JP6687362B2 - Heating cylinder - Google Patents

Description

  The technology disclosed herein relates to heating cylinders.

  BACKGROUND ART Conventionally, a heating cylinder including a cylinder body into which steam is introduced is known.

  For example, the heating cylinder described in Patent Document 1 includes a cylinder body into which steam is supplied, and heats an object that contacts the outer peripheral surface of the cylinder body. In the cylinder body, the heat-deprived vapor condenses into drainage, which is stored at the bottom of the cylinder body. The cylinder body is provided with a drain pipe for discharging the stored drain. The stored drainage is discharged from the cylinder body through the drain pipe by the pressure of the steam. A steam trap is provided in the pipe communicating with the drain pipe. The drain discharged through the drain pipe is discharged through the steam trap.

Utility model registration No. 3141003

  In the heating cylinder as described above, the upstream end of the drain pipe is usually immersed in the drain inside the cylinder body. However, when the water level of the drain is low, there are cases where the upstream end of the drain pipe is not submerged in the drain or only slightly submerged in the drain. In such a case, steam may enter the drain pipe. The steam that has entered the drain pipe is prevented from flowing out by the steam trap on the downstream side, and stays in the steam trap.

  When attempting to discharge the drain from such a state, since steam has first flowed into the steam trap, a phenomenon in which the drain cannot be properly discharged from the steam trap, so-called steam locking occurs. As a result, it becomes difficult to properly discharge the drain from the cylinder body through the drain pipe.

  The technique disclosed here is made in view of such a point, and the purpose is to eliminate steam locking and appropriately discharge drain.

  The heating cylinder disclosed herein includes a cylinder body to which steam is supplied, a drain pipe that discharges drain from the cylinder body due to the pressure in the cylinder, and a steam connected to a downstream side of the drain pipe. A trap, a bypass pipe that is connected to a downstream side of the drain pipe and bypasses the steam trap, a valve that opens and closes the bypass pipe, and a control unit that controls the valve, and the control unit includes the cylinder. It is characterized in that the valve is opened and closed according to the amount of drain stored in the main body.

  According to the heating cylinder disclosed herein, steam locking can be eliminated and drain can be appropriately discharged.

FIG. 1 is a schematic configuration diagram of a heating cylinder. FIG. 2 is a flowchart showing valve opening / closing control.

  Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration diagram of the heating cylinder 100.

  The heating cylinder 100 includes a cylinder body 10 to which steam is supplied, a drain pipe 20 that discharges drainage from the cylinder body 10 due to the pressure inside the cylinder body 10, and a drain pipe 31 connected to the drain pipe 20. A steam trap 40 provided in the drain pipe 31, a bypass pipe 32 that is connected to the drain pipe 31 and bypasses the steam trap 40, a valve 50 that opens and closes the bypass pipe 32, and a control unit 60 that controls the valve 50. I have it. The heating cylinder 100 is a heater that uses steam as a heat source, and heats an object (for example, paper or laundry) that contacts the outer peripheral surface of the cylinder body 10.

  The cylinder body 10 is a hollow columnar body extending along the axis X, and is configured to be able to store vapor therein. Shaft portions 11a and 11b extending along the axis X are provided at both ends of the cylinder body 10, and the shaft portions 11a and 11b are rotatably supported by bearings (not shown). That is, the cylinder body 10 is supported rotatably around the axis X. The cylinder body 10 is supported with the axis X extending horizontally. The steam supply pipe 12 is connected to the one shaft portion 11a. The steam from the steam supply pipe 12 is supplied into the cylinder body 10 through the inside of the shaft portion 11a.

  The steam supplied into the cylinder body 10 heats the cylinder body 10. The vapor that radiates heat to the cylinder body 10 condenses into a drain, which accumulates at the bottom of the cylinder body 10.

  A water level sensor 13 for detecting the water level of the drain stored in the cylinder body 10 is provided in the cylinder body 10. The water level sensor 13 detects that the water level of the drain has reached a predetermined first water level H1, and also detects that the water level of the drain has dropped to a second water level H2 lower than the first water level H1. Specifically, the water level sensor 13 includes a first sensor 13a that detects that the drain water level has reached the first water level H1, and a second sensor 13b that detects that the drain water level has dropped to the second water level H2. Contains.

