Device and control method for improving quality of temperature-increasing expansion steam of cut tobacco shreds

Abstract

The invention belongs to the technical field of tobacco production equipment, and particularly relates to a device and a control method for improving the quality of cut tobacco heating expansion steam. According to the device, a steam heating device and a steam dryness detector are installed on the side, close to a cut tobacco drying procedure, of a steam pipeline provided for the cut tobacco drying procedure; the steam dryness detector is installed on a steam pipeline at the inlet end of the cut tobacco drying process. According to the technical scheme, the steam heating device is additionally arranged on the steam pipeline close to the cut tobacco drying process, and the steam dryness can be stabilized by assisting adjustment of the pressure detection instrument and the PID controller, so that a steam heat source of the cut tobacco drying process does not change due to seasons and climates, and the quality of the steam source of the cut tobacco drying process is stable; and the quantity of hot air formed by heating is more stable among batches of the cut tobacco drying process.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco production equipment, and in particular relates to a device and a control method for improving the quality of steam for heating and expanding cut shreds. Background Art

[0002] Steam dryness refers to the percentage of steam in the total volume per unit time at a fixed steam pressure and temperature, that is, the mass of saturated steam contained in a unit mass of wet steam. Steam is the main heat source in the silk-making process. The steam pressure control of the drum drying tube wall and the steam injection ratio control for loosening moisture regain / leaf moistening are actually all about controlling the heat provided by steam.

[0003] In the article "The Effect of Steam Dryness on Product Quality in Different Silk Making Processes", the author, Wu Yusheng, etc., mentioned that in the direct contact process, with the increase of steam dryness, the temperature of tobacco tends to rise. When the steam dryness is greater than 85%, the rise of tobacco temperature increases. The moisture content of tobacco tends to slowly decrease with the increase of steam dryness. When the steam dryness is greater than 85%, the decline of tobacco moisture content decreases. That is, in the direct contact process, the steam dryness higher than 85% is selected, and the product quality is better. In the indirect contact process, with the increase of steam dryness, the dehydration rate of tobacco tends to increase. With the increase of steam dryness, the standard deviation of tobacco moisture content tends to decrease. When the steam dryness is greater than 80%, the rise of tobacco dehydration rate increases. With the increase of steam dryness, the standard deviation of tobacco moisture content tends to decrease. When the steam dryness is higher than 80%, the decline of the standard deviation of tobacco moisture content decreases. That is, in the indirect contact process, the steam dryness higher than 90% is selected, and the product quality is better.

[0004] However, in this article, it is only mentioned in theory that when the steam dryness is greater than 85% or 90%, the product quality will be good, but it does not mention how to implement this theory on a normal production line. Because, although the steam pressure or flow can be well controlled during the production process, the temperature and dryness of the steam are affected by changes in the supply pressure and environment, and there are batch differences. There are differences in the heat supplied between batches, which in turn causes fluctuations in processing intensity. In addition, factors such as pressure fluctuations in the steam supply or long conveying pipelines will affect the steam dryness. If the steam dryness is too low, it will not meet the process requirements of the subsequent silk making and drying process; if the steam dryness is too high, it will cause the steam to contain too much water, affecting the thermal efficiency and causing large batch differences. Therefore, stable and suitable steam dryness and stable steam pressure are key factors to ensure the stability of the silk making and drying process. Summary of the invention

[0005] The object of the present invention is to provide a device and a control method for improving the quality of steam expanded by heating after cutting blades, so as to solve the problems mentioned in the above background technology.

[0006] To achieve the above objectives, this application is implemented through the following technical solutions:

[0007] A device for improving the quality of steam for heating and expanding cut shreds, which is provided to the material heating and humidifying process and / or the thin plate drying cylinder wall steam pipeline, and includes a steam-water separation device, a steam heating device, a steam temperature detector and a steam dryness detector in sequence from the steam supply direction.

[0008] Furthermore, in the material heating and humidifying process, the steam flow path sequentially passes through the first pressure reducing valve, the first steam-water separation device, the first steam heating device, the first steam temperature detector, the first steam dryness detector, the first flow meter, the first pressure sensor, and the first pneumatic diaphragm valve before entering the material heating and humidifying process; and / or,

[0009] In the thin plate drying process, the steam flow path passes through the second pressure reducing valve, the second steam-water separation device, the second steam heating device, the second steam temperature detector, the second steam dryness detector, the second pneumatic diaphragm valve, and the second pressure sensor in sequence before entering the thin plate drying process.

