JP2005249253A - Drier for sawdust - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drier for sawdust formed so that the sawdust flowing down in a flow-down passage between an air supply shell and an air discharge shell installed in a drying tank oppositely to each other can flows down without being sucked by a ventilation hole in the air exhaust shell and well circulate in the drier in the drier for the sawdust for ventilatingly drying the sawdust while circulating. <P>SOLUTION: The amount of the air from a suction type blower connected to right and left hot air chambers on both sides of a collecting chamber collecting, at one end, the dried sawdust quantitatively discharged from a delivery roll in a collection part and the amount of the air from a suction type blower connected to an air discharge chamber are regulated to limit an air pressure (static pressure) in a flow-down passage in the drying tank within a specified range. Accordingly, since the sawdust is not sucked to the ventilation hole in the air discharge shell side face of the flow-down passage, the dried sawdust in the drying tank is allowed to flow down without accumulation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is applied to a sawdust drying apparatus for drying by ventilation while circulating sawdust to be dried.

  Sawdust generated by processing wood, sawing, etc. can be used in a wide range of sources, such as fuel, compost raw materials, and cultivation bases of potatoes. However, when sawdust is used as fuel, it must be sufficiently dry. In addition, when it is used as a raw material for compost or as a cultivation base for potatoes, it is important to dry it from its storage and transportation and to a moisture value according to the method of use.

  In general, sawdust generated by sawmills such as logs contains a lot of moisture, and sawdust generated by processing wood or cutting timber depends on the state of collection and storage, but it contains a lot of moisture. In many cases, the collected sawdust has to be dried to a predetermined moisture content because it is provided in a contained state.

  In addition, the driftwood that reaches the dam has been disposed of in the past, but is being used as a fuel for heaters from the viewpoint of effective use of resources. In order to make it easy to use driftwood as fuel for heaters, in recent years, it has been converted to pellets. In order to make driftwood into pellets, it is necessary to pulverize them and dry them to moisture that can easily be turned into pellets.

  For this reason, conventionally, various means for drying sawdust have been proposed. If it is roughly classified by function, it is dried by applying hot air to a stationary layer of sawdust to be dried (see Japanese Patent Laid-Open No. 48-2436), and dried by stirring the sawdust to be dried with a rotating drum. (See Japanese Laid-Open Patent Publication No. 60-2868), which is subjected to hot air while rotating dried sawdust with a cyclone (see microfilm of Japanese Utility Model Application No. 55-167157 (Japanese Utility Model Publication No. 57-89196)), There is a microfilm of sawdust that is dried with hot air while stirring with a stirring body in a drying drum (Japanese Utility Model Application No. 2-41864 (Japanese Utility Model Application No. 4-1394)).

  Further, this patent applicant has filed an application for a sawdust drying method and apparatus for drying by ventilation while circulating sawdust on May 26, 2003 (Japanese Patent Application No. 2003-148074).

Japanese Patent Laid-Open No. 48-2436 JP-A-60-2868 Japanese Utility Model Publication No. 57-89196 Japanese Utility Model Publication No. 4-1394

  In general, sawdust appears in the form of dumplings when it contains moisture, so even if it is deposited with hot air, the drying efficiency is very low, and even if only the surface is dried, the whole is evenly dried. Is not possible. In addition, even if the sawdust is agitated with a rotating drum or stirring body so that it can be easily dried, the mass of sawdust is only slightly reduced and it does not become a state of being broken up into particles, and it is also efficient and even. The reality is that it cannot be dried.

  Therefore, the present applicant filed on May 26, 2003 (Japanese Patent Application No. 2003-148074), invented a sawdust drying method and apparatus for drying by drying while circulating the sawdust to be dried, and efficiently sawdust. It is designed to be able to dry evenly.

  However, an appropriate amount of the previous dried sawdust is left in the drying tank, or an appropriate amount of dried sawdust is put into the drying tank, and the dry sawdust is removed while repeating the circulation of the dried sawdust. The drying method that mixes the dried sawdust with the dried sawdust to improve fluidity and prevent the sawdust from staying in the dryer, and the suction or pressure ventilation or alternate flow of them is used. However, sawdust that flows down the flow path between the air supply drum and the exhaust drum provided opposite to the drying tank is good for the sawdust in the vicinity of the air supply drum. Experiments have shown that sawdust is adsorbed by the vents of the wind tunnel and does not flow evenly.

