JPH03129198A - Condensed water discharge device - Google Patents

Abstract

PURPOSE:To discharge even a condensed water mixed with oil without clogging by providing a piping for accumulating the condensed water, an orifice, a pressure detecting means, and a controller for confirming the completion of discharging of the condensed water by pressure rise, detecting the pressure by the pressure detecting means and generating a valve closing signal. CONSTITUTION:A condensed water discharge pipe 8 is connected to the bottom of a receiver tank 6 for accumulating condensed water, a motor-operated valve 10 and an orifice 12 are arranged to the pipe, and a pressure detector 14 is provided between the motor-operated valve 10 and the orifice 12. The pressure detector 14 and the motor-operated valve 10 are then connected to a controller 16 by signal wires. The controller 16 generates a valve opening signal to the motor-operated valve 10 to discharge condensed water, confirms the completion of discharging of the condensed water by the pressure rise between the motor- operated valve 10 and the orifice 12, and detects the pressure by means of the pressure detector 14 to generate a valve closing signal to the motor-operated valve 10. As a result, even a bad condensed water mixed with oil can be discharged without clogging the motor-operated valve.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a condensate discharge device that automatically discharges condensate generated in steam or compressed air to the outside of the system.

<Prior Art> Steam traps and air traps are commonly used as conventional condensate discharge devices. There are many types of these, but for example, a float type is a valve that has a valve chamber formed within a valve housing that has an inlet and an outlet, and a valve port that communicates with the valve chamber and the outlet. A seat member is disposed, and a spherical hollow float valve is disposed in a free state within the valve chamber, and is disposed so as to close the valve port when the float valve is at its lowest position within the valve chamber. When condensate flows into the valve chamber from the inlet, the float valve floats up according to the water level, opens the valve port, and discharges the condensate to the outlet.

As the water level drops due to the discharge of condensate, the float valve also lowers, closing the valve port again and stopping the discharge of condensate.

This operation is repeated thereafter.

<Problems to be Solved by the Invention> However, in the above-mentioned trap, it is difficult to maintain a seal between the valve seat member and the float valve due to wear of the valve seat and the float valve. will be leaked. Especially in air traps, the condensate contains high viscosity oil mixed in by the compressor and oiler, which blocks the valve port and leaves a small amount of water inside the valve. There is a problem where the valve closes under certain conditions.

Therefore, the technical problem of the present invention is to check the liquid and gas, completely discharge only the liquid, close the valve without letting any gas escape, and prevent the valve from clogging even when the condensate is mixed with oil. It is to provide a discharge device.

<Means for Solving the Problems> The technical means of the present invention taken to solve the above problems are a pipe connected to a condensate reservoir and an operating valve such as an electric valve provided on the pipe. , an orifice provided on the secondary side of the operating valve, a pressure detection means for detecting the pressure in the piping between the operating valve and the orifice, and a timed valve opening signal to the operating valve to detect condensate water. The controller has a function of discharging the condensate, confirming the completion of condensate discharge by checking the pressure rise between the operation valve and the orifice, detecting the pressure at this time with the pressure detection means, and issuing a valve closing signal to the operation valve. It is equipped with the following.

<Operation> The operating valve opens in response to the valve opening signal issued by the controller, and the condensate in the condensate reservoir is discharged out of the system through the orifice. When the condensate has been discharged and a gas such as steam or compressed air passes through the operating valve and the orifice, the pressure in the pipe between the operating valve and the orifice becomes higher than the pressure when the condensate passes.

This is based on the well-known fact that when an incompressible fluid flows through two orifices and a compressible fluid flows, the pressure between the two orifices is higher for the compressible fluid. The increased pressure is detected by the pressure detection means, and a valve closing signal is issued from the controller to the operating valve, thereby stopping the outflow of gas such as steam or compressed air. Then, since the controller issues a valve opening signal to the operating valve on a time-limited basis, when a predetermined period of time has elapsed, the operating valve opens again and discharges the condensate.

<Example> An example showing a specific example of the above technical means will be described. (See Figures 1 and 2) The condensate discharge device of this embodiment is applied to discharge condensate generated in compressed air. Compressor (not shown)
A condensate discharge pipe 8 is connected to the bottom of the receiver tank 6 to which the pipe 2 connected to the apparatus and the supply pipe 4 to the apparatus are connected. The condensate discharge pipe 8 has an electric valve 10 and the electric valve 1 on the secondary side thereof.
An orifice 12 having a flow coefficient substantially equal to 0 is disposed, and a pressure detector 14 for detecting the pressure in the pipe between the motor-operated valve 10 and the orifice 12 is provided. And the pressure detector 14
and the electric valve 10 are connected to the controller 16 by a signal line.

The controller 16 outputs a valve opening signal to the electric valve 10 in a timed manner to open the electric valve 10 and discharge condensate, and confirms completion of discharge of condensate by increasing pressure between the electric valve 10 and the orifice 12. The pressure increased at this time is detected by the pressure detector 14.
It has a function to detect the valve and issue a valve closing signal to the operating valve.

