(35 - fan setting frequency) * 60 / 4 +352.5}, in which: at a lower frequency, the actual power of the motor is also very small, the volume of dehumidification wind processed per unit time is very limited, and the water quality in the water curtain purification tower is also relatively ideal; at this time, the fan setting frequency can be directly used, combined with the correction value, to obtain the threshold of the time TIME for processing the dehumidification wind when the frequency is in the range of 20 to 35. When the drainage interval reaches this threshold, drainage is carried out; (In the two stages of the frequency range of 20 to 35 and the frequency range of 35 to 50, the slope change of the designed time threshold TIME for processing the dehumidification wind is significantly different, which is more appropriate to actual production.)

[0025] The temperature limit T in the circulating water tank (8) in °C is = {57 °C + (60 °C-57 °C) * [(fan setting frequency - 20 Hz) / (35 Hz-20 Hz)]}, where: when the fan frequency is higher, more dehumidification air is processed per unit time, and the degree of temperature rise of the water tank caused by the dissolution of steam into the water tank is also greater. When the frequency increases within the range of 20 to 35, the temperature limit T of the circulating water tank increases within the range of 57 to 60 °C, and the two are positively correlated. When the temperature of the circulating water tank reaches the temperature limit T calculated by the formula, drainage is carried out. (In the two stages of frequency within the range of 20 to 35 and frequency within the range of 35 to 50, the slope change of the designed circulating water tank temperature limit T is significantly different, which is more in line with actual production.)

[0026] (3) According to step (1) or (2), when the water replacement conditions are met, the drain valve is opened through PLC control, the circulating water is discharged to the low water level, and then the drain valve is closed, and then the water replenishment solenoid valve is opened to replenish water to the middle water level.

[0027] Working principle of the present invention:

[0028] (1) The windshield in the air path changes the dehumidification gas flow route from a straight line to a zigzag line, reduces the airflow speed, increases the contact time between the airflow and the water curtain, and can fully purify the dehumidification gas, reducing the debris and steam entering the subsequent dehumidification and odor removal system;

[0029] (2) The present invention can achieve efficient water curtain purification without a high water level, and can solve the problem of gas path blockage. The water level detection and drainage principle is used to perform irregular drainage and water replenishment, thereby solving the problem that the water level in the water tank of the traditional water curtain dust collector increases after 1-2 hours of production due to the dissolution of more steam. The excessively high water level will flood the air passage, resulting in different gas paths. This avoids the subsequent increase in fan load due to different gas paths, resulting in damage to the soft connection and abnormal fan overload; and the phenomenon of temperature regulation out of control in the production host equipment due to the failure to discharge exhaust gas in time;

[0030] (3) The airflow at the dehumidification gas inlet is divided into three paths for purification and cooling, which can fully dissolve the impurities, particulate matter and steam in the dehumidification gas, thereby reducing the working pressure of subsequent dehumidification and odor removal and achieving thorough cooling;

[0031] (4) By adding a blade screen at the inlet section and cooperating with the moisture-removing screen of the front-end host equipment, it is possible to prevent the entry of slightly larger debris such as small blades, thereby avoiding blockage of the water circulation.

[0032] Beneficial effects of the present invention:

[0033] (1) It can improve the impurity removal effect. Through the wind shield in the air path, the dehumidification gas flow route is changed from a straight line to a zigzag line, which reduces the speed of the airflow and increases the contact time between the airflow and the water curtain. It further improves the impurity removal effect, fully purifies the dehumidification gas, and reduces the debris and steam entering the subsequent dehumidification and odor removal system.

[0034] (2) Solved the problem of gas path blockage. The present invention can achieve efficient water curtain purification without a high water level. The water level detection and drainage principle is used to perform irregular drainage and water replenishment, thereby solving the problem that the water level in the water tank of the traditional water curtain dust collector increases after 1-2 hours of production due to the dissolution of more steam. The excessively high water level will flood the air passage, resulting in different gas paths. Avoid the subsequent increase in fan load due to different gas paths, resulting in damage to the soft connection and abnormal fan overload; and the phenomenon of temperature regulation out of control in the production host equipment due to the failure to discharge the exhaust gas in time.

