JP2023141971A - Operation method of horizontal continuous heat conduction type drier - Google Patents

Abstract

To develop an operation method of a new horizontal continuous heat conduction type drier improving accuracy in a discharge amount control in response to increase/decrease of retained goods in a drier while maintaining an input amount of an object to be processed, adjusting the retained goods amount automatically and allowing a stable dry operation.SOLUTION: In an operation method of a horizontal continuous heat conduction type drier, a fuzzy control for adjusting an amount of retained goods P2 in a body shell 10 is executed, having any plurality of measurement values among a measurement value of a retaining level of retained goods P2 in the body shell 10 scraped up in a rotational direction of a heat transfer member 11, a measurement value of a discharge temperature and a measurement value of a load current of a motor M1 to drive the heat transfer member 11 as a condition part, and having a closing time of an overflow port 102 as a conclusion part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a horizontal continuous conduction heat transfer dryer that is suitable for drying materials such as mud, cake, and powder, and is particularly suitable for drying processed materials whose apparent density fluctuates significantly. This relates to a method of operating a horizontal continuous conduction heat transfer type dryer that allows for

Recently, environmental conservation efforts have become more popular, and companies are now drying and concentrating general waste such as food waste, food processing residue, and sewage sludge to reduce weight and prevent spoilage. After careful consideration, recycling and disposal are carried out.

As one of the devices used for drying such sludge, etc., there is a horizontal continuous conduction heat transfer type dryer 1'. For example, as shown in FIG. 8, this device includes a multi-tubular heating tube 11' inside a main body shell 10', and rotates the multi-tubular heating tube 11' while flowing heating steam inside it. This is a device that evaporates moisture by bringing the object to be treated P into contact with this object.
The material to be treated P supplied into the main body shell 10' from the input port 101' is scraped up by the lifter 117' and moves to the overflow port 102' side as drying progresses, and the desired moisture value is reached. In this state, the dried product D is discharged to the outside from the overflow port 102' via the duct 102'.
In this specification, the sludge and the like to be dried by the horizontal continuous conduction heat transfer dryer is referred to as the material to be treated P, and is fed into the horizontal continuous conduction heat transfer dryer until it reaches a certain value. The material to be treated whose moisture content has not decreased is referred to as the material to be treated P1, and the material to be treated P whose dryness has progressed beyond a certain value is referred to as the retained material P2. Note that the objects to be treated P located in the horizontal continuous conduction heat transfer dryer are collectively referred to as retained objects P2.
Generally, in a horizontal continuous conduction heat transfer type dryer, drying progresses when the accumulated product P2 inside the machine comes into contact with the surface of the heat transfer member 11. Therefore, in order to increase the drying efficiency, the accumulated product P2 is The operation is performed while maintaining a large amount of material P2, which is about half the capacity of the main body shell 10', and is mixed with the newly introduced material P1 to be processed. By lowering the moisture content, an efficient drying process is performed (see FIG. 4).

When the input amount of the material to be processed P is constant and the apparent density is constant, that is, when the properties of the material to be processed P supplied into the main body shell 10' are constant, the amount of the retained product P2 and the multi-tube type A correlation has been recognized between the driving current value of the heating tube 11' and the driving current value of the heating tube 11'. Therefore, by monitoring the drive current value and adjusting the amount of the accumulated product P2 discharged from the overflow port 102' according to the value, the amount of the accumulated product P2 in the main body shell 10' can be adjusted to a desired value. It can be done.
Note that the amount of accumulated product P2 in the main body shell 10' can be adjusted by opening and closing the lid member 102c' provided at the overflow port 102', and the opening time is 2 seconds as an example. For example, the closure time is 1 minute, 2 minutes, 3 minutes, 4 minutes, 8 minutes, or even longer.

On the other hand, if the material to be processed P has a property in which the apparent density varies greatly as it dries, the amount of retention in the main body shell 10 will fluctuate and the amount of discharge of the dried product P will also vary greatly, especially on the downstream side of the dryer. This will affect the operation of the equipment.
In this case, in the method of monitoring the driving current value, even if the input amount of the processed material P is constant, the property of the retained product P2 retained in the main body shell 10' changes, so the volume changes. could not be detected.
That is, for example, when managing the proportion of the accumulated product P2 in the capacity of the main body shell 10' to 40%, the weight of the accumulated product P2 was 1000 kg and its apparent density was 300 kg/m ³ . Assume that the drive current value of the heat transfer member in this case is 50A.
From this state, if the apparent density of the retained product P2 in the main body shell 10' changes to 600 kg/m ³ due to a change in the properties of the newly introduced workpiece P, then the drive current value of the heat transfer member is 50 A. If this continues, the control condition in which the weight of the accumulated product P2 is 1000 kg will continue, and the proportion of the accumulated product P2 in the capacity of the main body shell 10' will drop significantly to 20%.
Therefore, in order to perform appropriate operation in response to changes in the properties of the material to be processed P, the operator visually checks the inside of the main body shell 10', measures the apparent density, and changes the drive current setting to 70A, for example. Therefore, a setting-based operation was performed, such as setting the proportion of the accumulated product P2 to 40% of the capacity of the main body shell 10'.

