JPS6031960B2 - Drain collection method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-temperature drain recovery method and apparatus for removing and reusing drain generated in equipment that uses steam, such as a dryer of a paper manufacturing machine.

Conventionally, in order to remove drain generated from equipment that uses steam, a nozzle is installed in a circulation system equipped with a pump, the drain is sucked using the negative pressure generated by the jet from the nozzle, and the sucked drain is transferred to the circulation path. Attempts have been made to condense the condensed water through an air-cooled pipe and discharge it from a discharge port provided in the middle of the circulation path, before pumping it into a high-pressure system such as a boiler. In order to prevent the drop, it is necessary to convert re-evaporation caused by pressure fluctuations in the drain into condensation and condensation, and to condense and condense the steam sucked in when the steam reaches the drain inlet passage. Drains must be operated with constant circulation, so fluctuations in the drain can cause a drop in the efficiency of the jet pump and boiler.Furthermore, there are problems with thermal efficiency, making operation management complicated, and operating conditions are not always satisfied. In addition, the on-site installation work required a lot of incidental work and adjustments were time-consuming, which tended to cause disadvantages when used as equipment.

The present invention provides a drain recovery system that accurately eliminates these conventional drawbacks, minimizes the amount of heat discharged outside the system, and reuses it effectively, resulting in a high scarlet heat regeneration rate and remarkable thermal economy. The purpose is to try.

Another object of the present invention is to provide a useful system that is easy to operate stably, greatly improves cycle efficiency, and can be operated continuously under the best conditions with the function of a jet pump for drain suction.

Furthermore, it is an object of the present invention to provide a device that is easy to manufacture, simplifies on-site construction work when systematized, and at the same time is highly accurate and can significantly reduce equipment costs and operating costs.

The present invention is designed to suck and send out the drain of steam equipment such as a dryer that uses steam from a boiler by the depressurizing effect of the water ejected by the jet of a jet pump, further condense in the sending process, and remove all or part of this condensed water. In a system where the boiler feed water is circulated to the boiler and used as jet water for the jet pump, the flow rate of the boiler feed water flowing through the closed cycle line between the dryer and the boiler is controlled by the boiler liquid level or pressure detection, and the surplus is This is a drain recovery method in which the drain is distributed to equipment other than the poller and recirculated.

Further, as one of the important features of the present invention, a flow control valve is provided in the closed cycle line between the dryer and the boiler as an apparatus for implementing the method, and this flow control valve is connected to a liquid level or pressure detector provided in the boiler. a bypass line with a valve in the closed cycle line between the dryer and the boiler, and a piping system for recirculation through equipment other than the boiler. The goal is to create a drain recovery device that is An embodiment of the present invention will be described with reference to the drawings. A boiler 1 and a dryer 2, which is a steam-using device, are connected by a steam pipe 3 so as to utilize steam from a boiler 1, which is a steam generation source that uses steam from a boiler 1. The pipes 4 and 5 which are connected to each other and which circulate the drain generated in the dryer 2 to the boiler are provided with a jet pump 6 that sucks and sends out the drain, and the drain is sucked and sent out by the depressurizing action of the water jetted by the jet nozzle of the jet pump 6. The condensed water is further condensed in the delivery process, and all or part of this condensed water is circulated to the boiler and used as jet water for the jet pump, and drain transfer between the dryer 2 and the boiler 1 is carried out. A flow rate control valve 7 is provided in the piping 5 serving as a cycle line, and this flow rate control valve 7 is connected to a liquid level or pressure detector 8 provided in the boiler via a control mechanism 10 including a transmitter 9. A bypass line 15 with a valve 17 is provided in the closed cycle line between the dryer 2 and the boiler 1, and this is connected to a device other than the boiler 1, such as another boiler 11 in the example shown in FIG. drain tank 12,
It can also be connected to a drain header 13 or a head tank 14, and in any case is provided as a selectively recirculated piping system.

