Steam Boiler sewage is a key part of the normal operation of the boiler, the regular sewage device is also a key device. In operation, due to the continuous evaporation of the furnace, concentrated, so that the salt content of water is increasing. The so-called sewage that is continuous or regular discharge from the furnace part of the high concentration of salt water. To achieve the purpose of maintaining the quality of the furnace and the exclusion of the bottom of the boiler sludge, scale and other impurities purposes, which is the main role of sewage, and its second role is when the boiler full of water or shutdown when the discharge of water.
The regular sewage device is located in the Steam Boiler drum, the lowest point of the tank, usually by the two series of sewage valve and sewage pipe composition. Commonly used sewage valve has a cock type, rack gate type, swing gate type, slow open gate type and other types.
1. Cylindrical Drain Valve
The plug-type bleed valve consists of two parts: the spool and the valve body, as shown in Figure 6-12. The spool was large and small under the conical shape, the middle open to the oblong to the perforation to flow furnace water. When the spool is rotated 906, its long hole is in contact with the valve body and the valve is closed. The upper part of the spool is sealed with the packing and the valve body. This valve is fast open type, is characterized by simple structure, but the spool is very susceptible to thermal expansion, so that the spool rotation difficult, so now less used, only in the p <O. LMPa E2 level vertical horizontal Steam Boiler is still There are applications.
2. Rack gate type sewage valve
Rack gate valve is mainly composed of rack, gate, valve seat and valve body and other components. As shown. A small gear is engaged with the rack on the swing shaft of the handle, and the lower part of the rack is connected to the gate. The gate is made of two sleeves, and the middle spring pushes the sleeve on both sides so that the ram is close to the seat and the contact surface is tight. When the handle swing, the pinion rotation, while driving the rack and the shutter on the move, the gate will quickly open. Is fast open type.
3, swing gate type
Swing gate-type sewage valve main handle, drive shaft, valve plate and valve body and other components. As shown in the figure, the gate is composed of two valves, the middle of the spring to push the valve on both sides, so that the gate pull the valve seat, keep the contact surface tight. One end of the shutter is connected to the drive shaft, and the center line of both the handle shaft and the drive shaft is not on the same straight line (equivalent to the crankshaft rotation). When the handle is turned, the drive shaft and the shutter are swung. So as to achieve the purpose of opening and closing the channel. This kind of valve action agility, pollution effect is good, is fast open type.
4, slow open gate valve
Slow open gate type sewage valve structure and rack gate type is roughly the same, as shown in the figure, the lips is replaced with a screw to replace the rack, the top of the valve with hand wheel. When used with other ordinary gate valve, turn the hand wheel to open or close the valve. Compared with the quick opening valve, open and close the time required for a long time, so called slow open gate valve, is slow open type.