JP2020148272A - Heating cylinder - Google Patents

Abstract

To release steam locking and achieve proper discharge of drainage from a cylinder body with a simple structure.SOLUTION: A heating cylinder 100 includes: a cylinder body 10; a drain pipe 31 which discharges drainage from the cylinder body 10; a drain trap 4 provided at the drain pipe 31; a release mechanism 7 which allows a fluid, which is prevented from circulating by the drain trap 4, to flow to the downstream side of the drain trap 4; a first temperature sensor 33 which detects an outlet temperature t1 of the cylinder body 10; a second temperature sensor 34 which detects an inlet temperature t2 of the drain trap 4; and a control part 8 which controls the release mechanism 7. The control part 8 causes the release mechanism 7 to operate when the inlet temperature t2 is higher than the outlet temperature t1.SELECTED DRAWING: Figure 1

Description

The techniques disclosed herein relate to heating cylinders.

Conventionally, a heating cylinder provided with a cylinder body in which steam is supplied to the inside to heat an external object has been known.

For example, the heating cylinder described in Patent Document 1 includes a cylinder body to which steam is supplied, and heats an object in contact with the outer peripheral surface of the cylinder body. Inside the cylinder body, the steam that has been deprived of heat condenses into a drain, which is stored at the bottom of the cylinder body. A drain pipe for draining the stored drain is connected to the cylinder body. The stored drain is discharged from the cylinder body via the drain pipe by the pressure of steam. The drain pipe is provided with a drain trap. The drain discharged through the drain pipe is discharged through the drain trap.

In the drain trap, so-called steam locking may occur. Steam locking means that when steam tries to flow into the drain trap from the state where steam has flowed into the drain trap first, the valve closed state is maintained by the steam and the inflow of drain into the drain trap is delayed. It is a phenomenon. When steam locking occurs, the drainage from the cylinder body becomes stagnant.

Therefore, in the heating cylinder described in Patent Document 1, a bypass pipe that bypasses the drain trap is connected to the drain pipe. The bypass pipe is provided with a valve for opening and closing the bypass pipe. The cylinder body is provided with a water level sensor that detects the amount of drainage stored in the cylinder body. When the water level sensor detects that the water level of the drain in the cylinder body has risen to some extent, it is determined that steam locking has occurred, and the valve of the bypass pipe is opened. As a result, drainage can be discharged from the inside of the cylinder body, and steam locking is eventually eliminated.

JP-A-2017-86248

However, in the heating cylinder as described above, it is necessary to provide a water level sensor in the cylinder body, which complicates the configuration of the cylinder body.

The technology disclosed here was made in view of this point, and the purpose is to realize the elimination of steam locking and the proper drainage of drain from the cylinder body with a simple configuration. is there.

The heating cylinder disclosed here is provided in a cylinder body in which steam is supplied to the inside to heat an external object, a drain pipe for discharging drain from the cylinder body, and a drain pipe for drain flow. A drain trap that blocks the flow of steam while allowing it, a release mechanism that allows the fluid whose flow is blocked by the drain trap to flow to the downstream side of the drain trap, and an outlet that is the temperature of the fluid at the outlet of the cylinder body. The control unit includes a first temperature sensor for detecting the temperature, a second temperature sensor for detecting the inlet temperature which is the temperature of the fluid at the inlet of the drain trap, and a control unit for controlling the release mechanism. When the inlet temperature is higher than the outlet temperature, the release mechanism is activated.

According to the heating cylinder, it is possible to eliminate steam locking and appropriately discharge drainage from the cylinder body with a simple configuration.

FIG. 1 is a schematic configuration diagram of a heating cylinder according to the first embodiment. FIG. 2 is a cross-sectional view of the drain trap according to the first embodiment. FIG. 3 is a flowchart of control of the release mechanism by the control unit. FIG. 4 is a schematic configuration diagram of the heating cylinder according to the second and third embodiments. FIG. 5 is a cross-sectional view of the drain trap according to the second embodiment. FIG. 6 is a cross-sectional view of the drain trap according to the third embodiment.

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

<< Embodiment 1 >>
FIG. 1 is a schematic configuration diagram of a heating cylinder 100 according to the first embodiment. The heating cylinder 100 is a heater that uses steam as a heat source to heat an object (for example, paper or laundry). The heating cylinder 100 is provided in a cylinder body 10 in which steam is supplied to the inside to heat an external object, a drain pipe 31 for discharging drain from the cylinder body 10, and a drain pipe 31, and allows the flow of drain. On the other hand, the drain trap 4 that blocks the flow of steam, the release mechanism 7 that allows the fluid whose flow is blocked by the drain trap 4 to flow to the downstream side of the drain trap 4, and the temperature of the fluid at the outlet of the cylinder body 10 (hereinafter, It controls a first temperature sensor 33 that detects (referred to as "outlet temperature"), a second temperature sensor 34 that detects the temperature of the fluid at the inlet of the drain trap 4 (hereinafter referred to as "inlet temperature"), and a release mechanism 7. It includes a control unit 8. Hereinafter, "upstream" means upstream in the fluid flow direction, and "downstream" means downstream in the fluid flow direction.

The cylinder body 10 is formed in a substantially cylindrical shape extending along the axis X, and is configured to accommodate steam and drain inside the cylinder body 10. Shafts 11a and 11b extending along the axis X are provided at both ends of the cylinder body 10, and the shafts 11a and 11b are rotatably supported by bearings (not shown). That is, the cylinder body 10 is rotatably supported around the axis X. The cylinder body 10 is supported in a state where the axis X extends in the horizontal direction. The outer peripheral surface of the cylinder body 10 is in contact with an object to be transported in a predetermined transport direction. The cylinder body 10 rotates about the axis X as the object is conveyed.

A steam inflow pipe 12 and a drain outflow pipe 13 are provided on one of the shaft portions 11a. The steam inflow pipe 12 and the drain outflow pipe 13 form a double pipe. A drain outflow pipe 13 is arranged inside the steam inflow pipe 12.

