JPS607173B2 - Drain removal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drain removal device for recovering and removing drains from boilers, dryers of paper machines, and other steam equipment.

Generally, drain recovery involves steam supplied from a steam generation source dissipating heat within the equipment, then releasing the drain into the atmosphere using a steam trap, etc., and then recovering high-temperature drain water by returning it to the boiler using a pump or reduction device. This method is known, but since the steam is discarded in this open-to-atmosphere method, there is a limit to heat recovery, making it a small contribution to energy conservation, and there is also a problem with the pollution caused by the steam emitted.

For this reason, a nozzle is installed in the circulation path equipped with a conventional pump,
Drain removal involves sucking the drain using the negative pressure generated by the jet from the nozzle, passing the sucked drain through the air-cooled pipe in the circulation path, condensing it, and discharging it from the outlet provided in the middle of the circulation path. Attempts have been made to use a device to collect the drain directly and obtain extremely effective results. Not only will it no longer function properly, causing problems with the suction of the drain, but if the drain is no longer on the suction pipe side, steam from the suction side will leak to the discharge side, resulting in a significant drop in function, and the drop in pressure will cause the pump to fail. In addition to overloading the horsepower of the motor, this drain removal device may not perform satisfactorily if the equipment that generates the drain is located low and the drain piping slopes upward toward the drain removal device. Furthermore, the drain removal function is influenced by fluctuations in the drain pressure generated by the drain generating device, resulting in unstable operation. SUMMARY OF THE INVENTION The present invention aims to provide a device with a simple configuration and low cost that can accurately eliminate these conventional drawbacks, realize high performance of a drain removal device, and significantly improve and stabilize the drain removal ability of steam equipment.

Another object of the present invention is to provide a high-performance drain removal device that is compact and capable of reducing the load without reducing thermal efficiency, has a large cooling effect, and has a large suction capacity. . The present invention provides a jet nozzle section between the intake port and the discharge port of the drain, and includes a pump and a circulation path for jetting water from the jet nozzle section, and the negative pressure generated by the jet flow from the jet nozzle section. It has a mechanism that suctions and condenses the drain using the drain pipe, and can adjust the difference between the pressure on the suction side and the pressure on the discharge side to a certain pressure or more in the drain piping that runs to the drain intake port. It is characterized by the interposition of a pressure regulating valve.

An embodiment of the present invention will be described with reference to the drawings. The outlet of the nozzle 2 is faced into the nozzle chamber 1, and a jet receiving port 3 which also serves as a venturi is formed opposite to the outlet of the nozzle 2. The discharge port 7 of the pump 6 communicates with the nozzle 2 via a return waterway 8 to form a circulation path.

A drain inflow pipe 9 is connected to the nozzle chamber 1, and a drain outflow pipe 10 is connected to the return waterway 8 near the pump discharge port 7.
is connected. Then, an automatic pressure regulating valve 16 is interposed and provided on the discharge side of the drain outflow piping 10, that is, the drain piping, and the difference between the pressure of the suction side piping 9 and the pressure of the discharge side piping 10 is adjusted to a certain pressure or more. It has a configuration that can be adjusted so that For example, when the pressure in the piping 10 on the discharge side is lower than that in the piping 9 on the suction side, or when the pressure difference between the two becomes less than lk9/2, the automatic pressure control valve 16 is operated to increase the pressure on the discharge piping side. The driving pressure increases and the nozzle suction effect makes it easier to suction the drain. Furthermore, even if the drain is no longer on the suction pipe side, a constant pressure is maintained within the pump, and the suction side and discharge side are cut off, so that steam on the suction side does not leak to the discharge side. That is, in a centrifugal pump, when 20% or more of steam is sucked in by volume, the discharge pressure becomes 0.
In this way, when the discharge side is the atmosphere and the suction side is at atmospheric pressure or higher, steam on the suction side will leak to the discharge side, but this can also be prevented by the pressure regulating valve 16 in this case. The pressure regulating valve 16 may be opened and closed manually, but it may also be automatically operated by pressure detectors 17, 17' provided at least in either the discharge side piping 10 or the suction side piping 9. can. Also, the pressure detector 17,1
7' via a controller 30 including a calculator so that automatic operation can be performed when the pressure difference between the discharge side and the suction side fluctuates from a set value. It is also possible to choose to indirectly derive a result similar to pressure sensing using temperature sensing. Further, a warning buzzer or a warning lamp may be incorporated and set as necessary, in combination with these or alone. For example, if the discharge pressure of the discharge side piping 10 is higher than the inlet pressure of the suction side piping 9, if the pressure difference between the two decreases due to an increase in drain pressure, an excessive amount will be delivered due to the function of the pump 5, and the drain amount An excessive discharge amount when increasing due to a change in the pump motor horsepower will cause an overload of the pump motor horsepower, but the pressure regulating valve 16 can prevent the pressure difference from decreasing and keep the discharge amount constant, thereby reducing the motor horsepower. It will also function to prevent overload. The drain inlet pipe 9 forms a drain reservoir with a riser 11, and this drain reservoir also has an inlet 12 and an outlet 13 for a cooling liquid such as cooling water or cold soot. By installing a heat exchanger consisting of a coolant chamber 14 or a flash tank 15, or selecting a mechanism for injecting soft water by connecting to a soft water source via piping, the drain removal function can be optimized and stabilized. It is also effective to ensure proper operation. To utilize the soft water,
Soft water used in boilers or the like may be used, but it is also possible to purge the drain and store it in a tank for use as soft water. In the figure, 18 is a heat radiation fin formed in the return waterway, and 19 is a strainer, which is provided at the intake part of the drain inlet pipe 9.