  The drain pipe 20 penetrates the cylinder body 10 via the shaft portion 11a. The drain pipe 20 is a so-called siphon pipe, and drains the drain due to the pressure of the steam in the cylinder body 10. Hereinafter, along the flow of the drain, the inside of the cylinder body 10 in the drain pipe 20 will be referred to as the upstream side, and the outside of the cylinder body 10 will be referred to as the downstream side. The drain pipe 20 extends inwardly of the cylinder body 10 along the axis X from the shaft portion 11a and then bends toward the bottom portion of the cylinder body 10. The upstream end of the drain pipe 20 is close to the inner peripheral surface of the cylinder body 10 at the bottom of the cylinder body 10. A downstream end portion of the drain pipe 20 extends from the shaft portion 11a to the outside of the cylinder body 10 along the axis X. A drain pipe 31 is connected to the downstream end of the drain pipe 20.

  A steam trap 40 is provided in the middle of the drain pipe 31. The steam trap 40 is for blocking the passage of steam, allowing the steam to stay therein, allowing the drain to pass therethrough, and discharging the drain to the outside. For example, the steam trap 40 has a valve body that opens and closes a drain discharge port, and allows the drain body to be discharged by opening the valve body.

  The bypass pipe 32 connects the upstream side portion of the steam trap 40 and the downstream side portion of the steam trap 40 in the drain pipe 31. The fluid flowing through the drain pipe 31 can bypass the steam trap 40 and flow through the bypass pipe 32.

  The valve 50 switches between opening and closing the bypass pipe 32. When the valve 50 is closed, the flow of fluid through the bypass pipe 32 is blocked. The valve 50 can be opened and closed by a signal from the control unit 60.

  The control unit 60 receives the detection result of the water level sensor 13, and controls the opening / closing of the valve 50 according to the amount of drain stored in the cylinder body 10. Specifically, the control unit 60 normally closes the valve 50, opens the valve 50 when the drain storage amount increases, and then reduces the drain storage amount to a certain amount. Sometimes valve 50 is closed again.

  Hereinafter, the opening / closing control of the valve 50 by the control unit 60 will be described in detail with reference to the flowchart of FIG.

  The control unit 60 normally controls the valve 50 to be fully closed. As a result, all the fluid flowing through the drain pipe 31 will flow into the steam trap 40, so that the discharge of steam is suppressed.

  In step S1, the control unit 60 determines, based on the detection result of the water level sensor 13, whether or not the water level of the drain inside the cylinder body 10 has reached the first water level H1. When the drain water level has not reached the first water level H1, the control unit 60 repeats step S1. That is, the heating cylinder 100 continues to operate with the valve 50 closed.

  On the other hand, when the water level of the drain reaches the first water level H1, the control unit 60 opens the valve 50 in step S2. The first water level H1 is a water level at which it can be determined that steam locking has occurred and drain has not been appropriately discharged from the cylinder body 10. That is, when the water level of the drain reaches the first water level H1, steam rocking may occur. When steam rocking occurs, the drain and steam existing in the drain pipe 20 and the drain pipe 31 cannot flow and are in a stagnant state. As a result, the drain cannot be discharged from the cylinder body 10. On the other hand, by opening the valve 50, the fluid stagnant in the drain pipe 20 and the drain pipe 31 can flow by bypassing the steam trap 40. As a result, the drain inside the cylinder body 10 is discharged, and the water level of the drain is lowered.

  Subsequently, the control unit 60 determines, based on the detection result of the water level sensor 13, whether or not the water level of the drain inside the cylinder body 10 has dropped to the second water level H2. When the water level of the drain has not dropped to the second water level H2 (that is, the water level of the drain is higher than the second water level), the control unit 60 repeats step S3. That is, the heating cylinder 100 continues to operate with the valve 50 opened.

  On the other hand, when the water level of the drain has dropped to the second water level H2, the control unit 60 closes the valve 50 in step S4. Here, the second water level H2 is a water level lower than the first water level H1 and is a water level in which the state in which the upstream end of the drain pipe 20 is immersed in the drain is maintained. According to the processing from step S2 to step S4, the valve 50 is opened until the water level of the drain drops from the first water level H1 to the second water level H2, and the drain in the cylinder body 10 is At least the drain pipe 20, the drain pipe 31, a portion up to the connection portion with the upstream end of the bypass pipe 32, and the bypass pipe 32 are discharged. In this way, since a drain flow from the upstream side to the downstream side is generated in the drain pipe 20, even if the valve 50 is closed and the bypass pipe 32 is shut off, the drain flowing through the drain pipe 20 is still in the steam trap 40. Can flow into. This eliminates steam locking. Further, since steam in the steam trap 40 can condense during the time until the water level of the drain drops from the first water level H1 to the second water level H2, steam rocking can also be eliminated by this. Further, since the pressure in the steam trap 40 in the state where the steam is accumulated is higher than the pressure on the downstream side of the bypass pipe 32, the valve 50 is opened, so that the steam in the steam trap 40 flows through the bypass pipe 32. It can be discharged to the downstream side of the bypass pipe 32 via. This can also eliminate steam locking.

