JP7296624B2 - gas dryer - Google Patents

Description

The present invention relates to a gas dryer for drying linen products such as sheets, pillowcases and towels, mops and mats after washing with drying air using a gas burner.

Patent Document 1 describes a gas dryer for drying linen products such as sheets, pillowcases and towels, and washed laundry such as mops and mats. The gas dryer described in Patent Document 1 is composed of a drying chamber, a gas burner that supplies combustion gas (dry air) into the drying chamber, and an exhaust fan that discharges the dry air in the drying chamber to the outside. there is By activating the exhaust fan, the outside air is heated by the gas burner to form dry air, and this dry air is supplied into the drying chamber. Ejected.

In such a gas dryer, if the gas burner is ignited while combustible gas is leaking from a gas cutoff valve or the like and remaining in the dryer, an accident such as a fire or explosion may occur. In order to avoid such an accident, so-called prepurge is performed. In the gas dryer described in Patent Document 1, pre-purge is performed by providing a pilot burner that burns when the gas burner is not ignited.

JP 2018-126202 A

However, when pre-purging is performed using a pilot burner, the pilot burner must be provided in addition to the main gas burner, and control for burning the pilot burner is also required, so the structure of the gas dryer is complicated. Complicated. Furthermore, since fuel for the pilot burner is required in addition to fuel for the main gas burner, the cost for operating the gas dryer increases. In addition, the combustion of the pilot burner may raise the temperature inside the drying gas passage.

Therefore, as a method of pre-purging without using a pilot burner, the material to be dried is put into the drying chamber from the gas dryer's standby state, and the exhaust fan is operated to ventilate the inside of the gas dryer before the gas burner is ignited. , a pre-purge for discharging the gas remaining in the gas dryer to the outside has been proposed.

However, when the material to be dried is put into the drying chamber and the exhaust fan is operated for a predetermined time immediately before the gas burner is ignited, the exhaust fan is operated for a predetermined time every time the material to be dried is put into the drying chamber. Repeatedly drying items increases the drying time by the time the exhaust fan is activated.

In addition, due to the structure of the gas dryer, the exhaust fan is arranged downstream in the flow direction of the drying air to exhaust the drying air from the drying chamber, and the gas burner that heats the outside air and generates the drying air is the drying fan. It is arranged on the upstream side in the direction of wind flow. For this reason, if the exhaust fan is operated while the material to be dried in the drying chamber is open, the outside air will be sucked in through the opening, and the outside air will be discharged to the outside by the exhaust fan. The incombustible gas, etc. that remains behind the gas burner (on the upstream side in the flow direction of the dry air) cannot be discharged to the outside by the operation of the exhaust fan. I can't.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a gas dryer capable of shortening the drying time without using a pilot burner and capable of satisfactorily exhausting non-combustible gas.

One aspect of the present invention for solving the above problems is a dryer main body, a drying outer body fixed in the dryer main body, and a drying outer body disposed rotatably in the drying outer body, and a material to be dried is put. a drying drum to be dried, a drying air generating section for generating drying air to be supplied into the outer drying body, and a drying air generated by the drying air generating section to be supplied to the outer drying body to supply the drying air to the outer drying body. a dry air circulation unit that circulates the dry air drawn from the inside to the dry air generation unit and discharges it to the outside of the dryer main body, wherein the dry air circulation unit a blower for exhausting the drying air derived from the drying outer body after drying the material to be dried and for exhausting the gas in the drying air generating section through the drying outer body; and an exhaust circulation duct provided with an outlet through which the dry air drawn out from the body is discharged to the outside of the main body of the dryer and a circulation outlet for circulating the dry air drawn out to the dry air generator; an exhaust circulation damper capable of adjusting the amount of the dry air discharged from the outlet and the amount of the dry air circulated from the circulation port to the dry air generation unit, wherein in the standby state of the gas dryer, The exhaust circulation damper closes the circulation port in a fully closed state based on an advance notice signal for notifying the start of drying, and the blower is operated to discharge the gas in the drying air generating section and the drying air discharged from the drying outer body. to the outside of the dryer main body .

Further, one aspect of the present invention is characterized in that the notice signal is a signal for detecting that the material to be dried is conveyed from a process preceding the drying process by the gas dryer.