Therefore, in the horizontal continuous conduction heat transfer dryer 1', the present applicant has developed a new "conduction heat transfer dryer" that can grasp the properties of the accumulated product P2 and set various operating conditions that are more suitable for the properties of the accumulated product P2. He has already devised a patent application for a heat transfer dryer and a method for operating a conduction heat transfer dryer (see Patent Document 1).
As shown in FIG. 9, the present invention is a horizontal continuous conduction transmission system equipped with an in-machine level detection mechanism 13' for detecting the in-machine level of the accumulated product P2 that is scraped up in the rotational direction of the heat transfer member in the main body shell 10'. This relates to a thermal dryer 1'. When operating this horizontal continuous conduction heat transfer dryer 1', the value of the current flowing through the motor M1' for rotationally driving the multi-tubular heating tube 11', the amount of accumulated product P2 in the main body shell 10', Twelve cases are assumed depending on one or more of the level and the amount of change in the internal level, and the amount of the processed material P to the main body shell 10' is set in advance for each case. Either or both of the amount of input and the amount of dried product D discharged from the main body shell 10' is controlled.

However, since the interior of the main body shell 10' has a rotating multitubular heating tube 11', it is difficult to grasp the volume of the accumulated product P2 by monitoring only with a level meter, and furthermore, it is difficult to grasp the volume of the retained product P2. Changes in apparent density do not change significantly when the material to be processed P with high moisture content is introduced, but changes occur once drying has progressed to a certain extent, so it is extremely difficult to grasp the change in apparent density before the material is introduced. The moisture content of the material to be treated P, such as sludge, supplied to the horizontal continuous conduction heat transfer dryer 1' varies greatly depending on the concentration of the thickened sludge, the flow rate of dewatering, the amount of flocculant added, etc. Since materials to be treated P are brought into the facility from various areas, even with the above invention, it is difficult to stably operate a facility for drying sludge, etc. in response to changes in the properties of materials P to be treated. It has become clear that a difficult situation could arise.

JP2019-174044

The present invention was developed against this background, and while keeping the input amount of the material to be processed constant, it improves the accuracy of the discharge amount control according to the increase or decrease of the accumulated products in the dryer, and automatically reduces the amount of accumulated products. The technical objective is to develop a method for operating a new horizontal continuous conduction heat transfer dryer that allows stable drying operation.

That is, the method of operating a horizontal continuous conduction heat transfer type dryer according to claim 1 includes arranging a shaft body provided with a heat transfer member in a main body shell, causing heating steam to flow inside the shaft body and rotating it, The material to be processed, which is introduced into the main body shell through the input port, is dried by being brought into contact with a heat transfer member that rotates together with the shaft body while remaining in the main body shell, and the obtained dried product is discharged from the overflow port. In the operating method of a horizontal continuous conduction heat transfer dryer, a measured value of the accumulation level of accumulated products in the main body shell that is scraped up in the rotational direction of the heat transfer member, a measured value of the exhaust temperature, and the heat transfer member are determined. Fuzzy control that uses the measured value of the load current of the motor for driving the motor and any one of the plurality of measured values as the condition part, and uses the closing time of the overflow port as the conclusion part, and adjusts the amount of the product accumulated in the main body shell. It is characterized by the following.

Further, a method for operating a horizontal continuous conduction heat transfer dryer according to claim 2 is characterized in that, in addition to the requirements set forth in claim 1, the retention level of accumulated products in the main body shell is measured at two or more locations. It is what it is.
The above-mentioned problems can be solved by means of the configurations of the invention described in each of the claims.

First, according to the invention described in claim 1, the condition part is a measured value of the in-machine level of accumulated products in the main body shell, a measured value of the exhaust temperature, and a measured value of the load current of the motor for driving the heat transfer member. This makes it possible to accurately grasp the amount of retained products. For this reason, when operating a horizontal continuous conduction heat transfer type dryer, we have moved away from a setting-based operation that requires the operator to visually check the inside of the main body shell, measure the apparent density, and change the drive current setting, and instead operate a monitoring-based operation. can be moved to. In addition, it is possible to eliminate mistakes in setting changes and operation errors, and to maintain the amount of retained products at a desired value even when the apparent density or moisture content of the material to be processed changes, thereby enabling stable operation.

Further, according to the second aspect of the present invention, by installing a plurality of level meters, it is possible to accurately grasp the level of accumulated products located in the dryer (main body shell).
Furthermore, by installing multiple level meters, it is possible to reduce measurement errors caused by the presence of rotating objects (multi-tube heating tubes) inside the dryer (main body shell).