  Since steam locking can be eliminated by continuing the valve 50 in the opened state for a while, the drain in the cylinder body 10 is appropriately discharged through the steam trap 40 even if the valve 50 is closed. be able to.

  Further, when the valve 50 is closed, the drop of the drain water level is suppressed. The second water level H2 is a water level at which the state where the upstream end of the drain pipe 20 is immersed in the drain is maintained, so that the entry of steam into the drain pipe 20 is suppressed. When steam enters the drain pipe 20, steam locking may occur. That is, the valve 50 is closed before the drain water level reaches a water level at which steam rocking may occur, and further reduction of the drain water level is suppressed.

  Thereafter, in step S5, the control unit 60 counts (counts up) the number of times the valve 50 is opened and then closed (hereinafter, simply referred to as “opening / closing number”).

  Then, in step S6, the control unit 60 determines whether or not the number of times the valve 50 has been opened and closed within the predetermined determination time T is equal to or greater than the predetermined first determination number α. The determination time T is a period during which the number of times of opening and closing is monitored when the failure diagnosis of the heating cylinder 100 is performed according to the opening and closing frequency of the valve 50. The determination time T is, for example, one day, one week, or the like. The first determination number α is the number of times that it can be determined that the clogging failure of the steam trap 40 or the like occurs due to the number of times the valve 50 is opened and closed too much. When the number of times the valve 50 is opened and closed within the determination time T is equal to or larger than the first determination number α, the control unit 60 determines that a clogging failure of the steam trap 40 or the like has occurred and issues an alarm in step S7. For example, the control unit 60 turns on the alarm lamp.

  On the other hand, when the number of times the valve 50 is opened and closed within the determination time T is less than the first determination number α, the control unit 60 determines in step S8 that the number of times the valve 50 is opened and closed within the determination time T is the second predetermined determination number. It is determined whether or not β (β <α) or less. The determination time T may be the same as or different from that in step S6. The second determination number β is the number of times that it can be determined that the number of times the valve 50 is opened and closed is too small and a leak failure of the steam trap 40 or the like has occurred. If the steam trap 40 is normal, and if the drain storage amount in the cylinder body 10 is reduced, steam locking may occur. However, when the steam trap 40 or the like has a leak failure, steam locking is less likely to occur. Therefore, when the number of times of opening and closing the valve 50 is too small (the number of times of opening and closing is less than or equal to the second determination number β), the control unit 60 determines that the steam trap 40 or the like has a leak failure. In this case, the control unit 60 issues a warning in step S7 that the steam trap 40 or the like has a leak failure. The control unit 60 may differentiate the alarm when the number of times of opening and closing is too large and the alarm when the number of times of opening and closing is too small.

  When the number of times the valve 50 is opened and closed within the determination time T is greater than the second determination number β, the control unit 60 returns to step S1 and repeats the above-described flow.

  Thus, the control unit 60 normally closes the valve 50. Therefore, since the bypass pipe 32 is normally shut off, the fluid discharged through the drain pipe 20 passes through the steam trap 40, and the discharge of steam is suppressed. Thereby, energy loss can be reduced. On the other hand, when there is a possibility that the amount of drainage stored in the cylinder body 10 is large and steam locking has occurred, the control unit 60 opens the valve 50. As a result, steam locking is eliminated, and the drain can be appropriately discharged. Then, when the steam locking is canceled or can be canceled, the control unit 60 closes the valve 50. Therefore, it is possible to achieve both reduction of energy loss and elimination of steam locking.

  As described above, the heating cylinder 100 includes the cylinder body 10 to which steam is supplied, the drain pipe 20 that discharges the drain from the cylinder body 10 by the pressure in the cylinder body 10, and the drain pipe 20 on the downstream side. A steam trap 40 connected thereto, a bypass pipe 32 connected to the downstream side of the drain pipe 20 and bypassing the steam trap 40, a valve 50 for opening and closing the bypass pipe 32, and a control unit 60 for controlling the valve 50 are provided. The control unit 60 opens and closes the valve 50 according to the amount of drain stored in the cylinder body 10.