According to the present invention, in the standby state of the gas dryer before the material to be dried is put into the drying drum, the drying air circulation unit is operated based on the warning signal for operating the gas dryer, and the drying air inside the dryer body is dried. Since the exhaust is performed, the drying time can be shortened without using a pilot burner, and the non-combustible gas can be exhausted satisfactorily.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the whole gas dryer which concerns on embodiment of this invention. Schematic which shows the inside of the gas dryer which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The top view which shows the upper part of the gas dryer which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The schematic see-through|perspective perspective view which shows the outline of the dry air generation part of the gas dryer which concerns on embodiment of this invention. Explanatory drawing explaining the flow of the air in the outside air intake chamber of the gas dryer which concerns on embodiment of this invention. 1 is a block diagram showing a controller of a gas dryer according to an embodiment of the present invention, and devices and sensors connected to the controller; FIG. The flowchart which shows the effect|action of the control part of the gas dryer which concerns on embodiment of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a gas dryer according to the present invention will be described in detail below. The gas dryer according to the present invention dries linen products such as sheets, pillowcases, and towels, mops, and mats that have been dehydrated after washing with drying air using a gas burner.

[Overall Configuration of Gas Dryer and Features of Example]
The gas dryer 1 of the present embodiment comprises a dryer main body 2, a drying outer body 3 fixed inside the dryer main body 2, and a material to be dried which is placed in the drying outer body 3 so as to be freely rotatable. a drying drum 4, a drying air generating section 5 for generating drying air supplied to the outer drying body 3, and a drying air generated by the drying air generating section 5 being supplied into the outer drying body 3 to supply the drying air to the outer drying body 3. and a dry air circulation unit 6 for circulating the dry air drawn out from inside 3 to the dry air generation unit 5 and discharging it to the outside of the dryer main body 2 .

The dry air generating unit 5 includes an outside air intake chamber 21 formed with a circulating air intake 44 for taking in a part of the circulated dry air and an outside air intake 25 for taking in outside air. It has a heating part 26 for heating the circulating air taken in and the outside air.

The drying air circulation unit 6 includes a blower 42 for discharging the drying air after drying the material to be dried from the outer drying body 3, and the drying air drawn out from the outer drying body 3 by the blower 42 is discharged. and an exhaust circulation duct 46 provided with a circulation port 45 communicating with the circulation air intake port 44 .

Further, an exhaust humidity detection sensor 48 is provided in the exhaust circulation duct 46 to detect the humidity of the derivation drying air deriving from the interior of the drying outer body 3 . Further, the outside air intake port 25 is formed with an outside air intake damper 49 (see FIG. 4) capable of adjusting the intake amount of the outside air into the outside air intake chamber 21 . An exhaust circulation damper 47 capable of adjusting the amount of dry air discharged from the outlet 43 and the amount of dry air circulated into the outside air intake chamber 21 from the circulation port 45 is provided at the opening edge of the circulation port 45. is provided in

Furthermore, the gas dryer 1 of the present embodiment is in the standby state of the gas dryer 1 before the material to be dried is put into the drying drum 4, based on the advance notice signal for advance notice of the start of drying in the gas dryer 1. It has a control unit 50 for operating the drying air circulation unit 6 to exhaust the air inside the dryer main body 2 .

[dryer body]
As shown in FIG. 1, the dryer main body 2 is formed in a box shape by a front portion 7, a rear portion 8, side surfaces 9, 9, a top plate 10, and a bottom surface 11. As shown in FIG. The front part 7 is provided with an inlet/outlet port 12 through which the material to be dried is introduced and the material to be dried is taken out after drying. The loading/unloading port 12 is opened and closed by an opening/closing door 13 provided on the front face portion 7 so as to be vertically movable. The open/close door 13 is configured to be vertically movable by a drive mechanism (not shown). The opening/closing door 13 is provided with two circular confirmation windows 14. - 特許庁The dryer main body 2 is installed on the floor 16 by four legs 15 , 15 , 15 , 15 supporting the four corners of the bottom surface 11 .