[0035] (3) It has a better cooling effect. The airflow at the dehumidification gas inlet is divided into three paths for purification and cooling, which can fully dissolve the debris, particles and steam in the dehumidification gas. This reduces the subsequent dehumidification and odor removal work pressure.

[0036] (4) A new blade screen is added to the inlet section, which, together with the moisture-removing screen of the front-end host equipment, can prevent the entry of slightly larger debris such as small blades, thereby avoiding blockage of the water circulation.

[0037] (5) A method for automatically controlling water exchange in a water curtain purification tower was designed. The circulating water was automatically replaced according to an algorithm based on the treated air volume, water temperature, and water level. This allows for more scientific and rational water use, and achieves the optimal match between high-efficiency water curtain purification and water conservation.

[0038] (6) The three-nozzle water vapor mixing nozzle designed and adopted can greatly increase the proportion of the injection space, and can achieve high-density water vapor full coverage of the area where the dehumidifying gas passes through the confined space. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 : The structural representation of the water curtain purification tower of the present invention.

[0040] Figure 2 : Schematic diagram of the tower shell and inspection opening.

[0041] Figure 3 : Schematic diagram of a three-nozzle water vapor mixing nozzle.

[0042] Figure 4 : Schematic diagram of the cross section of a three-nozzle water vapor mixing nozzle.

[0043] Figure 5 : Schematic diagram of blade screen structure.

[0044] In the figure: 1-tower body, 11-transverse partition board, 12-inspection port; 21-main air inlet pipe, 22-blade screen; 3-spray purification channel, 31-upper channel, 32-middle channel, 33-lower channel; 41-upper wind shield, 42-lower wind shield, 43-water hole; 51-left air outlet pipe, 52-right air outlet pipe, 54-main air outlet pipe; 6-water curtain washing chamber, 61-bottom funnel, 62-water outlet pipe, 63-check valve; 7-spray nozzle, 70-spray head, 701-guide blade, 702-steam-water mixing chamber, 703-compressed air channel, 704-soft water channel; 71-purification channel nozzle, 72-washing chamber nozzle, 73-air outlet pipe nozzle, 74-spray pipe, 75-water pipe, 76-spray water pump, 77-compressed air pipeline; 8-circulating water tank, 81-water level detection switch, 82-overflow pipeline, 83-drain valve. DETAILED DESCRIPTION