A steam pipe 21 is connected to the upstream end of the steam inflow pipe 12. Steam is circulating in the steam pipe 21. The steam flowing through the steam pipe 21 is supplied to the cylinder body 10 via the steam inflow pipe 12. The steam pipe 21 is provided with a pressure sensor 22 that detects the pressure of steam flowing through the steam pipe 21. The downstream end of the steam inflow pipe 12 extends horizontally along the axis X inside the cylinder body 10. The downstream end of the steam inflow pipe 12 is open to the inside of the cylinder body 10.

The drain outflow pipe 13 penetrates the cylinder body 10 via the shaft portion 11a. The drain outflow pipe 13 is a so-called siphon pipe, and drains the drain by the pressure of the steam of the cylinder body 10. The drain outflow pipe 13 extends inward of the cylinder body 10 along the axis X from the shaft portion 11a, and then bends toward the bottom of the cylinder body 10. The upstream end of the drain outflow pipe 13 is close to the inner peripheral surface of the cylinder body 10 at the bottom of the cylinder body 10. The downstream end of the drain outflow pipe 13 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 outflow pipe 13.

Steam flowing through the steam pipe 21 is supplied to the cylinder body 10 via the steam inflow pipe 12. The steam supplied into the cylinder body 10 heats an object in contact with the outer peripheral surface of the cylinder body 10 via the cylinder body 10. The steam radiated to the cylinder body 10 (that is, to the object) condenses into a drain and accumulates at the bottom of the cylinder body 10. The upstream end of the drain outflow pipe 13 is immersed in the drain stored in the cylinder body 10. The drain in the cylinder body 10 flows into the drain outflow pipe 13 due to the pressure of the steam in the cylinder body 10. As a result, the drain is discharged from the cylinder body 10 to the drain pipe 31 via the drain outflow pipe 13. At this time, steam may be mixed with the discharged drain.

The drain pipe 31 is provided with a drain trap 4. The drain trap 4 allows the inflowing fluid to pass through the drain, while blocking the outflow of steam. That is, the drain and steam discharged from the cylinder body 10 flow into the drain trap 4 via the drain pipe 31. While the drain passes through the drain trap 4, the steam is blocked from flowing out from the drain trap 4 and stored in the drain trap 4.

The drain pipe 31 is provided with a first temperature sensor 33 and a second temperature sensor 34. The first temperature sensor 33 is arranged at the upstream end of the drain pipe 31, that is, in the vicinity of the drain outflow pipe 13. The first temperature sensor 33 detects the temperature of the fluid flowing out of the cylinder body 10 (that is, the outlet temperature of the cylinder body 10). The second temperature sensor 34 is located on the upstream side of the drain trap 4 of the drain pipe 31 and in the vicinity of the drain trap 4. The second temperature sensor 34 detects the temperature of the fluid flowing into the drain trap 4 (that is, the inlet temperature of the drain trap 4).

The release mechanism 7 has a bypass pipe 71 connected to the drain pipe 31 so as to bypass the drain trap 4, and a bypass valve 72 for switching between opening and closing of the bypass pipe 71.

The upstream end of the bypass pipe 71 is connected to the upstream portion of the drain trap 4 of the drain pipe 31, and the downstream end of the bypass pipe 71 is connected to the downstream portion of the drain trap 4. The fluid flowing through the drain pipe 31 can bypass the drain trap 4 and flow through the bypass pipe 71.

The bypass valve 72 is provided in the bypass pipe 71. When the bypass valve 72 is in the open state, the bypass pipe 71 is opened. When the bypass valve 72 is closed, the bypass pipe 71 is shut off. The bypass valve 72 is an electric valve. The bypass valve 72 is opened and closed by a signal from the control unit 8. The operation of the release mechanism 7 means the opening of the bypass valve 72, and the operation stop of the release mechanism 7 means the closing of the bypass valve 72.

The detection results of the pressure sensor 22, the first temperature sensor 33, and the second temperature sensor 34 are input to the control unit 8. The control unit 8 outputs a signal to the bypass valve 72 to control the bypass valve 72. When the control unit 8 determines that steam locking has occurred in the drain trap 4, the control unit 8 operates the release mechanism 7, that is, opens the bypass valve 72. As a result, the fluid whose flow is blocked by the drain trap 4 is circulated to the downstream side of the drain trap 4. The details of the control contents of the control unit 8 will be described later.

FIG. 2 is a cross-sectional view of the drain trap 4. The drain trap 4 includes a casing 41 in which a fluid flow path is formed, and a first valve 5 and a second valve 6 provided in the flow path for switching between opening and closing of the flow path. The drain that has flowed into the casing 41 basically flows out of the casing 41 through the first valve 5. The second valve 6 basically discharges the air that has flowed into the casing 41. However, the second valve 6 may discharge the drain that has flowed into the casing 41. The second valve 6 is an example of a valve that opens when the drain flows in and closes when the steam flows in.

In the casing 41, an inflow port 42 in which the fluid flows into the casing 41, a storage chamber 43 for storing the fluid, an outflow port 44 in which the fluid flows out from the casing 41, and a storage chamber 43 and a flow through the first valve 5. It has a first discharge passage 45 that communicates with the outlet 44, and a second discharge passage 46 that communicates the storage chamber 43 and the first discharge passage 45 via the second valve 6.

The inflow port 42, the storage chamber 43, the first discharge passage 45, and the outflow outlet 44 form a first flow path for draining the drain. The inflow port 42, the storage chamber 43, the second discharge passage 46, the first discharge passage 45, and the outflow outlet 44 form a second flow path for discharging air and drain.

The first valve 5 has a first valve body 51 and a first valve seat 52. The first valve body 51 is a hollow spherical float and is housed in the storage chamber 43 in a free state. The first valve seat 52 is provided at the upstream end of the first discharge passage 45. A part (upstream end) of the first valve seat 52 is located in the storage chamber 43. A valve hole 53 is formed in the first valve seat 52. When the amount of drain stored in the storage chamber 43 increases, the first valve body 51 rises and separates from the first valve seat 52 to open the valve hole 53. On the other hand, when the drain of the storage chamber 43 decreases, the first valve body 51 descends and sits on the first valve seat 52, closing the valve hole 53. In this way, the first discharge passage 45, and thus the first passage, is opened and closed.

