JPS58598B2 - condensate pump equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a condensate pump device that pumps condensate generated in a steam system to a high-pressure location such as a boiler or a condensate recovery pipe located at a high place.

Conventionally, a condensate pump device has a circulation passage that connects the discharge port and suction port of a pump driven by a motor to create a jet flow of condensate inside, and an inflow passage that opens into the jet flow portion of the circulation passage. and a discharge passage opening in the middle of the circulation passage are known.

The above condensate pump device uses a pump to create a jet flow of condensate in a circulation passage, sucks condensate from an inflow passage into a vacuum area generated around the jet flow, and pumps condensate in the circulation passage. The pressure of the condensate is increased and the pressure is sent through the discharge passage, and even when steam is sucked together with the condensate from the inlet passage, this steam can be cooled in the circulation passage and converted into condensation.

However, in the above pump device, it is necessary to fill the circulation passage with water and constantly circulate condensate as a jet flow source, and if the circulation passage is filled with air before starting, etc.
If the circulation passage is not filled with water by priming, air will be sucked into the pump upon startup, causing cavitation in the pump and requiring a long time to start up to normal operation.
Furthermore, the pump was locked by the air, causing the impeller to spin, causing the bearing to seize and the motor to burn out, significantly shortening the life of the device.

In addition, in the above pump device, if non-condensable gas such as air is sucked into the circulation passage from the inflow passage, the pump will cause cavitation or idle rotation as described above, and the pressurizing action will be inhibited, causing the inside of the circulation passage to The circulation of the condensate becomes slow and a jet stream is not formed, making it difficult to suck in the condensate, and the pressure-feeding action within the circulation passage is lost, causing a significant drop in the efficiency of the device.

In view of the above-mentioned circumstances, the present invention automatically performs priming before starting the device, and is designed to automatically prime the water when non-condensable gas such as air is sucked into the circulation passage and the pressure inside the circulation passage decreases, or when condensation The purpose of the present invention is to provide a condensate pump device that automatically stops the device when the pumping amount of water decreases, thereby preventing the pump from seizing or motor burnout, and allowing the device to operate safely and efficiently.

The above purpose is to provide a pump, a circulation passage that connects the discharge port and suction port of the pump and creates a jet flow of condensate inside, an inflow passage that opens into the jet flow portion of the circulation passage, and a In a condensate pump device consisting of a discharge passage, an exhaust valve is provided at the top of the pump device through which condensate flows, and the liquid level at the top is detected to control pump operation and open/close the exhaust valve. A liquid level detecting means is provided, and a pressure detecting means or a flow rate detecting means is further provided to detect the pressure in the circulation passage or the flow rate of condensate and to make an emergency stop of the device if the pressure or flow rate drops below a predetermined level during operation. This can be achieved by a condensate pump device consisting of:

In this case, a centrifugal pump is generally used as the pump.

The uppermost part of the pump device through which the condensate flows is the upper part of the pump when the circulation passage is made substantially horizontal as in the example below, and the upper part of the circulation passage when the circulation passage is provided vertically with respect to the pump. It will be at the top of the side.

Liquid level detection means include an electrode rod type that uses the energizing effect of water, a float type Ω that mechanically or electrically detects the floating and descending of the float, and a type that uses the reflection effect of electromagnetic waves, ultrasonic waves, etc. All kinds of things can be used.

As the exhaust valve, an electrically operated valve such as an electric valve or a solenoid valve or a fluid pressure operated valve is used.

As the pressure detection means, all common pressure detection means can be used, such as a conventional Bourdon tube type, a mercury column type, and a diaphragm type.

In addition, the above pressure detection means is installed on the suction port side of the pump,
By setting the operating pressure to the limit pressure that causes cavitation in the pump, cavitation in the pump can be prevented and the pump can be operated efficiently at all times.

Alternatively, as in the embodiment below, it may be provided on the discharge passage side and activated by the pressure drop of condensate discharged from the pump.

As the flow rate detection means, there are commonly used ones such as a venturi type, a pitot tube type, and an orifice type.