[0045] like Figure 1As shown, a tobacco moisture removal water curtain purification tower includes a tower body 1, which is composed of an upper and lower part connected by a transverse partition plate 11. The lower part is a water curtain washing chamber 6, and the bottom of the water curtain washing chamber 6 is funnel-shaped. The total air inlet pipe 21 and the total air outlet pipe 54 enter the upper half of the tower body 1 from the top of the upper half. The total air inlet pipe 21 is connected to the spray purification channel 3. The spray purification channel 3 is composed of an upper channel 31, a middle channel 32 and a lower channel 33 connected from top to bottom. The lateral size of the middle channel 32 is larger than the upper channel 31 and the lower channel 33. The upper channel 31 and the lower channel 33 are in a trumpet shape at the connection of the middle channel 32. The lower channel 33 extends into the water curtain washing bin 6 from above. A guide plate with an eight-shaped opening facing downward is horizontally arranged near the upper channel 31 of the middle channel 32. A group of purification channel nozzles 71 (a total of six groups) are arranged on the side walls on the left and right sides of the middle channel 32 near the upper channel 31 and on both sides of the left and right blades of the eight-shaped guide plate. These purification channel nozzles 71 are at the same height. The main air outlet duct 54 connects the left air outlet duct 51 and the right air outlet duct 52, and the left air outlet duct 51 and the right air outlet duct 52 are respectively located on the left and right sides of the upper half of the tower body 1 and are connected to the water curtain washing bin 6 through the transverse partition plate 11. A group of air outlet duct nozzles 73 are respectively arranged in the left air outlet duct 51 and the right air outlet duct 52, and four upper wind shields 41 are evenly spaced on the bottom surface of the transverse partition plate 11. The lower part of the upper wind shield 41 is rectangular, and a lower wind shield 42 is respectively arranged on the left and right sides of the bottom funnel of the water curtain washing bin 6 at the offset position of the upper wind shield 41. The upper part is rectangular and the lower part is provided with water holes 43. The height of the lower wind shield 42 is higher than the upper wind shield 41, and a zigzag air flow channel is formed in the middle. The bottom funnel 61 of the water curtain washing chamber 6 is connected to a horizontally arranged water outlet pipe 62, which is connected to the circulating water tank 8 through a check valve 63 and is used to connect the water curtain washing chamber 6 and the circulating water tank 8 to keep the water level consistent. Six groups of washing chamber nozzles 72 are arranged at equal intervals on the bottom surface of the transverse partition plate 11. The purification channel nozzle 71, the washing chamber nozzle 72 and the air outlet pipe nozzle 73 are connected to a spray pipe 74, and the spray pipe 74 is simultaneously connected to a spray water pipe supplied by a water pump 75 and a compressed air pipe 76. Three water level detection switches 81 are arranged in the circulating water tank 8 according to high, medium and low positions. The water level detection switch 81 is used to detect the water level in the circulating water tank 8 and send the water level switch signal to the controller for water replenishment control.

[0046] like Figure 2As shown, the outer shell of the tower body 1 is provided with an inspection port, the size of which is 500*500mm, and is composed of heat-resistant explosion-proof glass in the middle of the outer metal frame, which can be used to observe the internal operation of the equipment when it is running. The number of observation windows is as follows: two in front and behind the air flow branch spray purification channel (the first spray purification in the tower), for a total of four; two in front and behind the water curtain washing bin, and one on the left and right, for a total of six. The functions of the inspection port are: equipment cleaning and maintenance, equipment inspection and repair, and equipment operation observation.

[0047] A blade screen 22 is provided at the air inlet end of the main air inlet pipe 21. The main air inlet pipe 21 is square, and one side of the square pipe is designed to be open. There are convex grooves inside for erecting and fixing the blade screen 22. The blade screen 22 is 600 mm wide and 50 mm thick. The cubic screen design is stable and durable, and will not deform and cause air leakage during long-term use and cleaning. The frame is a stainless steel metal strip with a width of 20mm and a thickness of 3mm. The filter is a stainless steel mesh with an aperture of 3mm, which is used to screen out large debris such as small blades leaking from the host equipment (the host equipment has a dehumidification net at the dehumidification outlet, but if it is not airtight enough during daily installation, or the dehumidification net is damaged, some small blades will be sucked out by negative pressure to the designed water curtain purification tower. If there are many large debris, the circulating water circuit and the three-nozzle water vapor mixing nozzle will be blocked. The designed three-dimensional blade screen can effectively filter large debris, and cooperate with the dehumidification net of the host equipment to form a double insurance, thereby avoiding the risk of pipeline blockage.) The screen of the blade screen is in the middle to avoid damage caused by lateral collisions, and it is easy to install, disassemble and clean.

[0048] As an example, the total width of the spray purification channel 3 is 1.5 meters, which is three rectangular channels. Figure 1 It can be seen that there is a pair of figure-eight guide plates above the middle channel 32 to prevent a large amount of airflow from passing through the middle channel and ensure that the airflow of the three channels is uniform. There are two groups of three-nozzle water-steam mixing nozzles on both sides of each channel. The three groups of three-nozzle water-steam mixing nozzles on the left are transported with circulating water and compressed air from the left pipeline, and the three groups of three-nozzle water-steam mixing nozzles on the right are transported with circulating water and compressed air from the right pipeline. The three-nozzle water-steam mixing nozzles spray obliquely downward, keeping an angle of about 30 degrees with the side wall.