The second valve 6 is a heat-responsive type, that is, a thermostatic type, which discharges a fluid (for example, air or drain) having a temperature lower than a predetermined temperature while stopping the discharge of a fluid (for example, steam) having a temperature higher than a predetermined temperature. It is a valve. The second valve 6 has a valve unit 60 including a second valve body 61 and a second valve seat 62. A valve hole 63 is formed in the second valve seat 62.

The valve unit 60 is sealed with a temperature-sensitive medium that expands and contracts in response to temperature. The valve unit 60 drives the second valve body 61 with a temperature sensitive medium. The valve unit 60 is held by a holder 47 provided in the casing 41 via a spring 48. The valve unit 60 is urged toward the second valve seat 62 by the spring 48 and pressed against the holder 47.

In the second valve 6, when the temperature of the temperature-sensitive medium rises, the temperature-sensitive medium expands, the second valve body 61 sits on the second valve seat 62, and the valve hole 63 is closed. When the temperature of the temperature-sensitive medium becomes low, the temperature-sensitive medium contracts, the second valve body 61 separates from the second valve seat 62, and the valve hole 63 is opened. In this way, the second discharge passage 46, and thus the second passage, is opened and closed. In this example, the second valve body 61 is separated from the second valve seat 62 at a temperature similar to that of the drain, and the second valve body 61 is seated on the second valve seat 62 at a temperature similar to that of steam. A temperature sensitive medium is used.

When the temperature-sensitive medium expands more than the second valve body 61 is seated on the second valve seat 62, the valve unit 60 moves away from the second valve seat 62 against the elastic force of the spring 48. Move to. That is, the spring 48 absorbs the hyperexpansion of the temperature sensitive medium.

The operation of the drain trap 4 configured in this way will be described.

When the heating cylinder 100 is started, the temperature of the temperature sensitive medium is low, and the second valve body 61 is separated from the second valve seat 62. Further, when there is no drain in the casing 41 or when there is little drain, the first valve body 51 is seated on the first valve seat 52. That is, the first valve 5 is closed and the second valve 6 is open.

When the heating cylinder 100 is started from this state, drainage starts to flow into the casing 41 from the inflow port 42. At this time, the air existing in the drain pipe 31 also flows into the casing 41 together with the drain. The drain that has flowed into the storage unit 43 accumulates in the lower part of the storage unit 43. When the amount of drainage stored in the storage unit 43 increases, the first valve body 51 rises and separates from the first valve seat 52. As a result, the first valve 5 is opened. The drain flows out from the outflow port 44 through the first discharge passage 45.

The air that has flowed into the storage unit 43 stays in the upper part of the storage unit 43. Unless the temperature of the air is fairly high, the volume (ie, degree of expansion) of the temperature sensitive medium of the valve unit 60 is small and the second valve body 61 remains open. Therefore, the air flows into the second discharge passage 46 through the second valve 6 and flows out from the outflow port 44 through the first discharge passage 45.

When the amount of drain inflow from the inflow port 42 is larger than the amount of drain discharged from the first valve 5, the amount of drain stored in the storage unit 43 increases. Eventually, when the drain reaches the upper part of the storage unit 43, the temperature of the temperature sensitive medium approaches the temperature of the drain. In this example, when the temperature of the temperature-sensitive medium is about the same as that of the drain, the volume of the temperature-sensitive medium (that is, the degree of expansion) is small, and the second valve body 61 is separated from the second valve seat 62. The valve hole 63 remains open. Therefore, the drain flows into the second discharge passage 46 through the second valve 6, and flows out from the outflow port 44 through the first discharge passage 45.

On the other hand, when steam flows into the casing 41 from the inflow port 42, the drain of the storage unit 43 is discharged from the first valve 5 and decreases, and eventually the first valve body 51 is seated on the first valve seat 52. .. In this way, the first valve 5 is closed, and the discharge of steam from the first valve 5 is prevented.

In addition, a part of the steam stays in the upper part of the storage unit 43. Then, the temperature-sensitive medium of the valve unit 60 expands. Due to the expansion of the temperature sensitive medium, the second valve body 61 is displaced upward, and the second valve body 61 is seated on the second valve seat 62. In this way, the second valve 6 is closed, and the discharge of steam from the second valve 6 is prevented.

In this way, the drain trap 4 allows the inflowing drain and air to pass through and outflow, while blocking the outflow of the inflowing steam.

However, when both the first valve 5 and the second valve 6 are closed and steam is sealed in the drain trap 4, steam locking may occur when the drain tries to flow into the drain trap 4. is there. That is, since the first valve 5 and the second valve 6 are closed, the steam in the drain trap 4 cannot flow out from the outflow port 44. If the steam in the drain trap 1 is not properly replaced by the drain, the first valve 5 and the second valve 6 will not open. When the inflow of drain into the drain trap 4 is blocked by the steam in the drain trap 4, the valve closed state of the first valve 5 and the second valve 6 is continued. As a result, the flow of drain in the drain pipe 31 is stagnant, and as a result, the discharge of drain from the cylinder body 10 is stagnant.

Therefore, when steam locking occurs, the control unit 8 operates the release mechanism 7 to eliminate the steam locking. Hereinafter, the control of the release mechanism 7 by the control unit 8 will be described in detail with reference to the flowchart of FIG.

The control unit 8 does not normally operate the release mechanism 7. That is, the bypass valve 72 is controlled to be fully closed. Therefore, all the fluid flowing through the drain pipe 31 flows into the drain trap 4, and the discharge of steam is suppressed. The control unit 8 repeats the control shown in the flowchart at regular intervals.