As shown in FIG. 2, the jet pump 6 is equipped with an injection nozzle 62 facing the drain intake port 61 and a venturi 65 with a closed opening 66 facing the injection nozzle. - Outflow passage 7
0 and a conduit 64 with heat radiation fins 68 are connected to a suction port of a pump 63 driven by an electric motor 71 through a taber pipe 67, and the discharge port of this pump 63 is connected to the injection nozzle 62. A passage 70 connects to the pump outlet via a separate tank 19 and a lotus tube 20.
6 has a lotus shape and is connected to the piping 5 and the bypass piping 15. In this case, there is an injection nozzle 62 in the circulation conduit 64.
In the drain sucked from the drain intake pipe port 61 at the position shown in FIG. The heat is dissipated and condensed by the fins 68, and the liquid passes through the pump 63 together with the remaining liquid portion, becoming a jet at the intake pipe opening 61, which acts to reduce the pressure in this portion. In addition, the pressure at the position facing the passage 7, that is, the pressure at the discharge port, is higher than the pressure at the position of the nozzle 62 facing the intake pipe port 61, and the liquid tends to increase in the circulation path due to drain suction. Suction is performed at the intake port, and as a result, excess liquid in the circulation path is discharged from the drain outflow passage 70 on the high pressure side. In small boilers, water is supplied only by pressure at the discharge port, and in large boilers, a suitable feed pump is connected to the boiler and the passage 70.
For example, between the connecting pipe 20 and the boiler 1, the passage 7
It facilitates suction from 0. In addition, although the passage 70 may be contaminated with gas such as water vapor, this is separated and removed by the drain header 13 so that only the liquid part is sent to the boiler 1.

In the specific example shown in FIG. 1, two boilers 1 and 11 are installed and connected to a plurality of dryers 2, and when there is a surplus in the drain supply shed to boiler 1, the drain is distributed to other boilers 11. It is designed to be highly efficient and safe to operate. In this case, piping is installed so that the drain from each of the plurality of dryers 2 is introduced into the jet pump 6 via a drain header 13, and a valve 24 is provided in the piping 4 to bypass this valve 24. A bypass pipe 22 may be provided to connect the boilers 1 and 1 via a head tank 14 and a pipe 25 with pumps 21 and 21.
1 are connected to each other. Note that the valve 23 is the valve 2
This can be omitted when a three-way valve integrated with 4 is used to enable switching, or when distribution control is performed by adjusting the valve 24 using a bypass pipe 22 that bypasses the valve 24.
Further, the bypass line 15 may be branched from the pipe 5, but it is reasonable to connect it to one or more boilers 1, which are provided in a plurality, via a drain header 16. The bypass line 15 and the piping 5 of the closed cycle line are connected with a lotus tube 26 from a chemical injection device 27 for preventing pollutant corrosion, and the chemical liquid can be injected into the tube 16 from the pump outlet if necessary. You can also do it. In the figure, 18 is a liquid level detector, 28 is a condenser, 29 is a cooling water pump for mechanical seals, 3 rivers is a cooling water flow meter, 31 is a cooler, and 32 is a drain pipe connected to a soft water tank 33 or a drain bit. Become. A boiler detector 34 automatically controls a valve 35 provided in a pipe 25 including a bypass pipe 34.

A bypass pipe 36 has a safety valve 37 and is provided in the piping 5 and the bypass line 15, respectively, as necessary.

38 may be provided in the steam pipe 3 for steam distillation.

39 is a high temperature drain pipe circuit, 40 is a cooling water pump circuit, 41 is a chemical injection pump circuit, 42 is an alarm circuit, 43
4 is a water supply pump circuit for the boiler 1, 44 is a water supply pump circuit for the boiler 11, and 45 is an indicator light circuit.

Although the detectors 8 and 18 are liquid level detectors, they may be constructed in place of pressure detectors, and the transmitter 9 is not limited to a differential pressure transmitter, but may be any other electrical device.

