Mechanical Traps

Mechanical Traps


The mechanical traps use the density difference between the condensed water and the steam, and through the change of the condensed water level, the float lifts and drives the disc of the valve to open or close so as to achieve the purpose of preventing steam and drainage. The subcooling degree of the mechanical trap is small, and it is not affected by the working pressure and temperature changes. Water is discharged immediately, and there is no water in the heating equipment, so that the heating equipment can achieve the best heat exchange efficiency. The maximum back pressure rate is 80% and the working quality is high. It is the most ideal trap for the heating equipment in the production process. Mechanical traps include free float types, free semi-float types, lever floating ball types and inverted bucket types.
 
1. Free float traps
The structure of the free float trap is simple. There is only a stainless steel hollow floating ball with finely ground moving parts inside. It is both a float and an opening and closing part. It has no vulnerable parts and a long service life.
 
When the equipment is just started, the air in the pipeline is discharged through the Y series automatic air exhaust device. The low-temperature condensed water enters the trap, and the liquid level of the condensed water rises. The floating ball rises, and the valve opens; the condensed water is quickly discharged, and the steam enters the equipment quickly. The equipment heats up rapidly. The temperature-sensing liquid of the Y series automatic air exhaust device expands, and the automatic air exhaust device closes. The steam trap starts to work normally. The floating ball rises and falls with the condensate level, and the steam is blocked and the water is drained. The valve seat of the free floating ball trap is always below the liquid level, forming a water seal, and there is no steam leakage, which has good energy saving effect. The minimum working pressure is 0.01Mpa, and it is not affected by temperature and working pressure fluctuations within the range from 0.01Mpa to the highest working pressure, and it continuously drains. It can discharge condensed water at saturation temperature, and the minimum subcooling degree is 0℃. There is no water in the heating equipment, so that the heating equipment can achieve the best heat exchange efficiency. The back pressure rate is greater than 85%, making it one of the most ideal steam traps for production process heating equipment.
 
2. Free semi-floating ball traps
The free semi-floating ball trap has only one semi-floating ball barrel as the moving part, with the opening facing down, and the ball barrel is both the opening and closing part and the sealing part. The entire sphere can be sealed, which has a long service life, no wearing parts, no steam leakage, and is resistant to water hammer, trouble-free and durable. The back pressure rate is greater than 80%, which can drain the condensed water at the saturation temperature. The minimum subcooling degree is 0℃, and there is no water in the heating equipment, so that the heating equipment can achieve the best heat exchange efficiency.
 
When the device is just started, the air and low-temperature condensate in the pipeline enters the trap through the launch tube. The bimetallic sheet emptying element in the valve bounces the ball bucket; the valve opens, and the air and low-temperature condensate are quickly discharged. When the steam enters the ball barrel, the ball barrel generates upward buoyancy. Meanwhile, the temperature in the valve rises, and the bimetal emptying element shrinks; the ball barrel floats to the valve port, and the valve closes. When the steam in the ball barrel turns into condensed water, the ball barrel loses buoyancy and sinks. When the valve is opened, the condensed water is quickly discharged. When the steam enters the ball barrel again, the valve is closed again, which works intermittently and continuously.
 
3. Lever floating ball traps 
The basic features of the lever floating ball trap are the same as those of the free floating ball type. The inner structure of the lever floating ball trap is that the floating ball connected with the lever to drive the valve spool to open and close the valve with the rise and fall of the condensate level. The lever floating ball trap uses double valve seats to increase the condensate displacement, which can achieve a small volume and a large displacement, and the maximum drainage capacity can reach 100 tons/hour. It is the most ideal trap for large heating equipment.
 
4. Inverted bucket traps
The inside of the inverted bucket trap is an inverted bucket as a liquid level sensitive component. The opening of the bucket is downward, and the inverted bucket connected with the lever drives the valve core to open and close the valve. The inverted bucket trap can discharge air, is not afraid of water hammer, and dirt resistant. The degree of subcooling is small, and the steam leakage rate is less than 3%; the maximum back pressure rate is 75%. There are many connectors, and the sensitivity is not as good as that of the free floating ball trap. Because the inverted bucket trap relies on the upward buoyancy of steam to close the valve, when the working pressure difference is less than 0.1MPA, it is not suitable to be used.
 
When the device is just started, the air and low-temperature condensate in the pipeline enters the trap, and the inverted bucket falls under its own weight. The lever connected to the inverted bucket drives the valve spool to open the valve, and the air and low-temperature condensate are quickly discharged. When the steam enters the inverted bucket, the steam in the inverted bucket generates upward buoyancy, and the inverted bucket is connected to the lever to drive the valve core to close the valve. There is a small hole on the inverted bucket. When a part of the steam is discharged from the small hole, the other part of the steam produces condensed water; the inverted bucket loses its buoyancy and sinks down by its weight. The inverted bucket is connected to the lever to drive the valve core to open the valve, works circularly, and discharge the water discontinuously.
 
5. Combined superheated steam traps
The combined superheated steam trap has two isolated valve cavities, and the upper and lower valve cavities are connected by two stainless steel pipes. It is a combination of a floating ball type and an inverted bucket type, which has advanced and reasonable structure. It is a special trap for superheated steam, and has obtained two national patents, filling the domestic gap.
 
When the condensed water enters the lower valve cavity, the float ball of the auxiliary valve rises with the liquid level, and the floating ball closes the steam inlet pipe hole. The condensed water rises to the main valve cavity through the water inlet conduit, and the inverted bucket falls down by its own weight, which drives the valve core to open the main valve and discharges the condensed water. When the condensate level in the auxiliary valve cavity drops, the floating ball drops with the liquid level and the auxiliary valve opens. The steam enters the inverted bucket in the upper main valve cavity from the steam inlet pipe; the inverted bucket generates upward buoyancy, which drives the valve core to close the main valve. When the condensed water level in the auxiliary valve cavity rises again, the next cycle starts again, and the drainage is performed discontinuously.