In step S1, the control unit 8 determines whether or not there is a capacity adjustment that reduces the heating capacity of the cylinder body 10. For example, the control unit 8 determines whether or not the pressure of the steam supplied to the cylinder body 10 has decreased based on the detection result of the pressure sensor 22. When the object of the cylinder body 10 is changed to reduce the heating capacity of the cylinder body 10 or when the heating by the cylinder body 10 is stopped, the pressure of the steam supplied to the cylinder body 10 is reduced. That is, the intentional decrease in the heating capacity of the cylinder body 10 can be determined by the decrease in the pressure of the steam supplied to the cylinder body 10. In the steam locking determination method described later, it is difficult to discriminate between a decrease in the heating capacity of the cylinder body 10 due to capacity adjustment and a decrease in the heating capacity of the cylinder body 10 due to steam locking. When the heating capacity of the cylinder body 10 is reduced due to the capacity adjustment, the control unit 8 reduces the heating capacity of the cylinder body 10 due to the capacity adjustment so as not to operate the release mechanism 7 described later. The presence or absence is determined in step S1.

When the steam pressure drops, the control unit 8 determines that the heating capacity of the cylinder body 10 decreases due to the capacity adjustment, and ends the control of the release mechanism 7 without operating the release mechanism 7. On the other hand, when the steam pressure has not decreased, the control unit 8 determines that the heating capacity of the cylinder body 10 has not decreased due to the capacity adjustment, and proceeds to step S2.

The control unit 8 reduces the heating capacity of the cylinder body 10 from the control unit that controls the pressure of the steam supplied to the cylinder body 10 (for example, the control unit that controls the entire heating system including the heating cylinder 100). A signal indicating that the capacity is adjusted or a signal indicating the pressure to be supplied may be received, and a decrease in the heating capacity of the cylinder body 10 due to the capacity adjustment may be determined based on the signal. In that case, the pressure sensor 22 can be omitted.

In step S2, the control unit 8 determines whether or not the inlet temperature of the drain trap 4 is higher than the outlet temperature of the cylinder body 10 based on the detection results of the first temperature sensor 33 and the second temperature sensor 34. For example, the control unit 8 determines whether or not the following equation (1) is satisfied.

t1 + Δt <t2 ... (1)
Here, t1 is the outlet temperature of the cylinder body 10, t2 is the inlet temperature of the drain trap 4, and Δt is a predetermined temperature difference (constant).

That is, the control unit 8 determines whether or not the inlet temperature t2 of the drain trap 4 is higher than the outlet temperature t1 of the cylinder body 10 by a predetermined temperature difference Δt. The temperature difference Δt is predetermined based on the length of the drain pipe 31 between the cylinder body 10 and the drain trap 4.

If steam locking has not occurred, drain or steam flows through the drain pipe 31 from the cylinder body 10 to the drain trap 4, so that the outlet temperature t1 of the cylinder body 10 is higher than the inlet temperature t2 of the drain trap 4. .. However, when steam locking occurs, drainage from the cylinder body 10 is delayed. Since the cylinder body 10 dissipates heat to the object, the amount of drainage increases in the cylinder body 10. Eventually, steam does not flow into the cylinder body 10, the temperature of the cylinder body 10 decreases, and the heating capacity of the cylinder body 10 decreases. The outlet temperature t1 of the cylinder body 10 also drops. On the other hand, in the steam trap 4, the pressure rises due to the accumulation of steam and the drainage or steam being pushed from the inflow port 42, so that the inlet temperature t2 rises. As a result, the inlet temperature t2 can be higher than the outlet temperature t1.

How much the inlet temperature t2 becomes higher than the outlet temperature t1 when steam locking occurs depends on the length of the drain pipe 31 between the cylinder body 10 and the drain trap 4. The temperature difference Δt is set to the temperature difference between the inlet temperature t2 and the outlet temperature t1 assumed when steam locking occurs, or a value before and after the temperature difference. Although the occurrence of steam locking can be roughly determined by simply comparing the inlet temperature t2 and the outlet temperature t1, the steam locking can be determined by comparing the inlet temperature t2 and the outlet temperature t1 in consideration of the temperature difference Δt. The accuracy can be improved.

When the equation (1) is satisfied, the control unit 8 determines that steam locking has occurred, and proceeds to step S3. On the other hand, if the equation (1) is not satisfied, the control unit 8 determines that steam locking has not occurred, and ends the control of the release mechanism 7.

The control unit 8 opens the bypass valve 72 in step S3. The drain and steam stagnant in the drain pipe 31 will flow through the bypass pipe 71. Drain is discharged from the cylinder body 10, and steam flows into the cylinder body 10. As a result, the heating capacity of the cylinder body 10 is restored. On the other hand, in the drain trap 4, steam is eventually condensed and steam locking is eliminated. Further, since the pressure in the drain trap 4 in the state where steam is accumulated is higher than the pressure on the downstream side of the bypass pipe 71, the steam in the drain trap 4 goes to the downstream side of the bypass pipe 71 via the bypass pipe 71. Can be discharged. This can also eliminate steam locking.

Subsequently, in step S4, the control unit 8 determines whether or not the condition for stopping the operation of the release mechanism 7 (hereinafter, referred to as “stop condition”) is satisfied. The stop condition can be set in various ways. For example, the stop condition is that the steam locking has been eliminated or that the steam locking can be eliminated. For example, the control unit 8 sets the stop condition that the equation (1) is no longer satisfied. From the state where the formula (1) is satisfied, the inlet temperature t2 decreases and / or the outlet temperature t1 rises, so that the formula (1) is not satisfied. When the steam locking is eliminated, the first valve 5 of the drain trap 4 is opened, the steam in the drain trap 4 is discharged, and the pressure of the drain trap 4 is lowered, so that the inlet temperature t2 is lowered. At this time, the heating capacity of the cylinder body 10 is also restored, so that the outlet temperature t1 also rises.

Further, even when the first valve 5 and the second valve 6 are closed, when the drain of the cylinder body 10 is discharged via the bypass pipe 71, the heating capacity of the cylinder body 10 is restored and the outlet temperature t1 is set. To rise. At this time, since the drain flow is generated in the portion of the drain pipe 31 on the upstream side of the connection portion at the upstream end of the bypass pipe 71, the drain pipe 31 is circulated even if the bypass valve 72 is closed. The drain is likely to flow into the drain trap 4. When the steam in the drain trap 4 is replaced with the drain, the first valve 5 is opened and the steam locking is eliminated. That is, in such a case, the steam locking can be eliminated, and even if the operation of the release mechanism 7 is stopped, the steam locking can be eliminated as a matter of course.

