Drain recovery system

Abstract

To provide a drain recovery system capable of being easily installed regardless of the situation of an installation place SOLUTION: The drain generated in the steam using device 31 is stored in the valve chest 61 of the liquid pumping device 6, and high-pressure driving steam is introduced from the steam introduction pipe 22 as the float 62 floats. As a result, the drain in the valve chamber 61 is pressure-fed to the water supply tank 2 and refluxed. Drain generated from the heat exchanger 41 flows down through the pipe 18 and stays in the drain reservoir 40. A part of the high-pressure driving steam introduced into the liquid pumping device 6 is supplied to the drain reservoir 40 through the steam lead-out pipe 25, and the drain staying in the drain reservoir 40 is pumped toward the drain header 5 through the pipe 19.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The drain recovery system according to the present disclosure relates to a drain recovery system including a drain pumping device that pumps drain using a driving fluid such as steam. [Background technology]

[0002] An example of a drain recovery system is a steam system 1 relating to a drain recovery device described in Patent Document 1. This steam system 1 includes a boiler 2, a steam usage system 3, and a drain recovery system 10.

[0003] The boiler 2 heats water stored in a tank to generate steam, which is then supplied to the steam-using system 3 via an air intake pipe 6. The steam-using system 3 has three steam-using devices 4, each of which uses steam to, for example, heat an object. Through such heating processes, the steam releases heat and condenses, generating drain (condensate). Each steam-using device 4 is connected to a steam trap 5, which automatically discharges the drain into a drain inlet pipe 11.

[0004] The drain inlet pipe 11 is connected to the top of the recovery tank 21, and the drain discharged from the steam trap 5 flows into the recovery tank 21 through the drain inlet pipe 11 and is stored therein. A water supply pipe 12 is connected to the bottom of the recovery tank 21, and a water supply pump 22 is provided on this water supply pipe 12.

[0005] Then, by driving the feedwater pump 22, the drain is fed through the feedwater pipe 12 to the tank of the boiler 2, where it is heated again and turned into steam. The feedwater pump 22 is installed at a position lower than the recovery tank 21, and the difference in height is used to obtain the required lift (required inflow head for the pump).

[0006] In the recovery tank 21, the high-temperature drain discharged from the steam trap 5 re-evaporates to generate flash steam (re-evaporated steam). This flash steam is taken into the makeup water tank 24 through the exhaust pipe 13 connected to the top of the recovery tank 21.

[0007] The drain generated when the flash steam condenses again flows out into the makeup water pipe 14 connected to the bottom of the recovery tank 21. A feed water pump 25 is provided in the makeup water pipe 14, and the downstream end of the makeup water pipe 14 is connected to the feed water pipe 12. When the feed water pump 25 is driven, the drain that flows out into the makeup water pipe 14 is replenished to the tank of the boiler 2. Like the feed water pump 22, this feed water pump 25 is also provided at a position lower than the makeup water tank 24 in order to obtain the required lift (required inflow head for the pump) by the difference in elevation. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5901856 Summary of the Invention [Problem to be solved by the invention]

[0009] In the technology disclosed in the aforementioned Patent Document 1, the water supply pump 22 and the water supply pump 25 are provided at a position lower than the recovery tank 21 or the makeup water tank 24 in order to obtain the necessary lifting force due to the difference in elevation.

[0010] In this way, when recovering the drains from recovery tank 21 and makeup water tank 24, a water supply pump 22 and a water supply pump 25 are required for each tank. In particular, when a steam-driven liquid pressure-feeding device is used as the pump, the device configuration becomes complicated due to the need to install multiple liquid pressure-feeding devices.

