JPS6025638B2 - condensate recovery pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a condensate recovery pump that pumps condensate generated in steam-using equipment or the like to a boiler or the like, and particularly relates to a pump that can discharge non-condensable gas such as air to the atmosphere.

Conventionally, a combination pump of a centrifugal pump and an ejector pump has been used as a condensate recovery pump.

Even in this type of pump, the problem of air trapping is serious, and non-condensable gases such as air must be separated and released to the atmosphere before the ejector pump.

The present invention is a condensate recovery pump that pumps condensate generated in steam-using equipment, etc. to a boiler, etc., so that air can be discharged to the atmosphere before the pump even when used in a vacuum system.

A detailed description will be given below based on the illustrated embodiment.

1 is a centrifugal pump driven by an electric motor (not shown).

2 is a circulation passage connecting the discharge port 3 and the suction port 4 of the centrifugal pump 1.

An ejector member 5 is arranged in the circulation passage 2.

As is well known, the ejector section 5 consists of a nozzle 6, a jet section 7, and a diffuser 8, and the jet section lowers the pressure due to the jet flow from the nozzle 6 and sucks the surrounding fluid. Reference numeral 9 denotes a pressure feeding passage that branches from the circulation passage 2 midway from the discharge port 3 of the pump 1 to the nozzle 6, and is connected to a boiler (not shown) or the like.

Reference numeral 10 denotes a primary pressure regulating valve for maintaining the jet stream from the nozzle 6 in a predetermined state, and its configuration is schematically shown in FIG.

In Figure 2, 11 is the inlet, 12 is the outlet, and 13 is the valve □
It is. The valve port 13 is opened and closed by a valve body 14. A piston 15 is fixed to the valve body 14. The pressure from the inlet 11 side acts on the lower surface of the piston 15, and the elastic force of the spring 16 acts on the upper surface. Therefore, the pressure on the inlet 11 side moves the valve body 14 up and down against the elastic force set by the spring 16 to open and close the valve, thereby draining water while maintaining the pressure on the primary side at a predetermined value. The primary pressure regulating valve is not necessary if the pressure on the pumping side of the boiler or the like is stable and the pressure allows the jet flow from the nozzle 6 to be appropriate.

The jet section 7 of the ejector section 5 is closed with an inflow passage 17 from a steam-using device (not shown) or the like. Steam-using equipment may be a vacuum. 18 is an air separator;
A separation wall 19 is provided to facilitate air separation from running water.
The structure of the air separator 8 is not limited to this, and may be an enlarged security member, a tank, or the like. At the top of the air separator 18, a ventilation passage 20 is piped upright and a first electrically operated valve (electromagnetic valve or motor-operated valve 21) is disposed.

The ventilation passage 20 opens at the bottom of the tank 22. tank 2
An exhaust passage 23 that is open to the atmosphere is installed at the top of 2.
A second electrically operated valve 24 is arranged in the passage 23 .

Further, the tank 22 and the pressure-feeding passage 9 are connected to each other by a return passage 25, and a third electrically operated valve 26 is disposed in the return passage 25. Reference numeral 27 indicates a second-position detection level switch, which has three electrode rods 28, 29, and 30 of different lengths.

The illustrated electrode type level switch 27 is well known, and detailed explanation thereof will be omitted. The level switch 27 has a control circuit and is electrically connected to an electrically operated valve, but these are omitted.

The level switch 27 uses a well-known method to open the first electrically operated valve 21 and close the second and third electrically operated valves 24 and 26 when the liquid level in the tank 22 reaches the lower end of the electrode bar 28. .

Therefore, the air in the inflow passage 17 enters the tank 22 while performing air and water exchange and accumulates in the upper part. Thus tank 22
The liquid level inside gradually decreases. Then, the liquid in the tank 22 &
At a low level where the electrode lever 29 has descended to the lower end, the first electrically operated valve 21 is closed, and the second and third electrically operated valves 24 and 2 are closed.
6 opens.

Therefore, the high pressure water on the side of the pressure feed passage 9 enters the tank 22 through the return passage 25 and pushes out air from the exhaust passage 23.
In this way, the liquid level in the tank 22 rises. Thereafter, such an operation is repeated to release non-condensable gas such as air. still,
The level switch 27 is not limited to the electrode type as described above, but a well-known type such as a float type may be used.

As described above, according to the present invention, air mixed in condensate from steam-using equipment, etc. is released to the atmosphere before the pump, and the problem of so-called air trapping is eliminated.

Furthermore, air can be discharged even when condensate is pumped from a vacuum system. Thus, the condensate recovery pump of the present invention has the following features:
This prevents a decrease in the efficiency of the ejector unit due to air trapping.
It also prevents the centrifugal pump from running idle.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the present invention, and FIG. 2 is a schematic diagram of the principle of the primary pressure regulating valve 10. 1 is a centrifugal pump, 2 is a circulation passage, 3 is a discharge port, 4 is a suction port, 5 is an ejector member, 7 is a jet section, 9 is a pressure feeding passage,
17 is an inflow passage, 2 river ventilation passages, 21 is a first electrically operated valve, 22 is a tank, 23 is an exhaust passage, 24 is a second electrically operated valve, 25 is a return passage, 26 is a third electrically operated valve, 27 is the second position detection level switch. ``Illustrated Chrysanthemum 2''

Claims (1)

[Claims] 1. A centrifugal pump operated by an electric motor, a circulation passageway connecting the discharge port and suction port of the pump, an ejector member disposed in the circulation passageway, and a circulation passageway connecting the circulation passageway from the discharge port to the ejector member. a pressure-feeding passage branching from the inflow passageway, an inflow passageway opening into the jet portion of the ejector member, a ventilation passageway branching off from the inflow passageway and standing up from the inflow passageway, a tank with the ventilation passageway opening at the bottom, and a tank opening from the top of the tank. an exhaust passage open to the atmosphere; a return passage communicating the tank and the pressure-feeding passage; a first electrically operated valve disposed in the ventilation passage; a second electrically operated valve disposed in the exhaust passage; and the return passage. a third electrically operated valve disposed in the tank; the first electrically operated valve is opened when the liquid level in the tank is at a predetermined high level; the second and third electrically operated valves are closed when the liquid level in the tank is at a predetermined low level; A condensate recovery pump consisting of a second detection level switch disposed in the tank that operates to close the operating valve and open the second and third electrically operated valves.