JPS607175B2 - 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.

In general, drain recovery involves steam supplied from a steam generation source, which radiates heat within the equipment, then releases the drain into the atmosphere using a steam trap, etc., and then returns the high-temperature drain water to the boiler using a pump or reduction device to recover it. However, in this open-to-atmosphere type, the steam is discarded, so there is a limit to heat recovery, which contributes little 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 devices to directly collect the drain with very effective results, but the pressure difference between the discharge and suction pressures is too large. For example, if it exceeds 10k9', cavitation phenomenon will occur and the jet nozzle will not function properly, which will not only interfere with drain suction but also cause noise and make the jet discharge pressure unstable. There was a drawback that the function deteriorated significantly, the amount of tin was large, and the tailing state became uneconomical, and the drain removal function was 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 can reduce the load without reducing thermal efficiency, is compact, has a large cooling effect, and has a large suction capacity. be. 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 for suctioning and condensing the drain using the drain, and maintains a constant pressure difference between the pressure on the suction side in the drain piping connected to the drain intake and the pressure on the return waterway side of the circulation path. The present invention is characterized in that a pressure adjustment mechanism that can adjust the pressure as described above is interposed in the circulation path. 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. suction port 6 and lotus passage,
The discharge port 7 of the pump 5 communicates with the nozzle 2 via a return waterway to form a circulation path 8.

A drain inflow pipe 9 is connected to the nozzle chamber 1, and a drain outflow pipe 10 is connected to the vicinity of the pump discharge port 7 of the circulation path 8. Then, the drain outflow pipe 10, that is, an automatic pressure control valve 1 as required on the discharge side of the drain pipe.
A pressure regulating mechanism 18 is arranged to adjust the difference between the pressure of the drain inflow pipe 9 on the suction side and the pressure on the return waterway side of the circulation path 8 to a constant pressure difference. It is located inside. For example, when the pressure difference between the circulation path 8 and the drain inflow pipe 9 becomes 10 k9/min or more, the pressure detector 17 operates the motor 17' to insert the needle valve of the pressure adjustment mechanism 18 into the throttle wall 18'. By moving the body and making the circulation volume substantially smaller,
The nozzle drive pressure is optimized and the nozzle suction effect makes drain suction easy. Furthermore, even if the drain is no longer on the suction pipe side, the inside of the pump is maintained at a constant pressure, the suction side and the discharge side are cut off, and 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, the steam on the suction side, where the discharge side is atmospheric and the suction side is at atmospheric pressure or higher, leaks to the discharge pressure, but in this case, the pressure regulating valve 16
This can be prevented. The pressure regulating valve 16
Alternatively, the pressure adjustment mechanism 18 may be opened and closed manually, but it may also be automatically operated using at least the pressure detector 17. It is also possible to connect the pressure detector turtle 7 to the motor shaft 7' via a controller 30 including a computing unit so that it can be automatically operated when the pressure difference fluctuates from a set value. Alternatively, it is also possible to indirectly derive a result similar to pressure detection by detecting drain temperature, for example, at a temperature below 150°C.
Furthermore, a warning buzzer or a warning lamp may be incorporated and set as necessary, in combination with these or alone. Note that the pressure adjustment mechanism 18 uses a movable throttle resistance mechanism consisting of a needle valve that is inserted into the entrance portion formed by the throttle wall 18', but it may be replaced with a movable orifice or a throttle valve. It is also possible to use a hand-operated handle that omits the movement mechanism including ''.

Further, the drain inlet pipe 9 forms a drain reservoir with a rising pipe portion 11, and a cooling mechanism for cooling the drain is provided in this drain reservoir with 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 cooling liquid chamber 14 or a flash tank 15, or selecting and providing a mechanism for injecting soft water by connecting to a soft water source via piping, the function of drain removal can be optimized. It is also effective to ensure stable operation.

To utilize the soft water, the soft water used in a boiler 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, a strainer 19 is provided at the intake part of the drain inflow pipe 9.

20 is a separate tank with one drain outflow pipe interposed.

