JP5355011B2 - Method and feeder for improving the efficiency of organic plant raw material expansion and drying processes, especially in jet dryers - Google Patents

Abstract

The invention relates to a method and a feeder for increasing the efficiency of the expanding and drying process of organic plant materials, particularly in a jet dryer used for comminuted organic plant materials, particularly tobacco materials. The dryer works with the use of a gaseous expanding and/or drying agent under an absolute working pressure in the range from 2.5 kPa to 10 MPa. Preferably, overheated steam is used as the gaseous working, expanding and/or drying agent, and during transporting the material (1) from the feeding zone (6) to the zone (9) of the contact with the expanding and/or drying agent, a feeder, preferably a rotary vane feeder (4) is flushed, preferably in a continuous manner, with a gaseous medium (11, 12) which is capable of absorbing moisture, under an absolute pressure from 2.5 kPa to 10 MPa, the temperature of the gaseous medium (11, 12), preferably air, is from 50 to 200°C, and residues of the process gas are removed from the rotary vane feeder (4). Openings (5, 7) are formed in the housing of the feeder according to the invention, delivering the gaseous medium to the moving spaces between the vanes (3), as well as openings (5A, 7A) leading out the gaseous medium from the moving spaces between the vanes (3), the openings (5, 7, 5A, 7A) being arranged respectively in the walls of the housing of the feeder (4).

Description

  The present invention relates to a method and a supply device for improving the efficiency of the expansion and drying process of organic plant raw materials, in particular in jet dryers used for drying chopped tobacco raw materials.

  There are many methods known in the art for expanding and drying ground organic plant raw materials, and technical systems having dryers, particularly jet dryers that use superheated steam, Many technical systems are known in which the steam is at a temperature in the range up to 400 ° C., especially when using a gaseous desiccant. These systems are equipped with a rotary valve that functions as a valve for charging the pulverized product, particularly fluid.

In order to ensure continuity with respect to the supply of organic plant raw materials to be treated, especially chopped tobacco raw materials of any shape, the raw materials are made of gravity by a known method as shown, for example, in Patent Document 1. It is fed to the expansion and / or drying zone. However, such known methods can clog and plug the feedstock, especially tobacco feedstock, at the exit zone, resulting in a non-uniform flow of feedstock for processing. It will be subject to practical restrictions. Furthermore, such a solution makes it difficult or practically impossible to flow a vapor stream in the path for drying under a pressure higher than atmospheric pressure, via a layer fed with organic raw materials, in particular tobacco raw materials. , Loss of gaseous media (leakage), for example loss of air, carbon dioxide (CO ₂ ) or steam, and condensation of steam in the feed to wet the feed supplied for drying.

  Another solution relating to feeding organic plant material, in particular tobacco material, into the expansion zone is disclosed in US Pat. An improved rotary valve is disclosed that is configured such that the process of expansion is performed using steam and carbon dioxide.

  Still other solutions are disclosed in US Pat. Nos. 5,099,086 and 5,047,459, in which water and / or steam is introduced into the inlet valve assembly immediately prior to supply to the expansion and / or drying zone. The raw material is processed by spraying (adding) and the processed raw material is adjusted. The fluid added in this manner gives some degree of enthalpy (energy) of evaporation to the raw material supplied from the outside, and heats it to condense on the surface of the raw material. Due to the high motive force in the process of supplying the organic plant raw material to the expansion and / or drying equipment, the condensed layer on the surface of the raw material is not absorbed by the cell structure of the raw material and is heated until it is in direct contact with the expansion and / or drying medium. It will stay on the surface of the raw material without using heat insulation for energy.

FIG. 1 of the accompanying drawings shows an exemplary known jet dryer using a gaseous desiccant, particularly superheated steam at temperatures up to 400 ° C. According to this solution, the organic plant raw material, in particular the minced tobacco raw material 1, is fed from the production line via the input and flow control device 4 to the expansion and / or drying zone 9, after which the raw material is processed, It will be discharged via the supply and flow control device 10. The term “expansion” is understood here as increasing the specific volume of the processed raw material, measured in m ³ / g.
US Pat. No. 6,185,843 US Pat. No. 4,791,942 US Pat. No. 6,158,441 US Pat. No. 6,581,608 US Pat. No. 6,795,527

  Known methods used to process (directly) the organic plant raw material, particularly tobacco raw material, into the direct processing zone, i.e., the expansion and / or drying zone, are detrimental, particularly the tobacco raw material. Before being sent to the expansion and / or drying zone as a pathway, an undesirable layer of surface moisture (water) that is not absorbed by the cellular structure of the tobacco raw material and does not chemically bond is produced. Such a layer constitutes a thermal insulation of various thicknesses, which can be used to produce a crushed organic plant raw material, especially a tobacco raw material formed in an arbitrary shape, in a homogeneous and optimal wattage. • It is an efficient method on an hour-by-hour basis that significantly hinders or even prevents processing.