In addition, it is effective to incorporate the control mechanism 1 into a pump unit including the jet pump 6 and piping with each valve, and as shown in FIG. The water pump 29 and the water supply pump can be automatically controlled either unifiedly or individually. Further, as the drain flow rate regulating valves 7 and 17, electromagnetic valves or other automatic valves are used.

Thus, the steam generated in the boilers 1 and 11 is sent to the dryer 22 for drying, and the drain generated at this time is sucked by the negative pressure of the jet pump 6 through the piping 4. , the dryer 2 can be quickly sucked in without any drain remaining inside the dryer 2, and can be operated at high efficiency at all times without reducing the thermal efficiency of the dryer 2. Moreover, the drain, which has a relatively high temperature, can be brought to the boiler 1 with the piping 5 of the closed cycle line on its way. The heat loss in boiler 1 is reduced as much as possible, and saturated water at the same pressure or a drain close to it can be used for water supply to the boiler and 11, which improves thermal efficiency. 10
In addition to increasing the flow rate by ~30%, the detector 8 detects the state inside the boiler 1, for example, changes in the liquid level, and the transmitter 9 and control mechanism 10 control the flow rate control valves 7, 17 of the piping 5 and/or bypass line 15. The boiler 1 and boiler 15 are constantly operated at high performance by adjusting and distributing the amount of reflux in the drasso, minimizing the heat loss of the boilers 1 and 15, and enabling stable control and safe continuous operation. It is something that can be done. In the specific example shown in FIG. 4, the steam generated in one boiler 1 is supplied to a plurality of dryers 2, 2, etc. for drying work, and the bypass line 15 is connected to bypass the jet pump 6. For example, the pipe 4 is branched from the pipe 4, connected to the elevated drain tank 12 via a flash tank 46, and further has a water supply pipe 49 with a water supply adjustment valve 47 and a water supply pump 48. It is arranged so that it merges with 5. In this case, instead of or in addition to the bypass line 15, a branch pipe 50 with a valve 51 may be provided in the pipe 5 and connected to the pipe 4, the drain header 13, or the suction side line of the jet pump 6 to be attached as a circulation system. . In this case, the detector 8 in the boiler may be set to control the valve 17 and/or the feed water regulating valve 47 in the bypass line 15. The present invention allows the boiler that is the steam generation source and the equipment that uses the steam from this boiler to perform extremely well, allowing for highly efficient operation, accurate heat recovery from the drain, and a high waste heat regeneration rate, making it suitable for use as a system. A jet system that can significantly increase cycle efficiency and has good thermal efficiency because it uses saturated water at the same pressure or a drain close to it for water supply to the boiler, and the water supply is also adapted to the operating conditions of the boiler. It is possible to ensure safe operation of the boiler without causing damage to the pump or deterioration of its function, which simplifies operational management in terms of maintenance and safety.Furthermore, it is easy to operate, reduces running costs, and is relatively labor-intensive. Time-consuming installation of equipment can be simplified; for example, on-site installation work can be shortened to about 1'3 compared to conventional methods, and complicated adjustments and inspections can be made easier, resulting in more efficient work. This feature allows the control mechanism to be configured in one place, making the device extremely compact and easy to handle, making it extremely economical in terms of operation and maintenance costs.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1 is a system diagram, and FIG.
The figure is a cutaway side view of the jet pump, FIG. 3 is an electric circuit diagram, and FIG. 4 is a system explanatory diagram of another embodiment. 1...Boiler, 2...Dryer, 3...
...Steam pipe, 4,5...Piping, 6...
...Jet pump, 7...Flow rate control valve, 8.
...Detector, 9...Transmitter, 10...
・Control mechanism, 11... Boiler, 12...
・Drain tank, 13...Drain header, 14...
...Head tank, 15.../Gui/Gusliso, 16...Pump outlet header, 17...Valve, 18...
...Liquid level detector, 19...Separate tank,
20...Lotus tube, 21...Pump, 22...Bypass pipe,
23, 24... Valve, 25... Piping, 26...
...Lotus tube, 27...Medicine injection device, 28...
Condenser, 29... Cooling water pump, 30...
Cooling water flow meter, 31...Cooler, 32...
Drain pipe, 33... Soft water tank, 34...
・Boiler detector, 35... Valve, 36...
・Bypass pipe, 37...Safety valve, 38...
...Steam crab, 39...High temperature drain pipe circuit, 40...Cooling water pump circuit, 41...
・Medical solution injection pump circuit, 42...Alarm circuit, 43,
44...Water pump circuit, 45...Indicator light circuit, 46...Flash tank, 47...
...Water supply adjustment valve, 48...Water supply pump, 49...
... Water supply pipe, 50 ... Branch pipe, 51 ... Valve, 61 ... Drain intake port, 62 ... Nozzle, 63 ...
...Pump, 64...Circulation conduit, 65...
Venturi, 66...opening, 67...suction looper pipe, 68...fin, 70...passage,
71...Electric motor. Figure 1 Figure 4 Figure N Rudder of ship chart

