JP6076957B2 - Batch dryer - Google Patents

Description

  The present invention relates to a batch type drying apparatus configured to perform a drying process in which a workpiece is heated and dried.

  In a conventional batch type drying apparatus, generally, a work is put into the furnace body through a door (for example, a front door), and after setting a time for performing a drying process through an operation unit, a setting is made. The drying process is performed for a predetermined time, and after the drying process is finished, the door is opened and the workpiece is taken out from the furnace body. Among such batch-type drying apparatuses, there is a batch-type oven configured to heat and dry a workpiece with hot air circulated inside a furnace body (see, for example, Patent Document 1). ).

JP 2001-12870 A

  However, in the conventional batch type drying apparatus, the time for performing the heat treatment is set longer than necessary, and as a result, the drying treatment time is unnecessarily prolonged, and wasteful power may be consumed. It was. For example, it is not preferable from the viewpoint of energy saving to continue heating the workpiece even though the workpiece is completely dry.

  On the other hand, it is difficult to determine the optimum time for performing the drying process. This is because the optimum drying time varies depending on the type, size, shape, and the like of the workpiece. Further, in a situation where drying unevenness occurs in the workpiece, it becomes more difficult to determine the optimum time for performing the drying process.

  An object of the present invention is to provide a batch type drying apparatus capable of preventing unnecessary drying processing by ending drying processing on a workpiece at an appropriate timing and saving power.

The batch type drying apparatus according to the present invention is configured to perform a drying process for heating and drying a workpiece. This batch type drying apparatus includes a furnace body, a heating unit, a work support unit, a weight measuring unit, an operation unit, and a control unit. The furnace body accommodates the workpiece to be heated. The heating means generates hot air circulating in the furnace body by a heater that heats the atmosphere and a fan that circulates the atmosphere, and heats the workpiece with the hot air .

  The work support unit supports the work in a rotatable manner. The weight measuring means is configured to measure the total weight of the work support unit including the work. An example of the weight measuring means includes a load cell, but is not limited thereto.

  The operation unit is configured to receive a setting input related to the weight of the workpiece when the drying process is completed from the operator. The control means is configured to be able to control the operation of the heating means based on input information from the weight measuring means. The control means monitors the measurement result of the weight measurement means during the drying process, and when the reduction amount of the measurement result becomes zero based on the measurement result and its change state and the weight received by the operation unit, Alternatively, at least one of stopping the operation of the heating unit and notifying the completion of the drying process is performed when the measurement result matches the weight received by the operation unit.

Furnace body houses a workpiece therein, is arranged with a tank having a plurality of vent holes to flow into or out of the hot air is formed on the side surface covering the inside of the, spacing on the outside of the inner tub in between the inner and outer The heating means is arranged between the outer tub and the inner tub, and includes a heater that heats the atmosphere and a fan that circulates the atmosphere. Ru is circulated between the outer tank and the inner tank so as to pass through the inside and one of the vent holes and different vent tank.

In this configuration, it is more preferable that the heating means be arranged upstream of the heater in the path for circulating the hot air.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent performing an excessive drying process by complete | finishing the drying process with respect to a workpiece | work at an appropriate timing, and to attain power saving.

It is a figure which shows the outline of the drying apparatus which concerns on embodiment of this invention. It is a block diagram which shows the outline of a drying apparatus. It is a flowchart which shows an example of the operation | movement procedure of CPU at the time of a drying process. It is a flowchart which shows the other example of the operation | movement procedure of CPU at the time of a drying process. It is a figure which shows an example of the change state of the internal temperature of a workpiece | work with respect to time at the time of a drying process, and a weight.

  A basic configuration of a drying apparatus 10 according to an embodiment of the present invention will be described with reference to FIG. The drying apparatus 10 is a hot-air circulating batch oven, and is configured to heat and dry the work 14 carried into the furnace body 12 with the circulating hot air. Here, a gypsum mold is used as the workpiece 14, but a workpiece other than the gypsum mold can be dried. A door (not shown) for loading and unloading workpieces is provided on the front surface of the furnace body 12.

  The furnace body 12 includes an outer tub 122 and an inner tub 124, and a heater 22 and a circulation fan 24 are provided between the outer tub 122 and the inner tub 124. The heater 22 is configured to heat the atmosphere inside the furnace body 12 by receiving electric power via the heater driving unit 62. Here, a sheathed heater is used as the heater 22, but the type of the heater 22 is not limited to this.

  The circulation fan 24 is configured to forcibly circulate the atmosphere inside the furnace body 12 by receiving electric power via the fan drive unit 60. In this embodiment, a sirocco fan is used as the circulation fan 24, but other types of fans can also be used.

  The inner tank 124 is formed with a plurality of vent holes 126 on both sides for allowing circulating air to pass therethrough. In this embodiment, high-temperature circulating air generated between the outer tank 122 and the inner tank 124 by the circulation fan 24 enters the inner tank 124 from one side surface of the inner tank 124, and the other side surface of the inner tank 124. To the outside of the inner tub 124. Further, an exhaust port 30 and an intake port 32 are provided on the circulation air path.

