JPH0477199B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a steam trap that automatically discharges condensate from steam-using equipment, steam piping, etc., and particularly relates to a steam trap that automatically discharges condensate from steam-using equipment, steam piping, etc. This relates to a float type steam trap that opens and closes to discharge condensate outside the vessel.

Conventional technology A conventional float steam trap has a trap housing having an inlet and an outlet to form a condensate storage chamber.
A valve seat is placed below the condensate reservoir chamber, communicating with the outlet through the valve port, and a float valve is housed in the condensate reservoir chamber in a free state, and floats based on the difference in specific gravity of the condensate accumulated there. There is something that comes down and drains the condensate.

Problems to be Solved by the Invention In the trap having the above configuration, if water hammer or the like occurs in the secondary side piping of the trap, the float may be deformed or damaged due to the impactful backflow of condensate, or the condensate may flow into the primary side of the trap. It reached the steam-using equipment connected to the equipment, causing damage to the equipment and reducing thermal efficiency.

In addition, in recent years, drain recovery systems have become commonplace in which the secondary piping of individual steam traps are connected to collect condensate and pumped to a distant location in order to save energy, but one steam trap is blown out. In this case, there was a problem in that the pressure in the recovery pipe where the secondary pipes were gathered was high, and condensate flowed back into the trap.

Therefore, in order to solve the above problem, it has been considered and partially implemented to install a check valve on the outlet side of the trap, but this requires as many check valves as there are traps, which increases the cost and troublesome piping work. There was a problem.

Therefore, the technical problem of the present invention is to provide a steam trap that has a simple structure, is inexpensive, and can prevent backflow of condensate.

Means for Solving the Problems The technical means of the present invention taken to solve the above problems is to install an inlet valve seat in the upper part of a condensate reservoir chamber that accommodates a float valve that opens and closes a valve port by floating up and down. This is a float-type steam trap in which the steam trap is arranged and communicated with an inlet through a valve opening, and an outlet valve seat is arranged at the lower part of a condensate storage chamber and communicated with an outlet through the valve opening.

Function The float valve rises and falls depending on the amount of condensate flowing in from the inlet, that is, the water level, the valve opening opens and closes, and the condensate is discharged from there to the outside of the vessel. When the pressure on the secondary side of the trap becomes higher than the primary pressure, condensate in the secondary side piping flows backward into the condensate reservoir chamber through the outlet valve of the trap. As the water level in the condensate reservoir rises, the float valve also rises, eventually blocking the valve opening of the inlet valve seat provided at the top of the condensate reservoir and closing the valve, stopping the flow of fluid and preventing backflow. be done.

When the secondary side pressure decreases again and returns to the original level, the condensate is discharged from the outlet valve port to the secondary side as usual due to the primary side pressure.

Examples Examples showing specific examples of the present invention will be described. (See Figure 1) The trap housing consists of an upper body 1 and a lower body 2, with a condensate reservoir chamber 3 formed inside and a float valve 1.
8 is housed in a free state. The upper body 1 and the lower body 2 are fixed by tightening respective flanges 4 and 5 with a plurality of bolts 6. The inlet 7 communicates with the upper part of the condensate reservoir chamber 3, and an inlet valve seat 9 having an inlet valve port 8 is screwed onto the communicating portion from the condensate reservoir chamber 3 side. An outlet 10 provided on the same axis as the inlet 7 communicates with the lower part of the condensate reservoir chamber 3 through a valve seat member insertion opening 11 and a standing passage 12. The outlet valve seat 13 is approximately cylindrical and has an outlet valve port 14 formed therein, and is airtightly inserted into the valve seat member insertion port 11 via an O-ring 15, with its tip opening opening into the condensate reservoir chamber 3. do.
A blind plug 16 is tightly fitted to the terminal end of the outlet valve seat 13, and this portion is held by a retaining member 17 screwed into the valve seat member insertion opening 11. 19
is a branch hole provided in the radial direction of the outlet valve port 17,
The fluid flowing in from the outlet valve port 14 rises and flows out in the direction of the passage 12.

A bimetal chamber 22 is formed on the upper inner surface of the upper body 1 by a retaining plate 21 fixed via a snap spring 20, and an exhaust passage 24 curves as shown in the figure at low temperatures to communicate the condensate reservoir chamber 3 and the outlet 10.
A bimetallic valve 23 for opening is arranged.

The action is as follows. Condensate flowing in from the inlet 7 flows into the condensate storage chamber through the inlet valve port 8. When the water level rises, it is detected and the float valve 1
8 rises, opens the outlet valve port 14, and the condensate rises and flows out through the passage 12 to the outlet 10.
When the water level drops after draining condensate, the float valve 18
descends and closes the outlet valve port 14. The above is normal trap operation.

Next, when the pressure on the secondary side of the trap becomes higher than the primary pressure, the condensate in the secondary side pipe flows backward into the condensate reservoir chamber 3 through the outlet valve port 14. When the water level rises, the float rises accordingly, blocking the inlet valve port 8 and stopping the backflow (the float valve is at position 25).
Further, at this time, the float valve is seated on the inlet valve seat due to the pressure difference between the secondary side and the primary side. Then, when the secondary pressure decreases again, the primary pressure causes
The float valve 18 is separated from the inlet valve seat, and the internal condensate is discharged to the secondary side.

During normal operation, it seems that the float valve 18 rises due to condensate flowing in from the inlet valve port 8 and blocks the valve port 8, but in this case, the primary side pressure is higher than the secondary side pressure, so the condensate does not flow. There is no problem because it flows out continuously from the outlet valve port 14.

Effect: A simple structure installed inside the trap can prevent the backflow of condensate, which was a problem in the past.
This eliminates the need to install a check valve separately.
It is low cost and improves the productivity of steam-using equipment by preventing backflow.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the invention. 1: Upper body, 2: Lower body, 3: Condensate storage chamber,
7: Inlet, 9: Inlet valve seat, 10: Outlet, 13: Outlet valve seat, 18: Float valve.

Claims (1)

[Claims] 1. An inlet valve seat is arranged in the upper part of a condensate reservoir chamber housing a float valve that opens and closes a valve opening by floating up and down, and communicates with the inlet through the valve opening,
A float-type steam trap characterized in that an outlet valve seat is arranged at the lower part of the condensate reservoir chamber and communicated with the outlet through the valve opening.