Further, on the side of the front part 7 of the gas dryer 1, as shown in FIG. This conveyer 52 conveys the articles to be dried that have been washed and dehydrated by the washing machine, which is the previous process, to the loading/unloading port 12 provided on the front side of the dryer body 2, and the items to be dried are transported from the loading/unloading port 12. It is put into the drying drum 4 . In addition, a conveyor transport detection sensor 53 is provided near the conveyor 52 to detect the transport state of the conveyor 52 . The start of transporting the material to be dried from the previous process is detected by the conveyor transport detection sensor 53, and the result detected by the conveyor transport detection sensor 53 is transmitted to the control unit 50 as an advance notice signal. be done. Based on this advance notice signal, the control unit 50 operates blowers 42, 42 of the drying air circulation unit 6 of the gas dryer 1, which will be described later.

[Dry outer trunk]
The dryer outer body 3 is fixed to the inner wall of the dryer body 2 . The dryer outer body 3 is cylindrical and has an opening communicating with the loading/unloading port 12 of the dryer main body 2 at one end in the axial direction. When the loading/unloading port 12 is closed by the opening/closing door 13, the interior of the drying outer body 3 is sealed. A drying air inlet 17 is provided on one side of the upper portion of the drying outer body 3, and a drying air outlet 18 is provided on the other side of the upper portion. In addition, an infrared sensor 51 is provided on the surface opposite to the loading/unloading port 12 of the drying outer body 3 . This infrared sensor 51 detects the temperature of the material to be dried put into the drying drum 4 .

[Drying drum]
The drying drum 4 is cylindrical and has small-diameter holes formed by punching or the like all over its outer peripheral surface (side surface). Also, one side in the axial direction communicates with the loading/unloading port 12 of the dryer main body 2 . The drying drum 4 is rotatably supported in the drying outer body 3 by drive rollers 19,19. A rotational driving force of a driving motor 20 supported at the lower portion of the dryer main body 2 is transmitted to the driving rollers 19, 19 by transmission means (not shown). The drying drum 4 dries the material to be dried with the drying air generated by the drying air generating unit 5 and supplied into the drying outer body 3 while rotating.

[Dry air generator]
As shown in FIGS. 1 and 2, the drying air generating unit 5 is placed on the top plate 10 of the dryer main body 2 and installed within the projection plane of the top plate 10 in the vertical direction. As shown in FIG. 4, the dry air generator 5 includes an outside air intake chamber 21 in which a circulating air intake 44 for taking in part of the circulated dry air and an outside air intake for taking in outside air are formed. It has a heating unit 26 for heating the circulating air taken into the outside air intake chamber 21 and the outside air. The heating unit 26 includes an outer cylinder 22 whose one side communicates with the outside air intake chamber 21, a gas burner 23 that emits a flame inside the outer cylinder 22, and an inner cylinder that is provided inside the outer cylinder 22 and wraps the flame of the gas burner 23. 24.

The outside air intake chamber 21 has a box shape and an outside air intake port 25 is formed on the outer peripheral surface. The outside air intake 25 is formed by a first intake 27 provided in the side surface 26 a of the outside air intake chamber 21 and a second intake 28 provided in the top plate 26 b of the outside air intake chamber 21 . A first damper 29 and a second damper 30, which are external air intake dampers 49 capable of opening and closing the first and second intake ports 27 and 28, respectively, are provided in the first and second intake ports 27 and 28, respectively. . These first and second dampers 29 and 30 are rotatably supported by the opening edges of the first and second inlets 27 and 28, respectively, and are rotatable by driving means (not shown). . The opening areas of the first and second intake ports 27 and 28 change depending on the rotational angles of the first and second dampers 29 and 30, and the intake amount of outside air into the outside air intake chamber 21 can be adjusted. .

Further, as shown in FIG. 5, the first damper 29 guides outside air taken into the outside air intake chamber 21 from the first intake port 27 to the lower side inside the outside air intake chamber 21, and the second damper 30 acts as a second damper. The outside air taken into the outside air intake chamber 21 through the intake port 28 is led to the outside air taken in through the first intake port 27 . As a result, the outside air taken in from the first and second intake ports 27 and 28 circulates in the outside air intake chamber 21 and enters the outer cylinder 22 through the outside air circulation port 32 to be described later. flow.

The outside air intake chamber 21 communicates with one side of the outer cylinder 22 through an outside air flow port 32 on the front surface 31 side. Further, the outside air intake chamber 21 is provided with a part of a circulation air intake port 44 into which part of the dry air circulated by the dry air circulation unit 6 flows. The other part of the circulating air intake 44 is provided in the outer cylinder 22 . That is, the circulation air intake port 44 opens toward the outside air intake chamber 21 and the outer cylinder 22 .