[0011] Therefore, the drain recovery system of the present disclosure aims to provide a drain recovery system that can recover drain from multiple tanks without complicating the device configuration, even when a steam-driven liquid pumping device is used as a pump. [Means for solving the problem]

[0012] The drain recovery system according to the present disclosure comprises: An intermediate area that takes in the drainage flowing from upstream to downstream and discharges it to the downstream side. a drain pressure-feeding means having an inflow portion that takes in the drain discharged by the intermediate region from the upstream side, a storage space portion that stores the drain taken in by the inflow portion, an outflow portion that discharges the drain stored in the storage space portion to the downstream side, a detection portion that detects the amount of drain stored in the storage space portion, and an introduction portion that introduces a high-pressure driving fluid toward the storage space portion, wherein when the detection portion detects that the amount of drain stored in the storage space portion has reached a predetermined pressure-feed standard amount, the drain pressure-feeding means opens the introduction portion and introduces the high-pressure driving fluid into the storage space portion, thereby pressure-feeding and discharging the drain stored in the storage space portion from the outflow portion; a drain pumping flow path in which drain flows from upstream to downstream and whose downstream end is connected to the intermediate region, the drain pumping flow path having a drain retention region located vertically below the intermediate region; A drain recovery system comprising: the drain pressure-feeding means is formed with a discharge portion for discharging the high-pressure driving fluid introduced into the storage space, When the high-pressure driving fluid is introduced into the storage space, the driving fluid is discharged from the discharge portion and supplied toward the stagnation region of the drain pumping channel, thereby pumping the drain that has been stagnated in the stagnation region toward the intermediate region. It is characterized by: [Effects of the Invention]

[0013] In the drain recovery system according to the present disclosure, the drain pumping means is formed with an outlet portion for discharging the high-pressure driving fluid introduced into the storage space portion. When the high-pressure driving fluid is introduced into the storage space portion, the driving fluid is discharged from the outlet portion and supplied toward the stagnation region of the drain pumping channel, thereby pumping the drain that has accumulated in the stagnation region toward the intermediate region.

[0014] Therefore, the drain that has accumulated in the stagnation region of the drain pumping passage, which is located below the intermediate region, can be pumped toward the intermediate region by utilizing the high pressure of the driving fluid. That is, the drain that has accumulated in the stagnation region of the drain pumping passage can be pumped without using a pump or the like. Therefore, it is possible to recover drain from multiple tanks without complicating the device configuration. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an overall block diagram of a steam using system 1 illustrating a first embodiment of a drain recovery system according to the present disclosure. [Figure 2] 2 is a partially enlarged cross-sectional view of the liquid pressure-feeding device 6 shown in FIG. 1, and is a partially enlarged cross-sectional view of the vicinity of the connection points with the vapor inlet pipe 22 and the vapor outlet pipe 25. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Terminology used in the embodiments] The main terms used in the embodiments correspond to the following elements of the drain recovery system according to the present disclosure.

[0017] Steam Use System 1: Drain Recovery System Drain header 5...middle area Liquid pressure transfer device 6: Drain pressure transfer means Connection portion of the liquid pumping device 6 with the piping 15...inlet portion Connection portion of the liquid pumping device 6 with the piping 16...outlet portion Pipe 19: Drain pumping passage A connection portion between the vapor introduction pipe 22 and the liquid pressure-feeding device 6. A connection portion between the vapor outlet pipe 25 and the liquid pressure-feeding device 6. Drain reservoir 40...retention area Check valve 43: Check valve Valve chest 61: Storage space Float 62...Detection unit Orifice member 69: Discharge amount control means Pressure level L1: Standard pressure amount Steam...Drive fluid

[0018] [First embodiment] A first embodiment of a drain recovery system according to the present disclosure will be described using as an example a steam using system 1. The steam using system 1 is a system that transfers steam generated in a boiler to various steam using devices and performs predetermined processing in each steam using device, recovers drain (condensate) generated from the steam and supplies it to the boiler, and generates steam again from the recovered drain by recycling it through reflux.

[0019] (Explanation of the overall configuration of the steam using system 1) First, the overall configuration of the steam using system 1 will be described. Fig. 1 is an overall block diagram of the steam using system 1. As shown in Fig. 1, water is supplied to a boiler 3 from a water supply tank 2 through a pipe 11. The boiler 3 heats the supplied water to generate steam, and this steam is taken into a steam header 4 through a pipe 12. The taken-in steam is then branched in the steam header 4 and given to a steam using device 31 through a pipe 13.

[0020] In the steam-using device 31, drain is generated as steam is used, and a pipe 14 is connected to the bottom of the steam-using device 31, and the generated drain flows downstream through the pipe 14. A steam trap 32 is installed in the pipe 14. This steam trap 32 is an automatic valve that opens and closes according to the amount of drain that flows into the internal valve chest.