[0049] As an embodiment, a washing bin water level detection switch is also provided in the circulating water tank 8, which is used to control the water level in the water curtain washing bin (6) to be higher than the bottom funnel 61 of the lower wind shield 42 and lower than the upper wind shield 41. The highest water level in the water curtain washing bin 6 should be at least 3 cm lower than the upper wind shield 41 to ensure that the moisture removal gas channel is not blocked. The water level control is controlled by the washing bin water level detection switch and the controller. When the water level reaches the water hole 43 of the lower wind shield 42, water is replenished; when the water level reaches 3 cm from the upper wind shield 41, water is drained to the water level detection switch in the middle position. The specific position can be adjusted by the height of the washing bin water level detection switch. A check valve 63 is installed on the water outlet pipe 62 at the bottom of the water curtain washing bin 6 for drainage, and water can only pass through but not flow back.

[0050] As an embodiment, the circulating water tank 8 is equipped with a soft water inlet pipe, an overflow pipe for mechanical discharge when the water level is too high, a sewage outlet, a spray water pump 76, a water pipe 75, a water level detection switch 81 and an electronic water temperature thermometer. The soft water inlet pipe is controlled by a mechanical ball valve and a water replenishment solenoid valve. The sewage outlet is connected to a sewage valve, which is controlled by a pneumatic valve to achieve automatic opening and closing when the line is reached and a manual operation button to control the switch. The spray water pump 76 is connected to the start / stop signal of the dehumidification fan in the subsequent process. When the dehumidification fan is turned on, the spray water pump 76 and the compressed air electronic valve are automatically opened, and the circulating water and compressed air are mixed and sprayed through the three-nozzle water vapor mixing nozzle. When the dehumidification fan is turned off, the spray water pump 76 and the compressed air electronic valve are automatically closed. The water level detection switch 81 has three water levels in total: high water level, middle water level, and low water level. When the water level is high, water is drained to the middle water level; when the water level is low, water is replenished to the middle water level.

[0051] As an embodiment, the spray pipe 74 is a metal pipe. The circulating water and compressed air pipes at the side wall of the water curtain purification tower enter the water curtain purification tower together and are sent to the three-nozzle water vapor mixing nozzle for mixing and spraying.

[0052] As an example, Figure 4 As shown, the nozzle of the present invention adopts a three-nozzle water vapor mixing nozzle. The nozzle has three spray ports facing different angles, and the three nozzles are distributed on the hemispherical surface in the form of an equilateral triangle, thereby solving the shortcomings of other nozzles spraying water in a fixed direction for cooling, the water sprayed is in a thin line, the treatment area is limited, and the area involved by the nozzle cannot fully cover the entire space. It improves the cleaning and cooling effect of the exhaust gas, and can further reduce the smoke, tar, etc. accumulated in the subsequent odor absorption tower. Compressed air is introduced before the soft water spray, the spray atomization effect is optimized, the spray coverage area is increased, the exhaust gas is effectively washed and cooled, and the activated carbon material after cooling can effectively absorb the odor gas.

[0053] As an example, Figure 3 As shown, it is installed on the soft water metal pipeline, and the compressed air pipeline is connected to the designed three-nozzle water vapor mixing nozzle through a metal pipe. The compressed air is controlled by a pneumatic valve to switch, and the exhaust fan start signal is connected. When the spray tower starts working, the compressed air and the spray motor are turned on and run at the same time. Among them, the compressed air channel and the softened water channel enter the nozzle from the rear of the three-nozzle water vapor mixing nozzle, mix in the mixing chamber in front of the three-nozzle water vapor mixing nozzle, and spray out through the three scattering nozzles on the head, thereby achieving the purpose of atomization and wide-angle scattering.