Similarly, even if the first valve 5 and the second valve 6 are closed, if the steam in the drain trap 4 is discharged via the bypass pipe 71, the pressure in the drain trap 4 decreases and the inlet temperature. t2 decreases. At this time, even if the bypass valve 72 is closed, the pressure in the drain trap 4 is reduced, so that the drain in the drain pipe 31 easily flows into the drain trap 4. As a result, the first valve 5 is opened and steam locking is eliminated. That is, in such a case, the steam locking can be eliminated, and even if the operation of the release mechanism 7 is stopped, the steam locking can be eliminated as a matter of course.

In order to reduce the possibility of recurrence of steam locking, the control unit 8 may set the stop condition that the state in which the equation (1) is not satisfied continues for a predetermined time.

Further, as described above, when the bypass valve 72 is opened, a drain flow is generated in the portion of the drain pipe 31 on the upstream side of the drain trap 4, and the steam of the drain trap 4 passes through the bypass pipe 71. Since it is discharged, steam locking can be eliminated even if the bypass valve 72 is closed after a while. Therefore, the stop condition may be that the bypass valve 72 is kept open for a predetermined time.

When the stop condition is satisfied, the control unit 8 proceeds to step S5. On the other hand, if the stop condition is not satisfied, the control unit 8 repeats the determination in step S4 and waits for the stop condition to be satisfied.

In step S5, the control unit 8 closes the bypass valve 72 and stops the operation of the release mechanism 7. As a result, the flow of drain and steam via the bypass pipe 71 is cut off. At this time, since the drain or steam can flow into the drain trap 4, even if the flow of the fluid in the bypass pipe 71 is cut off, the drain or steam in the cylinder body 10 is discharged through the drain pipe 31. , Flows into the drain trap 4. By passing through the drain trap 4, the drain can be discharged while blocking the discharge of steam.

In this way, the control unit 8 normally closes the bypass valve 72. Therefore, since the bypass pipe 71 is normally shut off, all the fluid discharged from the cylinder body 10 flows into the drain trap 4, and the discharge of steam is suppressed. This makes it possible to reduce energy loss. On the other hand, when there is a possibility that steam locking has occurred, the control unit 8 opens the bypass valve 72. As a result, steam locking is eliminated, and drainage can be appropriately discharged from the cylinder body 10. Then, when the steam locking is eliminated or can be eliminated, the control unit 8 closes the bypass valve 72. Therefore, it is possible to achieve both reduction of energy loss and elimination of steam locking.

As described above, the heating cylinder 100 is provided in the cylinder body 10 in which steam is supplied to the inside to heat an external object, the drain pipe 31 for discharging the drain from the cylinder body 10, and the drain pipe 31. A drain trap 4 that allows the flow of steam, a release mechanism 7 that allows the fluid whose flow is blocked by the drain trap 4 to flow to the downstream side of the drain trap 4, and a fluid at the outlet of the cylinder body 10. A control unit including a first temperature sensor 33 that detects the outlet temperature t1 of the above, a second temperature sensor 34 that detects the inlet temperature t2 of the fluid at the inlet of the drain trap 4, and a control unit 8 that controls the release mechanism 7. 8 operates the release mechanism 7 when the inlet temperature t2 is higher than the outlet temperature t1.

According to this configuration, when the inlet temperature t2 of the drain trap 4 is higher than the outlet temperature t1 of the cylinder body 10, it is determined that steam locking has occurred, and the release mechanism 7 operates. When the release mechanism 7 is activated, the steam locking is eventually eliminated. Steam locking can be determined by a simple configuration in which the first temperature sensor 33 and the second temperature sensor 34 are provided. As a result, it is possible to eliminate steam locking and appropriately discharge the drain from the cylinder body 10 with a simple configuration.

Further, the control unit 8 operates the release mechanism 7 when the inlet temperature t2 becomes higher than the outlet temperature t1 by a predetermined temperature difference Δt.

According to this configuration, if the inlet temperature t2 accidentally becomes higher than the outlet temperature t1 even though steam locking has not occurred, it may be erroneously determined that steam locking has occurred. Be prevented. That is, the release mechanism 7 is prevented from operating even though steam locking has not occurred. When the release mechanism 7 is activated, steam may flow out to the downstream side of the drain trap 4. By suppressing the operation of the unnecessary release mechanism 7, the outflow of steam, that is, the loss of energy is reduced.

Further, the control unit 8 does not operate the release mechanism 7 even when the inlet temperature t2 is higher than the outlet temperature t1 when the heating capacity of the cylinder body 10 decreases due to the capacity adjustment.

According to this configuration, it is possible to prevent the decrease in the heating capacity of the cylinder body 10 due to the capacity adjustment from being erroneously determined to be due to the occurrence of steam locking. Specifically, the heating capacity of the cylinder body 10 may be intentionally lowered due to a change in the object or the like, and in such a case, the outlet temperature t1 of the cylinder body 10 is lowered. As a result, the inlet temperature t2 of the drain trap 4 may be higher than the outlet temperature t1. The cause is the adjustment of the heating capacity of the cylinder body 10, not the steam locking. Therefore, the control unit 8 does not operate the release mechanism 7 regardless of the outlet temperature t1 and the inlet temperature t2 when the heating capacity of the cylinder body 10 is reduced due to the capacity adjustment. As a result, unnecessary operation of the release mechanism 7 is suppressed, and steam outflow, that is, energy loss is reduced.

Specifically, the control unit 8 determines that the heating capacity of the cylinder body 10 decreases due to the capacity adjustment when the pressure of the steam supplied to the cylinder body 10 decreases.

According to this configuration, it is possible to easily determine the decrease in the heating capacity of the cylinder body 10 due to the capacity adjustment. That is, the heating capacity of the cylinder body 10 is adjusted by the pressure of the steam supplied to the cylinder body 10. Specifically, by reducing the pressure of the supplied steam, the heating capacity of the cylinder body 10 is reduced. Therefore, it is possible to determine the decrease in the heating capacity of the cylinder body 10 due to the capacity adjustment based on the pressure supplied to the cylinder body 10.