[0021] A drain header 5 is disposed downstream of the steam trap 32, and the downstream end of the piping 14 is connected to this drain header 5. An inlet pipe 15 is connected to the bottom of the drain header 5, and the downstream end of this inlet pipe 15 is connected to the liquid pressure-feeding device 6.

[0022] The liquid pumping device 6 is a condensate pumping device that pumps condensate stored in an internal valve chamber 61 using steam pressure as a driving source. A float 62 fixed to the tip of a float arm 63 is disposed in the valve chamber 61, and the float 62 rises or falls depending on the amount of condensate stored. The float arm 63 is rotatable around a rotation shaft 63a, and as the float 62 rises or falls, the float arm 63 rotates up and down around the rotation shaft 63a. An outflow pipe 16 is connected near the bottom of the liquid pumping device 6, and the downstream end of the outflow pipe 16 is connected to the water supply tank 2.

[0023] A check valve (not shown) is built into the connection between the liquid pumping device 6 and the inlet pipe 15, allowing only the flow of drain from the upstream inlet pipe 15 toward the valve chamber 61. A check valve (not shown) is built into the connection between the liquid pumping device 6 and the outlet pipe 16, allowing only the flow of drain from the valve chamber 61 toward the downstream outlet pipe 16.

[0024] An exhaust pipe 21 that is open to the outside is provided on the top surface of the liquid pressure-feeding device 6. A steam inlet pipe 22 is connected to the upper side wall of the liquid pressure-feeding device 6, and high-pressure driving steam is supplied from this steam inlet pipe 22 toward the valve chamber 61. A steam outlet pipe 25 is connected below the steam inlet pipe 22.

[0025] 2 is a partially enlarged cross-sectional view of the liquid pressure-feeding device 6, and is a partially enlarged cross-sectional view of the vicinity of the connection points with the steam inlet pipe 22 and the steam outlet pipe 25. An air intake valve 70 for opening and closing the communication between the valve chamber 61 and the steam inlet pipe 22 is provided at the top of the liquid pressure-feeding device 6.

[0026] Air inlet valve 70 comprises a valve case 71, a cylindrical screen 72, an air inlet valve body 73, and a lifting rod 74. A through hole 71a is formed in the interior of valve case 71 along the vertical direction, and the upper opening of this through hole 71a constitutes air inlet valve port 76. The lower end of through hole 71a opens toward valve chamber 61 of liquid pressure-feeding device 6.

[0027] The space above air inlet valve port 76 communicates with steam introduction pipe 22, and a mesh cylindrical screen 72 is placed in this space. Air inlet valve body 73 is provided within cylindrical screen 72. Air inlet valve body 73 is a spherical steel ball, and is located above air inlet valve port 76. Air inlet valve body 21 is guided by cylindrical screen 72 and is positioned so that it can freely reciprocate up and down (in the directions of arrows 91 and 92).

[0028] Under normal conditions, the intake valve element 73 descends in the direction of arrow 92 due to its own weight and the pressure of the high-pressure driving steam supplied from the steam inlet pipe 22, contacting the intake valve port 76 and closing the intake valve 70. This valve closure prevents the high-pressure driving steam from the steam inlet pipe 22 from flowing into the valve chest 61.

[0029] An elevator rod 74 is disposed in the through-hole 71a in the valve case 71. The thickness of this elevator rod 74 is sufficiently smaller than the inner diameter of the through-hole 71a, and both thickness surfaces are configured as flat surfaces. Therefore, a sufficient space is secured between the thickness surface of the elevator rod 74 and the inner surface of the through-hole 71a, and this space is configured as a flow path for high-pressure driving steam.

[0030] The tip 74a of the lifting rod 74 is formed as a thin, cylindrical bar, and when the lifting rod 74 rises in the direction of arrow 91, the tip 74a protrudes upward from the air intake valve port 76, pushing up the air intake valve body 73 and opening the air intake valve 70. A connecting shaft 74b protruding laterally is provided at the lower end of the lifting rod 74, and this connecting shaft 74b is connected to a sub-arm 75. The sub-arm 75 is swingable about a swing shaft 75a and is connected to the float arm 63 (Figure 1) described above by a link mechanism. Note that in Figure 2, the air intake valve body 73, lifting rod 74, and sub-arm 75 are shown as a side view rather than a cross-sectional view.