[0054] When the water curtain purification of the present invention is working, the dehumidified gas from the tobacco production host equipment first enters the tower body 1 from the upper end of the water curtain purification tower, and the dehumidified gas first passes through the square blade screen 22 for impurity removal (the blade screen is added here, and it can be used in conjunction with the dehumidification net at the dehumidification outlet of the front-end host equipment, which plays a double insurance role to avoid the damage of the front-end dehumidification net. Large debris such as leaves enter the tower body and cause pipeline blockage. And the three-dimensional structure design of the blade screen 22 in the present invention has better stability and filtering and leakage prevention capabilities than the planar structure dehumidification net of the front-end host equipment). The gas filtered by the blade screen 22 moves downward, and at the guide plate of the middle channel 32, three groups of dehumidified gas are sprayed and purified by six purification channel nozzles 71 and then merged into the water curtain washing bin 6. After entering the water curtain washing chamber 6, the exhaust gas is divided into two paths and moves to the left and right under the action of negative pressure. Under the action of the upper and lower wind shields (four upper wind shields 41 and two lower wind shields 42), the flow rate of the exhaust gas is reduced and moves along a zigzag route. Under the action of the six groups of three-nozzle water vapor mixing nozzles facing downward on the bottom surface of the transverse partition plate 11, the exhaust gas is cleaned and cooled. After the exhaust gas from the left and right outlet pipes 51 and 52 exit the water curtain washing chamber 6 and before merging into the main outlet pipe 54, there is another group (two groups in total) of outlet pipe nozzles 73 for cleaning and cooling. Under the action of the wind shield and the three-nozzle water vapor mixing nozzle, the steam, flavors and tobacco dust in the two-way exhaust gas will be dissolved in the water curtain washing bin in large quantities. After passing through the designed tobacco exhaust water curtain purification tower, the temperature of the exhaust gas is significantly reduced, and the impurities and air volume in the exhaust gas are significantly reduced.

[0055] The inner horizontal plane of the circulating water tank 8 is substantially level with the washing chamber horizontal plane of the water curtain purification tower 6. Under the action of the start signal, the spray motor delivers the water in the circulating water tank 8 to the spray pipe 74, and sprays it through the three-spray nozzle water vapor mixing nozzle after mixing with the compressed air. The unique three-spray nozzle of the designed water vapor mixing nozzle, combined with the action of compressed air, can achieve high-density water vapor full coverage of the area where the dehumidification gas in the enclosed space passes.

[0056] The present invention also provides a method for realizing automatic water replacement of a water curtain purification tower, comprising:

[0057] (1) The equipment starts to operate when it receives the start signal of the exhaust fan, and the particulate matter and steam in the exhaust gas are dissolved in it. The water is changed when one of the two conditions is met: first, when the water level detection switch 81 detects a high water level, the water is directly discharged to the middle water level. When the water level detection switch 81 can detect a low water level but cannot detect a middle water level, the water is immediately stopped from being drained. Second, when the water change requirement is met after calculation by the water change algorithm, the water is first drained to the low water level. At this time, the water level detection switch 81 detects a low water level and immediately stops draining, and opens the water replenishment solenoid valve to automatically replenish water until the water level detection switch 81 detects a middle water level.

