Traps

The steam trap is also called a steam block drain valve, a steam trap, a steam trap, a return water box, a water return door, and the like. Its function is to automatically drain the continuously generated condensate without letting the steam out.

There are many types of traps, such as float type, float type, bell-shaped float type, pulse type, thermodynamic type and thermal expansion type. Commonly used are buoy type, bell-shaped float type and thermodynamic type.

(1) Float type traps, float type traps, mainly composed of valves, shafts, pipes, buoys and casings. When the condensate in the equipment or pipeline enters the trap under the pressure of the steam, it gradually increases until it is close to the pontoon. As the weight of the pontoon exceeds the buoyancy, it falls down, causing the throttle valve to open. This causes the condensate in the cylinder to be discharged through the conduit and valve under the action of vapor pressure. When the condensate in the pontoon is nearly exhausted, the float is lifted upward due to the weight reduction of the pontoon, the throttle valve is closed, and condensed water is accumulated in the pontoon. This works periodically, which automatically discharges condensate and prevents steam from escaping.

(2) Bell-shaped float traps Bell-shaped float traps, also known as bucket-type traps (mainly consisting of regulating valves, buckets, casings and filter units). The bucket inside the trap is inverted and initially lowered. The regulating valve is opened. When the cold air and condensate in the equipment or pipeline enter the trap under the pressure of the steam, it is discharged by the regulating valve. On the one hand, when the steam and the small amount of air that is not discharged gradually fill the internal volume of the bucket, At the same time, the condensed water is continuously accumulated, the bucket rises due to the buoyancy, the regulating valve is closed, and the condensed water is stopped. On the other hand, a small portion of the steam and air inside the bucket is discharged from the small hole at the top of the bucket, and most of the condensation is condensed. The liquid is formed so that the buoyancy of the bucket gradually decreases and falls, the regulating valve is opened, and the condensed water is discharged again. This periodically works to automatically discharge the condensed water and prevent the steam from escaping.

(3) Thermodynamic steam trap When the condensate in the equipment or pipeline flows into the choke drain valve, the steam in the variable pressure chamber will condense to reduce the pressure, and the force under the valve plate is greater than the above force, so the valve The top of the piece. Because the condensed water has a higher viscosity than the steam and the flow rate is low, the negative pressure between the valve plate and the valve bottom is not easy to occur, and the condensed water does not easily flow into the pressure changing chamber through the gap between the valve plate and the outer casing, so that the valve plate remains open and condenses. Water flows through the annular trough.

When the steam in the equipment or pipeline flows into the trap, since the viscosity of the steam is smaller than the condensed water and the flow rate is high, the valve plate and the valve seat are likely to cause a negative pressure, and at the same time, part of the steam flows into the pressure changing chamber, so that the valve plate is above. The force is greater than the force below, allowing the valve to close quickly. This works periodically, which automatically discharges the condensate and prevents the steam from escaping.