Material moisture content control system, drum-type silk drying machine and material moisture content control method

Abstract

The present invention discloses a material moisture content control system, a drum-type tobacco drying machine and a material moisture content control method, which relate to the field of tobacco machinery and are used to improve the accuracy of material moisture content control. The system includes a drum, a temperature regulating device, a humidity regulating device, a feed flow detection device and a control device. The drum has a feed end, a discharge end and an inner cavity. The temperature regulating device conveys process air to the inside of the drum via the feed or discharge end of the drum. The humidity regulating device is connected to the inner cavity of the drum. The control device is signal-connected to the temperature regulating device, the humidity regulating device and the feed flow detection device, and the control device is constructed to control the temperature of the process air conveyed to the drum by the temperature regulating device and the humidity of the fluid conveyed to the drum by the humidity regulating device according to the flow detected by the feed flow detection device. The above technical scheme improves the accuracy of material moisture content control.

Description

Technical Field

[0001] The invention relates to the field of tobacco machinery, and in particular to a material moisture content control system, a drum-type tobacco drying machine and a material moisture content control method. Background Art

[0002] Cut tobacco drying is the core process of cigarette making, which is directly related to the sensory quality of cigarette products. Its technical coverage is relatively wide, involving complex heat and mass transfer and the heat and moisture carrying capacity of the carrier, and is closely related to the characteristics of cut tobacco and the scale of processing. It directly affects the style, shape, quality of the product, the control agility and response ability of the production operation system, material consumption, energy consumption, etc. It is a key link to realize product value and improve product quality. At present, the mainstream equipment for cutting tobacco drying is the drum type cutting tobacco drying machine.

[0003] In the related technology, tobacco shreds enter the drum of the drum-type tobacco drying machine from the feed hood through the feed vibration groove, and the drum rotates continuously under the action of the transmission device. The tobacco shreds roll up and down and move forward in a spiral under the joint action of the drum and the copying plate inside the drum. During the movement of the tobacco shreds, the hot air and the drum wall jointly provide heat to dry the tobacco shreds, and finally fall from the discharge port of the discharge hood to enter the next process. Under the action of the hot air fan, the hot air enters the heater from the natural wind in the equipment environment, and the heated hot air is sent to the drum through the hot air duct and the feed hood.

[0004] The inventors have discovered that there are at least the following problems in the related art: the hot air entering the drum is the air in the equipment environment after being heated by the heater, and the humidity of the hot air is greatly affected by the natural environment, which makes it difficult to control the dehydration rate of the material due to environmental changes and / or material flow changes, ultimately resulting in poor control of the moisture content of the material. Summary of the invention

[0005] The present invention provides a material moisture content control system, a drum-type wire drying machine and a material moisture content control method, so as to improve the accuracy of controlling the material moisture content.

[0006] Some embodiments of the present invention provide a material moisture content control system, including:

[0007] The drum has a feed end, a discharge end, and an inner cavity for accommodating materials; the feed end and the discharge end are both connected to the inner cavity;

[0008] A temperature regulating device, the temperature regulating device is connected to the feed end of the drum to convey process air to the inner cavity of the drum via the feed end of the drum; or the temperature regulating device is connected to the discharge end of the drum to convey process air to the inner cavity of the drum via the discharge end of the drum;

[0009] A humidity regulating device, which is in communication with the inner cavity of the drum, so as to change the humidity inside the drum;

[0010] a feed flow rate detection device, configured to detect the flow rate of material entering the drum; and

[0011] The control device is signal-connected to the temperature regulating device, the humidity regulating device and the feed flow detection device. The control device is constructed to control the temperature of the process air delivered to the drum by the temperature regulating device and the humidity of the fluid delivered to the drum by the humidity regulating device according to the flow detected by the feed flow detection device.

[0012] In some embodiments, the temperature regulating device comprises:

[0013] a first air duct connected to the inner cavity of the drum;

[0014] a second air duct connected to the inner cavity of the drum; and

[0015] The heater is arranged on the first air duct.

[0016] In some embodiments, the temperature regulating device further comprises:

[0017] A third air duct, wherein a first end of the third air duct is connected to the feed end of the drum, and a second end of the third air duct is connected to the discharge end of the drum.

[0018] In some embodiments, the material moisture content control system further comprises:

[0019] An exhaust assembly, wherein the third air duct is connected to the discharge end of the drum through the exhaust assembly.

[0020] In some embodiments, the exhaust assembly includes:

[0021] a first return air duct, a first end of which is connected to the discharge end of the drum, and a second end of which is connected to one end of the third air duct; and

[0022] The second return air duct has a first end which is also connected to the discharge end of the drum, and a second end which is connected to one end of the first air duct.

[0023] In some embodiments, the temperature regulating device further comprises:

[0024] a first fan, wherein the first air duct, the second air duct and the third air duct are all in communication with a fluid inlet of the first fan; and

[0025] The connecting pipe is connected to the fluid outlet of the first fan.

[0026] In some embodiments, the first air duct is provided with a first regulating valve; and / or, the second air duct is provided with a second regulating valve; and / or, the third air duct is provided with a third regulating valve.

[0027] In some embodiments, the first return air duct is provided with a fourth regulating valve, and / or the second return air duct is provided with a fifth regulating valve.

[0028] In some embodiments, a condensed water discharge pipe is provided at a lower portion of the heater.