The outer cylinder 22 is formed in an elongated shape with a semi-cylindrical outer peripheral wall 33 and a flat bottom wall 34 . The outside air circulation port 32 is formed on one side, ie, the side of the outside air intake chamber 21, and the dry air supply port 35 is provided on the bottom wall 34 on the other side. The generated drying air is supplied into the drying outer body 3 from the drying air supply port 35 . A flame discharge port 36 of the gas burner 23 provided through the outside air intake chamber 21 is open on one side of the outer cylinder 22 .

As shown in FIG. 3 , the gas burner 23 has a flame generating portion 38 provided on the rear surface 37 side of the outside air intake chamber 21 , and the flame generated by this flame generating portion 38 passes through the outside air intake chamber 21 and passes through the outer cylinder 22 . It is formed with a flame nozzle 39 leading inward. The tip side of the flame nozzle 39 serves as a flame discharge port 36 . Then, the flame generated by the flame generator 38 is radiated from the flame discharge port 36 of the flame nozzle 39 toward the dry air supply port 35 side of the outer cylinder 22 . The flame radiated into the outer cylinder 22 is radiated while being wrapped by the inner cylinder 24 provided at the center of the outer cylinder 22 .

The inner cylinder 24 is cylindrical and elongated from the base end on the side of the outside air intake chamber 21 to the side of the dry air supply port 35 so as to envelop the flame of the gas burner 23 emitted from the flame outlet 36 of the flame nozzle 39 . formed. The opening of the inner cylinder 24 on the side of the dry air supply port 35 serves as a hot air discharge port 40 through which hot air heated by flames is discharged. Further, the outer wall of the inner cylinder 24 forms a heating passage portion 41 with the inner wall of the outer cylinder 22 .

Then, as shown in FIG. 5, the outside air that has flowed into the outside air intake chamber 21 from the first intake port 27 flows to the lower side of the inner cylinder 24 from the outside air circulation port 32 while swirling inside the outside air intake chamber 21. , the outside air that has flowed into the outside air intake chamber 21 through the second intake port 28 flows through the outside air circulation port 32 to the upper side of the inner cylinder 24 . The outside air flowing to the lower side and the upper side of the inner cylinder 24 is mixed with the dry air circulated by the dry air circulating part 6 and passed through the heating passage part 41 in the outer cylinder 22 in a swirling state, and is heated. . That is, the outside air taken into the outside air intake chamber 21 and the circulated dry air flow toward the dry air supply port 35 while turning around the inner cylinder 24 like a tornado.

[Dry air circulation part]
The drying air circulation unit 6 includes two blowers 42, 42 for discharging the drying air after drying the material to be dried in the outer drying body 3 from the outer drying body 3. An exhaust circulation duct 46 provided with a discharge port 43 for discharging the dry air drawn from the inside and a circulation port 45 communicating with the circulation air intake 44, and the amount and circulation of the dry air discharged from the discharge port 43 It is formed of an exhaust circulation damper 47 capable of adjusting the amount of dry air circulated through the opening 45 into the outside air intake chamber 21 and the outer cylinder 22 .

The exhaust circulation duct 46 is arranged adjacent to the outer cylinder 22 of the dry air generator 5, as shown in FIG. The exhaust circulation duct 46 is provided with a circulation port 45 that opens across the outer cylinder 22 and the outside air intake chamber 21 and allows the circulated dry air to be taken into the outer cylinder 22 and the outside air intake chamber 21 . The circulation port 45 communicates with the circulation air intake port 44 . An exhaust circulation damper 47 is rotatably provided at the opening edge of the circulation port 45 . The rotational position of the exhaust circulation damper 47 adjusts the amount of dry air circulated into the outer cylinder 22 and the outside air intake chamber 21 .

Two blowers 42 , 42 are provided on the opposite side of the outer cylinder 22 with the exhaust circulation duct 46 interposed therebetween. These blowers 42 , 42 lead the drying air after drying the material to be dried in the outer drying body 3 into the exhaust circulation duct 46 from the drying air outlet 18 of the outer drying body 3 . Further, the drying air after drying the material to be dried in the outer drying body 3 is led out from the outer drying body 3, so that the drying air whose temperature is adjusted from the drying air generating section 5 flows through the drying air inlet 17. and supplied into the drying outer body 3. As a result, the dry air generated by the dry air generator 5 circulates through the drying outer body 3 , the exhaust circulation duct 46 and the outer cylinder 22 .