  The drying apparatus 10 includes a workpiece support unit 15 configured to rotatably support the workpiece 14. The work support unit 15 includes a rotary table 16 and a rotation drive unit 18. The turntable 16 is arranged inside the inner tub 124 and configured to support the workpiece 14. The turntable 16 is configured to rotate with the work 14 placed thereon by receiving a driving force from the rotation drive unit 18.

  The rotation drive unit 18 is arranged outside the outer tub 122 and configured to supply a rotation force to the turntable 16. The rotation drive unit 18 includes a housing member 180. The rotation drive unit 18 includes a housing member 180 and a rotation shaft 182 disposed so as to penetrate the furnace body 12, and is configured to transmit a rotational force to the turntable 16 via the rotation shaft 182. Is done. The rotation shaft 182 is pivotally supported by a bearing portion 184 provided in the housing member 180, and a rotation transmission member (for example, a pulley, a gear, etc.) 186 is provided in the vicinity of the lower end portion. A driving device 188 such as a motor is connected to the rotation transmitting member 186, and the rotational driving force from the driving device 188 is transmitted to the rotary table 16 via the rotation transmitting member 186 and the rotating shaft 182.

  Under the rotary drive unit 18 outside the furnace body 12, the total weight of the rotary drive unit 18, the rotary table 16, and the work 14 on the rotary table 16 is measured, and an electrical signal corresponding to the measurement result is output. The load cell 20 configured as described above is arranged. Around the load cell 20, a plurality of (for example, three or more) guide members 26 for maintaining the parallel state of the housing member 180 are arranged.

  As shown in FIG. 2, the drying apparatus 10 includes a CPU 50. The CPU 50 includes a ROM 52, a RAM 54, a sensor unit 56, an I / F unit 58, a fan driving unit 60, a heater driving unit 62, a rotation driving unit 18, The load cell 20, the operation unit 64, the display unit 66, and the like are connected. The ROM 52 stores a plurality of programs necessary for the operation of the CPU 50. The RAM 54 is a volatile memory for the CPU 50 to temporarily record data. The sensor unit 56 is constituted by a plurality of instruments for collecting information such as the temperature and pressure inside the furnace body 12. The I / F unit 58 has a function of communicating with an external device.

  The fan drive unit 60 is configured to drive the circulation fan 24 based on a signal from the CPU 50. The heater driving unit 62 is configured to drive the heater 20 based on a signal from the CPU 50.

  The operation unit 64 is configured to accept input of operation commands and setting information from an operator and transmit them to the CPU 50 as electrical signals. For example, the operation unit 64 can accept a setting input related to the weight of the workpiece when the drying process is completed from the operator. The display unit 66 is configured to display necessary information (operation completion, warning, etc.) for the operator based on a signal from the CPU 50.

  The CPU 50 is configured to comprehensively control each part of the heating device based on a plurality of programs stored in the ROM 52. In particular, the CPU 50 controls the operations of the fan drive unit 60, the heater drive unit 62, the display unit 66, and the rotation drive unit 18 based on input information from the load cell 20.

  Next, the operation procedure of the CPU 50 during the drying process will be described using the flowchart of FIG. Here, an example will be described in which the drying process is stopped based on a setting input related to the weight of the workpiece upon completion of the drying process from the operator.

  First, the CPU 50 stands by until the operator performs an operation related to execution of the drying process on the operation unit 64 (S1). In the S1 standby step, when the operator places the work 14 on the turntable 16 and closes the door to perform the drying operation, the CPU 50 operates the fan drive unit 60 and the heater drive unit 62 to dry the work 14. The processing is started, and the operation of the rotation driving unit 18 is started to rotate the rotary table 16 (S2). Further, the CPU 50 stores in the RAM 54 the set value of the final weight of the workpiece when the drying process is completed, which is input by the operator via the operation unit 64.

  During the drying process, the CPU 50 detects the output value of the load cell 20 constantly or intermittently and monitors the total weight of the work support unit 15 and the work 14 (S3).

  Then, the CPU 50 determines whether or not the weight of the workpiece calculated based on the output value of the load cell 20 has reached the weight of the workpiece according to the setting input by the operator (S4). In the determination step of S4, the CPU 50 subtracts the preset weight of the work support unit 15 from the total weight detected by the load cell 20 to obtain the work weight.

  In the determination step of S4, when the weight of the workpiece reaches the weight of the workpiece according to the setting input by the operator, the CPU 50 stops the operation of the heating device 10 and displays a display of processing completion on the display unit 66. Perform (S5). Specifically, the CPU 50 stops the operations of the fan drive unit 60 and the heater drive unit 62 and also stops the operation of the rotation drive unit 18. Further, the operator is notified through the display unit 66 that the processing is completed.