[0010] Furthermore, it includes a PID controller, which is respectively connected to the first steam heating device, the first steam temperature detector, the first steam dryness detector, the first flow meter, the first pressure sensor, and the first pneumatic diaphragm valve by electrical signals, and / or is respectively connected to the second steam heating device, the second steam temperature detector, the second steam dryness detector, the second pressure sensor and the second pneumatic diaphragm valve by electrical signals.

[0011] A control method for improving the quality of steam for heating and expanding cut blade shreds, using any of the above-mentioned devices for improving the quality of steam for heating and expanding cut blade shreds, adopts the following steps:

[0012] S1, compile a data table of the corresponding steam pressure and steam dryness at the corresponding temperature of the incoming steam, and store the data table into the PID controller;

[0013] S2, determining the steam dryness range to be set for entering the silk drying process, and storing the data of the set steam dryness range in the PID controller; and calculating the steam temperature of the steam in the set steam dryness range at the corresponding pressure, and storing the statistical table in the PID controller;

[0014] S3, a steam-water separation device separates excess water from the decompressed steam;

[0015] S4, heating the steam after water separation to superheated steam with a dryness of 100% and a constant temperature through a heating device;

[0016] S5. The PID controller is adjusted to stably provide the material heating and humidification process and / or the thin plate drying process.

[0017] Furthermore, in step S4, after the heating device is turned on, the steam dryness meter will feed back the detected instant steam dryness to the PID controller, and the PID controller will adjust the heating device according to the steam dryness data. When the steam detector detects that the steam dryness reaches 100%, the PID controller records the steam temperature A0, and the steam temperature detector detects the instant temperature and feeds it back to the PID controller. The PID controller will adjust the heating device according to the temperature data detected by the steam temperature detector, and heat the steam until the steam temperature reaches A0+T, where T≥0 and is a constant value.

[0018] Furthermore, in the process of heating and humidifying the materials, T is determined according to the sensory needs of the product; in the thin plate drying process, T is determined according to the equipment process control requirements.

[0019] The beneficial effects of the present invention are:

[0020] This technical solution uses a device to increase the mass of steam for heating and expanding the cut blades, so that the moisture content of the heated and humidified materials and the temperature of the wall of the drying tube for drying the strands do not change with the seasons or the climate. The superheated steam with a dryness of 100% and a constant temperature heats and humidifies the materials, avoiding the fluctuation of the moisture content of the materials and the wet clumps of the materials caused by the wet steam containing droplets or liquid mist formed due to heat loss in the transmission process. The superheated steam with a dryness of 100% and a constant temperature heats the wall of the sheet drying tube, ensuring that the wall temperature (converted into steam pressure) does not change with the seasons or the climate when the sheet drying process outputs the same amount of heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic diagram of a device for improving the quality of steam for heating and expanding cut blades.

[0022] Description of reference numerals:

[0023] 1. The first pressure reducing valve; 2. The first steam-water separation device; 3. The first steam heating device; 4. The first steam temperature detector; 5. The first steam dryness detector; 6. The first flow meter; 7. The first pressure sensor; 8. The first pneumatic diaphragm valve; 9. The material heating and humidifying device; 10. The second pressure reducing valve; 11. The second steam-water separation device; 12. The second steam heating device; 13. The second steam temperature detector; 14. The second steam dryness detector; 15. The second pneumatic diaphragm valve; 16. The second pressure sensor; 17. The thin plate drying cylinder wall. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0025] like Figure 1 As shown, the present application provides a device for improving the quality of steam for heating and expanding cut tobacco shreds, which is a technical improvement on the steam pipeline that currently provides steam for the wire drying process. The wire drying process of the present application can be a wire drying machine or other equipment, specifically, it is an improvement on the pipeline that provides steam for direct contact with tobacco shreds or non-direct contact with tobacco shreds.