As shown in FIG. 6, the outside air intake damper 49, the exhaust circulation damper 47, the gas burner 23, the blower 42, the drive motor 20, and the infrared sensor 51 are connected to the control section 50. As shown in FIG. The control unit 50 controls the outside air intake damper 49 to open and close the outside air intake 25 , and controls the exhaust circulation damper 47 to open and close the discharge port 43 . The outside air intake damper 49 and the exhaust circulation damper 47 are rotated by a driving means (not shown), and the opening areas of the outside air intake port 25 and the exhaust port 43 change depending on the rotation angle.

An exhaust humidity detection sensor 48 , an infrared sensor 51 , and a conveyor transport detection sensor 53 are also connected to the controller 50 . The exhaust humidity detection sensor 48 detects the humidity of the derivation drying air discharged from the drying outer body 3 . Also, the infrared sensor 51 detects the temperature of the laundry put into the drying drum 4 . Further, the conveyor transport detection sensor 53 detects the transport state of the conveyor that transports the material to be dried from the previous process to the gas dryer 1 .

Next, operation of the gas dryer 1 will be described. First, the blowers 42 and 42 are operated, and the gas burner 23 is operated to generate drying air at a predetermined temperature, and the drying air is discharged from the drying outer body 3 to circulate. When the drying air reaches a predetermined temperature, the opening/closing door 13 is opened, and a predetermined amount of material to be dried is put into the drying drum 4 with the loading/unloading port 12 opened. At this time, the drying drum 4 is stopped without rotating. Note that the material to be dried may be thrown into the rotating drying drum 4 from the inlet/outlet 12 while the blowers 42, 42 are in operation. In this case, since the material to be dried is sucked into the drying drum 4, the material to be dried does not jump out or spill out of the drying drum 4. - 特許庁

After the material to be dried is put into the drying drum 4 and the loading/unloading port 12 is closed by the opening/closing door 13, the drying drum 4 is rotationally driven at a predetermined number of revolutions. The rotation angles of the exhaust circulation damper 47 and the first and second dampers 29 and 30 are adjusted according to the degree of dryness of the material to be dried, and the intake amount of the outside air and the circulation amount of the circulating drying air are changed to change the temperature of the drying air. to adjust.

To generate the dry air in the dry air generator 5, the blowers 42, 42 are driven to circulate the dry air, the gas burner is ignited, and the circulating dry air and outside air are mixed and heated. When the blowers 42 , 42 are driven to circulate the dry air, outside air flows into the outside air intake chamber 21 through the first and second intake ports 27 , 28 .

In this case, the outside air that has flowed in through the first intake port 27 is guided to the first damper 29 and flows through the outside air circulation port 32 to the lower side of the inner cylinder 24, and the outside air that has flowed in through the second intake port 28 flows through the second damper. 30 and flows to the upper side of the inner cylinder 24 from the outside air circulation port. The dry air flowing into the outside air intake chamber 21 and the outer cylinder 22 from the circulation air intake 44 flows around the inner cylinder 24 and mixes with the outside air. Air in which the circulating dry air and the outside air are mixed moves toward the dry air supply port 35 side while swirling around the inner cylinder 24 . The air mixed with the circulating dry air and the outside air swirls in the heating passage part 41 around the inner cylinder 24, so that the dry air and the outside air are further mixed and heated to become the dry air with a uniform temperature.

The air moves to the dry air supply port 35 side while swirling around the inner cylinder 24, and has a uniform temperature distribution. The drying air is supplied from the drying air supply port 35 into the drying outer body 3 through the drying air introduction port 17 . The drying air having a predetermined temperature supplied into the drying outer body 3 dries the material to be dried in the drying drum 4 , and then is discharged from the drying air outlet 18 to the exhaust circulation duct 46 . Then, the dry air is mixed with the outside air again in the dry air generating section 5 to generate dry air having a predetermined temperature.

