JPH0467040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a condensate discharge device using a combination pump of a jet pump and an electric pump for discharging condensate from various types of steam-using equipment such as cylinder dryers, and particularly to a condensate discharge device for discharging condensate from various types of steam-using equipment such as cylinder dryers. The present invention relates to a condensate discharge device that maintains the pressure difference between the inlet side and the outlet side at a predetermined value to facilitate condensate discharge.

Increasing production efficiency in steam-using equipment,
In order to maintain constant product quality, condensate generated within the equipment must be promptly drained.

BACKGROUND ART Conventionally, therefore, a condensate discharge device for a combination pump as shown in Japanese Patent Publication No. 57-51559 has been used. This takes advantage of the fact that the pressure in the suction chamber of a jet pump is equal to the saturation pressure at the temperature of the liquid passing through the nozzle.In a combination pump of a jet pump and an electric pump, the temperature of the liquid spouted from the nozzle of the jet pump is controlled. In order to lower the suction pressure of the jet pump to a desired value, a low temperature water injection means is provided in front of the nozzle via a low temperature water pressurizing pump that communicates with the low temperature water source and a valve that adjusts the amount of low temperature water to be injected. A pressure detection means is provided in the inflow passage leading from the steam trap to the suction chamber of the jet pump, and the detected pressure from the pressure detection means is compared with a predetermined reference pressure necessary for operation of the steam trap, and the temperature is lowered to match the pressure. By sending an operation signal to the control means of the water injection amount control valve and adjusting the amount of low-temperature water injected, the suction pressure generated in the suction chamber of the jet pump is set to the desired value, and the pressure difference required for the operation of the steam trap is adjusted. It is used to secure, suction and discharge condensate.

Problems to be Solved by the Present Invention In this case, even if low-temperature water is injected into the liquid ejected from the nozzle of the jet pump, the temperature of the ejected liquid does not fall to a predetermined value, so the problem is that the desired suction pressure cannot be obtained. It was hot. This is because high-temperature circulating water circulates at high speed in front of the nozzle, so even if low-temperature water is injected, it is not sufficiently mixed, resulting in variations in the temperature of the ejected liquid.

In addition, the front part of the nozzle is pressurized by an electric pump, and injecting low-temperature water requires a separate pump for pressurizing low-temperature water, which raises the problem of increased equipment costs.

Therefore, the technical problem of the present invention is to uniformly lower the temperature of the liquid ejected from the nozzle and obtain a desired suction pressure with low equipment costs.

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is a combination of a jet pump and an electric pump in which the inlet passage of condensate generated in steam-using equipment is communicated with the suction chamber. In the pump, a constriction section is provided in the inflow passage, pressure detection means is arranged on the inlet side of the steam-using equipment and on the secondary side of the constriction section, and a condensate reservoir is provided between the suction chamber of the jet pump and the suction port of the electric pump. A cooling water injection passage is connected to the condensate reservoir, and a cooling water injection amount adjusting means is provided in the cooling water injection passage, and the condensate is injected into the steam-using equipment according to a signal from the pressure detection means. A control section is provided that calculates a pressure difference that does not stagnate and sends an adjustment signal for injecting cooling water according to the pressure difference to the cooling water injection amount adjusting means.

Function Necessary for the pressure detection means placed on the inlet side of the steam-using equipment and the secondary side of the throttle section to detect the respective pressures, and the control unit to discharge condensate from the steam-using equipment based on this pressure value. calculates the pressure difference and sends the signal to the cooling water injection amount adjusting means. Cooling water is injected into the condensate reservoir formed between the suction chamber of the jet pump and the suction port of the electric pump according to the above signal. Since the condensate reservoir has a reservoir, the flow rate of condensate is slow, and since it is formed between the suction chamber of the jet pump and the suction port of the electric pump, it does not flow when pressurized by the pump. The pressure is relatively low.

Effects of the Invention The flow rate of condensate is slow in the condensate reservoir portion into which cooling water is injected. Therefore, the injected cooling water is sufficiently mixed with the condensate, and by uniformly lowering the temperature of the condensate, a desired suction pressure in the suction chamber of the jet pump can be obtained.

In addition, since the condensate reservoir has a relatively low pressure, there is no need for a pump to inject cooling water.
The device can be manufactured at low cost.

Example An example showing a specific example of the above technical means will be described.

First embodiment (see FIG. 1).

Steam supply pipe 2 that supplies steam to steam-using equipment 1
0 and an inflow passage 21 for allowing condensate to flow into the jet pump 2. An orifice 3 as a constriction part for generating a differential pressure is arranged in the inflow passage 21, and pressure detection means 4, 4' are attached to the secondary side of the orifice 3, that is, to the jet pump 2 side and to the steam supply pipe 20, respectively. . pressure detection means 4,
4' is a conventionally used type such as a diaphragm type or a piezoelectric type, and a type that emits an electric signal is suitable.

