JPS6225924B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drain recovery device that recovers steam drain and supplies it to a boiler as high-temperature water, and uses a strong drain suction force to remove drain obstructions that occur during recovery. purpose.

The details of the present invention will be explained below based on an illustrated embodiment. 1 is a drain recovery tank, 2 is a hot water pump, and the hot water pump 2 is connected to the lower part of the drain recovery tank 1 and is inside the tank 1. It is designed to suck in and discharge hot water. A mixer 3 mixes hot water from the hot water pump 2 and drain, and is composed of an ejector 4 and a mixing pipe 5. The ejector 4 uses hot water discharged from the hot water pump 2 as a driving liquid, and has an injection nozzle 6 directly connected to a discharge pipe 7 of the hot water pump 2, and a suction port 8 connected to drains from various steam devices. A recovery pipe 9 is connected. Further, the mixing tube 5 is attached to the ejector 4 so as to wrap around the tapered tube 10 on the discharge side of the ejector 4. Reference numeral 11 denotes a secondary ejector that sucks the mixed liquid from inside the mixing tube 5 of the mixer 3, and its suction port 1
A suction pipe 13 introduced from the mixing pipe 5 is connected to 2. This secondary ejector 11 uses a part of the hot water discharged from the hot water pump 2 as a driving liquid, and its injection nozzle 14 has a discharge pipe 7 of the hot water pump 2.
A branch pressure feed pipe 15 branched from is directly connected. A discharge part of the secondary ejector 11 is connected to the upper part of the drain recovery tank 1. Reference numeral 16 denotes a pressure chamber for storing hot water in order to send it to the boiler 17, and has a delivery port 18 to the boiler 17. A branch pressure feed pipe 1 is arranged so that a part of the hot water discharged from the hot water pump 2 constantly flows into the pressure feed chamber 16.
9, 20 to the discharge pipes 7 and 2 of the hot water pump 2.
The injection nozzles 14 of the next ejector 11 are communicated with each other. Reference numeral 21 denotes a cold water supply pipe that feeds cold water into the pressure-feeding chamber 16, and a solenoid valve 22 is provided in the middle of the pipe. Due to the operation of the sensor 23, the pumping chamber 16
It is designed to open when the internal temperature rises abnormally.

24 is a cold water supply pipe to the drain recovery tank 1,
A valve 26 that is opened and closed by a float 25 is attached to the tip. 27 is an overflow pipe of the drain recovery tank 1, 28 is a hot water delivery pipe of the pressure feeding chamber 16, 29 is a boiler feed pump connected to this hot water delivery pipe 28, 30 and 31 are testers for visually checking the condition of the drain, It is provided midway between the suction pipe 13 and the drain recovery pipe 9.

The hot water discharged from the hot water pump 2 is not only sent under pressure to the ejector 4 of the mixer 3, but also to the branch pressure pipe 15.
85% of the flow is distributed to the mixer 3 side and 85% to the branch pressure feed pipe 15 side.
10%, and 5% on the pressure feeding chamber 16 side.

In the above configuration, when the hot water pump 2 is driven, the hot water in the drain recovery tank 1 is sucked and fed under pressure to the mixer 3 through the discharge pipe 7, and the hot water is sent to the mixer 3 through the injection nozzle 6.
is sprayed from. This jet creates a suction force,
Since the drain is sucked from the drain recovery pipe 9, there is no back pressure inside the drain recovery pipe 9, which improves the operation of the steam trap and improves the thermal efficiency of various steam devices.

The drain sucked into the ejector 4 flows into the mixing pipe 5 together with the hot water jetted from the jet nozzle 6, and is stirred by the jet stream and sufficiently mixed with the hot water. This mixed liquid flows into the drain recovery tank 1 through the suction pipe 13 and the secondary ejector 11, and the injection nozzle 1 of the secondary ejector 11
By jetting hot water from 4, the suction pipe 1
Since the mixed gas is sucked from the mixer 3 and the inside of the mixer 3 becomes almost pressureless, the drain suction force inside the mixer 3 is kept at a high level, and the temperature of the mixed liquid decreases inside the mixer 3, causing it to flash. I won't.

Most of the hot water discharged from the hot water pump 2 is injected into the mixer 3 as described above, and the remaining hot water is injected into the secondary ejector 11 via the branch pressure feed pipes 15 and 19. For this reason, hot water always flows inside the pressure feeding chamber 16, and the water supply pump 29
When driven, the hot water in the pressure chamber 16 is fed into the boiler 17. If the hot water temperature in the pressure feeding chamber 16 rises abnormally (over 100°C) and is sucked into the water supply pump 29, the pump 29 will cause a water supply failure. Accordingly, since the electromagnetic valve 22 is opened and cold water is supplied into the pressure feeding chamber 16, the temperature of the hot water in the pressure feeding chamber 16 is maintained below a certain limit, and water supply failure of the pump does not occur.

As described above, this invention sucks hot water stored in a drain recovery tank and injects it into a mixer having an ejector, and the injection sucks drain and mixes it with hot water, which then pumps the drain into the drain recovery tank. Since the recovered hot water and drain are mixed together, high-temperature hot water can be obtained, and the temperature of the water supplied to the boiler can be raised to save fuel.

In addition, the mixed liquid of drain and recovered hot water in the mixer is sucked by the secondary ejector, so the inside of the mixing pipe of the mixer is always reduced to an almost pressureless state, and the mixture of drain and recovered hot water is When the recovered hot water is injected into the reduced pressure mixing pipe, its temperature drops all at once to below its boiling temperature. Therefore, even though the recovered hot water and drain are mixed, the mixed liquid is kept below the boiling temperature and does not cause flashing or noise even when sent to the recovery tank.

Furthermore, since the secondary ejector suctions the condensate, the condensate suction capacity inside the mixer is maintained at a high level, and condensate is strongly suctioned from the condensate collection pipe, which makes the steam trap work better and improves the steam thermal efficiency. do.

In addition, since cold water is automatically replenished into the pressure-feeding chamber that sends hot water to the boiler, there is no risk that the hot water in the pressure-feeding chamber will reach a higher temperature than the limit, and a defective water supply to the boiler can be prevented.

In addition, as in the illustrated example, there are a passage for directly sending hot water (branch pressure feed pipe 15) and a passage via a pressure feed chamber (branch pressure feed pipes 19, 20) between the discharge pipe of the hot water pump and the secondary ejector. When installed in parallel, even if the amount of hot water taken out from the pressure chamber changes,
The injection force of the injection nozzle of the secondary ejector is kept almost constant, and the suction force in this secondary ejector hardly changes.

[Brief explanation of the drawing]

The drawing is a block diagram of the apparatus of the present invention. 1...Drain recovery tank, 2...Hot water pump, 3...
Mixer, 4... Ejector, 9... Drain collection pipe, 11
...Secondary ejector, 16...Pressure chamber, 17...Boiler, 21...Cold water supply pipe, 22...Solenoid valve.

Claims (1)

[Claims] 1. A drain recovery tank, a hot water pump that sucks and discharges hot water in the tank, and an ejector that uses hot water from the hot water pump as a driving liquid, and the ejector sucks drain from a drain recovery pipe and converts it into the hot water. A mixer for mixing, a secondary ejector that uses part of the hot water discharged from the hot water pump as a driving liquid to suck the mixed liquid from the mixer and sends it into a recovery tank, and a hot water outlet to the boiler. A drain recovery device comprising a pressure feeding chamber which stores a portion of hot water discharged from a hot water pump, and a cold water supply pipe which feeds cold water into the pressure feeding chamber in response to a rise in temperature within the pressure feeding chamber.