1 is a skeletal diagram showing a horizontal continuous conduction heat transfer type dryer and peripheral equipment to which the present invention is applied. FIG. 2 is a partially transparent front view of the horizontal continuous conduction heat transfer dryer. FIG. 2 is a left side view and a right side view partially showing a horizontal continuous conduction heat transfer type dryer. FIG. 2 is a partially enlarged cross-sectional view showing the vicinity of the in-machine level detection mechanism in the main body shell. It is a graph showing a membership function of "retention level L1" which is a conditional part of fuzzy inference. It is a graph showing a membership function of "retention level L2" which is a conditional part of fuzzy inference. It is a graph showing a membership function of "exhaust temperature T1" which is a conditional part of fuzzy inference. It is a graph showing a membership function of "load current A1" which is a conditional part of fuzzy inference. It is a table showing a fuzzy inference rule in which the condition part is "retention level L1," "retention level L2," and "exhaust temperature T1," and the conclusion part is "lid member closing time DT1." It is a table showing a fuzzy inference rule in which the condition part is "retention level L1," "retention level L2," and "load current A1," and the conclusion part is "lid member closing time DT1." It is a table showing a fuzzy inference rule in which the condition part is "exhaust temperature T1" and "load current A1" and the conclusion part is "lid member closing time DT1." FIG. 2 is a partially transparent front view of a horizontal continuous conduction heat transfer dryer provided with three in-machine level detection mechanisms. FIG. 2 is a partially transparent front view of an existing horizontal continuous conduction heat transfer dryer disclosed in Patent Document 1. FIG. 2 is a partially transparent front view of an existing horizontal continuous conduction heat transfer dryer.

The best mode of the "operating method for a horizontal continuous conduction heat transfer dryer" of the present invention is as shown in the following example, but modifications may be made to this example as appropriate within the scope of the technical idea of the present invention. It is also possible to add

The horizontal continuous conduction heat transfer type dryer 1 to which the present invention is applied is a device suitable for drying a material to be processed P in the form of mud, cake, powder, etc. This is an apparatus for obtaining dried product D by evaporating and retaining volatile components such as the like.
The horizontal continuous conduction heat transfer dryer 1 and its peripheral equipment will be described below, and then the operating method of the present invention will be described.
As shown in FIGS. 2 and 3, the horizontal continuous conduction heat transfer type dryer 1 includes a main body shell 10 provided on a machine frame F, and a multi-tube heating tube 11 as a heat transfer member. A dryer that rotates a multi-tubular heating tube 11 while flowing heating steam V inside it, and makes the object to be processed P stay in the main body shell 10 while bringing it into contact with the multi-tubular heating tube 11 for drying. be.

The main body shell 10 is, for example, a hollow member having an oblong cross section as shown in FIG. 3, and has an input port 101, an overflow port 102, a carrier gas port 103, and an exhaust port 104.
Hereinafter, in this specification, the side of the overflow port 102 (the right side in FIGS. 1 and 2) will be referred to as "rear" and "rear", and the opposite side will be referred to as "front" and "front".
Here, the input ports 101 are formed at a plurality of locations on the upper part of the main body shell 10, and as an example, in FIGS. A distributed input port 101a is formed. Further, in front of the carrier gas port 103 formed at the rear upper part of the main body shell 10, a second distribution inlet 101b and a third distribution inlet 101c are formed.
Note that the installation locations of the input port 101, the carrier gas port 103, and the exhaust port 104, as well as the number of the exhaust ports 104, can be changed as appropriate within the scope of the technical idea of the present invention.

Further, the main body shell 10 and the multi-tubular heating tube 11 are installed in the machine frame F in a horizontal state, or are installed in the machine frame F in an inclined manner so that the overflow port 102 side is somewhat lower.
Furthermore, the main body shell 10 has a double jacket structure, and a steam passage path is formed from the steam supply port 106 formed near the bottom of the input port 101a to the drain port 107 formed below the overflow port 102. The structure is such that the temperature inside the main body shell 10 can be increased. Note that trace piping or the like may be installed instead of such a double jacket structure.

The overflow port 102 is formed at a desired height by blocking a rectangular opening formed in the main body shell 10 from the bottom to the top with a plurality of plate materials 102a each having a width of about 10-odd centimeters. It is something that can be done. The dried product D then passes over this plate material 102a and is discharged to the outside of the main body shell 10.
Since such a configuration is adopted, if the plate materials 102a are piled up high, the opening of the overflow port 102 will only open narrowly at the top, and the amount of retained products P2 in the main body shell 10 will increase. Conversely, if the number of plate members 102a is small, the opening becomes wider and the amount of retained product P2 in the main body shell 10 becomes smaller.
In addition, a lid member 102c is provided to close the overflow port 102, and in the "closed state" in which the overflow port 102 is closed by the lid member 102c, the dried product D is not discharged from the main body shell 10. On the other hand, in the "open state" in which the overflow port 102 is not blocked by the lid member 102c, the dried product D is discharged from the main body shell 10. The amount of the accumulated product P2 in the main body shell 10 increases or decreases according to the time interval of repeated "closing" and "opening" operations of the lid member 102c, which are adjusted by control signals from the control panel 4.
The lid member 102c is configured to move toward and away from the overflow port 102 by an opening/closing mechanism (not shown) that includes an appropriate cylinder or link mechanism.