Further, the release mechanism 7 has a bypass pipe 71 connected to the drain pipe 31 so as to bypass the drain trap 4, and a bypass valve 72 for opening and closing the bypass pipe 71, and the control unit 8 has an inlet temperature t2. When the outlet temperature is higher than t1, the bypass valve 72 is opened.

According to this configuration, when steam locking occurs, the drain or steam stagnant on the upstream side of the drain trap 4 in the drain pipe 31 flows out to the downstream side of the drain trap 4 via the bypass pipe 71. With a simple configuration in which the bypass pipe 71 and the bypass valve 72 are provided in the drain pipe 31, the drain and steam stagnant in the drain trap 4 and the drain trap 4 can be released to the downstream side of the drain trap 4.

<< Embodiment 2 >>
Subsequently, the heating cylinder 200 according to the second embodiment will be described. FIG. 4 is a schematic configuration diagram of the heating cylinder 200 according to the second embodiment. The configuration of the drain trap and the release mechanism is different between the heating cylinder 100 and the heating cylinder 200. Therefore, the same configuration as the heating cylinder 100 of the heating cylinder 200 will be described with the same reference numerals, and the description will be omitted, and the configuration of the heating cylinder 200 different from that of the heating cylinder 100 will be mainly described.

The heating cylinder 200 is provided in the cylinder body 10, the drain pipe 31, and the drain pipe 31, and while allowing the flow of drain, the flow is blocked by the drain trap 204 and the drain trap 204, which block the flow of steam. It includes a release mechanism 207 that circulates fluid to the downstream side of the drain trap 204, a first temperature sensor 33, a second temperature sensor 34, and a control unit 8 that controls the release mechanism 207. The release mechanism 207 is incorporated in the drain trap 204.

FIG. 5 is a cross-sectional view of the drain trap 204. The basic configuration of the drain trap 204 is the same as that of the drain trap 4. The drain trap 204 includes a casing 41 in which a fluid flow path is formed, and a first valve 5 and a second valve 6 provided in the flow path for switching between opening and closing of the flow path. Unlike the drain trap 4, the drain trap 204 has a release mechanism 207.

The release mechanism 207 is formed in the drain trap 204, and has a bypass path 271 for communicating the upstream side and the downstream side of the second valve 6, and a bypass valve 272 for switching the opening and closing of the bypass path 271.

The bypass passage 271 is formed in the casing 41 so as to communicate the storage chamber 43 and the second discharge passage 46. The bypass passage 271 allows the fluid in the storage chamber 43 to flow into the second discharge passage 46.

The bypass valve 272 includes a needle valve 273 and an electric motor 274 that advances and retreats the needle valve 273. The bypass valve 274 is attached to the casing 41 so as to penetrate the casing 41.

The needle valve 273 crosses the second discharge passage 46. The tip of the needle valve 273 faces the open end (hereinafter, referred to as “downstream end”) of the bypass passage 271 on the second discharge passage 46 side.

The electric motor 274 advances and retreats the needle valve 273 in the axial direction of the needle valve 273. The electric motor 274 shuts off the bypass path 271 by bringing the tip of the needle valve 273 into contact with the downstream end of the bypass path 271. On the other hand, the electric motor 274 opens the bypass path 271 by separating the tip of the needle valve 273 from the downstream end of the bypass path 271. The operation of the release mechanism 207 means the opening of the bypass valve 272, and the operation stop of the release mechanism 207 means the closing of the bypass valve 272.

The detection results of the pressure sensor 22, the first temperature sensor 33, and the second temperature sensor 34 are input to the control unit 8. The control unit 8 outputs a signal to the bypass valve 272 (specifically, the electric motor 274) to control the bypass valve 272. When the control unit 8 determines that steam locking has occurred in the drain trap 204, the control unit 8 operates the release mechanism 207, that is, opens the bypass valve 272. As a result, the fluid whose flow is blocked by the drain trap 204 is circulated to the downstream side of the drain trap 204.

Specifically, the control unit 8 controls the release mechanism 207 according to the flowchart of FIG. 3 except for steps S3 and S5. In step S3, the control unit 8 operates the release mechanism 207 to open the bypass valve 272. The steam stagnant in the storage chamber 43 flows into the second discharge passage 46 via the bypass pipe 271. As a result, the steam in the storage chamber 43 is reduced, so that the drain flows from the inflow port 42 into the storage chamber 43, and the first valve 5 is opened. In this way, steam locking is eliminated. Further, the drain and steam stagnant in the drain pipe 31 flow into the drain trap 204, so that the drain is discharged from the cylinder body 10 and the steam flows into the cylinder body 10. As a result, the heating capacity of the cylinder body 10 is restored.

Further, in step S5, the control unit 8 closes the bypass valve 272 to stop the operation of the release mechanism 207. As a result, the drain trap 204 operates normally, and the outflow of steam from the drain trap 204 is prevented.

As described above, the heating cylinder 200 is provided in the cylinder body 10 in which steam is supplied to the inside to heat an external object, the drain pipe 31 for discharging the drain from the cylinder body 10, and the drain pipe 31. A drain trap 204 that allows the flow of steam while blocking the flow of steam, a release mechanism 207 that allows the fluid whose flow is blocked by the drain trap 204 to flow to the downstream side of the drain trap 204, and a fluid at the outlet of the cylinder body 10. A control unit including a first temperature sensor 33 that detects the outlet temperature t1 of the above, a second temperature sensor 34 that detects the inlet temperature t2 of the fluid at the inlet of the drain trap 4, and a control unit 8 that controls the release mechanism 207. No. 8 operates the release mechanism 207 when the inlet temperature t2 is higher than the outlet temperature t1.