Further, the flow rate detection means may be provided on the discharge passage side as in the embodiment described below to detect the amount of condensate being pumped, or may be provided on the circulation passage to detect the amount of circulating condensate.

The present invention will be explained in detail based on illustrated embodiments.

In FIG. 1, 1 is a pump driven by a motor 2, and a centrifugal pump is generally used.

3 is a base for the pump 1 and motor 2.

- The discharge port 4 and the suction port 5 of the pump 1 are connected by pipe members 6a to 6h that form a substantially horizontal circulation passage 6.

Reference numeral 7 represents a base of the tube members 6a to 6h. The pipe member 6a is connected to the discharge port 4 of the pump 1.

The pipe member 6a branches into a side to which a pipe member 6c described below is connected and a discharge passage 8 side communicating with a pumping side of a boiler or the like.

Reference numeral 9 denotes a pipe member connected to the discharge passage 8 side, on which a pressure switch 10 is attached, and a detection end of the switch 10 projects toward the discharge passage 8 side.

The tube member 6c reverses the direction of the circulation passage 6 with a gentle radius.

A nozzle 11 for producing a jet stream is screwed onto the tip of the tube member 6d.

The tube member 6e forms a suction chamber 12 around the nozzle 11.

Reference numeral 13 denotes an inflow passage that opens into the suction chamber 12 and communicates with the condensate generation side.

Here, the condensate pipe connected to the inflow passage 13 includes:
A water head sufficient to fill the circulation passage 6 and pump 1 with water is provided.

The pipe member 6f receives a jet stream ejected from the nozzle 11,
It forms a throat part that rectifies the condensate sucked from inside the inflow passage 13.

The pipe member 6g constitutes a diversion user section that expands in the direction of flow of condensate.

The pipe member 6h is connected to the suction port 5 of the pump 1.

In this embodiment, since the circulation passage 6 is provided approximately horizontally, the top of the device through which the condensate flows is the top of the pump 1, as shown in the plan view of FIG. A level switch 14 and an electric valve 15 are attached to the upper part.

The level switch 14 has the structure shown in FIG.

Reference numeral 16 denotes a main body, to which a top cover is fixed and forms a cavity 20 in which an inlet 18 communicating with the upper part of the pump 1 and an exhaust port 19 connected to an electric valve 15 open.

24 is a gasket.

Reference numeral 21 denotes an electrode rod that penetrates the upper lid and protrudes into the cavity 20. When the tip is submerged in water, it becomes conductive and closes, and when the tip is above the water surface, it opens.

22 is a cover that covers the upper part of the electrode rod 21, and 23 is a partition wall that prevents disturbance of the water surface.

The electric valve 15 has a structure shown in FIG.

25 is a motor, and an output shaft 26 of the motor 25 is connected to a valve shaft 28 of the valve portion.

29 is a valve ball that is driven by the rotation of the valve shaft 28, and has a through hole 30.
The fluid passage 31 communicating with the exhaust port 19 of the level switch 14 is opened and closed every predetermined rotation.

32 is a control switch unit that controls the rotation of the motor 25;
As shown in FIG. 5, it consists of a cam 33 connected to the output shaft 26 of the motor 25, and microswitches 34 and 35 that cooperate with the outer circumference of the cam 33 to perform a switching action. ) are opened and closed alternately.

Here, the control switch section 32 and the motor 2
5 is connected as shown by the two-dot chain line 42 in FIG.
If the cam is located in the groove No. 3, it takes the position of the b contact and the cam 3
If it is located on the 30th circumference, it will take the position of the a contact point.

When the motor-operated valve 15 is in the state shown in FIG. 6, it is closed, and when it is energized, the circuit I is closed, so it changes to the open state, and the microswitch 35 is in the b contact position. The microswitch 34 is in the a contact position, forming a circuit (2) in which the valve is closed from the next opening.

Also, while the cam 33 is rotating, the microswitches 34 and 35
Since both are located on the circumference of the cam 33, they are located at the a contact point, and even if the relay 40 described below is switched during rotation, the command can be followed.

FIG. 6 shows a schematic diagram of the circuit of this embodiment.

However, parts corresponding to those in FIGS. 1 to 5 are given the same reference numerals.