[0029] In some embodiments, the humidity regulating device comprises:

[0030] a steam supply pipeline, connected to the inner cavity of the drum, and configured to transport steam into the drum;

[0031] a dehumidification pipeline, also in communication with the inner cavity of the drum; and

[0032] a dehumidification device, disposed in the dehumidification pipeline, the dehumidification device being configured to reduce the humidity of the airflow entering the dehumidification pipeline;

[0033] Wherein, the steam supply pipeline and the dehumidification pipeline are either connected or both are not connected.

[0034] In some embodiments, the steam supply pipeline is provided with a flow regulating valve; and / or the dehumidification pipeline is provided with a sixth regulating valve.

[0035] In some embodiments, the material moisture content control system further comprises:

[0036] The vibration trough is arranged upstream of the drum, and the feed flow detection device is configured to weigh the weight of the material entering the vibration trough.

[0037] In some embodiments, the feed flow detection device includes a belt scale, and the belt scale is configured to calculate the material flow rate based on the weighed material weight.

[0038] Other embodiments of the present invention provide a drum-type silk drying machine, including a material moisture content control system provided by any technical solution of the present invention.

[0039] Some other embodiments of the present invention provide a material moisture content control method, which is implemented by using a material moisture content control system provided by any technical solution of the present invention, and the method comprises the following steps:

[0040] Determining the flow rate of material entering the drum;

[0041] According to the material flow rate, the control device controls the temperature of the process air in the drum through the temperature regulating device, and the control device controls the humidity of the process air in the drum through the humidity regulating device.

[0042] In some embodiments, if the material flow rate is lower than the set flow rate value, the temperature of the process air in the drum is reduced and / or the humidity of the process air in the drum is increased; if the material flow rate is higher than the set flow rate value, the temperature in the drum is increased and / or the humidity in the drum is reduced.

[0043] In some embodiments, before the step of determining the material flow rate entering the drum, the following steps are also included:

[0044] Determine whether the drum is in a preheating mode; wherein when the drum is in the preheating mode, there is no material in the drum;

[0045] If the drum is in the preheating mode, the exhaust assembly of the drum is connected to the first air duct and / or the third air duct to preheat the drum using the return air of the drum.

[0046] In some embodiments, the material moisture content control method further comprises the following steps:

[0047] Detecting the moisture content of the material output through the drum;

[0048] If the moisture content of the material is greater than the set humidity value, increase the temperature of the process air in the drum and / or reduce the humidity of the process air in the drum; if the moisture content of the material is less than the set humidity value, reduce the temperature of the process air in the drum and / or increase the humidity of the process air in the drum.

[0049] In the above technical solution, the control device controls the temperature of the process air output by the temperature regulating device and the humidity of the process air output by the humidity regulating device according to the flow rate of the material, so as to finally make the moisture content of the material output from the discharge end of the drum meet the process requirements. In the head mode, tail mode of production and when the material flow rate fluctuates during the production process, the temperature and humidity in the drum can be targeted and accurately controlled according to the flow rate of the material. It can be seen that the above technical solution realizes the closed-loop control of the moisture content of the material, and can feedback control (or be called closed-loop control) the temperature regulating device and the humidity regulating device according to the moisture content of the material output from the drum, thereby improving the sensitivity of the temperature and humidity regulation of the process air, thereby realizing the precise control of the moisture content of the material and improving the energy utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0051] Figure 1 A schematic diagram of the structure of a material moisture content control system provided by some embodiments of the present invention;

[0052] Figure 2 A schematic diagram of the principle of a humidity regulating device for a material moisture content control system provided by other embodiments of the present invention;

[0053] Figure 3 A schematic flow chart of a material moisture content control method provided in some embodiments of the present invention. DETAILED DESCRIPTION

[0054] Combine the following Figure 1 to Figure 3 The technical solution provided by the present invention is described in more detail.

[0055] See also Figure 1 to Figure 2 Some embodiments of the present invention provide a material moisture content control system, including a drum 1, a temperature regulating device 2, a humidity regulating device 3, a feed flow detection device 4 and a control device (not shown).

[0056] The drum 1 has a feed end 11, a discharge end 12 and an inner cavity 13 for accommodating materials; the feed end 11 and the discharge end 12 are both connected to the inner cavity 13. The drum 1 is supported by a bracket 8. The temperature regulating device 2 is connected to the feed end 11 and / or the inner cavity 13 of the drum 1 to change the temperature inside the drum 1, specifically, the temperature inside the drum 1 can be changed by changing the temperature of the process air entering the drum 1. The humidity regulating device 3 is connected to the inner cavity 13 of the drum 1 to change the humidity inside the drum 1, specifically, the humidity inside the drum 1 can be increased by increasing the humidity of the process air entering the drum 1 or by delivering steam alone, or by reducing the humidity of the process air entering the drum 1 or by delivering dry gas to the drum 1. The feed flow detection device 4 is configured to detect the flow of materials entering the drum 1. The control device is signal-connected with the temperature regulating device 2, the humidity regulating device 3 and the feed flow detection device 4. The control device is configured to control the temperature of the process air delivered to the drum 1 by the temperature regulating device 2 and the humidity of the fluid delivered to the drum 1 by the humidity regulating device 3 according to the flow detected by the feed flow detection device 4. The fluid is specifically steam or dried air.

[0057] The control device, for example, uses a control component such as a PLC, and the control device is used to control the temperature of the process air output by the temperature regulating device 2 and the humidity output by the humidity regulating device 3, so as to ultimately make the moisture content of the material output from the discharge end 12 of the drum 1 meet the process requirements. The above technical solution realizes the closed-loop control of the moisture content of the material, and can feedback control (or closed-loop control) the temperature parameters of the temperature regulating device 2 and the humidity parameters of the humidity regulating device 3 according to the moisture content of the material output from the drum 1, thereby realizing the precise control of the moisture content of the processed material.