  According to this configuration, even if steam locking occurs and the amount of drain stored in the cylinder body 10 increases, the drain can be appropriately discharged by opening the valve 50 to eliminate steam locking. In addition, since the valve 50 is not always open, it is possible to suppress the outflow of steam and reduce energy loss.

  Further, the control unit 60 opens the valve 50 when the water level of the drain inside the cylinder body 10 reaches a predetermined first water level H1.

  That is, when steam locking occurs, the drain storage amount may increase. The control unit 60 opens the valve 50 when the drain storage amount increases to some extent, so that steam locking is eliminated.

  Furthermore, when the water level of the drain in the cylinder body 10 is lower than the first water level H1 and the upstream end of the drain pipe 20 is lowered to a predetermined second water level H2 in which the state of being immersed in the drain is maintained. Then, close the valve 50.

  According to this configuration, after the drain water level reaches the first water level H1 and the valve 50 is opened, when the drain water level drops to the second water level H2, the valve 50 is closed. By opening the valve 50, the discharge amount of drain from the cylinder body 10 is increased as compared with before the valve 50 is opened. As a result, the drain water level will decrease. If the drain discharge continues for a while, the steam rocking can be eliminated, so that the valve 50 is closed when the drain water level drops to the second water level H2. Since the drain passes through the steam trap 40 by closing the valve 50, the discharge of steam is suppressed and the loss of energy is suppressed. Further, by closing the valve 50, it is possible to prevent the drain water level from decreasing. When the water level of the drain drops and the upstream end of the drain pipe 20 is exposed from the drain, steam enters the drain pipe 20 and steam rocking is induced again. The second water level H2 is a water level at which the upstream end of the drain pipe 20 is maintained so that the upstream end of the drain pipe 20 is submerged in the drain, so that the entry of steam into the drain pipe 20 is suppressed. Thereby, recurrence of steam locking can be suppressed.

<< Other Embodiments >>
As described above, the embodiment has been described as an example of the technique disclosed in the present application. However, the technique in the present disclosure is not limited to this, and can be applied to the embodiment in which changes, replacements, additions, omissions, etc. are appropriately made. Further, it is also possible to combine the constituent elements described in the above-described embodiment to form a new embodiment. In addition, in the constituent elements described in the accompanying drawings and the detailed description, not only constituent elements essential for solving the problem but also constituent elements not essential for solving the problem in order to exemplify the above-mentioned technology. Can also be included. Therefore, it should not be immediately recognized that these non-essential components are essential, because the non-essential components are described in the accompanying drawings and the detailed description.

  The above embodiment may have the following configurations.

  The configuration of the heating cylinder 100 is merely an example, and may have a different configuration. Further, the heating cylinder 100 can be applied to any heating target.

  Further, the water level sensor 13 is only an example, and various sensors capable of detecting the drain storage amount in the cylinder body 10 can be applied.

  The opening degree of the valve 50 is not limited to fully closed and fully opened, and may be appropriately adjusted.

  Further, the condition for closing the valve 50 after opening the valve 50 after the drain water level becomes the first water level H1 is not limited to the drain water level dropping to the second water level H2. For example, the valve 50 may be opened and the valve 50 may be closed after a predetermined time has elapsed. When the flow of drain from the upstream side to the downstream side of the drain pipe 20 occurs, steam locking can be eliminated, and therefore the valve closing condition of the valve 50 may be set by the valve opening period of the valve 50. In addition, any condition can be set as the valve closing condition of the valve 50 as long as it is a condition related to the flow of the drain in the drain pipe 20.

  The flowchart shown in FIG. 2 is merely an example, and may be appropriately changed or omitted. For example, the failure determination after step S5 may be omitted.

  As explained above, the technique disclosed here is useful for a heating cylinder.

100 heating cylinder 10 cylinder body 20 drain pipe 32 bypass pipe 40 steam trap 50 valve 60 controller

Claims (1)

A cylinder body to which steam is supplied,
A drain pipe for discharging drain from the inside of the cylinder body by the pressure inside the cylinder body;
A steam trap connected to the downstream side of the drain pipe,
A bypass pipe connected to the downstream side of the drain pipe and bypassing the steam trap,
A valve for opening and closing the bypass pipe,
A control unit for controlling the valve,
The control unit is
Opening and closing the valve according to the amount of drain stored in the cylinder body,
A heating cylinder, wherein a failure of the steam trap is diagnosed based on the opening / closing frequency of the valve.

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