The time interval for issuing the valve closing signal can be arbitrarily set depending on the amount of condensate generated.

To explain the operation, the electric valve 10 opens in response to a valve opening signal issued from the controller 16, and the condensate accumulated at the bottom of the receiver tank 6 is discharged to the outside of the system through the orifice 12. After the condensate has been discharged, the electric valve 10 and orifice 12
When air passes through, the pressure in the piping between the electric valve 10 and the orifice 12 becomes higher than the pressure when condensate passes through.

This consists of two orifices 18°20° as shown in Figure 2.
When a fluid passes through the pipe 22 having an inlet pressure of P
l, intermediate pressure P2. If the outlet pressure is P3 and the flow coefficients Cvl and Cv2 of the two orifices 18.20 are approximately equal, then for an incompressible fluid such as condensate, P2 = (P1 + P3)/2, and for a compressible fluid such as air. Then, P2> (P1
+P3)/2. Detailing the case where air flows, P
If l is about 7Kg/cmG, the first orifice 1
8, the flow is non-choked, and the air flow rate is Q = 0.
．． 4*Cvla■■d2) [Represented by mγminl, it becomes a choke flow at the second orifice 20, and q = 0.2*Cv2*P2 [m'/
It is expressed as m1nl. The density ratio of air at PI and P2 is necessarily 1: P2/P1, and from the continuity of the flow, 0, 4 * Cv 1 house ■ 10,000 ears = (P2/PI) * 0.
2*Cv2*P2...A Here, since Cvl and Cv2 are approximately equal, the above formula is 2*
P2/Pi)*[1-(P2/PI)]=(P2/P
I) 2, and if we set x = P2/Pi, then 4*(1
-x) = X3 Therefore, the solution to the above equation is X = 0.848. For example, if Pl is 7Kg/cmG (8 is 'j/crAab
s ), then P2=8*0.848 = 6.78
KFI/ctrrG-5,78Kl/criabs, and P2>(P1+P3)/2 is proven. At this time, in the case of condensate, P2 is 3.5 Kg/c*iG. In the above calculation, P3 is treated as atmospheric pressure.

The pressure between the motor-operated valve 10 and the orifice 12, which has increased as described above, is detected by the pressure detector 14, and is detected in advance by 0.0 of Pl.
The controller 16 to which the pressure value 848 times higher is compared with the signal value, issues a valve-closing signal to the electric valve, and stops the outflow of compressed air. Thereafter, the controller 16 issues a time-limited valve opening signal to the electric valve 10, so when a certain predetermined period of time has elapsed, the electric valve 10 opens again and discharges the condensate accumulated in the receiver tank 6. .

In the above embodiment, the flow coefficient C of the electric valve 10 and the orifice 12 is
This is a case where vl and Cv2 are approximately equal, but they do not have to be equal, and this case will be described below.

In the above formula A, Z=Cv2/Cvl, x=P2/P
If I, it is expressed as x'=(4/Z2) (1-X). Based on this formula, we find the relationship between Z and X.
It will look like this:

For example, if the flow coefficient Cv2 of the orifice 12 is
When the flow rate coefficient Cvl is selected to be 1.25 times, if the intermediate pressure P2 becomes 0.8 times or more the inlet pressure P1, it means that the fluid passing there has changed from condensate to compressed air. That is, it means that the discharge of condensate has been completed. Therefore, by inputting a pressure value 0.8 times Pl into the controller 16 in advance, a valve closing signal is output to the electric valve 10 when this pressure value is reached.

X must be greater than 0.6 to ensure non-choked flow in the motor operated valve 10 through the first orifice. Furthermore, when X is too large, such as 0.9, Z is small, that is, the orifice 12 is greatly constricted, resulting in poor efficiency. Therefore, the recommended values for X and l range from -0.9 to x=0.7 and z=0.8 to 1.8.

<Effects of the Invention> According to the present invention, even condensate of poor quality, such as water mixed with oil, can be discharged without clogging due to the electric valve. Furthermore, since it is not a combination of a float valve and a valve seat member like a trap, leakage of steam or compressed air due to erosion is eliminated.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a condensate discharge device according to an embodiment of the present invention;
The figure is a simulated diagram of a pipe with two orifices.

Claims (1)

[Claims] 1. The piping connected to the condensate reservoir, the operating valve such as an electric valve installed on the piping, the orifice installed on the secondary side of the operating valve, and the piping between the operating valve and the orifice. A pressure detection means for detecting pressure and a timed valve opening signal are issued to the operation valve to discharge condensate, and the completion of condensate discharge is confirmed by the pressure rise between the operation valve and the orifice. A condensate discharge device comprising: a controller having a function of detecting pressure with the pressure detection means and issuing a valve closing signal to an operating valve.