Next, the pre-purge performed before operating the gas dryer 1 will be described with reference to the flow chart shown in FIG. In the standby state of the gas dryer 1 before starting the drying operation, the control section 50 closes the opening/closing door 13 in step S1, and closes the exhaust circulation damper 47 in step S2. From this state, in step S3, the control unit determines whether or not the conveyor 52, which conveys the material to be dried from the preceding process, has started to convey the material to be dried, that is, whether or not the advance notice signal from the conveyor conveyance detection sensor 53 has been input. 50 judges.

When the controller 50 determines that the conveyer 52 has started transporting the material to be dried, the controller 50 operates the blowers 42, 42 in step S4. When the blowers 42 and 42 operate, the air inside the drying outer body 3 and the air inside the drying air generating section 5 are discharged to the outside of the dryer main body 2 through the discharge port 43 . At this time, outside air flows into the outside air intake chamber 21 from the outside air intake port 25 (the first intake port 27 and the second intake port 28), passes through the outer cylinder 22, enters the drying outer body 3, and passes through the drying outer body 3. It is then discharged from the discharge port 43 . As a result, the non-combustible gas remaining in the outer cylinder 22 is also discharged to the outside of the dryer main body 2 through the discharge port 43 together with the outside air.

In this case, the processes of steps S1 to S5 in the flow chart shown in FIG. Therefore, while the material to be dried is conveyed to the front side of the gas dryer 1 by the conveyor 52, the incombustible gas or the like remaining in the dryer main body 2 is discharged to the outside, and pre-purge is performed.

In step S5, the controller 50 determines whether or not a predetermined time has passed since the blowers 42, 42 were operated. If the predetermined time has not passed, the operation of the blowers 42, 42 is continued. In step S5, when a predetermined time has elapsed since the blowers 42, 42 started operating, the control unit 50 determines that the pre-purge is completed, opens the open/close door 13 in step S6, and opens the exhaust circulation damper 47 in step S7. .

Next, the control part 50 ignites the gas burner 23 in step S8. When the gas burner 23 is ignited, the object to be dried is put into the drying drum 4 from the loading/unloading opening 12 with the opening/closing door 13 open, and it is confirmed in step S9 that the object to be dried has been put into the drying drum 4. Then, the controller 50 starts the drying operation in step S10. In step S11, the control unit 50 determines whether or not the drying operation has ended, and if it has not ended, the drying operation continues. When the drying operation ends, the control unit 50 determines in step S12 whether or not the drying work has ended. If the drying work has not ended, step S1 and subsequent steps are repeatedly executed. When the drying work is completed, the controller 50 terminates the series of controls.

The drying operation in step S10 will be described below. A predetermined amount of the material to be dried, that is, the material to be dried which has been dehydrated after washing, is put into the drying drum 4, and the gas dryer 1 is operated. Heated drying air is supplied to the drying outer body. At this time, the control unit 50 drives the outside air intake damper 49 and the exhaust circulation damper 47 to control the intake amount of outside air and the amount of air to be circulated.

The control unit 50 determines whether or not the moisture content of the material to be dried put into the drying drum 4 is equal to or less than a set value. In this case, when the moisture content of the material to be dried is known in advance, by inputting to the control unit 50 whether or not the moisture content is equal to or less than a set value using a switch for selecting the magnitude of the moisture content, the control unit 50 can It is determined whether or not the moisture content of the material to be dried is equal to or less than the set value. The moisture content of the dried matter may be measured by a sensor capable of measuring the moisture content of the dried matter, and whether or not the moisture content of the dried matter is equal to or less than a set value may be determined based on the measurement result. . In addition, the material to be dried is put into the drying drum 4, the external air intake damper 49 and the exhaust circulation damper 47 are fully closed, and the operation is performed for a predetermined time. If so, it may be determined that the moisture content of the material to be dried is equal to or less than the set value.

When the control unit 50 determines that the moisture content of the material to be dried put into the drying drum 4 is equal to or less than the set value, that is, when the moisture content of the material to be dried is extremely small due to excessive squeezing in the dehydration process, , the control unit 50 causes the outside air intake damper 49 to be fully closed, and the exhaust circulation damper 47 to be fully closed.

When the outside air intake damper 49 and the exhaust circulation damper 47 are fully closed, the dry air drawn out from the drying outer body 3 is completely circulated, or if not all, for example, at a circulation rate of 99%, it becomes a state of total circulation. . That is, all the drying air drawn out from the drying outer body 3 is circulated without taking in outside air, and this drying air is blown onto the material to be dried.