  In order to show how moisture (water) can be an effective insulation, we have the thermal properties of two different materials: water (insulation) and, for example, copper (very good) Two coefficients for defining thermal properties with respect to a thermal conductor).

  For comparison of specific heat Cp for both materials, heating a unit mass of water by 1 degree (° C. or 1 K) is about 10 times compared to heating the same amount of copper by 1 degree (° C. or 1 K). It has been shown that double the heat energy must be transmitted. On the other hand, for the comparison of thermal conductivity λ, the water layer acts inconveniently as a very efficient thermal insulation, ie the water layer on the surface with a thickness of 1 mm is as much as the copper layer with a thickness of about 600 mm. Of the heat energy (665 times more in the above data).

  Furthermore, it must be taken into account that the surface moisture needs to evaporate and therefore a significant amount of extra thermal energy needs to be delivered to cause the phase change to vaporize the liquid. However, this phase change deprives the material of a considerable amount of thermal energy, so-called evaporation enthalpy, which is about 2250 kJ / kg for water, which in turn cools the material (instead of heating). Cause undesirable results.

  In view of the above problems, surface moisture becomes a thermal energy insulation, which requires increasing the residence time of the product staying in the drying path, resulting in increased dryer dimensions and energy demands In view of this, it is advantageous to ensure that the raw material supplied to the dryer, in particular the “flash” type jet dryer, does not contain surface moisture.

  The present invention relates to a method for improving the efficiency of expansion and drying processes of organic plant raw materials, in particular in jet dryers used for ground organic plant raw materials, in particular chopped tobacco raw materials. This jet dryer will work with the use of gaseous expansion and / or desiccants under absolute pressures of 2.5 kPa to 10 Mpa. Preferably superheated steam is used as the gaseous expansion and / or drying process medium.

  The object of the present invention is that when conveying the raw material from the supply zone to the zone in contact with the expansion and / or desiccant, the supply device, preferably the rotary blade supply device, is under an absolute pressure in the range of 2.5 kPa to 10 MPa. Thus, the gaseous medium capable of absorbing moisture is preferably flushed (released vigorously) in a continuous manner. The temperature of the gaseous medium, preferably air, is in the range of 50 ° C to 200 ° C. Then, the remainder of the process gas is removed from the rotary blade supply device.

  Preferably, according to the present invention, the conveyed raw material is heated by direct contact with the gaseous medium stream, the remaining surface moisture is removed from the surface of the raw material, and the conveyed raw material is of the gaseous medium. The use of the stream saturates and the raw material becomes defiberized.

  The invention also relates to a feeding device for improving the efficiency of the expansion and drying process of organic plant raw materials, in particular in jet dryers used for ground organic plant raw materials, in particular chopped tobacco. The supply device includes blades that rotate within the housing.

  In the present invention, an opening for feeding the gaseous medium into the moving space between the blades and an opening for discharging the gaseous medium from the moving space between the blades are formed in the housing of the supply device. And based on the idea that these openings are correspondingly arranged in the wall part of the housing of the supply device. The openings are oblong in one direction and are arranged radially along a longitudinal axis that is perpendicular to the product inlet and outlet axes, some of which are They are offset from each other in the radial direction. The feeding device according to the invention comprises a deflection plate for the flow of the raw material.

  The solution according to the invention guarantees the homogeneity and continuity of the process, so that an optimized high expansion and drying effect is obtained to the desired level. Experts in the field of tobacco processing have estimated this level in the range of 10% to 14% humidity.

  The present invention is illustrated by the embodiments shown in the accompanying drawings below.

  According to the invention, in an apparatus for expanding and / or drying chopped tobacco material, a rotary vane supply in which an inlet rotary valve is arranged between the supply zone 6 and the expansion and / or drying zone or processing zone 9. Used in the form of device 4. The organic plant raw material, particularly the tobacco raw material 1, 1 </ b> A, eliminates or remarkably puts the wet gaseous medium PG into the supply zone 6 of the organic plant raw material, particularly the tobacco raw material 1, via the rotating blade supply device 4. It is supplied to the processing zone 9 in a decreasing manner.

  FIG. 2 shows a cross-sectional view of a supply device 4 for administering an organic plant raw material, in particular tobacco raw material 1, 1 </ b> A, to the treatment zone 9. The standard (typical) rotary valve is improved by forming two zones, the active zone and the passive zone shown in FIG. Organic plant raw materials, particularly tobacco 1, crushed in the active zone will be conveyed to the treatment zone 9. In the passive (return) zone, only the gaseous processing medium PG is transported between the valve blades.