In addition, a duct 102b is installed so as to cover the overflow port 102, and a rotary valve, a double damper discharge device, etc. are provided upstream of a discharge port 109 formed at the bottom of the duct 102b. Furthermore, a side opening 108 for maintenance is formed on the side surface of the main body shell 10, and is closed by a lid during normal operation.

Further, the multi-tube type heating tube 11 includes end plates 112 on both sides of a heat tube bundle 116 as a heat transfer member made up of a plurality of tubes arranged in a cylindrical shape, and a shaft body 113 in the center of the end plate 112. A shaft body 113 is rotatably supported by a bearing block 114 provided in the machine frame F. Note that a motor M1 is provided on the machine frame F as a driving device for rotating the multi-tubular heating tube 11.
Rotary joints 115 (115a, 115b) are attached to both ends of the shaft body 113 and connected to a heat tube bundle 116. Further, a sealing mechanism is provided between the shaft body 113 and the main body shell 10 to isolate it from outside air.
The side circumference of the heat tube bundle 116 is provided with a large number of angles 111 (12 in this embodiment) to which a plurality of lifters 117 and feeding blades 118 with appropriate angles are attached. The object to be processed P is scraped up and comes into contact with the heat tube bundle 116, and also advances from the input port 101 side to the overflow port 102 side.

Although not shown in the drawings, the horizontal continuous conduction heat transfer type dryer 1 is also provided with a steam generator, and an appropriate device such as a U-shape, a straight pipe type, a helical coil type, etc. is applied. A pipe line is connected from this steam generator to the rotary joint 115a and the steam supply port 106 in the horizontal continuous conduction heat transfer dryer 1.
Further, carrier gas C is supplied into the main body shell 10 from the carrier gas port 103. Volatile components evaporated from the object P by heating with the multi-pipe heating tube 11 are carried away by the carrier gas C to the outside of the main body shell 10 through the exhaust port 104. In addition to the volatile components, this carrier gas C also contains fine powder generated from the object to be processed P, so a dust collector 3, which will be described later, is provided on the path through which the carrier gas C flows after the exhaust port 104. .

Furthermore, an exhaust gas temperature sensor 121 for measuring the temperature of the exhaust gas G1 is provided near the exhaust port 104, and the measurement result is transmitted to the control panel 4.
Furthermore, the control panel 4 contains the value of the current consumption (load current) of the motor M1 for rotating the multi-tubular heating tube 11, and the amount of accumulated product P2 in the main body shell 10 detected by the in-machine level detection mechanism 13 described below. The in-flight level value is transmitted.

Next, the in-machine level detection mechanism 13 will be explained. As shown in FIG. 4, this mechanism includes a slidable rod 131 that is inserted into the main body shell 10 from the outside. By coming into contact with the surface layer of the object P, it is configured to move up and down as the height position of the object P changes. By adopting such a configuration, it is possible to recognize the height position of the object to be processed P (in-machine level of the retained object P2 in the main body shell 10) from the outside based on the vertical position of the rod 131.
Specifically, as an example, a sleeve 132 is fitted into a casing 130 made of a transparent material such as engineering plastic or glass that has excellent impact resistance and heat resistance, and a rod is inserted into a hollow hole 132a of the sleeve 132. 131 is provided so that it can move up and down.
Note that by making the casing 130 freely splittable at appropriate locations in the longitudinal direction, the sleeve 132 can be installed at a suitable position in the longitudinal direction within the casing 130.

A stopper 133 is provided near the top of the rod 131 to prevent it from falling off, while a stopper 133 is provided at the bottom end of the rod 131 as a mechanism to prevent the rod 131 from sinking into the workpiece P. A contact piece 135 is provided.
The contact piece 135 may have a truncated cone shape as shown in FIG. 4, a pyramid shape, a spherical shape, etc. by substantially expanding the bottom surface of the rod 131 to increase the contact area with the object P. , a form is adopted that can prevent the rod 131 from sinking into the workpiece P lifted from below. Incidentally, in a test using sewage sludge as the material to be treated P in the conduction heat transfer type dryer 1 in operation, if the pressure applied to the lower surface of the contact piece 135 is about 2.2 kg/cm ² , the rod 131 and It has been confirmed that the level of the object to be processed P inside the machine can be accurately detected without the contact piece 135 sinking into the object to be processed P.
Note that as the material for the rod 131 and the contact piece 135, in addition to metal such as SUS, silicone, fluororesin, or a combination of these may be used.