In the figure, 36 is a power supply, and 37 is a main switch.

Reference numeral 38 denotes a delay relay, which is normally in the a-contact position and assumes the b-contact position only for a predetermined time after the coil 39 is excited.

This relay 38 generally consists of a delay circuit and a relay circuit, and there are some that use a solid type delay circuit, and others that use a bimetal type or motor type delay circuit.

However, in the figure, for convenience, it is shown with the same symbol as the relay.

Reference numeral 10 denotes the pressure switch, which assumes the B contact position when the pressure in the circulation passage 6 is below a predetermined pressure, and assumes the A contact position when the pressure is above a predetermined pressure.

Reference numeral 40 denotes a relay which takes the a contact position only when the coil 41 is excited, and normally takes the b contact position.

42 is a schematic circuit of the electric valve 15 shown in FIG. 45. When the circuit I connecting the B contact of the relay 40 and the A contact of the microswitch 35 is closed, the electric valve 15 changes from the closed state to the open state. When the circuit 2 connecting the A contact of the relay 40 and the A contact of the microswitch 34 is closed, the electric valve 1
5 changes from the open state to the closed state.

In the figure, M indicates the motor 25 of the electric valve 15.

Further, p indicates a motor 2 that drives the pump I.

2 is a circuit to the motor 2. Next, the operation of the condensate pump device of the above embodiment will be explained.

Before starting, the level switch 14 is open and the pressure switch 10 is closed.
is in the B contact position at low pressure, and the motorized valve 15 is closed. When the main switch 37 is closed in the circuit shown in FIG. 6, the motorized valve 15 is in the state where circuit , the motor 25 of the electric valve 15 is operated, the valve 15 is opened, and the top of the pump 1, which is the top of the device, communicates with the atmosphere.

Therefore, in the circulation passage 6 and the pump 1, there is an inflow passage 13.
The condensate on the side begins to flow in due to the head difference, and at the same time, the air filling the circulation passage 6 and the pump 1 flows into the pump 1.
through the upper part of the air 20 and the level switch 14,
The fluid is discharged from the fluid passage 31 of the motor-operated valve 15 to the atmosphere.

Further, since the pressure inside the circulation passage 6 is atmospheric pressure, the pressure switch 10 is at the b contact position, the coil of the delay relay 38 is energized, and the relay 38 moves to the b contact position, but after a predetermined time,
Return to the a contact position.

Therefore, when the circulation passage 6 and the pump 1 are filled with water and the electrode rod 21 of the level switch 14 is submerged and conductive, the coil 41 of the relay 40 is energized, the relay 40 assumes the a contact position, and the electric valve 15 is opened. state to closed state.

At the same time, the circuit ■ to motor 2 of pump 1 is closed, and motor 2
starts and pump 1 is driven.

In the circulation passage 6, condensate begins to circulate due to the action of the pump 1, a jet stream of condensate is ejected from the nozzle 11, and a vacuum area is generated around the jet stream. On the other hand, condensate on the inflow passage 13 side is sucked through the suction chamber 12.

The mixed flow of this jet flow and the sucked condensate flows through the pipe member 6
The flow is rectified at the throat formed by f, and further passes through the diffuser formed by the pipe member 6g, where the dynamic pressure is converted into static pressure and flows toward the suction port 5 of the pump.

Therefore, since the static pressure of the condensate on the suction port 5 side of the pump 1 is increased, the suction head is high and the pump 1 can efficiently apply condensate water on the suction port 5 side more than the discharge port 4 without causing cavitation. Press and drain.

The condensate discharged from the pump 1 is pumped through the discharge passage 8, and a portion thereof circulates within the circulation passage 6 to become a jet flow source.

During this process, when the pressure in the discharge passage 8 exceeds a predetermined value, the pressure switch 10 becomes an a contact.

Here, when non-condensable gas such as air is sucked into the circulation passage 6 through the inflow passage 13, it reaches the inside of the pump 1 and causes cavitation in the pump 1, reducing pressurization efficiency.

Furthermore, if a large amount of gas is sucked in, the inside of the pump 1 is locked by this gas, and the impeller spins idly, eliminating the pressurizing effect.

