JPH01181004A - Condensate recovery pump - Google Patents

Abstract

PURPOSE:To control the temperature of circulating water to remain constant so as to accomplish a stable degree of vacuum by providing a cooling device at a position along the length of a circulating path of a liquid pump in which a suction port and a discharge port thereof are caused to communication with a diffuser of an ejector via a tank and the ejector, respectively and in which liquid is adapted to circulate the system so formed. CONSTITUTION:When an electrode 23 detects that the water level inside a tank is low, an electric valve 16 is caused to remain closed, and circulating water sent from a pump 1 under pressure creates a negative pressure area by means of an ejector 3 so as to suck high- temperature steam condensate via a suction path 14. Circulating water that has become high-temperature after having been mixed with the steam condensate is caused to flow into a tank 5 after having been cooled at a cooling device portion 4. When the water level inside the tank increases above a predetermined level, the electric valve 16 is caused to open so as to discharge the steam condensate mixed with circulating water to a distant position. The number of revolutions of a motor 2 of a radiator is controlled such that the temperature of circulating water becomes a predetermined value after a signal sent from a temperature sensor 24 has been compared with a set temperature. In the event that the load remains stable and that circulating water may be cooled below the predetermined temperature, the temperature sensor 24 may be eliminated so as to forcibly rotate a fan 20.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a condensate recovery pump that sucks condensate generated in a low-pressure process such as a low-pressure or vacuum heat exchanger and pumps it back to a boiler.

This type of pump communicates the jet pump and the suction port of the liquid pump through a tank, creates a vacuum area at the jet pump's ejector, and sucks in the condensate generated in the low-pressure process and returns it under pressure. . The degree of vacuum generated in the ejector is the saturation pressure with respect to the temperature of the liquid passing through it, and various improvements have been made to keep this pressure constant.

2. Description of the Related Art Conventionally, there is a condensate recovery pump as shown in Japanese Patent No. 1,142,395. This is a combination of an ejector, a liquid pump, and a tank connected to each other.A cooling water supply passage is provided to supply cooling water to the tank, and a control valve is installed in the passage to control the temperature of the liquid circulating between the ejector and the liquid pump. A detection means is provided to control the control valve to maintain the circulating water at a predetermined temperature or lower.

Problems to be Solved by the Invention In the above condensate recovery pump, a large amount of cooling water must be used to maintain the liquid passing through the ejector at a predetermined temperature or lower, which is uneconomical. Also, when installing the pump, piping for cooling water must be installed. Therefore, the technical problem of the present invention is to be able to easily control the temperature of circulating water at a constant level and to generate a stable degree of vacuum.

Means for solving the problems The technical means of the present invention taken to solve the above problems are as follows:
In a system in which the suction port of the liquid pump and the diffuser of the ejector are connected through a tank, and the discharge port of the liquid pump and the ejector are connected, and the liquid is circulated in this system, a cooler is provided in the circulation path. It is something that

Condensate generated during the process in the working low pressure area is sucked into the negative pressure area of the ejector section and circulated through the diffuser, tank and liquid pump. During circulation, the circulating water is cooled by a cooler provided on the circulation path, and passes through the ejector again to maintain a negative pressure region.

Embodiment (See FIG. 1) An embodiment illustrating the above specific example will be described. The entire system is composed of a pump 1 rotationally driven by an electric motor 2, an ejector 3, a cooler section 4, a tank 5, and piping connecting these.

The bottom of the tank and the suction port 6 of the pump 1 are communicated through a circulation passage 7, while the discharge port 8 of the pump 1 and the ejector 3 are communicated through a circulation passage 9. The ejector 3 includes a nozzle 10 that injects circulating water from the pump 1 at high speed, a suction chamber 11 formed around the injection port of the nozzle 10, a nozzle portion 12 facing the injection port of the nozzle 10, and a nozzle section 12 that widens at the end. It consists of 13 diffusers. A suction passage 14 is opened in the suction chamber 11 of the ejector 3, and a condensate generation process such as a heat exchanger, process side (
(not shown).

A return passage 15 communicating from the circulation passage 9 to a high pressure side (not shown) of a boiler or the like is provided, and an electric valve 16 is installed in the middle thereof. A circulation passage 17 connects the diffuser 13 of the ejector 3 and the cooler part 4, and a circulation passage 18 connects the cooler part 4 and the tank 5.
communicate with each other.

The cooler part 4 has the same structure as a car radiator, and when the liquid passes through the radiator part 19, it is cooled by air from a fan 20 rotated by a motor 21. The tank 5 is open to the atmosphere through a communication pipe 22, and a circulation passage 18 communicates with the upper part of the tank 5.

An electrode 23 is attached from the top, and the electric discharge valve 16 is opened and closed by a signal from the electrode 23. Further, the tank 5 is provided with a temperature sensor 24 for detecting the temperature of condensate accumulated therein, and the rotation of the radiator motor 21 is controlled by the signal from the temperature sensor 24.

The action is as follows. When the water level in the tank is low as detected by the electrode 23, the electric valve 16 is closed, and the circulating water pumped from the pump 1 creates a negative pressure area in the ejector 3 and draws high-temperature condensate from the suction passage 14. Suction. The circulating water mixed with condensate and heated to a high temperature is cooled by the cooler section 4 and flows into the tank 5.

When the water level in the tank reaches a predetermined level or higher, the electric valve 16 opens and discharges condensate mixed with circulating water to a distant place.

The rotation speed of the radiator motor 21 is determined by the temperature sensor 24.
The signal from the pump is compared with the set temperature, and the circulating water temperature is controlled to the desired value.

In the above embodiment, the temperature sensor 24 controls the rotation of the radiator motor 21, but if the load is stable and it is sufficient to cool the circulating water to a level above a desired value, the temperature sensor 24 may be omitted and the rotation of the radiator motor 21 may be All you have to do is rotate the fan 20. Further, in such a case, the electric motor 2 of the pump 1 can also be used as a driving source for the fan 20.

Effects of the Invention Therefore, according to the present invention, since no cooling water is required, there is no need for piping work for the cooling water, and a condensate recovery device that can be installed anywhere can be obtained.

Since no cooling water is required, a large tank is not required, and the overall result is a compact condensate recovery pump.

Since there is no variation in the temperature of circulating water due to supply and stop of cooling water as in the conventional case, a stable negative pressure region can be obtained in the ejector.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the present invention. 1: Pump 2: Electric motor 3: Ejector 4: Cooler section 5: Tank

Claims (1)

[Claims] 1. In a system in which the suction port of the liquid pump and the diffuser of the ejector are connected through a tank, and the discharge port of the liquid pump and the ejector are connected, and the liquid is circulated in this system, a cooler is installed in the circulation path. A condensate recovery pump characterized by being provided with.