Further, a sensor S for detecting the vertical position of the rod 131 is provided. In this embodiment, as an example, a light transmitting/receiving type sensor S is provided outside the casing 130 and above the sleeve 132, and as an example, five sensors S1, S2, S3, S4, S5 are provided in the vertical direction. are now arranged.
As an example, the state at the moment when S1 at the bottom of the in-machine level detection mechanism 13 is turned on is set such that the retention amount (retention level) of the processed material P in the main body shell 10 is 20%.
Similarly, the state at the moment when the sensor S2 is turned on is set such that the retention amount (retention level) of the processed material P in the main body shell 10 is 30%.
Similarly, the state at the moment when the sensor S3 is turned on is set such that the retention amount (retention level) of the processed material P in the main body shell 10 is 40%.
Similarly, the state at the moment when the sensor S4 is turned on is set such that the retention amount (retention level) of the processed material P in the main body shell 10 is 50%.
Similarly, the state at the moment when the sensor S5 is turned on is set such that the retention amount (retention level) of the processed material P in the main body shell 10 is 60%.
Here, the rod 131 of the in-machine level detection mechanism 13 moves up and down relatively frequently because the multitubular heating tube 11 rotates and the workpiece P is lifted by the lifter 117 or the like. Therefore, each sensor S turns on and off relatively frequently in any one of the ranges of sensors S1 to S5, and when specifically determining the height of the object P in the main body shell 10, The retention level (retention amount) as an average value within a certain period of time is calculated in the control panel 4 using the integrated value of the ON time of the sensor S within the time and the value of the retention level at the moment when the sensor S is turned on. are doing.

Note that when the rod 131 is made of metal, a non-contact type proximity sensor or a capacitance type sensor may be employed as the sensor S.
Furthermore, since the casing 130 is made of a transparent material, a gauge may be attached to the side circumference of the casing 130 so that the vertical position of the rod 131 can be visually confirmed.

Further, an air purge mechanism is provided at the sliding portion of the rod 131 to prevent the atmosphere inside the main body shell 10 from flowing out. Specifically, a purge air supply port 130a is formed at the top or side circumference of the casing 130, and by supplying purge air there from an appropriate pump, the purge air passes through the inner hole 132a of the sleeve 132 and is supplied to the main body shell. Therefore, the atmosphere and odor inside the main body shell 10 are prevented from flowing out. Furthermore, in order to prevent dust and steam from flowing into the casing 130, if the casing 130 is made of a transparent material, the movement and position of the rod 131 can be visually confirmed.

In this embodiment, as shown in FIGS. 1 and 2, a plurality of the in-machine level detection mechanisms 13 are provided. A first in-machine level detection mechanism 13A is provided between the two.
Furthermore, in this embodiment, a second in-machine level detection mechanism 13B is provided between the input port 101c and the carrier gas port 103 on the rear side (driven side) of the multi-pipe heating tube 11.

Next, as shown in FIG. 1, the peripheral devices of the horizontal continuous conduction heat transfer dryer 1 include a charging device 2, a dust collector 3, a control panel 4, a deodorizing furnace 5, a heat exchanger 6, and a depressurizing device. The valve 7, flow rate adjustment valve 8, and heat exchanger 9 will be explained.
First, the charging device 2 will be explained. This device is configured by, for example, a screw conveyor 20a at the bottom of a hopper 20, and its discharge port is a distributed charging port in the horizontal continuous conduction heat transfer dryer 1. 101a, distributed input port 101b, and distributed input port 101c. Note that a valve 21 and a valve 22 are provided between the distribution input port 101a, the distribution input port 101b, and the input device 2.
Further, the screw conveyor 20a is driven by an inverter motor M2.
Further, instead of this screw conveyor 20a, a uniaxial eccentric screw pump such as Mono Pump (registered trademark) or the like may be used.

Further, as described above, the dust collecting device 3 is provided for removing dust contained in the exhaust gas G1 discharged from the exhaust port 104 in the main body shell 10, and is of an appropriate type such as a cyclone type or a bag filter type. Equipment is adopted.

Furthermore, a deodorizing furnace 5 is provided next to the dust collector 3 for deodorizing the exhaust gas G1 by burning it. This deodorizing furnace 5 supplies high-temperature combustion gas generated by burning fuel with a burner 51 into the furnace body 50, and heats exhaust gas G1 supplied into the furnace body 50 from the air supply port 52. - It is a device that performs deodorizing treatment by burning, and discharges it from the exhaust port 53 as deodorized exhaust gas G2. A temperature sensor 54 is provided for measuring the internal temperature of the furnace body 50 near the exhaust port 53. Further, a metering valve 55 is provided in the fuel supply line to the burner 51.

Furthermore, a heat exchanger 6 is provided at the next stage of the deodorizing furnace 5, and the heat exchanger 6 is used to capture the heat in the exhaust gas G2 discharged from the exhaust port 53 into the exhaust gas G1 before being supplied to the air supply port 52. It is configured so that it can be done.