[0058] (2) The water replacement algorithm is calculated as follows: When to replace the water, the influencing factors are the processing air volume and the circulating water temperature; the temperature is transferred to the air through thermal radiation, and the processing air volume is converted by the frequency of the dehumidification fan. According to previous work data, the water level storage capacity in the water curtain purification tower of the present invention is 3.0 cubic meters, and the dehumidification fan frequency operating range is 20-50Hz, which is relatively stable;

[0059] (2.1) When the frequency of the dehumidification fan is set to [35, 50Hz], the water change instruction START={the time TIME for processing dehumidification wind reaches the threshold}OR{the temperature T of the circulating water tank reaches the limit}; that is: after the last water change is completed, the program timer starts to count again, but the water level detection switch 81 detects that the drainage caused by the high water level is not reset to zero and recalculated. When the time TIME for processing dehumidification wind reaches the threshold or the temperature T of the circulating water tank reaches the limit, as long as any one of these two conditions is met, the water is changed; where:

[0060] The threshold of the time TIME in minutes for processing the dehumidification wind = {(50 - fan setting frequency)³ * 60 / 10³ + 150}. In this formula: at a higher frequency, the motor frequency and power are in a cubic relationship, and the power and the processed air volume are in a linear relationship. Therefore, the cubic value of the frequency is combined with the correction value to obtain the threshold of the time TIME for processing the dehumidification wind when the frequency is in the range of 35 to 50. When the drainage interval reaches this threshold, drainage is carried out;

[0061] The temperature limit T of the circulating water tank 8 in °C = {60 °C + (65 °C-60 °C) * [(fan setting frequency-35Hz) / (50Hz-35Hz)]}, in which: when the fan frequency is higher, more exhaust air is processed per unit time, and the steam dissolves and enters the water tank, causing the water tank temperature to rise to a greater extent; when the frequency increases within the range of 35 to 50, the circulating water tank temperature limit T increases within the range of 60 °C to 65 °C, and the two are positively correlated. When the circulating water tank temperature reaches the temperature limit T calculated by the formula, drainage is carried out;

[0062] (2.2) When the frequency of the dehumidification fan is set to [20, 35 Hz), the water change instruction START = {the time TIME for processing dehumidification wind reaches the threshold} OR {the temperature T of the circulating water tank reaches the limit}, that is: after the last water change is completed, the program timer starts to count again, but the water level detection switch 81 detects that the drainage caused by the high water level is not reset to zero and recalculated. When the time TIME for processing dehumidification wind reaches the threshold or the temperature T of the circulating water tank reaches the limit, as long as any one of these two conditions is met, the water is changed; where:

[0063] The threshold of the time TIME in minutes for processing the dehumidification wind = {(35 - fan setting frequency) * 60 / 4 +352.5}, in which: at a lower frequency, the actual power of the motor is also very small, the volume of dehumidification wind processed per unit time is very limited, and the water quality in the water curtain purification tower is also relatively ideal; at this time, the fan setting frequency can be directly used, combined with the correction value, to obtain the threshold of the time TIME for processing the dehumidification wind when the frequency is in the range of 20 to 35. When the drainage interval reaches this threshold, drainage is carried out; (In the two stages of the frequency range of 20 to 35 and the frequency range of 35 to 50, the slope change of the designed time threshold TIME for processing the dehumidification wind is significantly different, which is more appropriate to actual production.)

[0064] The temperature limit T in the circulating water tank 8 in °C = {57 °C + (60 °C-57 °C) * [(fan setting frequency - 20Hz) / (35Hz-20Hz)]}, in which: when the fan frequency is higher, more dehumidification air is processed per unit time, and the degree of temperature rise of the water tank caused by the dissolution of steam into the water tank is also greater. When the frequency increases in the range of 20 to 35, the temperature limit T of the circulating water tank increases in the range of 57 °C to 60 °C, and the two are positively correlated. When the temperature of the circulating water tank reaches the temperature limit T calculated by the formula, drainage is carried out. (In the two stages where the frequency is in the range of 20 to 35 and the frequency is in the range of 35 to 50, the slope change of the designed circulating water tank temperature limit T is significantly different, which is more appropriate for actual production.)

[0065] (3) According to step (1) or (2), when the water replacement conditions are met, the drain valve is opened through PLC control, the circulating water is discharged to the low water level, and then the drain valve is closed, and then the water replenishment solenoid valve is opened to replenish water to the middle water level.