[0031] 1 is also connected to a pipe 17, and the downstream end of this pipe 17 is connected to a heat exchanger 41. The heat exchanger 41 is a device that exchanges heat between the re-evaporated steam in the drain header 5 and cold water to discharge hot water. The bottom of this heat exchanger 41 is connected to a pipe 18 equipped with a steam trap 42, and the drain generated from the heat exchanger 41 flows into the pipe 18. A check valve 43 is provided downstream of the steam trap 42.

[0032] The downstream end of the pipe 18 is connected to a drain reservoir 40. The drain reservoir 40 is configured to retain a certain amount of drain discharged from the heat exchanger 41. The upstream end of the pipe 19 is connected to a lower part of the drain reservoir 40, and the downstream end of the pipe 19 is connected to the drain header 5. The downstream end of the steam outlet pipe 25 is connected to an upper part of the drain reservoir 40. For example, a relatively small tank can be used as the drain reservoir 40. Note that a pipe having a larger diameter than the pipes 18 and 19 may also be used as the drain reservoir 40.

[0033] (Explanation of the operation of the steam using system 1) Next, the operation of the steam using system 1 will be described. The boiler 3 receives water from the water supply tank 2, heats the water, generates steam, and supplies it to the steam using device 31 through the piping 13. The steam using device 31 uses the provided steam to, for example, heat-treat an object. The steam used in the steam using device 31 condenses due to heat release and heat exchange with the object during the heat treatment, and drainage is generated from the steam.

[0034] The steam trap 32 provided in the piping 14 automatically opens or closes depending on the amount of condensate flowing down from the steam-using device 31, allowing the condensate to flow appropriately toward the drain header 5. The condensate that has flowed into the drain header 5 flows into the valve chest 61 of the liquid pressure-transfer device 6 via the inlet pipe 15. The amount of condensate flowing into the valve chest 61 increases over time, but the air and steam inside the valve chest 61 are mainly discharged from the exhaust piping 21 to the outside or to the drain header 5, so the condensate flows into the valve chest 61 smoothly.

[0035] The float 62 rises according to the amount of condensate that has flowed into the valve chamber 61, and the float arm 63 also rotates about the rotation shaft 63a. This rotation of the float arm 63 is transmitted to a link mechanism (not shown) connected to the float arm 63. Then, when the amount of condensate stored in the valve chamber 61 reaches the pumping level L1, the link mechanism performs a snap operation, causing the sub-arm 75 connected to the link mechanism to suddenly rotate counterclockwise in FIG. 2.

[0036] The rotation of sub-arm 75 is transmitted via connecting shaft 74b to lifting rod 74 of air inlet valve 70, causing lifting rod 74 to rise in the direction of arrow 91. As a result, tip 74a of lifting rod 74 pushes up air inlet valve body 73, opening air inlet valve port 76. With air inlet valve port 76 open, high-pressure driving steam that has been introduced through steam inlet pipe 22 flows from air inlet valve port 76 through through-hole 71a of valve case 71 and into valve chest 61.

[0037] When high-pressure driving steam flows into the valve chamber 61, the pressure inside the valve chamber 61 rises, and the drain stored inside is pushed out into the outflow pipe 16. This drain then passes through the outflow pipe 16 and is supplied to the water supply tank 2, and the drain generated from the steam is returned to the water supply tank 2.

[0038] The heat exchanger 41 converts cold water into hot water using steam, and generates drain according to the drain heat exchange amount. The drain flowing out from the heat exchanger 41 passes through a steam trap 42 and a check valve 43, flows down the pipe 18, and flows into a drain reservoir 40. As shown in FIG. 1, the drain reservoir 40 is located at a lower position than the drain header 5, the liquid pressure-feeding device 6, and the steam outlet pipe 25.