[0058] The specific implementation methods of each component are described in detail below.

[0059] See also Figure 1 The drum 1 is the main component of material drying. Driven by the external transmission device, the drum 1 keeps rotating around its own axis. A drum heating component 14 is installed on the drum 1. A feed cover 15 is installed at one end of the drum 1, and a discharge cover 16 is installed at the other end. A shoveling plate is arranged in the inner cavity 13 of the drum 1. One axial end of the drum 1 is the feed end 11, and the other axial end is the discharge end 12. The material enters the drum 1 through the feed end 11. Under the joint action of the inner wall of the drum 1 and the shoveling plate, the material turns upside down and moves forward in a spiral until it moves to the discharge end 12 of the drum 1, and then is discharged. During the movement of the tobacco in the drum 1, the tobacco is dried to the set humidity under the joint action of the process air delivered by the temperature regulating device 2 and the steam delivered by the humidity regulating device 3.

[0060] The wind delivered by the temperature regulating device 2 is delivered to the inner cavity 13 of the drum 1 through the feed end 11 of the drum 1, and the wind flows along the forward direction of the material, and finally outputted from the discharge end 12 of the drum 1. In order to reduce the amount of tobacco contained in the outputted gas, a separate air outlet can be provided on the side where the discharge end 12 of the drum 1 is located to discharge the gas in the drum 1. Alternatively, a filter assembly is provided at the discharge end 12 of the drum 1 to block the tobacco inside the drum 1 and only discharge the wind from the air duct. The material is discharged from the discharge cover 16 to prevent debris and dust from entering the temperature regulating device 2.

[0061] The temperature regulating device 2 is used to supplement heat energy to the drum-type silk drying machine to dry the material. The temperature regulating device 2 can convey process air along the flow direction of the material, and can also convey process air against the flow direction of the material. Specifically, conveying process air along the flow direction of the material means: the process air conveyed by the temperature regulating device 2 is input into the drum 1 from the feed end 11 of the drum 1, and is output from the drum 1 from the discharge end 12 of the drum 1. Conveying process air against the flow direction of the material means: the process air conveyed by the temperature regulating device 2 is input into the drum 1 from the discharge end 12 of the drum 1, and is output from the drum 1 from the feed end 11 of the drum 1. The following will introduce in detail according to different situations.

[0062] The exhaust assembly 6 is used to discharge the water vapor evaporated from the material out of the equipment. The humidity regulating device 3 can be directly connected to the process air in the temperature regulating device 2 to supplement and / or reduce the moisture, so as to increase and / or reduce the humidity of the process air. The humidity regulating device 3 can also change the humidity inside the drum 1 by separately conveying steam or dry air to the inside of the drum 1.

[0063] In some embodiments, the temperature adjustment device 2 includes a first air duct 21, a second air duct 22 and a heater 23. The first air duct 21 is connected to the inner cavity 13 of the drum 1. The second air duct 22 is also connected to the inner cavity 13 of the drum 1. The heater 23 is disposed on the first air duct 21.

[0064] The first air duct 21 is provided with a heater 23, and the first air duct 21 is used to transport high-temperature gas into the drum 1 to heat the material in the drum 1. The second air duct 22 is not provided with a heater 23, and the second air duct 22 is used to transport low-temperature gas into the drum 1. When the control device detects that the temperature inside the drum 1 is higher than the set temperature value, the temperature inside the drum 1 is lowered through the second air duct 22 to prevent the material from being over-dried. When the control device detects that the temperature inside the drum 1 is lower than the set temperature value, the temperature inside the drum 1 is increased through the first air duct 21 to prevent the moisture content of the material from being too high and / or the material from shrinking when it is cold.

[0065] The gas in the first air duct 21 may be sourced from air, which is heated into high-temperature gas by entering the heater 23 and then transported to the feed end 11 of the drum 1. In order to reduce the impurities in the air from entering the drum 1 and affecting the quality of the material in the drum 1, a filter component, such as a filter screen, may be provided at the air inlet of the first air duct 21.

[0066] The gas source in the second air duct 22 can also be the air in the surrounding environment of the equipment. The air does not need to be heated. When introduced into the drum 1, it can play a role in reducing the temperature inside the drum 1. The above setting is based on the material being tobacco. The temperature required for drying tobacco is about 130°C, so using air can play a cooling role. In situations where rapid cooling is required, a lower temperature airflow can also be introduced into the second air duct 22.

[0067] In other embodiments, the temperature regulating device 2 further includes a third air duct 24, a first end of the third air duct 24 is communicated with the feed end 11 of the drum 1, and a second end of the third air duct 24 is communicated with the discharge end 12 of the drum 1. The third air duct 24 and the first return air duct 61 described later may be one end of the same pipe, or two pipes may be connected together.

[0068] The gas source of the third air duct 24 is the exhaust gas discharged from the drum 1. During the preheating operation of the drum 1, the temperature of the exhaust gas discharged from the drum 1 is higher than the temperature of the air. The preheating time of the drum 1 can be greatly shortened by using the method of using the exhaust gas discharged from the drum 1 to be led back into the drum 1 for heating. Compared with the method in the related art of using a heater 23 to heat the air and then passing it into the drum 1, and the drum 1 normally discharges the exhaust gas, the time required for preheating the drum 1 is reduced from about 30 minutes to less than 10 minutes, the preheating efficiency is greatly improved, and energy waste is reduced.