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, and 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 into the nozzle chamber 1 through the discharge port 7 and the circulation path 8 of the return waterway, enters the suction waterway 4 from the jet socket 3, and is sucked into the nozzle chamber 1. The water reaches the port 6 and circulates, but as a high-speed jet is ejected from the outlet of the nozzle 2, the pressure inside the nozzle chamber 1 decreases.Due to this pressure reduction, drain is sucked from the drain source such as the dryer 26 through the drain inflow pipe 9. It enters the nozzle chamber 1 and enters the circulation path 8 along with the jet from the jet socket 3.Since the circulation path 8 is always operating in a full state, the drain is sucked in from the drain inflow pipe 9 and condenses in the circulation path 8. Then, the amount of water increases, and this excess water is discharged from the drain outflow pipe 10 and the drain is directly collected, but the pressure difference between the drain inflow pipe 9 on the suction side and the drain outlet side on the circulation path 8 side is 10 kg/ or more, or when the differential pressure fluctuates greatly, operate the pressure regulating mechanism 18 to substantially correct the circulation amount and adjust so that a constant differential pressure is maintained. The jet nozzle 2 can properly perform its functions, improve the drain removal effect, and moreover properly prevent cavitation of the pump and suppress noise generation. A jet nozzle section is provided between the jet nozzle section and the discharge port, and a pump and a circulation path are provided to jet water from the jet nozzle section, and the drain is sucked by using the negative pressure generated by the jet from the jet nozzle section. In a device that condenses and recovers water, a pressure adjustment mechanism is installed in the circulation path that can adjust the difference between the pressure on the suction side of the drain piping connected to the intake port of the drain and the pressure on the circulation path side to maintain a constant pressure difference. As a result, the jet discharge pressure can be optimized, and drain can be quickly sucked and recovered 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 constant, allowing the jet nozzle to perform its proper function, making drain suction easy and accurate, preventing cavitation during operation, and reducing noise. It is possible to accurately suppress generation, perform drain collection operations properly, operate efficiently and safely, increase drain suction volume, improve drain discharge capacity and improve equipment performance. In terms of installation, maintenance, etc., it has the great advantage of shortening the length of the pump ditch and increasing the economic efficiency of the skirting condition.It also stabilizes the drain discharge pressure, facilitates drain transportation, and helps in heat recovery, and is extremely effective. It can be applied to drain recovery from a wide range of steam-using equipment and can be used for discharge and reduction, making it a closed system, making it easy to improve heat management and save energy by recovering heat from drains. It also contributes to economical operation and has the effect of allowing the drain removal device to operate stably and efficiently.

[Brief explanation of the drawing]

The drawing is a partially cutaway 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...Circulation path, 9.
...Drain inflow pipe, '0...Drain outflow pipe, 11...Rising pipe section, 12...Inlet, 13...Outlet, 14...Cooling liquid chamber , 15...
・...Flash tank, 16...Pressure control valve,
17...Pressure detector, 17'...Motor, 18
...Pressure adjustment mechanism, 18'... Throttle wall, 19... Strainer, 20... Separate tank, 21...
...Gas separator, 22...Boiler, 23...
...Flow 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 use pressure to suction drain to condense and recover, the difference between the pressure on the suction side in the drain piping that communicates with the intake port of the drain and the pressure on the return waterway side of the circulation path becomes a constant pressure difference. A drain removal device characterized in that a pressure adjustment mechanism that can adjust the pressure as described above is interposed in the circulation path. 2. The drain removal device according to claim 1, wherein the pressure regulating mechanism in the drain piping is a movable throttle resistance mechanism that can open and close the flow path of the circulation path. 3. Claim 1 or 2, wherein the pressure adjustment mechanism is an automatic needle valve, which is operated when the pressure difference between the return waterway side pressure and the suction side pressure of the circulation path is too large. Drain removal device as described in section. 4. The drain removal device according to claim 2 or 3, wherein the pressure adjustment mechanism is operated by detecting pressure on the drain suction side. 5. Claim 2, wherein the pressure adjustment mechanism has a computing unit connected to pressure detectors provided on the ejection side and the drain suction side of the jet nozzle section.
3. Drain removal device according to item 3 or item 3. 6. The drain removal device according to claim 2 or 3, wherein the pressure regulating mechanism is operated by detecting a drain temperature in drain piping including a pump and a jet. 7. Claim 4, wherein the pressure adjustment mechanism is equipped with an interlocking mechanism that can be operated to substantially reduce the amount of circulation in the circulation path, and the interlocking mechanism is a member that can be manually or automatically operated. , the drain removal device according to item 5 or 6.