[0026] In the embodiment of the present application, taking material heating and humidification as an example, the steam source provides steam to the material heating and humidification device through a steam pipeline. On the steam pipeline, the steam pipeline near the material heating and humidification device 9 in the direction of the steam source is provided with a first pressure reducing valve 1, a first steam-water separation device 2, a first steam heating device 3, a first steam temperature detector 4, a first steam dryness detector 5, a first flow meter 6, a first pressure sensor 7, and a first pneumatic film valve 8. The PID controller is respectively connected to the first steam heating device, the first steam temperature detector, the first steam dryness detector, the first flow meter, the first pressure sensor, and the first pneumatic film valve by electrical signals.

[0027] In the embodiment of the present application, a wire drying machine is used as an example for explanation. The steam source provides steam to the wire drying machine through a steam pipeline. On the steam pipeline, the second pressure reducing valve 10, the second steam-water separation device 11, the second steam heating device 12, the second steam temperature detector 13, the second steam dryness detector 14, the second pneumatic film valve 15, and the second pressure sensor 16 are sequentially arranged on the steam pipeline from the feed port of the thin plate drying cylinder wall 17 of the wire drying machine to the steam source. The steam source of the present application is the existing technology, which is a power workshop or a boiler workshop, etc., which is determined according to different enterprises.

[0028] In this embodiment, the steam heating device is installed in the vertical pipe section between the steam main pipe grid of the silk drying machine and the equipment room. The steam is secondary heated by the steam heating device to increase the steam dryness, reduce the water content in the steam, and ensure the stability of the steam heat.

[0029] This device adopts a PID controller (not shown in the figure) to control the secondary heating of steam accordingly. The specific second steam heating device, the second steam temperature detector, the second steam dryness detector, the second pressure sensor and the second pneumatic diaphragm valve are all connected to the PID controller electrical signal.

[0030] The steam dryness detector of the present application can collect the dryness, mass flow, temperature and pressure of steam, and the steam dryness can be achieved by controlling the steam heating intensity.

[0031] The steam dryness, pressure and temperature provided by the existing steam source are usually lower than the steam dryness, pressure or temperature required by the tobacco drying machine, and there are many fluctuations in the values. This technical solution aims to improve the problem of quality differences in tobacco batches caused by fluctuations in relevant steam parameter values.

[0032] The present application also provides a control method for improving the quality of steam for heating and expanding the cut blade shreds, using any of the above-mentioned devices for improving the quality of steam for heating and expanding the cut blade shreds, and adopting the following steps:

[0033] S1. Statistically calculate the steam pressure of the incoming steam and the steam dryness data table at the corresponding temperature, and store the data table in the PID controller; specifically, for example, when the dryness of the incoming steam is 85%, when the pressure is 0.5MPa, 0.48MPa, 0.49MPa, 0.51MPa, 0.52MPa, etc., the corresponding temperature also changes accordingly; similarly, for example, when the steam dryness of the incoming steam is 86%, when the pressure is 0.5MPa, 0.48MPa, 0.49MPa, 0.51MPa, 0.52MPa, etc., the corresponding temperature also changes accordingly. In this step, the dryness values ​​of the incoming steam corresponding to the corresponding pressure and temperature values ​​are statistically calculated, and the data table is stored in the PID controller. In the actual production process, the PID controller performs corresponding control according to the data table.

[0034] S2. Determine the steam dryness range to be set for entering the tobacco drying process, and store the data of the set steam dryness range into the PID controller; and count the steam temperature of the steam in the set steam dryness range at the corresponding pressure, and store the statistical table into the PID controller; the specific range is adjusted accordingly according to the recipe requirements of different brands of tobacco shreds. In other embodiments of the present application, the steam dryness can also be determined as a fixed value, such as 100%, 99%, 98%, 97%, 96%, 95%, 94%, 93%, etc., which is determined specifically according to production needs. Similarly, the determined range of steam dryness required by the tobacco drying machine, such as the range data of 90%-100%, is stored in the PID controller. At the same time, the pressure range of the steam required by the tobacco drying machine also needs to be determined, because the pressure has a significant impact on the quality of tobacco. The pressure of the steam usually provided to the tobacco drying machine is difficult to achieve a certain point value and should be within a range. For example, taking the steam pressure of the tobacco drying machine of this embodiment as 0.5 MPa as an example, its range value can be 0.5±0.05 MPa, for example, if it is 0.4 MPa, its range value can be 0.4±0.05 MPa; for example, if it is 0.3 MPa, its range value can be 0.3±0.05 MPa; for example, if it is 0.2 MPa, its range value can be 0.2±0.05 MPa, and so on. Those skilled in the art can make corresponding determinations as needed, and similarly store the pressure range in the PID controller.