[0039] In this embodiment, the downstream end of the steam outlet pipe 25 is connected to the top of the drain reservoir 40, and part of the high-pressure driving steam introduced into the valve chamber 61 of the liquid pressure-feeding device 6 is used to pressure-feed the drain accumulated in the drain reservoir 40 toward the drain header 5. That is, when the air inlet valve 70 of the liquid pressure-feeding device 6 is opened and high-pressure steam is introduced to increase the pressure in the valve chamber 61, part of the high-pressure driving steam is supplied to the drain reservoir 40 through the steam outlet pipe 25, and the drain accumulated in the drain reservoir 40 is pressure-feed toward the drain header 5 through the piping 19 all at once.

[0040] A check valve 43 is provided in the pipe 18, which allows fluid to flow only from upstream to downstream in the pipe 18 and prevents backflow from downstream to upstream. Therefore, the high-pressure driving steam supplied to the drain reservoir 40 through the steam outlet pipe 25 does not flow back through the drain reservoir 40 toward the heat exchanger 41.

[0041] The drain pressure-fed through the pipe 19 flows into the drain header 5, where it joins with the drain discharged from the steam-using device 31 and flows into the liquid pressure-fed device 6. Then, the liquid is returned to the water supply tank 2 according to the pressure-fed function of the liquid pressure-fed device 6.

[0042] Here, the amount of drain in drain reservoir 40 that is pumped through piping 19 to drain header 5 at one time (the combined amount of drain in drain header 5 or discharged from steam-using device 31 and the amount of drain in drain reservoir 40) is less than the amount of drain indicated by pumping reference level L1 in valve chamber 61 of liquid pumping device 6. Therefore, excessive flow of drain from drain header 5 into valve chamber 61 of liquid pumping device 6 can be prevented.

[0043] The high-pressure driving steam used to pump out the drain accumulated in the drain sump 40 flows together with the drain through the pipe 19 into the drain header 5, where it condenses and turns into drain. Therefore, the drain generated from the driving steam is also returned to the water tank 2 by the liquid pumping device 6 and is reused.

[0044] The liquid pressure-feeding device 6 repeatedly opens and closes the air intake valve 70 in response to the rising or falling of the float 62. Therefore, driving steam is intermittently supplied to the drain reservoir 40 from the steam outlet pipe 25, and the drain remaining in the drain reservoir 40 is appropriately sent to the drain header 5. In this way, the drain remaining in the drain reservoir 40 is pressure-fed through the piping 19 without using multiple pumps or the like, so that the drain can be collected from multiple tanks without complicating the device configuration.

[0045] If the amount of driving steam drawn from the valve chest 61 to the steam lead-out pipe 25 is greater than necessary, the pressure in the valve chest 61 may not rise significantly even when the intake valve 70 opens. In this case, the original pumping function of the liquid pumping device 6, which is to pump the drain in the valve chest 61 through the outflow pipe 16 to the water tank 2, is impaired.

[0046] 2 may be provided at the connection point between the liquid pressure-feeding device 6 and the steam outlet pipe 25. This orifice member 69 has an orifice (throttling flow path) formed by a flow path with a small inner diameter, and the amount of steam that is discharged is restricted to a small amount according to the size of the inner diameter.

[0047] This allows a sufficient amount of steam to be led to the steam lead-out pipe 25 to pressure-feed the drain remaining in the drain reservoir 40 toward the drain header 5 without impeding the pumping function of the liquid pumping device 6 that pumps the drain inside the valve chamber 61 to the water supply tank 2. Note that the amount of steam led to the steam lead-out pipe 25 can be easily adjusted by replacing the orifice member 69 with one having a different inner diameter.

[0048] [Other embodiments] In the above-described embodiment, examples are given for each of the intermediate region, inlet section, storage space section, outlet section, detection section, driving fluid, introduction section, drain pressure-feeding means, pressure-feeding reference amount, drain pumping flow path, retention region, outlet section, check valve, and outlet amount control means, but these are merely examples, and different configurations can also be adopted for each.

[0049] That is, for example, in the above-described embodiment, a float-type liquid pressure-feeding device 6 incorporating a float 62 (detection unit) was exemplified as the drain pressure-feeding means, but an automatic valve other than a float type, etc., can also be used as the drain pressure-feeding means. Also, in the above-described embodiment, steam was used as the driving fluid, but air can also be used instead.