  Therefore, the present invention provides a sawdust drying apparatus that circulates and drys the sawdust to be dried, and the sawdust flowing down the flow path between the air supply drum and the exhaust drum provided in the drying tank is discharged. Left and right across the collection chamber that collects dried sawdust quantitatively fed from the feed roll inside the collection unit at one end so that it flows down without being adsorbed by the vents of the wind tunnel and circulates well inside the dryer. By adjusting the air volume of the suction blower connected to the hot air chamber and the suction blower connected to the exhaust air chamber, the air pressure (static pressure) of the flow channel in the drying tank is limited to a certain range, and the flow channel An object of the present invention is to provide a sawdust drying device configured such that sawdust is not adsorbed to the vent holes on the side surface of the exhaust wind tunnel, and the to-be-dried sawdust in the drying tank flows down without delay.

  In order to achieve the above object, the present invention provides a sawdust drying apparatus according to claim 1 or claim 2.

  That is, the sawdust drying apparatus according to claim 1 is a sawdust drying apparatus that ventilates air while circulating the sawdust to be dried, and a drying tank that ventilates and drys the sawdust to be dried and the drying tank. A sawdust pump that feeds and circulates dried sawdust to the inside of the drying tank. Collecting of the sawdust collection unit that collects the dried sawdust that is quantitatively fed from the feed roll at one end, provided with a ventilation drying unit, sawdust storage unit and feed regulating body, and a feed roll below it Air pressure (static pressure) in the downflow path inside the drying tank is ventilated in a sawdust drying device with a hot air chamber connected to the pressure blower on the left and right across the chamber and an exhaust air chamber connected to the suction fan Temperature range from 20 ℃ to 80 ℃ In some cases, it is 0 Pa to -30 Pa, and sawdust is not adsorbed to the air supply and exhaust vents on the side of the downflow passage, and the dried sawdust in the drying tank is allowed to flow without any delay. It is a feature.

  The sawdust drying apparatus according to claim 2 is the Padding sawdust drying apparatus according to claim 1, wherein the air pressure (static pressure) in the flow path inside the drying tank is 0 Pa when the airflow temperature is in the range of 20 ° C to 80 ° C. The air volume of one or both of the pressure blower and the suction blower can be controlled so that the pressure becomes -30 Pa.

  According to the present invention, when air-drying while circulating the sawdust to be dried, sawdust flowing down the flow path between the air supply drum and the exhaust drum provided facing the air-drying unit in the drying tank, Left and right across the collection chamber that collects dried sawdust quantitatively fed from the feed roll inside the collection unit at one end so that it can be circulated in the drying device without being adsorbed by the ventilation holes of the exhaust duct Since the air flow (static pressure) in the drying tank in the drying tank was limited to a certain range by adjusting the air volume of the pressure blower connected to the hot air chamber and the suction fan connected to the exhaust chamber, Sawdust is not adsorbed in the vent holes on the side of the exhaust wind tunnel, and the dried sawdust in the drying tank can flow down without delay.

  Furthermore, the suction air blower and the pressure blower can change the air volume so that the air pressure (static pressure) of the flow path of the ventilation drying unit is always within a predetermined range. Even if there is a change in the air pressure in the downflow, it can be adjusted so that it immediately falls within the set range, so that high-moisture sawdust reaches the sawdust near the end of drying, and the sawdust is adsorbed to the vent holes in the exhaust drum in the drying layer. In addition, the fluidity is improved, and the effect of being able to efficiently and uniformly dry the whole can be obtained.

  FIG. 1 is a schematic external perspective view of a sawdust drying apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view showing a part cut away from FIG. 1 and the target direction, and FIG. FIG. 4 is a plan sectional view of the embodiment of the present invention.

  The sawdust drying apparatus 1 according to the present invention shown in FIGS. 1 to 2 and 3 includes a drying tank 2 and a sawdust feeder 3 having a sawdust inlet. The drying tank 2 includes a sawdust storage unit 4, a ventilation drying unit 5, a sawdust retention unit 6, and a sawdust collection unit 10 in that order from the top, and sawdust is delivered by a plurality of feeding rolls 7 at the upper end of the sawdust collection unit 10. Part 8 is formed. 9 is the Yamagata pay-out restricting body. A sawdust discharge screw conveyor 11 is provided at the lower end of the sawdust collection unit 10. Further, an equalizing screw conveyor 12 for evenly dispersing sawdust is provided at the upper portion of the sawdust accommodating portion 4, that is, the top surface of the drying tank 2. The transport end of the sawdust discharge screw conveyor 11 in the drying tank 2 and the lower end side of the sawdust lifter 3, and the transfer start end of the leveling screw conveyor 12 and the upper end side of the sawdust lifter 3 are connected to circulate sawdust. Can be performed smoothly.