Further, the rotary joint 115a is supplied with heating steam V for heating the multi-pipe heating tube 11, and this heating steam V is provided with a pressure reducing valve 7 and a flow rate regulating valve 8. Supplied from the steam piping route.
Note that the pressure of the heating steam V is adjusted to about 0.1 to 0.7 MPaG (corresponding to a temperature of 120 to 170° C.) depending on the properties of the object to be processed P.
In addition, the steam piping route for the heating steam V branches before the pressure reducing valve 7, and this branch route is connected to the heat exchanger 9 so that the heated outside air can be supplied to the carrier gas port 103 as the carrier gas C. It is composed of This branch path is also connected to the steam supply port 106, and is configured to be able to raise the temperature inside the main body shell 10.

The horizontal continuous conduction heat transfer type dryer 1 and peripheral equipment to which the present invention is applied are configured as described above as an example. How to operate a thermal dryer" will be explained.

(1) Preparation of the dryer First, prior to charging the material P to be processed, the temperature of the multi-tube heating tube 11 and the main body shell 10 in the horizontal continuous conduction heat transfer dryer 1 is raised, and the rotary joint After supplying the heating steam V to the steam supply port 115a and the steam supply port 106, the motor M1 is started to rotate the multi-tubular heating tube 11. The heating steam V supplied to the rotary joint 115a raises the temperature of the multi-pipe heating tube 11 while passing through the heat tube bundle 116, and eventually becomes a drain and is discharged to the outside from the rotary joint 115b at the other end. Further, the heating steam V supplied to the steam supply port 106 raises the temperature of the main body shell 10, and eventually becomes a drain and is discharged to the outside from the drain port 107.
Note that a siphon pipe (not shown) is provided in the end plate 112 on the rotary joint 115b side, and a steam trap (not shown) is provided in the path through which drain discharged from the rotary joint 115b flows. Further, a steam trap (not shown) is also provided in the path through which drain is discharged from the drain port 107.

(2) Drying of the object to be processed Next, the object to be processed P (70 to 80% W.B. as an example) is placed in the input port 101.
This material is moved from the front to the rear by the action of the feed blade 118, and is further scraped up by the lifter 117 and comes into contact with the heat tube bundle 116, etc. At this time, it receives heat and the drying progresses. It is something. Note that since the interior of the end plate 112 is filled with heating steam V, the surface portion of the end plate 112 also effectively acts on drying the object P to be processed.
The dried object P usually has a moisture content of about 15%W. B. This state flows out from the overflow port 102 and is discharged to the outside from the discharge port 109 as a dried product D.
As already mentioned, the processed material P that has been put into the horizontal continuous conduction heat transfer dryer 1 and whose moisture content has not decreased to a certain value is referred to as the processed material P1, and is The processed material P that has progressed is called a retained product P2.

When the start-up operation for drying the object P is started with the inside of the main body shell 10 being empty, the object P is gradually introduced from the input port 101 and is dried inside the main shell 10. However, after the moisture content reaches a predetermined amount due to the workpiece P1 whose moisture content has not decreased to a certain value and the retained product P2 whose moisture content has dried more than the certain value, or when the product temperature reaches a predetermined temperature. The operation method of the present invention is then carried out until reaching .
In addition, the start-up operation may be performed when the inside of the main body shell 10 is not empty, for example, when restarting the drying operation after being interrupted, or when a predetermined amount of the workpiece P whose moisture content has been reduced in advance is introduced into the main body shell 10. After that, there are cases where the original material to be processed P (whose moisture content has not been reduced in advance) is introduced, and the operating method of the present invention is similarly executed using the retention amount or predetermined product temperature as an index.

As mentioned in [Background Art], in general, in horizontal continuous conduction heat transfer type dryers, drying progresses when the processed material P inside the machine comes into contact with the surface of the heat transfer member. Although it is preferable for drying efficiency to operate while maintaining a high retention amount of the processed material P, if fluctuations in the properties of the processed material P are expected, the dryer and peripheral equipment should be In order to operate stably and continuously, it is necessary to maintain an appropriate amount of retention, which results in a highly efficient drying operation.
If the apparent density of the material to be processed P changes greatly as it dries, the amount of retention in the main body shell 10 will change, and the amount of discharge of the dried product D will also change greatly. This will affect the operation.
Therefore, the present applicant focused on the correlation between the in-machine level of the accumulated product P2 in the main body shell 10, the exhaust temperature, and the load current of the motor M1 for driving the heat transfer member, and This is to improve the accuracy of the discharge amount control according to the increase or decrease of the accumulated product P2 in the drying process, automatically adjust the amount of the accumulated product P2, and use it for stable drying operation.

(3) Fuzzy control The present invention automatically maintains and adjusts the retention amount of the processed material P within the main body shell 10 to an appropriate amount to achieve high drying efficiency, and also to reduce the amount of dried product D discharged. It can also be adjusted so as not to impose a large load on the operation of equipment downstream of the dryer, and this is achieved by fuzzy control.
Specifically, the measurement value of the "retention level" of the retained product P2 in the main body shell 10 that is scraped up in the rotational direction of the multi-tubular heating tube 11, which is a heat transfer member, and the change in accordance with the volume change of the retained product P2. the measured value of the "exhaust temperature" that is measured, and the measured value of the "load current" of the motor M1 for driving the heat transfer member, which changes with the change in the weight of the retained product P2. Fuzz control is performed using the value as the condition part and the closing time of the overflow port 102 as the conclusion part.