According to this configuration, when the inlet temperature t2 of the drain trap 204 is higher than the outlet temperature t1 of the cylinder body 10, it is determined that steam locking has occurred, and the release mechanism 207 operates. When the release mechanism 207 is activated, the steam locking is eventually eliminated. Steam locking can be determined by a simple configuration in which the first temperature sensor 33 and the second temperature sensor 34 are provided. As a result, it is possible to eliminate steam locking and appropriately discharge the drain from the cylinder body 10 with a simple configuration.

Further, the drain trap 204 has a second valve 6 (valve) that opens when the drain flows in and closes when the steam flows in, and the release mechanism 207 is formed in the drain trap 204 and of the second valve 6. It has a bypass path 271 that communicates the upstream side and the downstream side, and a bypass valve 272 that switches between opening and closing of the bypass path 271, and the control unit 8 bypasses when the inlet temperature t2 is higher than the outlet temperature t1. The valve 272 is opened.

According to this configuration, when steam locking occurs, the drain or steam stagnant on the upstream side of the drain trap 204 flows out to the downstream side of the drain trap 204 via the bypass path 271. Even if the drain pipe 31 is not provided with a bypass pipe and a bypass valve, by adopting the drain trap 204 having the bypass path 271 and the bypass valve 272, the drain and steam stagnated on the upstream side of the drain trap 204 and the drain trap 204 can be removed. It is possible to realize a configuration in which the drain trap 204 is released to the downstream side.

<< Embodiment 3 >>
Subsequently, the heating cylinder 300 according to the third embodiment will be described. The configuration of the drain trap and the release mechanism is different between the heating cylinder 100 and the heating cylinder 300. Therefore, the same configuration as the heating cylinder 100 of the heating cylinder 300 will be described with the same reference numerals, and the description will be omitted, and the configuration of the heating cylinder 300 different from that of the heating cylinder 100 will be mainly described.

FIG. 4 is not only a schematic configuration diagram of the heating cylinder 200, but also a schematic configuration diagram of the heating cylinder 300 according to the third embodiment. The heating cylinder 300 is provided in the cylinder body 10, the drain pipe 31, and the drain pipe 31, and while allowing the flow of drain, the flow is blocked by the drain trap 304 and the drain trap 304, which block the flow of steam. It includes a release mechanism 307 that circulates fluid to the downstream side of the drain trap 304, a first temperature sensor 33, a second temperature sensor 34, and a control unit 8 that controls the release mechanism 307. The release mechanism 307 is incorporated in the drain trap 304.

FIG. 6 is a cross-sectional view of the drain trap 304. The basic configuration of the drain trap 304 is the same as that of the drain trap 4. The drain trap 304 includes a casing 41 in which a fluid flow path is formed, and a first valve 5 and a second valve 6 provided in the flow path for switching between opening and closing of the flow path. Unlike the drain trap 4, the drain trap 304 has a release mechanism 307.

The release mechanism 307 has a valve opening mechanism 375 that forcibly opens the second valve 6.

The valve opening mechanism 375 includes a needle 376 and an electric motor 377 that advances and retreats the needle 376. The valve opening mechanism 375 is attached to the casing 41 so as to penetrate the casing 41.

The needle 376 crosses the second discharge passage 46 and extends along the axis of the valve hole 63. The tip of the needle 376 faces the second valve body 61.

The electric motor 377 advances and retreats the needle 376 in the axial direction of the needle 376. When the electric motor 377 retracts the needle 376, the needle 376 moves to a position where it does not protrude upstream from the valve hole 63 (hereinafter, referred to as a “retracted position”) as shown in FIG. When the release mechanism 307 is not operating, the needle 376 is in the retracted position. The needle 376 located at the retracted position does not affect the opening / closing of the second valve body 61 and the flow of fluid through the valve hole 63. When the release mechanism 307 is activated, the electric motor 377 advances the needle 376. The tip of the needle 376 penetrates the valve hole 63 and projects upstream from the valve hole 63. When the second valve body 61 is seated on the second valve seat 62, the needle 376 pushes the valve unit 60 in a direction away from the second valve seat 62 against the elastic force of the spring 48. As a result, the second valve body 61 is forcibly separated from the second valve seat 62, and the valve hole 63 is opened. As a result, the steam or the like staying in the storage chamber 43 passes through the valve hole 63, flows into the second discharge passage 46, and flows out from the outflow port 44. The operation of the release mechanism 307 means the advance of the needle 376 such as opening the second valve 6, and the operation stop of the release mechanism 307 means the movement to the retracted position of the needle 376.

The detection results of the pressure sensor 22, the first temperature sensor 33, and the second temperature sensor 34 are input to the control unit 8. The control unit 8 outputs a signal to the valve opening mechanism 375 (specifically, the electric motor 377) to control the valve opening mechanism 375. The control unit 8 activates the release mechanism 307 when it is determined that steam locking has occurred in the drain trap 304. That is, the valve opening mechanism 375 opens the second valve 6. As a result, the fluid whose flow is blocked by the drain trap 304 is circulated to the downstream side of the drain trap 304.

Specifically, the control unit 8 controls the release mechanism 307 according to the flowchart of FIG. 3 except for steps S3 and S5. In step S3, the control unit 8 operates the release mechanism 307 to forcibly open the second valve 6. The steam stagnant in the storage chamber 43 flows into the second discharge passage 46 via the valve hole 63. As a result, the steam in the storage chamber 43 is reduced, so that the drain flows from the inflow port 42 into the storage chamber 43, and the first valve 5 is opened. In this way, steam locking is eliminated. Further, the drain and steam stagnant in the drain pipe 31 flow into the drain trap 304, so that the drain is discharged from the cylinder body 10 and the steam flows into the cylinder body 10. As a result, the heating capacity of the cylinder body 10 is restored.

Further, in step S5, the control unit 8 retracts the needle 376 of the valve opening mechanism 375 and stops the operation of the release mechanism 307. As a result, the drain trap 304 operates normally, and the outflow of steam from the drain trap 304 is prevented.