  In the drying tank 2, the ventilation drying unit 5, the sawdust retention unit 6 and the sawdust collection unit 10 are divided into right and left by the collection chamber 13 of the sawdust collection unit 10, one of which is a hot air chamber 19 and the other is exhausted. It becomes the room 20.

  The hot air chamber 19 is provided with a dry air blower 21, which burns the burner 22 in the combustion pipe 23 and passes the pressure blown air from the pressure blower 24 near the combustion pipe 23. The dried air is forcibly sent to the drying chamber 19. In FIG. 4, the combustion air of the burner 22 is discharged from the combustion pipe 23 to the outside of the machine. However, even if the combustion air of the burner 22 is mixed with the outside air by the pressure blower 24 of the drying air blowing unit 21 and sent into the drying chamber 19. Good. In FIG. 4, the dry air blowing unit 21 is installed outside the hot air chamber 19, but the dry air blowing unit 21 may be built in the hot air chamber 19 (not shown).

  The exhaust fan 20 is equipped with a suction blower 25 outside the apparatus so as to pass air from the pressure blower 24 to the hot air chamber 19 and from the exhaust fan 20 to the suction fan 25 via the ventilation drying unit 5. The suction blower 25 may also be built in the exhaust air chamber 20 (not shown).

  The top surface of the drying tank 2 is provided with suction / exhaust fans 26 for sucking and exhausting air from the upper space of the sawdust storage unit 4, and drying from the hot air chamber 19 to the sawdust storage unit 4 is performed at four corners in the plane of the drying tank 2. An air duct 27 that guides a part of the wind is connected to an exhaust duct 28 that guides the air in the sawdust accommodating portion 4 to the exhaust chamber 20, and a part of the dry air is vented to the sawdust accommodating portion 4, thereby sawdust. Moist air in the housing part 4 is quickly discharged out of the machine, so that condensation on the top surface and sawdust housing part 4 is prevented.

  The sawdust lifting machine 3 is provided with a moisture measuring means 29 for collecting dried sawdust scattered during the feeding and measuring the moisture, and the sawdust drying device 1 according to the present invention has this moisture. When the measuring means 29 detects that the moisture content of the sawdust being circulated and dried reaches a predetermined value, the drying is terminated.

  The ventilation drying section 5 of the drying tank 2 is provided with alternately arranged exhaust wind drums 31 similar to the air supply drum 30 having a mountain shape at the top and a sawdust downflow path 32 formed between them. The air supply drum 30 communicates with the hot air chamber 19 and the air exhaust drum 31 communicates with the air exhaust chamber 20, respectively. The dry air is supplied from the hot air chamber 19 through the air supply drum 30 and the sawdust flow path 32. It crosses into the wind exhaust drum 31 and is discharged into the wind exhaust chamber 20.

  The sawdust flow path 32 is provided with a sensor for measuring the air pressure (static pressure) at that portion. Any one of the collection chamber 13, the hot air chamber 19, and the exhaust chamber 20 may be provided with a sensor for measuring air pressure (static pressure), and each sensor is provided in the control unit of the sawdust drying device. It is connected (not shown).

  Dried sawdust introduced from the sawdust feeding port of sawdust lifter 3 is fed into the desiccated sawdust from the upper part of the drying tank 2 provided with the ventilation drying section 5 inside, and flows down the downflow path 32 and is fed out. 7, the circulation process from the sawdust discharging screw conveyor 11 at the bottom of the collection chamber 13 to the sawdust lifter 3 is repeated until the drying is completed.

  In the middle of this process, in the downstream channel 32 of the ventilation drying unit 5, even if there is dry wind passing from the air supply drum 30 to the exhaust drum 31 as the air pressure (static pressure) of the downstream channel 32 approaches 0 Pa, the downstream channel is present. It has been found from experiments that the phenomenon of sawdust sticking to the vent holes on the side surface of the 32 exhaust cylinders 31 does not occur. In particular, it has been found that when the drying air is in the range of 20 ° C. to 80 ° C., the air pressure (static pressure) of the downflow passage 32 is 0 Pa to −30 Pa, and particularly the occurrence of the sawdust adsorption phenomenon is suppressed. Therefore, by adjusting the air flow rate of the pressure blower 24 and the suction blower 25 so that the drying air is in the range of 20 ° C. to 80 ° C., and adjusting the air pressure (static pressure) of the flow down passage 32 from 0 Pa to −30 Pa. Since sawdust is not adsorbed in the vent holes on the side surface of the exhaust duct 31 of the downflow path 32, the sawdust flows down the downflow path 32 without stagnation.