[0035] S3. The steam-water separation device separates excess water from the decompressed steam.

[0036] S4. The steam after water separation is heated by a heating device to a dryness of 100% and a constant temperature superheated steam.

[0037] S5. The PID controller is adjusted to stably provide the material heating and humidification process and / or the thin plate drying process.

[0038] In the present application, in step S4, after the heating device is turned on, the steam dryness meter will feed back the detected instant steam dryness to the PID controller, and the PID controller will adjust the heating device according to the steam dryness data. When the steam detector detects that the steam dryness reaches 100%, the PID controller records the steam temperature A0, and the steam temperature detector detects the instant temperature and feeds it back to the PID controller. The PID controller adjusts the heating device according to the temperature data detected by the steam temperature detector, and heats the steam until the steam temperature reaches A0+T, where T≥0 and is a constant value.

[0039] In the process of heating and humidifying the materials, T is determined according to the sensory needs of the product; in the thin plate drying process, T is determined according to the equipment process control requirements.

[0040] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for improving the quality of steam expansion after cutting, characterized in that: The steam pipeline provided to the material heating and humidifying process and / or the thin plate drying tube wall includes, from the steam supply direction, a steam-water separation device, a steam heating device, a steam temperature detector and a steam dryness detector.

2. The device for improving the quality of steam for heating and expanding the cut blades according to claim 1 is characterized in that: In the material heating and humidification process, the steam flow path passes through the first pressure reducing valve, the first steam-water separation device, the first steam heating device, the first steam temperature detector, the first steam dryness detector, the first flow meter, the first pressure sensor, and the first pneumatic diaphragm valve in sequence before entering the material heating and humidification process; and / or, In the thin plate drying process, the steam flow path passes through the second pressure reducing valve, the second steam-water separation device, the second steam heating device, the second steam temperature detector, the second steam dryness detector, the second pneumatic diaphragm valve, and the second pressure sensor in sequence before entering the thin plate drying process.

3. The device for improving the quality of steam for heating and expanding the cut blades according to claim 2 is characterized in that: It includes a PID controller, which is respectively connected to the first steam heating device, the first steam temperature detector, the first steam dryness detector, the first flow meter, the first pressure sensor, and the first pneumatic diaphragm valve by electrical signals, and / or is respectively connected to the second steam heating device, the second steam temperature detector, the second steam dryness detector, the second pressure sensor and the second pneumatic diaphragm valve by electrical signals.

4. A control method for improving the quality of steam expansion after cutting, characterized in that: The device for improving the quality of steam for heating and expanding cut blades according to any one of claims 1 to 3 is used, and the following steps are adopted: S1, compile a data table of the corresponding steam pressure and steam dryness at the corresponding temperature of the incoming steam, and store the data table into the PID controller; S2, determining the steam dryness range to be set for entering the silk drying process, and storing the data of the set steam dryness range in the PID controller; and calculating the steam temperature of the steam in the set steam dryness range at the corresponding pressure, and storing the statistical table in the PID controller; S3, a steam-water separation device separates excess water from the decompressed steam; S4, heating the steam after water separation to superheated steam with a dryness of 100% and a constant temperature through a heating device; S5. The PID controller is adjusted to stably provide the material heating and humidification process and / or the thin plate drying process.

5. The control method for improving the quality of steam for heating and expanding the cut shreds according to claim 4 is characterized in that: In step S4, after the heating device is turned on, the steam dryness meter feeds back the detected instant steam dryness to the PID controller, and the PID controller adjusts the heating device according to the steam dryness data. When the steam detector detects that the steam dryness reaches 100%, the PID controller records the steam temperature A0. The steam temperature detector detects the instant temperature and feeds it back to the PID controller. The PID controller adjusts the heating device according to the temperature data detected by the steam temperature detector, and heats the steam until the steam temperature reaches A0+T, where T≥0 and is a constant value.

6. The control method for improving the quality of steam for heating and expanding the cut blades according to claim 5 is characterized in that: In the process of heating and humidifying the materials, T is determined according to the sensory needs of the product; in the thin plate drying process, T is determined according to the equipment process control requirements.

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