As described above, the heating cylinder 300 is provided in the cylinder body 10 in which steam is supplied to the inside to heat an external object, the drain pipe 31 for discharging drain from the cylinder body 10, and the drain pipe 31. A drain trap 304 that allows the flow of steam while blocking the flow of steam, a release mechanism 307 that allows the fluid whose flow is blocked by the drain trap 304 to flow to the downstream side of the drain trap 304, and a fluid at the outlet of the cylinder body 10. A first temperature sensor 33 that detects the outlet temperature t1 that is the temperature of the above, a second temperature sensor 34 that detects the inlet temperature t2 that is the temperature of the fluid at the inlet of the drain trap 304, and a control unit 8 that controls the release mechanism 307. The control unit 8 operates the release mechanism 307 when the inlet temperature t2 is higher than the outlet temperature t1.

According to this configuration, when the inlet temperature t2 of the drain trap 304 is higher than the outlet temperature t1 of the cylinder body 10, it is determined that steam locking has occurred, and the release mechanism 307 operates. When the release mechanism 307 is activated, the steam locking is eventually eliminated. Steam locking can be determined by a simple configuration in which the first temperature sensor 33 and the second temperature sensor 34 are provided. As a result, it is possible to eliminate steam locking and appropriately discharge the drain from the cylinder body 10 with a simple configuration.

Further, the drain trap 304 has a second valve 6 (valve) that opens when the drain flows in and closes when the steam flows in, and the release mechanism 307 forcibly opens the second valve 6. The control unit 8 has a valve mechanism 375, and when the inlet temperature t2 is higher than the outlet temperature t1, the valve opening mechanism 375 opens the second valve 6.

According to this configuration, when steam locking occurs, the drain or steam stagnant on the upstream side of the drain trap 304 flows out to the downstream side of the drain trap 304 via the second valve 6 in the valve open state. Even if the drain pipe 31 is not provided with a bypass pipe and a bypass valve, by adopting the drain trap 304 having the valve opening mechanism 375, the drain trap 304 can collect the drain and steam stagnated on the upstream side of the drain trap 304 and the drain trap 304. It is possible to realize a configuration that releases to the downstream side of.

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

For example, any drain trap can be adopted as long as it allows the flow of drain while blocking the flow of steam, and is not limited to drain traps 4, 204, 304. For example, drain traps 4, 204, 304 have two valves, a first valve 5 and a second valve 6, but may have only one valve. Further, the drain trap is not limited to the float type, and a disk type or thermostatic type (type such as the second valve 6) drain trap can also be adopted.

The release mechanism can adopt any configuration as long as the fluid whose flow is blocked by the drain trap is circulated to the downstream side of the drain trap. For example, the bypass valve 272 of the release mechanism 207 is not limited to the needle valve, but may be a ball valve or the like. Further, the valve opening mechanism 375 of the release mechanism 307 may be configured according to the target valve.

The first temperature sensor 33 can be arranged at any position as long as the temperature of the fluid at the outlet of the cylinder body 10 can be detected. For example, the first temperature sensor 33 may be provided in the heating cylinder 10 (specifically, a portion of the drain outflow pipe 13 exposed to the outside of the cylinder body 10).

Similarly, the second temperature sensor 34 can be placed at any location as long as it can detect the temperature of the fluid at the inlet of the drain trap. For example, the second temperature sensor 34 may be provided in drain traps 4, 204, 304 (specifically, a portion of the casing 41 corresponding to the inflow port 42, etc.).

In the above description, the release mechanism is operated when the equation (1) is satisfied, but the conditions for operating the release mechanism are not limited to this. For example, it may be a condition that t1 <t2 is satisfied.

As described above, the techniques disclosed herein are useful for heating cylinders.

100,200,300 Heating cylinder 31 Drain pipe 33 First temperature sensor 34 Second temperature sensor 4,204,304 Drain trap 6 Second valve (valve)
7,207,307 Release mechanism 71 Bypass pipe 72 Bypass valve 271 Bypass path 272 Bypass valve 375 Valve opening mechanism 8 Control unit

Claims (7)

The cylinder body, which is supplied with steam to heat the external object,
A drain pipe that drains drain from the cylinder body,
A drain trap provided in the drain pipe, which allows the flow of drain while blocking the flow of steam,
A release mechanism that allows the fluid whose flow is blocked by the drain trap to flow to the downstream side of the drain trap,
A first temperature sensor that detects the outlet temperature, which is the temperature of the fluid at the outlet of the cylinder body,
A second temperature sensor that detects the inlet temperature, which is the temperature of the fluid at the inlet of the drain trap,
A control unit that controls the release mechanism is provided.
The control unit is a heating cylinder that operates the release mechanism when the inlet temperature is higher than the outlet temperature. In the heating cylinder according to claim 1,
The control unit is a heating cylinder that operates the release mechanism when the inlet temperature becomes higher than the outlet temperature by a predetermined temperature difference. In the heating cylinder according to claim 1 or 2.
The control unit is a heating cylinder that does not operate the release mechanism even when the inlet temperature is higher than the outlet temperature when the heating capacity of the cylinder body decreases due to capacity adjustment. In the heating cylinder according to claim 3,
The control unit is a heating cylinder that determines that the heating capacity of the cylinder body is reduced by adjusting the capacity when the pressure of steam supplied to the cylinder body is reduced. In the heating cylinder according to any one of claims 1 to 4.
The release mechanism has a bypass pipe connected to the drain pipe so as to bypass the drain trap, and a bypass valve for switching between opening and closing of the bypass pipe.
The control unit is a heating cylinder that opens the bypass valve when the inlet temperature is higher than the outlet temperature. In the heating cylinder according to any one of claims 1 to 4.
The drain trap has a valve that opens when the drain flows in and closes when the steam flows in.
The release mechanism has a bypass path formed in the drain trap and communicating the upstream side and the downstream side of the valve, and a bypass valve for switching between opening and closing of the bypass path.
The control unit is a heating cylinder that opens the bypass valve when the inlet temperature is higher than the outlet temperature. In the heating cylinder according to any one of claims 1 to 4.
The drain trap has a valve that opens when the drain flows in and closes when the steam flows in.
The release mechanism has a valve opening mechanism for forcibly opening the valve.
The control unit is a heating cylinder that opens the valve by the valve opening mechanism when the inlet temperature is higher than the outlet temperature.

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