  However, it is known that the air resistance of the downflow path 32 in the ventilation drying unit 5 varies depending on the moisture value of the material to be dried, and the air pressure in the dryer fluctuates. Therefore, in the implementation according to the present invention, since a sensor for measuring the air pressure (static pressure) is provided in the downflow passage 32, a signal from the sensor is judged by the control panel, and either the pressure blower 24 or the suction blower 25 or By changing both of the air volumes so that the air pressure (static pressure) of the flow path 32 is always changed from 0 Pa to −30 Pa, the good flowability of sawdust can be maintained. For this reason, even if it is to-be-dried sawdust containing much moisture, the whole can be dried efficiently and uniformly.

  Depending on where the sensor for measuring the air pressure (static pressure) is provided in the downflow path 32, there is a possibility that an obstacle for the flow of sawdust will be provided in the downflow path 32. Therefore, in the present invention, when the air pressure (static pressure) in the flow path 32 during drying of the sawdust to be dried is changed from 0 Pa to −30 Pa, the air pressure (static pressure) of the exhaust chamber 20 is −300 Pa to −350 Pa, the hot air chamber 19. It has also been found from experiments that the air pressure (static pressure) of air is 0 Pa to −10 Pa, and the air pressure (static pressure) of the collection chamber 13 is in the vicinity of −30 Pa to −100 Pa. Efficient sawdust by providing air pressure measurement sensors on one or more of them, and controlling either one or both of the pressure blower 24 and suction blower 25 so that the air pressure (static pressure) is within the set value. The whole can be dried evenly.

  In the sawdust drying device of the present invention, circulation ventilation drying is possible not only for sawdust but also for a light-weight powdered granule, so that it is possible to dry food processed products or industrial waste from an agricultural grain drying device. It can be used as a wide range of drying equipment such as drying chips.

1 is a schematic external perspective view of a sawdust drying apparatus according to an embodiment of the present invention. The perspective view which fractures | ruptures and shows a part shown from FIG. 1 and an object direction. The front sectional view of an embodiment of the invention. The top sectional view of an embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sawdust drying apparatus 2 Drying tank 3 Sawdust transporter 4 Sawdust accommodating part 5 Ventilation drying part 6 Sawdust retention part 7 Feeding roll 8 Sawdust delivery part 9 Feeding regulation body 10 Sawdust collection part 11 Sawdust discharge screw conveyor 12 Uniform screw conveyor 13 Collection chamber 19 Hot air chamber 20 Ventilation chamber 21 Dry air blower 22 Burner 23 Combustion tube 24 Pressure blower 25 Suction blower 26 Suction exhaust fan 27 Intake duct 28 Exhaust duct 29 Moisture measuring means 30 Air supply drum 31 Exhaust drum 32 Downstream

Claims (2)

A sawdust drying device for drying by ventilation while circulating dried sawdust,
It comprises a drying tank that stores and circulates dried sawdust, and a sawdust lifter that feeds and circulates dried sawdust into the drying tank.
In the inside of the drying tank, a ventilation drying section formed by facing the air supply drum and the exhaust drum and the flow of dried sawdust between them,
A sawdust retention part, a feeding regulation body, and a lowering roll are provided below,
A hot air chamber connected to a pressure blower on both sides across a collection chamber of a sawdust collection unit that collects dry sawdust quantitatively fed from a feed roll at one end, and an exhaust chamber connected to a suction blower In sawdust drying equipment,
When the air pressure (static pressure) in the downflow channel inside the drying tank is in the range of 20 ° C to 80 ° C in the ventilation temperature range of 0 ° C to -30Pa, A sawdust drying apparatus, wherein sawdust is not adsorbed in the pores, and the dried sawdust in the drying tank is allowed to flow smoothly. When the air pressure (static pressure) in the flow path inside the drying tank is in the range of 20 ° C. to 80 ° C., the air volume of one or both of the pressure blower and the suction blower is adjusted so as to be 0 Pa to −30 Pa. The sawdust drying apparatus according to claim 1, wherein the sawdust drying apparatus is controllable.

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