[0050] Furthermore, in the above-described embodiment, an example has been shown in which the steam introduction pipe 22 (introduction section), the steam discharge pipe 25 (discharge section), the inlet pipe 15 (inlet section), and the outlet pipe 16 (outlet pipe) are connected to the liquid pressure-feeding device 6 (drain pressure-feeding means) in this order from the top, but they may also be connected in a different positional relationship.

[0051] Furthermore, in the above-described embodiment, the drain header 5 is exemplified as the intermediate region, but other configurations may be used as long as they are regions that combine drains flowing in from a plurality of flow paths.

[0052] In the above-described embodiment, the pipe 19 through which the drain flows down from the heat exchanger 41 is exemplified as the drain pumping passage, but any other passage may be used as long as it has a drain retention area located vertically below the intermediate area. Furthermore, in the above-described embodiment, an example is shown in which a portion of the high-pressure driving steam (driving fluid) introduced into the liquid pumping device 6 (drain pumping means) is supplied through the steam outlet pipe 25 (outlet portion) to a point just before the drain reservoir 40 (retention area), but a portion of the driving steam may be supplied to a different position as long as the configuration is such that the drain retained in the drain reservoir 40 (retention area) can be pumped.

[0053] Furthermore, in the above-described embodiment, the orifice member 69 is exemplified as the discharge amount control means, but other shapes and structures may be used as long as they control the discharge amount of driving steam (driving fluid) discharged from the liquid pressure-feeding device 6 (drain pressure-feeding means) to the steam discharge pipe 25 (discharge section). Note that the above-described embodiments may be arbitrarily combined to form new embodiments. [Explanation of symbols]

[0054] 1: Steam using system 5: Drain header 6: Liquid pressure transfer device 15, 16, 18: Piping 22: Steam inlet pipe 25: Steam outlet pipe 40: Drain reservoir 43: Check valve 61: Valve chamber 62: Float 69: Orifice member L1: Pressure level

Claims

1. An intermediate area that takes in the drainage flowing from upstream to downstream and discharges it to the downstream side. a drain pressure-feeding means having an inflow portion that takes in the drain discharged by the intermediate region from the upstream side, a storage space portion that stores the drain taken in by the inflow portion, an outflow portion that discharges the drain stored in the storage space portion to the downstream side, a detection portion that detects the amount of drain stored in the storage space portion, and an introduction portion that introduces a high-pressure driving fluid toward the storage space portion, wherein when the detection portion detects that the amount of drain stored in the storage space portion has reached a predetermined pressure-feed standard amount, the drain pressure-feeding means opens the introduction portion and introduces the high-pressure driving fluid into the storage space portion, thereby pressure-feeding and discharging the drain stored in the storage space portion from the outflow portion; a drain pumping flow path in which drain flows from upstream to downstream and whose downstream end is connected to the intermediate region, the drain pumping flow path having a drain retention region located vertically below the intermediate region; A drain recovery system comprising: the drain pressure-feeding means is formed with a discharge portion for discharging the high-pressure driving fluid introduced into the storage space, When the high-pressure driving fluid is introduced into the storage space, the driving fluid is discharged from the discharge portion and supplied toward the stagnation region of the drain pumping channel, thereby pumping the drain that has been stagnated in the stagnation region toward the intermediate region. A drain recovery system characterized by:

2. 2. The drain recovery system according to claim 1, the maximum amount of drain remaining in the retention area is less than the reference amount of drain pressure-fed in the storage space of the drain pressure-fed means; A drain recovery system characterized by:

3. In the drain recovery system according to claim 1 or 2, a check valve for preventing backflow of the drain from downstream to upstream, the check valve being disposed upstream of a portion where the driving fluid is supplied toward the retention region, in the drain pumping passage; A drain recovery system characterized by:

4. In the drain recovery system according to claim 1, claim 2 or claim 3, The outlet portion of the drain pressure-feeding means is provided with an outlet amount regulating means for regulating the amount of the driving fluid under high pressure that is discharged. A drain recovery system characterized by:

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