Since the suction effect of condensate from the inflow passage 13 also decreases, the internal pressure of the circulation passage 6 decreases rapidly.

When the internal pressure of the circulation passage 6 falls below a predetermined level, the pressure switch 10 is switched to the B contact position, and the delay relay 38 is switched to the S contact position for a predetermined period of time as the coil 39 is energized.

The circuit of the relay 40 to the coil 41 is therefore opened, and the relay 40 returns to the b contact position and the motor 2 of the pump 1
The motor-operated valve 15 opens again at the same time as the circuit to the motor is opened.

Then, the gas such as air in the circulation passage 6 and the pump 1 reaches the uppermost part of the pump 1, passes through the cavity 20 of the level switch 14 and the fluid passage 31 of the electric valve 15, and is discharged to the atmosphere. Condensate on the passage 13 side flows into the circulation passage 6 using the water head difference.

In this case, the delay relay 38 returns to the a contact position after a predetermined time, but if there is gas such as air inside the pump 1,
When the electrode rod 21 of the level switch 14 is above the water surface,
The motor-operated valve 15 continues to open.

Further, after a predetermined period of time, if the gas such as air in the pump 1 is released and the electrode rod 21 is submerged in water, the circuit to the coil 41 of the relay 40 is closed, and the relay 40 changes to the a contact position again. At the same time as the electric valve 15 closes, the motor 2 of the pump 1 is started, and the condensate suction and pumping operations are resumed as described above.

As described above, in the condensate pump device of the present invention, priming is automatically performed before starting the motor that drives the pump, and the start-up time can be omitted.

In addition, if non-condensable gas such as air is sucked into the circulation passage from the inflow passage and the pressurization and pumping efficiency of the device decreases, and the internal pressure of the circulation passage drops below a predetermined pressure, the pump will automatically stop operating. This prevents the pump from seizing or motor burnout due to cavitation or idling, and allows the pump to resume operation once air and other gases have been automatically discharged, allowing the equipment to operate safely and efficiently.

Furthermore, instead of using the pressure detection means as in the above embodiment, the same effect can be obtained by emergency stopping the operation of the pump due to a decrease in the amount of condensate being pumped or a decrease in the amount of condensate circulating in the circulation passage.

[Brief explanation of the drawing]

Figures 1 and 2 are a cross-sectional view and a front view of the condensate pump device of the embodiment, Figure 3 is a cross-sectional view of the level switch, and Figures 4 and 5 are a cross-sectional view and a diagram of the main parts of the electric valve. , FIG. 6 shows a one-time schematic diagram of the embodiment. 1 is the pump, 2 is the motor, 4 is the discharge port, 5 is the suction port, 6
is a circulation passage, 8 is a discharge passage, 10 is a pressure switch, 13
14 is an inflow passage, 14 is a level switch, and 15 is an electric valve.

Claims (1)

[Scope of Claims] 1. A pump, a circulation passage that connects the discharge port and suction port of the pump and creates a jet flow of condensate inside, an inflow passage that opens into the jet flow portion of the circulation passage, and In a condensate pump device consisting of a discharge passage from a passage, an exhaust valve and a liquid level detection means are installed at the top of the device in which condensate circulates,
The liquid level detecting means controls the operation of the pump and the opening and closing of the exhaust valve according to the liquid level in the device, and furthermore, a pressure detecting means is installed in the circulation passage, and when the pressure in the circulation passage drops below a predetermined level. A condensate pump device that makes an emergency stop of the pump. 2. A pump, a circulation passage that connects the discharge port and suction port of the pump and creates a jet flow of condensate inside, an inflow passage that opens to the jet flow portion of the circulation passage, and a discharge passage from the circulation passage. In the condensate pump device, an exhaust valve and a liquid level detection means are installed at the top of the device through which condensate flows, and the liquid level detection means operates the pump and opens and closes the exhaust valve according to the liquid level in the device. In addition, the circulation passage or inflow/
A condensate pump device that has a flow rate detection means installed on the discharge passage side and makes an emergency stop of the pump when the flow rate falls below a predetermined amount.