Claims (1)

[Scope of Claims] 1. After the drain is collected in a drain header from a plurality of steam devices such as a dryer that utilizes steam from a boiler, the drain is sucked into an ejector suction section by the depressurizing effect of water jetted by a jet of a jet pump, and the discharge process is as follows. In this system, the boiler feed water flowing through the closed cycle line between the dryer and the boiler is further condensed and all or part of this condensed water is circulated to the boiler and used as jet water for the jet pump. A drain recovery method in which the flow rate is controlled by the boiler's liquid level or pressure detection, and the drain is supplied to the boiler as saturated water at the same pressure or a drain close to this pressure, and the excess drain is distributed to equipment other than the boiler and recirculated. . 2. The drain recovery method according to claim 1, wherein a school prevention chemical solution is injected and mixed into a closed cycle line between the dryer and the boiler and circulated. 3. A system in which the condensed water is distributed to a plurality of boilers using a jet pump, in which one of the boilers is operated while maintaining a set level at all times, and only the surplus drain supplied to the boiler is transferred to the other boilers. A drain collection method according to claim 1 or 2, wherein the drain collection method is controlled so that the drain is distributed and supplied to the drains. 4 A boiler and a plurality of dryers are connected via drain headers so as to utilize the steam of the boiler, and a jet pump is provided to suck and send out the drain during a cycle in which the drain of the dryer is circulated to the boiler, and the drain is connected to the jet of the jet pump. The jet pump is provided with piping for sucking in and sending out by the depressurizing action of the water jetted out, further condensing in the delivery process, and circulating all or part of this condensed water to the boiler, and a bypass pipe with a valve in the piping, and In a device that circulates water as jet water, a flow control valve is provided in a closed cycle line between the dryer and the boiler, and the flow control valve communicates with a liquid level or pressure detector provided in the boiler via a transmitter. In addition, a bypass line with a valve is provided in the closed cycle line between the dryer and the boiler, and a piping system that is recirculated via a drain tank or drain header other than the boiler is connected to the boiler or drain supply piping to the boiler. A drain recovery device characterized by being equipped with. 5. The jet pump is provided with an injection nozzle and a ventilate facing the end of the drain inflow passage, and a conduit that is continuous with the ventilium and has a drain outflow passage is connected to an inlet of a pump driven by an electric motor, and the discharge of the pump is Claim 4, wherein the outlet is connected to the injection nozzle.
Drain collection device as described in section. 6. The drain recovery device according to claim 5, wherein the closed cycle line or the bypass line is a pipe connected to a chemical injection device for boiler corrosion prevention. 7. Claim 5 or 6, wherein the transmitter is a differential pressure transmitter and is incorporated into a control mechanism that also controls the flow rate control valve, the electric motor of the jet pump, and other maintenance equipment. Drain collection device as described in section.