  Here, both the stop of the operation and the notification to the operator are performed, but only one of them may be performed. Further, the notification method is not limited to the display on the display unit 66, and notification to the operator may be performed using voice.

  Next, another example of the operation procedure of the CPU 50 during the drying process will be described using the flowchart of FIG. The flowchart of FIG. 4 is substantially the same as the flowchart of FIG. 3 except for the step of S14 for determining the completion of the drying process, and thus description thereof is omitted here.

  In the determination step of S <b> 14, the CPU 50 determines whether or not the drying process is completed based on the change state of the output value of the load cell 20 over time. Specifically, when the amount of change in the measurement result per unit time becomes equal to or less than a predetermined value set in advance, the CPU 50 stops the operation of the drying apparatus 10 and displays that the drying process has been completed. The process 66 is displayed on the unit 66.

  Here, an example of a change state of the output value of the load cell 20 with the passage of time will be briefly described with reference to FIGS. 5 (A) and 5 (B). FIG. 5A shows a change state of the internal temperature of the work 14 over time, and FIG. 5B shows a change state of the work weight over time.

  For a while after the heat treatment for the workpiece 14 is started, the material preheating period P1 is reached. During this time, the temperature of the workpiece 14 rises, but no moisture evaporation occurs, so there is no change in the weight of the workpiece 14. Subsequently, when shifting to the constant rate drying period P2, the amount of heat received from the circulating hot air is all consumed for moisture evaporation, so that the temperature of the work 14 is kept constant. At this time, since the drying speed is also constant, the rate of decrease of the weight of the work 14 per unit time is constant. And if it transfers to the decreasing rate drying period P3, the amount of moisture evaporation will begin to decrease, and the temperature of the workpiece | work 14 will begin to rise with the amount of heat which was not spent on moisture evaporation among the amount of heat received from the circulating hot air. At this time, since the drying speed decreases, the rate of decrease of the weight of the work 14 per unit time begins to decrease and eventually becomes zero.

  5A and 5B can be used to predict the amount of water contained in the work 14, so that the determination of the completion of the drying process can be made according to the required degree of drying. It is possible to determine the completion of the drying process by appropriately setting a weight reduction value (including zero) of the workpiece 14 per unit time as a threshold value.

  According to the above embodiment, by monitoring the total weight of the workpiece 14 and the workpiece support unit 15 (or the weight of the workpiece 14 calculated from the total weight), the timing of completion of the drying process can be efficiently determined. Since it becomes possible to grasp | ascertain, it can prevent performing a drying process more than necessary, and it becomes possible to aim at power saving.

  In the above-described embodiment, the example in which the determination step of S4 in FIG. 3 or the determination step of S14 in FIG. 5 is alternatively executed has been described, but these determination steps may be executed in combination. . For example, if the rate of decrease of the weight of the work 14 per unit time becomes zero before the weight of the work reaches the weight of the work related to the setting input by the operator, it is determined that the drying process is completed at that time. Then, the operation of the heating device 10 may be stopped. In this case, even when the operator's setting regarding the weight of the work is inappropriate, it is possible to prevent the occurrence of energy loss due to excessive heating.

  Further, at the start of the drying process, it is determined whether or not a work weight setting input is made by the operator. If there is a setting input, steps S1 to S5 shown in FIG. May execute steps S11 to S15 shown in FIG.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10-drying device 12-furnace body 14-work 15-work support unit 16-rotation table 18-rotation drive unit 20-load cell 22-heater 24-circulation fan 50-CPU
60-fan drive unit 62-heater drive unit

Claims (2)

A batch-type drying apparatus that performs a drying process for heating and drying a workpiece,
A furnace body containing a workpiece to be heated;
Heating means for generating hot air circulating in the furnace body with a heater for heating the atmosphere and a fan for circulating the atmosphere, and heating the workpiece with the hot air;
A work support unit for supporting the work;
Weight measuring means configured to measure the total weight of the work support unit including the work; and
Control means capable of controlling the operation of the heating means based on input information from the weight measuring means;
An operation unit configured to receive a setting input related to the weight of the workpiece when the drying process is completed from the operator,
The furnace body accommodates a work inside, and a plurality of vent holes for allowing hot air to flow in or out between the inside and outside are formed on a side surface covering the inside, and arranged outside the inner tank with a space therebetween An outer tub, and
The heating means is disposed between the outer tub and the inner tub, and passes the hot air from one of the plurality of vent holes to a different vent hole from the inside of the inner tub and the one of the vent holes. Circulate between the outer tank and the inner tank,
The control means monitors the measurement result of the weight measurement means during the drying process, and the amount of decrease in the measurement result is zero based on the measurement result and its change state and the weight received by the operation unit. The batch-type drying apparatus that performs at least one of the stop of the operation of the heating unit or the notification of the completion of the drying process, either when the measurement result matches the weight received by the operation unit . The batch-type drying apparatus according to claim 1 , wherein the heating unit arranges the fan upstream of the heater in a path for circulating the hot air.

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