[0069] In order to simplify the structure of the material moisture content control system and make it more compact, in some embodiments, the third air duct 24 is connected to the discharge end 12 of the drum 1 through the exhaust assembly 6.

[0070] See also Figure 1 , the specific implementation method of the exhaust component 6 is introduced below.

[0071] In some embodiments, the exhaust assembly 6 includes a first return air duct 61 and a second return air duct 62. The first end of the first return air duct 61 is connected to the discharge end 12 of the drum 1, and the second end of the first return air duct 61 is connected to one end of the third air duct 24. The first end of the second return air duct 62 is also connected to the discharge end 12 of the drum 1, and the second end of the second return air duct 62 is connected to one end of the first air duct 21.

[0072] The first return air duct 61 leads the return air of the drum 1 directly back to the third air duct 24, and then enters the drum 1. The second return air duct 62 leads the return air of the drum 1 to the air inlet end of the heater 23, so that the return air of the drum 1 can be further heated before being transported to the drum 1, and the heating efficiency of the process air is higher. The above technical scheme allows the return air and / or process air to be heated by the heater 23 under the action of the first fan 27, thereby increasing the temperature of the process air, and recycling the process air discharged by the exhaust component 6 to save energy and shorten the preheating time of the drum.

[0073] In some embodiments, the exhaust assembly 6 further includes an exhaust pipe 65, one end of which is connected to the discharge end 12 of the drum 1, and the other end of which is directly connected to the outside atmosphere. The exhaust pipe 65 is used to directly discharge the gas discharged from the drum 1.

[0074] The exhaust pipe 65, the first return air pipe 61 and the second return air pipe 62 can all be connected to the second fan 63, and the second fan can discharge the exhaust gas discharged from the drum 1 into each air pipe more smoothly. The second fan 63 adopts a variable frequency control fan. The first fan 27 and the second fan 63 are far apart, which can reduce or even avoid the mutual interference between the second fan and the first fan, which is conducive to the gas in the exhaust assembly 6. Control of the flow in the exhaust assembly 6.

[0075] The exhaust assembly 6 provided by the above technical solution can discharge the exhaust gas: discharge it outside the equipment, recycle it into the temperature regulating device 2, recycle part of it into the temperature regulating device 2 and discharge part of it outside the equipment. In addition, the airflow recycled into the temperature regulating device 2 can pass through the heater 23 completely, not pass through the heater 23 completely, pass through the heater 23 partially and not pass through the heater 23 partially. It can be seen that the exhaust assembly 6 provided by the above technical solution can realize a variety of different working modes, and is very flexible and convenient to use.

[0076] In some embodiments, the temperature regulating device 2 further includes a first fan 27 and a connecting pipe 25. The first fan 27 is a variable frequency speed regulating fan. The first air duct 21, the second air duct 22 and the third air duct 24 are all connected to the fluid inlet of the first fan 27, so that the return air and the process air can be more fully mixed under the turbulence of the first fan 27 and then sent to the drum 1, so that the tail gas with high moisture content and high temperature can be recycled, the humidity and temperature of the process air in the connecting pipe 25 can be increased, and the medium and heat energy can be humidified at the same time. The connecting pipe 25 is connected to the fluid outlet of the first fan 27. A temperature detection element 251 can be set on the connecting pipe 25 to detect the fluid temperature in the connecting pipe 25. A humidity detection element 252 can be set on the connecting pipe 25 to detect the fluid humidity in the connecting pipe 25. The above technical solution is provided with the first fan 27, so that the airflow in the first air duct 21, the second air duct 22 and the third air duct 24 is more easily transported to the inside of the drum 1. The connecting pipe 25 is provided to simplify the piping arrangement of the material moisture content control system, making its structure more compact and reasonable.

[0077] In order to facilitate the control of the connection state of each pipeline, each pipeline can be individually provided with a regulating valve to control its own on-off and fluid flow. Specifically: the first air duct 21 is provided with a first regulating valve 211. The second air duct 22 is provided with a second regulating valve 221. The third air duct 24 is provided with a third regulating valve 241. The first return air duct 61 is provided with a fourth regulating valve 611. The second return air duct 62 is provided with a fifth regulating valve 621.

[0078] See also Figure 1 In some embodiments, a condensate discharge pipe 26 is provided at a lower part of the heater 23, such as the lowest part. The first air duct 21 can be arranged at the lowest part by changing its structure and installation direction, such as by tilting it relative to the horizontal plane, and the heater 23 is arranged near the lowest part. Condensate in the process air can be discharged through the condensate discharge pipe 26.

[0079] See also Figure 1 and Figure 2 , the specific implementation method of the humidity adjustment device 3 is introduced below.