As the "retention level", "retention level L1" measured by the in-machine level detection mechanism 13A and "retention level L2" measured by the in-machine level detection mechanism 13B are used.
Further, as the "exhaust temperature", "exhaust temperature T1" measured by the exhaust gas temperature sensor 121 installed near the exhaust port 104 is used.
Further, as the "load current", a "load current A1" measured as a current flowing through the motor M1 for driving the multi-tubular heating tube 11 (heat transfer member) is used.

(i) Creation of membership function First, for each of the "retention level L1", "retention level L2", "exhaust temperature T1", and "load current A1", which are the condition parts of fuzzy inference, Membership functions for language variables and attributes are determined as shown in Figures 5-1, 5-2, 5-3, and 5-4.
The number of linguistic variables (labels) for such attributes and the membership functions for these linguistic variables are determined based on empirical rules, and are based on the type of workpiece P, physical properties, system scale and configuration, etc. Tuning is performed as appropriate.

(ii) Derivation of attributes and suitability The suitability for each attribute is derived using the membership function.
Specifically, for example, when the value of the retention level L1 is 28%, it is read from the membership function graph shown in FIG. 5-1 that the attribute is NL and the fitness is 1.0.
Similarly, when the value of the retention level L2 is 37%, it is read from the membership function graph shown in FIG. 5-2 that the attribute is ZR and the fitness is 1.0.
Further, when the value of the exhaust gas temperature T1 is 103° C., it can be read from the membership function graph shown in FIG. 5-3 that the attribute is PL and the fitness is 1.0.
Furthermore, when the value of the load current A1 is 73 A, it is read from the membership function graph shown in FIG. 5-4 that the attribute is ZR and the fitness is 1.0.

(iii-1) Pattern A: Fuzzy inference where the condition part is "retention level L1", "retention level L2", and "exhaust temperature T1" Specifically, this example is based on the rules in the table of FIG. No. 1 to 27, the fuzzy inference is performed using "retention level L1,""retention level L2," and "exhaust temperature T1" as condition parts, and "closing time DT1" of overflow port 102 as conclusion part. It is something to do.

(iii-2) Pattern B: Fuzzy inference where the condition part is "stagnation level L1", "stagnation level L2" and "load current A1". No. 28 to 54, and performs fuzzy inference using "retention level L1", "retention level L2" and "load current A1" as condition parts and "closing time DT1" of overflow port 102 as conclusion part. It is something.

(iii-3) Pattern C: Fuzzy inference where the condition parts are "exhaust temperature T1" and "load current A1" Specifically, this example is based on rule No. 1 in the table of FIG. 6-3. 55 to 63, fuzzy inference is performed using "exhaust temperature T1" and "load current A1" as condition parts and "closing time DT1" of overflow port 102 as conclusion part.

(iv) Conclusion part Next, the conclusion part for the linguistic variables of the condition part is determined, and this is done according to the rules shown in FIG. 6 as an example. Specifically, the basic operation is when the attribute of the "closing time DT1" is set to ZR, and the "closing time DT1" in this case is 3 minutes.
When the attribute of "closing time DT1" is set to NS, "closing time DT1" is set to 4 minutes, and when the attribute of "closing time DT1" is set to NL, "closing time DT1" is set to 8 minutes. be done.
On the other hand, when the attribute of "closing time DT1" is set to PS, "closing time DT1" is set to 2 minutes, and when the attribute of "closing time DT1" is set to PL, the closing time "closing time DT1" is set to 2 minutes. It is said to be 1 minute.

Note that the opening time of the overflow port 102 is fixed to 2 seconds, as an example, and only the "closing time DT1" is changed according to the conclusion of the above-mentioned fuzzy inference.
Therefore, the overflow port 102 is in the "open state" for 2 seconds and then shifts to the "closed state", and the above fuzzy inference is executed at regular intervals, and the conclusion part of the "closing time DT1" is The time for which the device is in the “closed state” is determined depending on the attribute.
Therefore, the opening/closing state of the overflow port 102 is, for example, "open state" for 2 seconds, "closed state" for 4 minutes, "open state" for 2 seconds, "closed state" for 3 minutes, "open state" for 2 seconds, and "closed state" for 3 minutes. "closed state", "open state" for 2 seconds, and "closed state" for 4 minutes.

Furthermore, the above-mentioned fuzzy inference is performed using only pattern A, only pattern B, only pattern C, a combination of pattern A and pattern B, or a combination of pattern A and pattern C. In this case, it is assumed that pattern B and pattern C are combined, pattern A, pattern B, and pattern C are combined, and it is also assumed that these patterns are combined randomly. Ru.