[0066] The words expressing position and direction described in this application are all explained by taking the drawings as examples, but they can be changed as needed, and the changes are all included in the protection scope of this application. The drawings of this application are only used to illustrate the relative position relationship and do not represent the true proportion.

Claims

1. A tobacco moisture removal water curtain purification tower, comprising a tower body (1), characterized in that: The tower body (1) is divided into an upper and lower part, with a transverse partition plate (11) arranged in the middle. The lower part is a water curtain washing chamber (6), and the bottom of the water curtain washing chamber (6) is funnel-shaped. A total air inlet pipe (21) and a total air outlet pipe (54) enter the upper part from the top of the tower body (1). A spray purification channel (3) is connected below the total air inlet pipe (21). The spray purification channel (3) is composed of an upper channel (31), a middle channel (32) and a lower channel (33) connected from top to bottom. The lateral dimension of the middle channel (32) is larger than that of the upper channel (31). The upper channel (31) and the lower channel (33) are in a bell-mouth shape at the connection of the middle channel (32); the lower channel (33) extends from the top of the water curtain washing bin (6) into the middle channel; a guide plate with an eight-shaped opening facing downward is transversely arranged near the upper channel (31) of the middle channel (32); a group of purification channel nozzles (71) are arranged on the left and right side walls of the middle channel (32) near the upper channel (31) and on both sides of the left and right blades of the guide plate; these purification channel nozzles (71) are arranged at The main air outlet pipe (54) is connected to the left air outlet pipe (51) and the right air outlet pipe (52), and the left air outlet pipe (51) and the right air outlet pipe (52) are respectively located on the left and right sides of the upper half of the tower body (1) and pass through the transverse partition plate (11) to communicate with the water curtain washing chamber (6). A group of air outlet pipe nozzles (73) are respectively arranged in the left air outlet pipe (51) and the right air outlet pipe (52). Four upper wind shields (41) are arranged at equal intervals on the bottom surface of the transverse partition plate (11). The upper wind shields (41) are arranged on the left and right sides of the bottom funnel of the water curtain washing chamber (6). (41) A lower wind shield plate (42) is provided at each offset position; the bottom funnel (61) of the water curtain washing chamber (6) is connected to a horizontally arranged water outlet pipe (62), the water outlet pipe (62) is connected to the circulating water tank (8) through a check valve (63) and is used to connect the water curtain washing chamber (6) and the circulating water tank (8) to achieve consistent water levels; a plurality of groups of washing chamber nozzles (72) are provided on the bottom surface of the transverse partition plate (11) facing downward; the purification channel nozzle (71), the washing chamber nozzle (72) and the air outlet pipe nozzle (73) are connected to a spray pipe (74); Three water level detection switches (81) are arranged in the circulating water tank (8) at high, middle and low positions; the high, middle and low positions of the three water level detection switches (81) are used to control the water level in the water curtain washing chamber (6) to be higher than the water-passing hole (43) of the lower wind shield (42) and lower than the upper wind shield (41); the purification channel nozzle (71), the washing chamber nozzle (72) and the air outlet pipe nozzle (73) are three-nozzle type water vapor mixing nozzles.

2. The tobacco moisture removal water curtain purification tower according to claim 1 is characterized in that: The lower part of the upper wind shield (41) is rectangular, the upper part of the lower wind shield (42) is rectangular, and a water hole (43) is provided at the lower part. The lower wind shield (42) is higher than the upper wind shield (41), and a zigzag airflow channel is formed in the middle.

3. The tobacco moisture removal water curtain purification tower according to claim 1 is characterized in that: The spray pipe (74) is connected to a spray water pipe supplied by a water pump (75) and a compressed air pipe (76).

4. The tobacco moisture removal water curtain purification tower according to claim 1, characterized in that: The water level detection switch (81) is used to detect the water level in the circulating water tank (8) and send a water level switch signal to the controller for water replenishment control.