[0080] In some embodiments, the humidity regulating device 3 includes a steam supply pipeline 31, a dehumidification pipeline 32 and a dehumidification device 33. The steam supply pipeline 31 is used to increase the humidity of the process air in the drum 1, reduce the dehydration rate of the material to increase the moisture content of the material. The dehumidification pipeline 32 and the dehumidification device 33 are used to reduce the humidity of the process air in the drum 1, accelerate the dehydration rate of the material to reduce the moisture content of the material. The dehumidification pipeline 32 may not be a separate pipeline, but directly utilize the pipeline or connecting pipe 25 for conveying process air. In some embodiments, the connecting pipe 25 is used as the dehumidification pipeline 32, and the dehumidification device 33 is arranged upstream of the first fan 27 to dehumidify the process air entering the first fan 27. The first fan 27 can be arranged at the inlet of the connecting pipe 25 or the outlet of the first air duct 21. There is no necessary direct connection between the steam supply pipeline 31 and the dehumidification pipeline 32. The two can be independent pipelines, each connected to the inner cavity 13 of the drum 1, Figure 2 It shows that the two are directly connected. Figure 1 The diagram shows a case where the first air duct 21 is used as the dehumidification pipeline 32. However, it is understandable that the steam supply pipeline 31 and the dehumidification pipeline 32 may also have other relative positional relationships.

[0081] The steam supply pipeline 31 is connected to the inner cavity 13 of the drum 1, and is configured to supply steam to the drum 1. If the process air is provided along the flow direction of the material, the steam supply pipeline 31 is connected to the feed end 11 of the drum 1. If the process air is provided against the flow direction of the material, the steam supply pipeline 31 is connected to the discharge end 12 of the drum 1.

[0082] In order to simplify the number of components, the steam supply pipeline 31 can also be connected to the connecting pipe 25 described above or the air inlet end of the first fan 27. The steam supply pipeline 31 transports the steam to the upstream of the first fan 27, so that the applied steam can be mixed with the process air in the first air duct 21 under the turbulent effect of the first fan 27, so that the temperature and humidity of the process air entering the drum 1 through the connecting pipe 25 are more uniform and stable.

[0083] The return air, process air and steam are all introduced into the connecting pipe 25. The process air in the connecting pipe 25 is a gas obtained by fully mixing the return air, process air and steam. In this way, the temperature and humidity of the process air entering the drum 1 can be measured more accurately.

[0084] In some embodiments, the steam supply pipeline 31 is provided with a flow regulating valve 311. A steam nozzle may be installed at the output end of the steam supply pipeline 31, and a flow regulating valve 311 is installed in the steam supply pipeline 31. The input end of the steam pipe is connected to a steam source.

[0085] The dehumidification pipeline 32 is also connected to the feed end 11 of the drum 1. The dehumidification device 33 is arranged on the dehumidification pipeline 32, and the dehumidification device 33 is configured to reduce the humidity of the airflow entering the dehumidification pipeline 32. The steam supply pipeline 31 and the dehumidification pipeline 32 are selectively connected or both are not connected. In some embodiments, the dehumidification pipeline 32 is provided with a sixth regulating valve 321.

[0086] See also Figure 1 The material moisture content control system further includes a vibration trough 7, which is used to loosen and transport the material. The vibration trough 7 is arranged upstream of the drum 1, and the feed flow detection device 4 is configured to weigh the weight of the material entering the vibration trough 7.

[0087] In some embodiments, the feed flow detection device 4 includes a belt scale, which is used to adjust the material flow, control the stability of the material flow, and detect the material incoming and outage conditions. The belt scale is connected to the control device signal to send the material weight measured by the belt scale to the control device. The control device calculates the material flow according to the material weight, and then controls the process air temperature of the temperature adjustment device 2 to the inside of the drum 1 and the humidity of the process air of the humidity adjustment device 3 to the inside of the drum 1.

[0088] In other embodiments, the air delivered by the temperature regulating device 2 is delivered to the inner cavity 13 of the drum 1 via the discharge end 12 of the drum 1, and the process air flows against the moving direction of the material and is finally output from the feed end 11 of the drum 1. In this arrangement, the return air of the drum 1 can still be used to improve the efficiency of preheating the drum 1, and to control the temperature and / or humidity of the process air.

[0089] The following introduces the specific working process of the material moisture content control system used in tobacco drying.

[0090] The whole working process is divided into four stages: preheating mode, material head mode, production mode, and material tail mode. There will be special processing operations under abnormal circumstances, which will be introduced later.

[0091] First, the preheating mode is introduced: in the preheating mode, there is no material inside the drum 1.

[0092] The drum-type silk drying machine, the first fan 27 , the second fan 63 , the heater 23 and the drum heating assembly 14 are started, and the humidity regulating device 3 is turned off.

[0093] At the same time, the first regulating valve 211, the second regulating valve 221, the third regulating valve 241 and the exhaust gas discharge valve 64 are closed, and the fifth regulating valve 621 is opened. Based on this, the air in the drum 1 and the temperature regulating device 2 enters the inner cavity 13 of the drum 1 through the heater 23, the first air duct 21, the connecting pipe 25 and the feed cover 15 under the action of the first fan 27. Afterwards, under the action of the second fan 63, the process air enters the heater from the drum through the discharge cover 16, the exhaust assembly 6, and the second return air duct 62. This cycle is repeated, and the process air is continuously heated and heated by the heater 23. In this process, the drum 1 and the temperature regulating device 2 are heated and heated.

[0094] The temperature detection element 251 timely detects the temperature of the process air transported in the connecting pipe 25. When the process air temperature reaches the set temperature range required by the process, the heat energy supply of the heater 23 is reduced, the opening of the third regulating valve 241 is increased, and the opening of the fifth regulating valve 621 is reduced, so that the process air temperature is always maintained within the preset preheating temperature range.

[0095] After the preheating of the drum-type silk drying machine is completed, it enters the standby state, and the belt scale and the vibration trough 7 also enter the standby state to wait for the material to enter the drum 1 to complete the preheating process.

[0096] The following introduces the material head mode: In the material head mode, the material flow rate entering the drum 1 is relatively small (lower than the material flow rate during normal production).