  The rotary blade 3 is in contact with the housing of the supply device 4 so that the flow of the gaseous processing medium is sent via the opening 5 and / or the opening 7 and then removed via the openings 5A, 7A. A closed and moving space is formed. At this time, the gaseous processing medium is, for example, high-temperature air having a temperature of 50 ° C. to 150 ° C. under an absolute pressure in a range of 2.5 kPa to 1 MPa.

  As shown in FIG. 3, the supply device 4 includes supply paths 13 and 14 for supplying the flow of the gaseous processing medium to the openings 5 and 5A, and a discharge path 13A for discharging the flow of the gaseous processing medium. , 14A.

  In order to improve the effect of flashing gas out of the space between the vanes 3, the openings 7 and 7A are arranged radially offset as shown in FIGS. The path of the gas flow in the space becomes long. In the passive zone in which only the gas PG is transported between the blades 3 and the raw material, in particular the tobacco raw material 1 is not present, the openings 5 which do not need to be offset from each other as shown in FIGS. Different shapes and arrangements can be applied for the opening 5A.

  An opening 5 and an opening 7 for feeding the gaseous processing medium 11 and / or the gaseous processing medium 12 into the housing of the supply device 4, and an opening 5A and an opening for discharging the gaseous processing medium 11A and the gaseous processing medium 12A In the illustrated embodiment, the portion 7A is an elliptical opening extending in one direction as shown in FIGS. 2 and 4, and this elliptical opening is expanded and / or dried. Is arranged perpendicular to the inlet / outlet direction of the raw materials 1 to 1A supplied for the purpose and in the radial direction.

  For optimum and advantageous use of the valve operating space, i.e. the space between the drive vanes 3 and the housing of the supply device 4, the deflection plates 2, 2A and the deflection plates for the flow of the raw material as shown in FIG. 8 is used. Furthermore, these deflecting plates advantageously lengthen the path of contact between the blades 3 of the supply device 4 and the housing, which advantageously extends the duration of the treatment of the gaseous media 11, 11A. Will be. At the same time, as shown in FIG. 4, the deflection plate can prevent adverse effects (leakage) such that the gaseous medium sent to the supply device 4 enters the processing zone 9 and the supply zone 6.

  The raw material 1A that has left the supply device 4 is present in the processing zone 9 and the space between the blades 3 and the housing of the supply device 4 where the raw material directly contacts the expansion and / or desiccant PG in the processing zone 9. Stop occupying the space immediately filled with the swelling and / or desiccant PG. Next, the desiccant is conveyed between the blade 3 of the supply device 4 and the housing. In this zone, as shown in FIGS. 2 and 3, for example, an opening 5 and an opening 7 for supplying a gaseous treatment agent 11 and / or a gaseous treatment agent 12 such as ambient air to the supply device; The opening 5A and the opening 7A for discharging (sucking out) the gaseous mixture 11A and the gaseous mixture 12A are formed.

  As a result of using the above solution in reopening the rotational operating chamber of the supply device 4, no remaining of the moist gaseous medium PG enters the supply zone 6, so that the organics sent to the process Any condensation of moisture will not occur in the plant material, especially the tobacco material 1. The organic plant raw material, in particular tobacco raw material 1 supplied according to the method for expansion and / or drying, is a free and chemically unbonded insulation and inhibitor for chemical reactions occurring in the treatment zone 9. It does not have an insulating layer of surface moisture, allowing a considerable reduction in the amount of externally delivered energy required to obtain a proper expansion and / or drying process.

  As a result of using such a solution, all or a substantial amount of moisture, in particular the gaseous processing medium PG which is a carrier for the vapor, is removed from the supply device 4 which supplies the raw material 1 and separates it from the processing zone 9. It will be. The absence of saturated steam in the feed zone 6 of the feedstock 1 to the feed device 4 reduces or prevents the condensation of steam (humidity) into the organic plant feedstock, particularly tobacco feed, supplied for processing. Even do. The raw material does not come into contact with a moist gaseous medium, in particular steam, and is preferably affected by hot dry air (streams 11 and 12 in FIG. 3), thereby providing an organic plant raw material supplied for processing, in particular The temperature of the tobacco raw material (internal energy) can be increased and at the same time the remaining layer of surface moisture remaining after the previous treatment can be removed without generating a further inconvenient layer for surface moisture.

  The ground organic plant material, especially tobacco material, supplied for processing is usually fibrous and swirled. Due to the contact between such organic plant raw material, in particular tobacco raw material, and the gaseous medium 11, 12, for example air stream, the raw material supplied for processing disaggregates (decomposes) the fibers and thereby the raw material. The individual particle expansion and / or the homogeneity of the drying process will be significantly improved. Also, by not losing a portion of the energy required to remove unwanted surface moisture, the energy consumption for this solution will be significantly reduced, i.e. the efficiency of the process will be improved. It will be.