5. The tobacco moisture removal water curtain purification tower according to claim 1, characterized in that: The purification channel nozzle (71) sprays obliquely downward, and the angle between it and the side wall is 30 degrees.

6. The tobacco moisture removal water curtain purification tower according to claim 1, characterized in that: The three-nozzle type water vapor mixing nozzle has three spray outlets facing different angles, and the three nozzles are distributed on the hemispherical surface in the form of an equilateral triangle.

7. The tobacco moisture removal water curtain purification tower according to claim 1, characterized in that: The washing bin nozzles (72) are arranged in six groups at equal intervals.

8. The tobacco moisture removal water curtain purification tower according to any one of claims 1 to 7, characterized in that: A blade screen (22) is provided at the air inlet end of the main air inlet pipe (21); the main air inlet pipe (21) is square in shape, one side of the square pipe is designed to be open, and a convex groove for supporting and fixing the blade screen (22) is provided inside.

9. The tobacco moisture removal water curtain purification tower according to claim 8, characterized in that: The upper channel (31), the middle channel (32) and the lower channel (33) of the spray purification channel (3) are three rectangular channels.

10. A method for automatically changing water in a water curtain purification tower, using the tobacco dehumidification water curtain purification tower according to any one of claims 1 to 9, wherein the method changes water when one of the following two conditions is met after the dehumidification fan is started: (1) When the water level detection switch (81) detects a high water level, the water is directly discharged to the middle water level; when the water level detection switch (81) can detect a low water level but cannot detect a middle water level, the water is immediately stopped from being discharged; (2) The water replacement requirement is met after calculation by the water replacement algorithm. When the water replacement requirement is met, the water is first drained to a low water level. At this time, the water level detection switch (81) detects the low water level and immediately stops draining the water. The water replenishment solenoid valve is opened to automatically replenish water until the water level detection switch (81) detects a medium water level. The water exchange algorithm calculation includes: (2.1) When the exhaust fan frequency is set to [35, 50 Hz], the water change instruction START = {the time TIME for processing the exhaust air reaches the threshold} OR {the temperature T of the circulating water tank reaches the limit}; that is, after the last water change is completed, the program timer starts to count again, but the water level detection switch (81) detects that the drainage caused by the high water level is not reset to zero and recalculated. When the time TIME for processing the exhaust air reaches the threshold or the temperature T of the circulating water tank reaches the limit, as long as any one of these two conditions is met, the water is changed; where: The threshold value of the time in minutes for processing dehumidification wind = {(50 - fan setting frequency)³ * 60 / 10³ + 150}; The temperature limit of the circulating water tank (8) in °C is T = {60 °C + (65 °C - 60 °C) * [(fan setting frequency - 35 Hz) / (50 Hz - 35 Hz)]}; (2.2) When the frequency of the dehumidification fan is set to [20, 35 Hz), the water change instruction START = {the time TIME for processing the dehumidification wind reaches the threshold} OR {the temperature T of the circulating water tank reaches the limit}, that is: after the last water change is completed, the program timer starts to count again, but the water level detection switch (81) detects that the drainage caused by the high water level is not reset to zero and recalculated. When the time TIME for processing the dehumidification wind reaches the threshold or the temperature T of the circulating water tank reaches the limit, as long as any one of these two conditions is met, the water is changed; where: The threshold value of the time in minutes for processing dehumidification wind = {(35 - fan setting frequency) * 60 / 4 +352.5}; The temperature limit T in the circulating water tank (8) in °C = {57 °C + (60 °C - 57 °C) * [(fan setting frequency - 20 Hz) / (35 Hz - 20 Hz)]}; (3) According to step (1) or (2), when the water replacement conditions are met, the drain valve is opened through PLC control, the circulating water is discharged to the low water level, and then the drain valve is closed, and then the water replenishment solenoid valve is opened to replenish water to the middle water level.

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