20 is a separate tank, and a drain outflow pipe 101 is interposed therebetween.

21 is a gas separator, 22 is a boiler, 23 is a flow rate control valve,
24 is a check valve, 25 is a discharge valve, 26 is a dryer, 2
7 is a steam valve, 28 is a pump motor, 29 is a cooling water source,
31 is a valve, and 32 is a water injection pipe.

When the pump 5 is operated, water is injected as a jet from the nozzle 2 through the discharge port 7 and the return channel 8/into the nozzle chamber 1, enters the suction channel 4 from the jet receiver □3, and enters the suction port 6. However, as a high-speed jet is ejected from the outlet of the nozzle 2, the pressure inside the nozzle chamber 1 decreases, and this reduced pressure causes the drain from the drain source such as the dryer 26 to be sucked through the drain inflow pipe 9.
It enters the nozzle chamber 1 and enters the circulation path along with the jet from the jet receiving port 3.

Since the circulation path operates in a full state at all times, the drain is sucked in from the drain inflow pipe 9 and condenses in the circulation path, increasing the amount of water, and this excess water is discharged from the drain outflow pipe 10 and drains. is collected directly, but when the pressure difference between the drain inflow pipe 9 on the suction side and the drain outflow pipe 10 on the discharge side becomes less than lk9', or when the pressure on the discharge side is lower than that on the suction side. The pressure regulating valve 16 is operated to correct the drop in pressure, and the pressure is adjusted to a certain level or higher, so that the jet nozzle 2 can properly perform its function and improve the drain removal effect.
Furthermore, it is possible to prevent overload of the pump motor horsepower. The present invention provides a jet nozzle section between the intake port and the discharge port of the drain, and includes a pump and a circulation path for jetting water from the jet nozzle section, and reduces the negative pressure generated by the jet flow from the jet nozzle section. In devices that use drains to suction and condensate recovery, the difference between the pressure on the suction side and the pressure on the discharge side can be adjusted to a certain pressure or higher in the drain piping that runs through the drain intake port. By installing a pressure control valve, drain can be quickly sucked and collected without remaining in the drain generation equipment, and the drain removal equipment can always operate at high performance in good condition without reducing the thermal efficiency of the equipment. At the same time, the pressure difference between the discharge side and the suction side can always be kept above a certain level, allowing the jet nozzle to function properly, making drain suction easy and accurate, and ensuring that the steam on the suction side is There is no leakage on the discharge side, which prevents functional deterioration. It also prevents the pressure difference from decreasing and keeps the discharge amount constant, which prevents the pump motor horsepower from overloading and allows safe operation. This increases the amount of drain suction, improves the drain discharge capacity, and improves equipment performance. It also has great advantages in terms of installation and maintenance, and the drain discharge pressure can be increased, making drain transport easier. It is useful for heat recovery, and it can also be applied to drain recovery from a wide range of steam-using equipment, allowing drain discharge and reduction use, making it a closed system, improving heat management and drain heat recovery. Energy saving can be easily achieved, contributing to economical operation, and the drain removal device can be operated stably and efficiently.

[Brief explanation of the drawing]

The drawing is a system explanatory diagram showing an embodiment of the present invention. 1... Nozzle chamber, 2... Nozzle, 3... Jet socket, 4... Suction channel, 5... Pump, 6...
...Suction port, 7...Discharge port, 8...Return waterway, 9...Drain inflow pipe, 10...Drain outflow pipe, 11...Rise Pipe part, 12・
...Entrance, 13...Exit, 14...
・・Cooling liquid chamber, 15・・・Flash tank, 16・
...Pressure control valve, 17, 17'...Pressure detector, 18...Radiation fin, 19...
・Strainer, 20...Separate tank, 21...Gas separator, 22...Poiler, 23...
Flow rate control valve, 24... Check valve, 25...
・Discharge valve, 26...Dryer, 27...Steam valve, 28...Pump motor, 29...Cooling water source, 30...Controller, 31... Valve, 32... Water injection pipe.

Claims (1)

[Scope of Claims] 1. A jet nozzle section is provided between the intake port and the discharge port of the drain, and a pump and a circulation path are provided for jetting water from the jet nozzle section, and the negative water generated by the jet flow from the jet nozzle section is provided. In devices that utilize pressure to suction and condensate the drain, the pressure in the drain piping that communicates with the drain intake port is such that the difference between the pressure on the suction side and the pressure on the discharge side can be adjusted to a certain level or higher. A drain removal device characterized by having a control valve interposed therein. 2. The drain removal device according to claim 1, wherein the pressure regulating valve in the drain pipe is provided on the discharge side, which is a drain outflow pipe. 3. The drain removal device according to claim 1 or 2, wherein the pressure regulating valve is an automatic pressure regulating valve and is operated when the pressure on the discharge side is lower than the pressure on the suction side. 4. The drain removal device according to claim 2 or 3, wherein the pressure regulating valve is operated by detecting the discharge side pressure. 5. The drain removal device according to claim 2 or 3, wherein the pressure regulating valve has a computing unit connected to pressure detectors provided on the discharge side and the suction side. 6. The drain according to claim 2 or 3, wherein the pressure regulating valve is operated by detecting a temperature difference between a suction side and a discharge side in drain piping including a pump and a jet. removal device.