[0097] After the belt scale detects the incoming material signal, in the preheating mode, the third regulating valve 241 is adjusted to a larger value, the fifth regulating valve 621 is adjusted to a smaller value, and the opening of the exhaust gas discharge valve 64 is adjusted;

[0098] After the belt scale detects the incoming signal, after a delay of t01, the flow regulating valve of the humidity regulating device 3 is opened to provide a certain flow of steam to the temperature regulating device 2 to increase the humidity of the process air. In this process, part of the exhaust gas discharged from the exhaust assembly 6 is discharged out of the equipment through the exhaust pipe 65 to take away some moisture, and part is recovered to the temperature regulating device 2 through the first return air duct 61 and / or the second return air duct 62, thereby reducing exhaust gas emissions and energy waste. Based on this, when the material has not yet reached the rated flow of the equipment, the moisture transfer rate between the material and the process air is reduced, so that the dehydration rate of the material in the drum at the head stage is reduced, thereby reducing the amount of material at the head stage whose moisture content is lower than the moisture content required by the process standard;

[0099] The steam flow rate applied by the steam nozzle of the humidity regulating device 3 can obtain an empirical value through debugging, which is used as the preset valve opening K0 of the flow regulating valve. Based on this, each time the material head mode is entered, the valve opening is set to the preset valve opening value K0. When the moisture content of the material head is lower than the process standard, the steam flow rate of the humidity regulating device 3 is increased, and when the moisture content of the material head is higher than the process standard, the steam flow rate of the humidity regulating device 3 is decreased.

[0100] When part of the material flows out from the discharge hood 16, after a delay of t02, the flow regulating valve 311 of the humidity regulating device 3 is closed, and the application of steam to the temperature regulating device 2 is stopped, and the material head mode ends.

[0101] The production mode is introduced below: In the production mode, the positive product flow enters the drum 1 normally.

[0102] After the material head mode ends, it will switch to production mode immediately;

[0103] In the material head mode, the openings of the third regulating valve 241 and the fifth regulating valve 621 are reduced, and the exhaust gas discharge valve 64 and the first regulating valve 211 are opened. Based on this, part of the exhaust gas discharged from the exhaust component 6 is recycled.

[0104] According to the moisture content of the export material, the humidity of the process air is adjusted in time. When the moisture content of the export material is lower than the process standard, the humidity of the process air is increased. When the moisture content of the export material is higher than the process standard, the humidity of the process air is lowered.

[0105] The temperature detection element 251 timely detects the temperature of the process air transported in the connecting pipe 25. When the process air temperature is not within the set temperature range required by the process, the opening of the second regulating valve 221 is timely adjusted. When the process air temperature is lower than the set temperature range, the opening of the second regulating valve 221 is reduced or closed. When the process air temperature is higher than the set temperature range, the opening of the second regulating valve 221 is increased, so that the process air temperature is always kept within the preset temperature range. And / or, when the process air temperature is not within the set temperature range required by the process, the opening of the third regulating valve 241 and the fifth regulating valve 621 are timely adjusted. When the process air temperature is lower than the set temperature range, the opening of the third regulating valve 241 is reduced or closed and the opening of the fifth regulating valve 621 is increased; when the process air temperature is higher than the set temperature range, the opening of the third regulating valve 241 is increased and the opening of the fifth regulating valve 621 is reduced or closed, so that the process air temperature is always kept within the preset temperature range. Based on this, the process air temperature can be quickly adjusted to avoid the lag in process air temperature adjustment caused by the thermal inertia of the heater, and the energy utilization rate can be improved by recycling the exhaust gas.

[0106] The following introduces the tail mode: In the tail mode, the material flow rate gradually decreases.

[0107] After the belt scale detects the signal of no material and / or significant decrease in material flow, after a delay of t11 in the production mode, the third regulating valve 241 is opened, and the opening of the exhaust gas discharge valve 64 and the first regulating valve 211 is reduced, so that part or all of the tail gas discharged from the discharge end of the drum 1 is recovered to the temperature regulating device through the first return air duct 61 and / or the second return air duct 62. The humidity regulating device 3 is opened, and steam is applied to the temperature regulating device 2. Based on this, in the process of reducing the material flow, the moisture transfer rate between the material and the process air is reduced, and the rate of dehydration of the material in the drum at the tail stage is reduced, thereby reducing the amount of material at the tail stage whose moisture content is lower than the moisture content required by the process standard.

[0108] The steam flow rate applied by the steam nozzle of the humidity regulating device 3 can be obtained through debugging to obtain an empirical value, which is used as the preset valve opening K1 of the flow regulating valve. Based on this, each time the tail material mode is entered, the valve opening is set to the preset valve opening value K1. When the moisture content of the material at the tail material is lower than the process standard, the steam flow rate of the humidity regulating device 3 is increased, and when the moisture content of the material at the tail material is higher than the process standard, the steam flow rate of the humidity regulating device 3 is decreased.

[0109] After the material-free signal is delayed for a time period of t12, the flow regulating valve 311 of the humidity regulating device 3 is closed, the application of steam to the temperature regulating device 2 is stopped, and the material tail mode ends.

[0110] Abnormal mode:

[0111] During the production process, a sharp drop in material flow or a sudden material cutoff is called an abnormal state, and the abnormal mode is used to control the moisture content of the material;

[0112] During the production process, when the belt scale detects a sharp drop in material flow or a sudden material cut, it enters the tail mode. After the tail mode ends, it enters the preheating mode; when the belt scale detects an increase in material flow or resumes feeding, it enters the head mode; after the head mode ends, it enters the production mode; if the preheating mode runs for more than the preset time and the belt scale has not detected the material flow, it will stop production.