Here, as an example, a combination of pattern A and pattern C will be described.
When the retention level L1 in pattern A is 38%, the attribute is ZR and the fitness is 1.0.
If the retention level L2 at this time is 42%, the attribute regarding the retention level L2 is ZR and the degree of suitability is 1.0.
If the exhaust gas temperature T1 at this time is 92.5° C., the degree of conformity of the attribute NL with respect to the exhaust temperature T1 is 0.5, and the degree of conformity of ZR is 0.25.
The rule for pattern A that corresponds to this situation is rule No. 13 and no. 14, and the conclusion part is ZR in both cases, so the "closing time" of the overflow port 102 is set to be 3 minutes.
On the other hand, in pattern C, when the load current A1 is 80 A, the suitability of attribute NL with respect to the load current A1 is 0.5, and the suitability of ZR is 0.25.
The rule for pattern C that corresponds to this situation is rule No. 56, No. 57, No. 59 and no. 60, and the "closing time" of the overflow port 102 calculated by the simplified inference method is 3.08 minutes.
Using the calculated values (inferred values) of these patterns A and C, in this embodiment, the operation is performed with the arithmetic mean value of 3.04 minutes as the set value for the "closing time" of the overflow port 102. be.

[Other Examples]
Although the present invention is based on the above-described embodiments, the following modifications can be made within the scope of the technical idea of the present invention.
That is, in the basic embodiment described above, the first in-machine level detection mechanism 13A is provided between the dispersion input port 101a and the exhaust port 104 on the front side (drive side) of the multi-pipe heating tube 11, Furthermore, a second in-machine level detection mechanism 13B is provided between the dispersion input port 101c and the carrier gas port 103 on the rear side (driven side) of the multi-pipe heating tube 11, but other installations are possible. It can take any form.
Specifically, three or more in-machine level detection mechanisms 13 may be provided, and as an example, as shown in FIG. A third in-machine level detection mechanism 13C may be provided between the input port 101c and the input port 101c.
On the other hand, it is also possible to have a single in-machine level detection mechanism 13, and in this case, for example, the dispersion inlet 101c and the carrier gas inlet 103 on the rear side (driven side) of the multi-tube heating tube 11 are connected. It is preferable to provide an in-machine level detection mechanism 13 between them.

1 Conduction heat transfer dryer 10 Main body shell 101 Inlet 101a Dispersion inlet 101b Dispersion inlet 101c Dispersion inlet 102 Overflow outlet 102a Plate material 102b Duct 102c Cover member 103 Carrier gas port 104 Exhaust port 106 Steam supply port 107 Drain port 108 Side opening 109 Discharge port 11 Multi-tube heating tube (heat transfer member)
111 Angle 112 End plate 113 Shaft 114 Bearing block 115a Rotary joint 115b Rotary joint 116 Heat tube bundle 117 Lifter 118 Feed vane 121 Exhaust gas temperature sensor 13 In-machine level detection mechanism 13A In-machine level detection mechanism 13B In-machine level detection mechanism 13C In-machine level detection mechanism 130 Casing 130a Purge air supply port 131 Rod 132 Sleeve 132a Hole 133 Stopper 135 Contact piece 2 Feeding device 20 Hopper 20a Screw conveyor 21 Valve 22 Valve 3 Dust collector 4 Control panel 5 Deodorizing furnace 50 Furnace body 51 Burner 52 Air supply port 53 Exhaust port 54 Temperature sensor 55 Metering valve 6 Heat exchanger 7 Pressure reducing valve 8 Flow rate adjustment valve 9 Heat exchanger C Carrier gas D Dry product F Machine frame G1 Exhaust gas G2 Exhaust gas M1 Motor M2 Inverter motor P Processed object P1 Processed material Processed material P2 Stagnant product (processed material that is highly dried)
S sensor S1 sensor S2 sensor S3 sensor S4 sensor S5 sensor V Heating steam

Claims (2)

A shaft body equipped with a heat transfer member is arranged inside the main body shell, heating steam is caused to flow inside this shaft body, and the shaft body is rotated.
The material to be processed, which is introduced into the main body shell through the input port, is dried by being brought into contact with a heat transfer member that rotates together with the shaft while remaining within the main body shell, and the obtained dried product is discharged from the overflow port. In the operating method of a horizontal continuous conduction heat transfer dryer,
a measured value of the retention level of retained products in the main body shell that is scraped up in the rotational direction of the heat transfer member;
The measured value of exhaust temperature,
A condition part is a measured value of a load current of a motor for driving the heat transfer member;
The closing time of the overflow port is the conclusion part,
A method of operating a horizontal continuous conduction heat transfer dryer characterized by performing fuzzy control to adjust the amount of products retained in the main body shell.
2. The method of operating a horizontal continuous conduction heat transfer dryer according to claim 1, further comprising measuring the level of accumulated products in the main body shell at two or more locations.

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