  Further, the gaseous medium PG is sucked out from the processing zone 9 via the opening 5A provided between the blades 3 of the supply device 4 and the path 13A. The processing gas PG is removed from the supply device 4 through the openings 5A arranged in the radial direction as shown in FIG. 3 by the gas 11 fed from the outside, preferably air taken in from the environment, and the path 13 and opening 5 and then to recover heat energy (enthalpy) from a waste stream of gas 11A, for example, optionally further processing outside the supply device 4, for example. It will be removed via the opening 5A and the path 13A. As a result, these effects allow for a shorter residence time of organic plant materials, particularly tobacco materials, in the expansion and / or drying zone, thereby reducing the overall size of the drying path and jet dryer. Is possible. Furthermore, a significant improvement in efficiency in watt-hours can be achieved in the expansion and / or drying process of organic plant materials, in particular tobacco materials.

1 schematically shows a known device used for expanding and / or drying ground organic plant raw materials, in particular tobacco raw materials, equipped with a supply and flow control device. It is sectional drawing which shows the inlet supply apparatus by this invention. It is a top view which shows the supply apparatus of FIG. 2 which has the path | route which sends a processing medium to a valve | bulb, and the path | route which discharge | releases a processing medium from this valve | bulb. It is sectional drawing which shows the supply apparatus in the operation position of the drive blade | wing of a supply apparatus, The operation | movement range of the gaseous medium sent in the supply apparatus is shown by this figure.

Claims (8)

A method for improving the efficiency of the expansion and drying process of organic plant raw materials, in particular a gaseous expansion and / or drying agent which is superheated steam in the course of treatment, preferably under absolute pressure in the range of 2.5 kPa to 10 MPa. A method for improving efficiency in a jet dryer used for milled organic plant raw materials, in particular for minced tobacco raw materials, working together with
When conveying the material (1) from the feed zone (6) in the treatment zone (9) in contact with the expanding and / or drying agent, rotary vane feeder (4), the range of 2.5kPa~10Mpa The gaseous medium (11, 12), which is capable of absorbing moisture and is preferably at a temperature in the range of 50 ° C. to 200 ° C., is preferably released in a continuous manner in a flash manner under the absolute pressure in the process. Gaseous expansion and / or the remainder of the desiccant being superheated steam is removed from the rotary blade feeder (4).   The transported raw material (1) is heated in direct contact with the flow of the gaseous medium (11, 12), and the remainder of the surface moisture is removed from the surface of the raw material (1). The method described in 1.   The method according to claim 1, comprising saturating the conveyed raw material (1) with the flow of the gaseous medium (11, 12).   The method according to claim 1 or 3, wherein the process of disaggregating the fibers for the raw material (1) is performed by the flow of the gaseous medium (11, 12). In order to improve the efficiency of the organic plant raw material expansion and drying process , the housing has a plurality of blades rotating around one rotation axis , and is a gaseous expansion that is superheated steam in the process And / or a rotary blade feeder that works in conjunction with the use of a desiccant to improve efficiency in a jet dryer used for the crushed raw material ,
Said housing includes said blades (3) the first opening for feeding the gaseous medium to allow absorption of moisture (11, 12) in a space moving between each other (5,7), said blade ( 3) a second opening for releasing the gaseous medium (11, 12) from the moving spaces between each other (5A, 7A) and are formed,
The first openings (5, 7) are disposed on one of the wall portions of the housing facing each other in the rotational axis direction , and the second openings (5A, 7A) are mutually disposed in the rotational axis direction. Arranged on the other of the opposite wall portions of the housing,
The raw material (1) is brought into contact with the raw material (1) and the expansion and / or desiccant sent from the outside of the housing from a supply zone (6) for supplying the raw material (1) to the inside of the housing. The gaseous medium (11, 12) is supplied to the interior of the housing through the first opening (5, 7) and conveyed to the treatment zone (9) The gaseous medium (11, 12) is flushed in a continuous manner so as to be discharged to the outside of the housing through the openings (5A, 7A), and a gaseous state which is superheated steam in the processing process. A rotary blade feeder configured to remove expansion and / or residual desiccant from the rotary blade feeder (4) . It said first and second openings (5,7,5A, 7A) is formed in an elliptical shape extending in one direction, and are disposed radially, the first and second openings (5,7,5A , the longitudinal axis is arranged perpendicularly to the inlet and outlet axis of the material (1) in 7A), rotary vane feeder according to claim 5. The rotary blade supply device according to claim 5 or 6, wherein the first and second openings are arranged so as to be offset from each other in the radial direction. The rotating blade supply device according to claim 5, wherein a deflection plate (2, 8) for the flow of the raw material is provided.

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