The control unit 50 determines whether or not the exhaust humidity detected by the exhaust humidity detection sensor 48 has reached or exceeded a first set value. When the exhaust humidity is not equal to or higher than the first set value, the outside air intake damper is fully closed and the exhaust circulation damper is fully closed.

In this case, since the entire amount is circulated, the exhaust humidity of the circulated dry air gradually rises, including moisture evaporated from the surface of the material to be dried. As a result, the drying air with increased humidity, that is, containing moisture, is blown against the material to be dried in the drying drum 4, so that the material to be dried, which has a small amount of moisture, gradually becomes saturated with moisture. As a result, the material to be dried is so-called "steamed", so that fibers that have collapsed (fallen) due to dehydration and piles of fibers are raised (raised). In addition, the rotation of the drying drum 4 causes the material to be dried, which has a low moisture content, to move within the drying drum 4, and is raised by hot air containing moisture and beating.

When the control unit 50 determines that the exhaust humidity has reached or exceeded the first set value, the control unit 50 gradually opens the fully closed external air intake damper 49 and gradually opens the fully closed exhaust circulation damper 47. do. In other words, the intake/exhaust control state takes in outside air and exhausts the circulated dry air to the outside. In this case, when the exhaust air humidity is high, the circulation ratio is decreased and the air volume of the blower 42 is increased. That is, a large amount of circulating dry air is discharged from the outlet 43, and a large amount of outside air is taken in. When the humidity of the exhaust air becomes low, the amount of circulating dry air is increased and the amount of air from the blower 42 is decreased.

Then, the control unit 50 determines whether or not the exhaust humidity has become equal to or less than the second set value. When the humidity of the exhaust gas is not equal to or lower than the second set value, the outside air intake damper 49 is gradually opened, and the exhaust circulation damper 47 is gradually opened. When the humidity of the exhaust gas becomes equal to or lower than the second set value, the control unit 50 fully closes the outside air intake damper 49 and fully closes the exhaust circulation damper 47 for full circulation. From this state, it is determined whether or not the exhaust humidity has become equal to or less than the third set value, ie, the exhaust humidity value indicating that the drying has been completed. When the exhaust air humidity is not equal to or lower than the third set value, the outside air intake damper is fully closed and the exhaust circulation damper is fully closed. The drying operation ends when the humidity of the exhaust air becomes equal to or lower than the third set value. Here, in the present embodiment, each setting value is set so as to satisfy the relationship of "first setting value">"second setting value">"third setting value".

When the material to be dried has a large amount of moisture, the control unit 50 fully opens the outside air intake damper 49 and fully opens the exhaust circulation damper 47 to perform full intake/exhaust control. Then, the control unit 50 determines whether or not the exhaust humidity has become equal to or less than the second set value. When the humidity of the exhaust gas is not equal to or lower than the second set value, the outside air intake damper is fully opened, and the exhaust circulation damper is fully opened. When the exhaust humidity becomes equal to or lower than the second set value, the controller 50 fully closes the outside air intake damper and the exhaust circulation damper.

If it is judged that the material to be dried has a high moisture content, the material to be dried contains a large amount of moisture and has not been squeezed excessively during dehydration, so the fibers have not fallen down and can be dried by a general drying method. . That is, in the case of the material to be dried with a small amount of water, the material to be dried is "steamed" by circulating the entire amount, but in the case of the material to be dried with a large amount of water, since it contains a large amount of water, It does not need to be "steamed" and is dried by the normal drying process.

According to the embodiment of the present invention, in the standby state of the gas dryer 1 before the material to be dried is put into the drying drum 4, an advance notice signal, i.e., a conveyer transfer detection sensor, which gives an advance notice of the start of drying by the gas dryer 1 Since the dry air circulation unit 6 is operated based on the signal from 53 to exhaust (pre-purge) the inside of the dryer main body 2, the non-combustible gas can be discharged from the inside of the dryer main body 2 without using a pilot burner. .

Further, according to the embodiment of the present invention, since it is not necessary to provide a pilot burner for pre-purge, control for burning the pilot burner becomes unnecessary, the structure of the gas dryer becomes simple, and the pilot burner Since no fuel is required for burning the gas dryer, the cost for operating the gas dryer can be reduced.