[0113] Based on the above technical solution, the humidity of the process air can be adjusted by the humidity regulating device in the material head mode, production mode, material tail mode and / or abnormal mode, thereby adjusting the dehydration rate of the tobacco shreds in the material drying process and reducing the amount of materials whose moisture content does not meet the process requirements; the return air device of the exhaust assembly can be used to circulate the process air to reduce the preheating time of the equipment, or the tail gas can be recovered to the temperature regulating device 2 when the material flow rate decreases, and the process air temperature and humidity can be adjusted to avoid excessive drying of the material. At the same time, energy utilization is improved and environmental pollution is reduced.

[0114] See also Figure 2 The embodiment of the present invention further provides a material moisture content control method, which is implemented by using the material moisture content control system provided by any embodiment of the present invention, and the method includes the following steps:

[0115] Step S100, determining the material flow rate entering the drum 1.

[0116] A flow sensor may be used to directly detect the flow of the material entering the drum 1. The belt scale introduced above may also be used to weigh the material, and the material flow may be calculated by the weight of the material added to the drum 1 per unit time.

[0117] Step S200 , according to the material flow rate, the control device controls the temperature of the process air in the drum 1 through the temperature adjustment device 2 , and the control device controls the humidity of the process air in the drum 1 through the humidity adjustment device 3 .

[0118] In step S200, if the material flow rate is lower than the set flow rate value, the temperature inside the drum 1 is reduced and / or the humidity inside the drum 1 is increased; if the material flow rate is higher than the set flow rate value, the temperature inside the drum 1 is increased and / or the humidity inside the drum 1 is reduced.

[0119] In the above step S200, if the material flow rate is lower than the set flow rate value, three methods can be adopted for adjustment: lowering the temperature in the drum 1 alone, increasing the humidity in the drum 1 alone, and lowering the temperature in the drum 1 and increasing the humidity in the drum 1 at the same time. In the method of lowering the temperature in the drum 1 alone, the humidity in the drum 1 can remain unchanged. In the method of increasing the humidity in the drum 1 alone, the temperature in the drum 1 can remain unchanged.

[0120] Similarly, in the above step S200, if the material flow rate is higher than the set flow rate value, three methods can be adopted for adjustment: increasing the temperature in the drum 1 alone, decreasing the humidity in the drum 1 alone, and increasing the temperature in the drum 1 and decreasing the humidity in the drum 1 at the same time. In the method of increasing the temperature in the drum 1 alone, the humidity in the drum 1 can remain unchanged. In the method of decreasing the humidity in the drum 1 alone, the temperature in the drum 1 can remain unchanged.

[0121] Before the above step S100, the following steps are also included:

[0122] Step S300, determining whether the drum 1 is in the preheating mode. When the drum 1 is in the preheating mode, there is no material in the drum 1.

[0123] Step S400: If the drum 1 is in the preheating mode, the exhaust assembly 6 of the drum 1 is connected to at least one of the third air duct 24 and the first air duct 21, so as to use the return air of the drum 1 to preheat the drum 1. If the exhaust assembly 6 is connected to the third air duct 24, the return air of the drum 1 is directly used to preheat the drum 1. If the exhaust assembly 6 is connected to the first air duct 21, the return air of the drum 1 is heated and then transported to the drum 1 to preheat the drum 1, and the preheating efficiency is higher. Regulating valves can be set in the third air duct 24 and the first air duct 21 to control whether each air duct is connected.

[0124] After the above step S200, the following steps are also included:

[0125] S500 , detecting the moisture content of the material outputted from the drum 1 .

[0126] S600. If the moisture content of the material is greater than the set humidity value, increase the temperature of the process air in drum 1 and / or reduce the humidity of the process air in drum 1; if the moisture content of the material is less than the set humidity value, reduce the temperature of the process air in drum 1 and / or increase the humidity of the process air in drum 1.

[0127] The above method first enters the preheating mode to preheat the drum-type silk drying machine.

[0128] After the production conditions are met, the material is transported to the vibrating trough at a preset constant flow rate through the belt scale. When the material passes through the belt scale, the incoming material signal is sent to the drum dryer, and the drum dryer enters the material head mode.

[0129] After the material head mode ends, it enters the production mode. When an abnormal situation occurs in the production process, it enters the abnormal mode.

[0130] After the production mode ends, it enters the tail mode until the production ends.

[0131] Optionally, all exhaust gases discharged from the discharge end of the drum 1 do not pass through the second return air duct 62 and the heater 23 in the head mode, production mode and tail mode, so as to prevent the smoke oil, dust and the like contained in the exhaust gas from adhering to the heater 23 and reducing the thermal efficiency of the heater 23.

[0132] Through the above-mentioned adjustment method, the control accuracy of the moisture content of the material is greatly improved, the moisture content SD of the exported material is controlled within 0.15%, and the amount of dry head and dry tail materials is reduced by more than 60%.