The combination pump 5 is formed by a jet pump 2 and an electric pump 6. The jet pump 2 and the electric pump 6 are connected through a circulation passage 7, and the jet pump 2
A condensate reservoir 10 having a passage area larger than the circulation passage 7 between the suction chamber 8 of the electric pump 6 and the suction port 9 of the electric pump 6.
will be established. A cooling water injection passage 11 for supplying cooling water is connected to the upper part of the condensate reservoir 10. A control valve 12 is disposed in the cooling water injection passage 11 as a cooling water injection amount adjusting means for adjusting the amount of cooling water injected. The control valve 12 has a control section 13 that controls the valve opening degree. A lower part of the condensate reservoir 10 communicates with a suction port 9 of the electric pump 6.

Pressure detection means 4, 4' and control section 1 of control valve 12
3 are connected by a signal line 15 via a control unit 14.

In addition, the circulation passage 7 is provided with a pressure passage 22 for pressurizing the condensate to a boiler (not shown) or a water supply pump (not shown) when the amount of condensate accumulated in the condensate reservoir 10 increases. . In the upper part of the condensate reservoir section 10,
A pressure relief valve 32 is provided to relieve the pressure in the condensate reservoir 10 to the outside of the system and to more easily generate a pressure difference.

The pressure detection means 4 and 4' detect the pressure on the inlet side of the steam-using equipment 1 and the pressure on the secondary side of the orifice 3, and detect the pressure necessary to quickly discharge condensate without accumulating it in the steam-using equipment 1. The difference is calculated by the control unit 14,
The calculation result is transmitted to the control unit 13, and the control valve 12
The amount of cooling water to be injected is adjusted by adjusting the opening degree of the cooling water. That is, when the pressure difference between the secondary side of the steam-using equipment 1 and the orifice 3 is smaller than a predetermined value, the opening degree of the control valve 12 becomes large, and more cooling water is injected into the condensate reservoir 10, and the inside of the circulation passage 7 is increased. The pressure difference is maintained at a predetermined value by lowering the water temperature and lowering the pressure generated at the nozzle portion 23 of the jet pump 2.

A fixed amount of the condensate accumulated in the condensate reservoir 10 may be constantly discharged to the outside of the system, or as in this embodiment, liquid level detection means 30,
A control valve 31 having a diameter of 30' and disposed in the pressure feeding passage 22
The condensate may be collected separately by opening and closing.

Second embodiment (see Figure 2).

This embodiment shows a case where a plurality of steam-using devices are installed and condensate is discharged using the same combined pump. Note that the same members as in the first embodiment are given the same reference numerals, and detailed explanations will be omitted.

Inlet side of steam using equipment 1, 1' and orifice 3,
On the secondary side of 3', pressure detection means 4, 4', 4a, 4
a′ is attached. The control unit 14 calculates the pressure difference between the pressure detection means 4, 4' and 4a, 4a', and a signal corresponding to the maximum pressure difference is transmitted to the operation unit 13 to adjust the opening degree of the control valve 12. , the condensate of the steam-using equipment 1, 1' is discharged as in the first embodiment.

In this embodiment, the orifice 3 is used as the throttle part, but a steam trap having the same function as the orifice may also be used. In addition, in this embodiment, cooling water was injected to lower the temperature of the circulating water, but instead of cooling water, the circulating water was You can also adjust the temperature. That is, by making the condensate reservoir 10 function as a flash tank and discharging flash steam out of the system through the pressure relief valve 32, the temperature inside the condensate reservoir 10 can be reduced.
As a result, the temperature of the circulating water can also be lowered. Further, in this embodiment, pressure detection means 4, 4', 4a, 4a' were used to measure the pressure difference, but when used in a state where there is a certain correlation between pressure and temperature, temperature detection means may be used instead. You can also.

[Brief explanation of drawings]

1 and 2 are configuration diagrams of a condensate discharge device according to an embodiment of the present invention. 1... Steam-using equipment, 2... Jet pump,
3... Orifice, 4... Pressure detection means, 5...
Combination pump, 6... Electric pump, 8... Suction chamber, 9... Suction port, 10... Condensate reservoir, 11...
Cooling water injection passage, 12... control valve, 13... operating section, 14... control section, 21... inflow passage.

Claims (1)

[Claims] 1 In a combination pump of a jet pump and an electric pump in which the condensate inflow passage is connected to the suction chamber,
A constriction section is provided in the inflow passage, pressure detection means is arranged on the inlet side of the steam-using equipment and on the secondary side of the constriction section, and a condensate reservoir section is formed between the suction chamber of the jet pump and the suction port of the electric pump. A cooling water injection passage is connected to the condensate reservoir, and a cooling water injection amount adjusting means is provided in the cooling water injection passage, and the signal from the pressure detection means is used to prevent condensate from accumulating in the steam-using equipment. A condensate discharge device, comprising a control section that calculates a pressure difference between the two and sends an adjustment signal for injecting cooling water according to the pressure difference to the cooling water injection amount adjusting means.