Further, according to the embodiment of the present invention, in the standby state of the gas dryer 1, while the material to be dried is being conveyed by the conveyor, the blowers 42, 42 are actuated to exhaust the air inside the dryer body 2 and pre-purge. is performed, the pre-purge is not performed after the gas dryer 1 is operated, and the drying time can be shortened accordingly.

In addition, according to the present invention, the control unit 50 fully closes the outside air intake port 25 by the outside air intake damper 49 and exhausts the exhaust port 43 at the initial stage of drying the material to be dried whose moisture content is less than a predetermined amount. The circulation damper 47 is fully closed. As a result, the material to be dried whose moisture content is less than a predetermined amount is dried by the deriving circulating air until the exhaust humidity detected by the exhaust humidity detection sensor 48 reaches or exceeds the first set value. Therefore, it is possible to obtain a finished state with a good texture by "texture drying" in which the material to be dried with a low moisture content is dried and steamed by the circulating drying air with high humidity.

Further, according to the present embodiment, outside air and the circulated dry air are mixed around the inner cylinder 24 which is elongated so as to enclose the flame of the gas burner 23, and the dry air is supplied to the dry air supply port 35 side. Since the drying air is generated by swirling, the drying air having a uniform temperature can be supplied to the inside of the drying drum 4 with little temperature unevenness.

Further, according to the gas dryer 1 of the present embodiment, since the inner cylinder 24 is elongated up to the dry air supply port 35, as shown in FIG. The mixed air is further heated at the hot air outlet 40 of the inner cylinder 24 . As a result, it is possible to adjust the drying air having a uniform temperature with little temperature unevenness to a predetermined temperature.

In addition, according to the gas dryer 1 of the present embodiment, there is little temperature unevenness, and a long duct for mixing, which was conventionally required in order to generate dry air with a uniform temperature, becomes unnecessary. The dry air generator 5 can be made compact. Thereby, the drying air generating unit 5 can be installed on the top plate 10 of the dryer body 2 . Since the dry air generating unit 5 can be installed on the top plate 10 of the dryer main body 2, when a plurality of gas dryers 1 are installed side by side, the plurality of gas dryers 1 can be installed in close proximity. can be done. Thereby, the installation space for a plurality of gas dryers can be reduced.

In the above-described embodiment, the signal from the conveyor transfer detection sensor 53 is used as the notice signal, but the notice signal is not limited to this. It is good as

While embodiments of the present invention have been disclosed above, it will be apparent that modifications may be made by those skilled in the art without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

The gas dryer according to the present invention can be used not only for drying linen products such as sheets, pillowcases and towels, mops and mats after washing, but also for drying clothes and other items.

REFERENCE SIGNS LIST 1 gas dryer 2 dryer main body 3 drying outer body 4 drying drum 5 drying air generating section 6 drying air circulation section 50 control section

Claims (2)

the dryer body,
a drying outer body fixed in the dryer body;
a drying drum that is rotatably arranged in the drying outer body and into which the material to be dried is put;
a drying wind generator for generating drying wind to be supplied into the drying outer body;
The drying air generated by the drying air generation section is supplied into the drying outer body, and the drying air led out from the drying outer body is circulated to the drying air generation section and discharged to the outside of the dryer main body. A gas dryer comprising a dry air circulation unit that
The drying air circulation unit includes a blower that exhausts the drying air derived from the drying outer body after drying the material to be dried and also exhausts the gas in the drying air generation section through the drying outer body. a discharge port through which the drying air drawn out from the drying outer body by the blower is discharged to the outside of the dryer main body; an exhaust circulation duct, and an exhaust circulation damper capable of adjusting the amount of the dry air discharged from the outlet and the amount of the dry air circulated from the circulation port to the dry air generating unit,
In the standby state of the gas dryer, the exhaust circulation damper blocks the circulation port in a fully closed state based on an advance notice signal for notifying the start of drying, and the blower is operated to operate the gas and air in the drying air generating section. A gas dryer comprising a control section for discharging the drying air drawn out from the drying outer body to the outside of the dryer main body . 2. The gas dryer according to claim 1 , wherein said advance notice signal is a signal for detecting that said material to be dried is transported from a process preceding a drying process by said gas dryer.

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