[0133] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A material moisture content control system, characterized in that: include: The drum (1) has a feed end (11), a discharge end (12) and an inner cavity (13) for accommodating materials; the feed end (11) and the discharge end (12) are both in communication with the inner cavity (13); a temperature regulating device (2), the temperature regulating device (2) being in communication with the feed end (11) of the drum (1) so as to convey process air to the inner cavity (13) of the drum (1) via the feed end (11) of the drum (1); or the temperature regulating device (2) being in communication with the discharge end (12) of the drum (1) so as to convey process air to the inner cavity (13) of the drum (1) via the discharge end (12) of the drum (1); A humidity regulating device (3) is communicated with the inner cavity (13) of the drum (1) to change the humidity inside the drum (1); A material flow rate detection device (4) configured to detect the material flow rate entering the drum (1); a control device, connected to the temperature regulating device (2), the humidity regulating device (3) and the feed flow detection device (4) by signals, the control device being configured to control the temperature of the process air delivered to the drum (1) by the temperature regulating device (2) and the humidity of the fluid delivered to the drum (1) by the humidity regulating device (3) according to the flow detected by the feed flow detection device (4); as well as A vibration trough (7) is arranged upstream of the drum (1), and the feed flow detection device (4) is configured to weigh the weight of the material entering the vibration trough (7); Wherein, the temperature regulating device (2) comprises: A first air duct (21) communicates with the inner cavity (13) of the drum (1); a second air duct (22) connected to the inner cavity (13) of the drum (1); and The heater (23) is arranged on the first air duct (21).

2. The material moisture content control system according to claim 1, characterized in that: The temperature regulating device (2) further comprises: A third air duct (24), wherein a first end of the third air duct (24) is connected to a feed end (11) of the drum (1), and a second end of the third air duct (24) is connected to a discharge end (12) of the drum (1).

3. The material moisture content control system according to claim 2, characterized in that: Also includes: An exhaust assembly (6), wherein the third air duct (24) is connected to the discharge end (12) of the drum (1) through the exhaust assembly (6).

4. The material moisture content control system according to claim 3, characterized in that: The exhaust assembly (6) comprises: A first return air duct (61), a first end of which is in communication with the discharge end (12) of the drum (1), and a second end of which is in communication with one end of the third air duct (24); and The second return air duct (62) has a first end which is also connected to the discharge end (12) of the drum (1), and a second end which is connected to one end of the first air duct (21).

5. The material moisture content control system according to claim 4, characterized in that: The temperature regulating device (2) further comprises: a first fan (27), wherein the first air duct (21), the second air duct (22) and the third air duct (24) are all in communication with a fluid inlet of the first fan (27); and A connecting pipe (25) is connected to the fluid outlet of the first fan (27).

6. The material moisture content control system according to claim 3, characterized in that: The first air duct (21) is provided with a first regulating valve (211); and / or the second air duct (22) is provided with a second regulating valve (221); and / or the third air duct (24) is provided with a third regulating valve (241).

7. The material moisture content control system according to claim 4, characterized in that: The first air return duct (61) is provided with a fourth regulating valve (611), and / or the second air return duct (62) is provided with a fifth regulating valve (621).

8. The material moisture content control system according to claim 1, characterized in that: A condensed water discharge pipe (26) is provided at the lower part of the heater (23).

9. The material moisture content control system according to claim 1, characterized in that: The humidity regulating device (3) comprises: a steam supply pipeline (31) connected to the inner cavity (13) of the drum (1), the steam supply pipeline (31) being configured to transport steam into the drum (1); A dehumidification pipeline (32) is also connected to the inner cavity (13) of the drum (1); and a dehumidification device (33), arranged in the dehumidification pipeline (32), the dehumidification device (33) being configured to reduce the humidity of the airflow entering the dehumidification pipeline (32); Wherein, the steam supply pipeline (31) and the dehumidification pipeline (32) are either connected or both are not connected.

10. The material moisture content control system according to claim 9, characterized in that: The steam supply pipeline (31) is provided with a flow regulating valve (311); and / or the dehumidification pipeline (32) is provided with a sixth regulating valve (321).

11. The material moisture content control system according to claim 1, characterized in that: The feed flow detection device (4) comprises a belt scale, and the belt scale is configured to calculate the material flow rate based on the weighed material weight.

12. A drum-type silk drying machine, characterized in that: It comprises the material moisture content control system described in any one of claims 1 to 11.

13. A method for controlling moisture content of materials, characterized in that: The method is implemented by using the material moisture content control system according to any one of claims 1 to 11, and the method comprises the following steps: Determining the flow rate of material entering the drum; According to the material flow rate, the control device controls the temperature of the process air in the drum through the temperature regulating device, and the control device controls the humidity of the process air in the drum through the humidity regulating device.

14. The material moisture content control method according to claim 13, characterized in that: If the material flow rate is lower than the set flow rate value, the temperature of the process air in the drum is reduced and / or the humidity of the process air in the drum is increased; if the material flow rate is higher than the set flow rate value, the temperature in the drum is increased and / or the humidity in the drum is reduced.

15. The material moisture content control method according to claim 13, characterized in that: Before the step of determining the material flow rate entering the drum, the following steps are also included: Determine whether the drum is in a preheating mode; wherein when the drum is in the preheating mode, there is no material in the drum; If the drum is in the preheating mode, the exhaust assembly of the drum is connected to the first air duct and / or the third air duct to preheat the drum using the return air of the drum.

16. The material moisture content control method according to claim 13, characterized in that: The following steps are also included: Detecting the moisture content of the material output through the drum; If the moisture content of the material is greater than the set humidity value, increase the temperature of the process air in the drum and / or reduce the humidity of the process air in the drum; if the moisture content of the material is less than the set humidity value, reduce the temperature of the process air in the drum and / or increase the humidity of the process air in the drum.

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