Purpose

The G and Y6-51 induced draft fans are mainly used in the induced draft systems of 2t/h~670t/h steam boilers in thermal power plants, and also meet the high-pressure head performance parameters of fluidized bed boilers. This series of fans can also be used for dust removal, mine ventilation, and general ventilation systems.

The medium transported by the supply fan is air, and the medium transported by the induced draft fan is flue gas or gas containing particulate matter. When the impurity concentration is less than 200mg/m³, it can be used for more than four years. If the impurity content is high, it can still be used, but the service life will be shortened. The maximum operating temperature of the induced draft fan should not exceed 250℃.

Type

Supply fans and induced draft fans are usually made in a single-suction type. There are 20 model numbers for N8D~29.5D, totaling 40 specifications.

Each fan can be made in either left-hand or right-hand rotation. Viewed from the motor end, the impeller rotating clockwise is called a right-hand rotation fan, indicated by "right"; otherwise, it is called a left-hand rotation fan, indicated by "left".

The outlet position of the fan is indicated by the outlet angle of the casing.

The fan drive method is type D, i.e., cantilever structure, and the motor and fan are connected by direct drive with an elastic coupling.

Examples of full product names are as follows: G6-51-1N18D right 90°, Y6-51-1N18D left 0°. Among them, G and Y represent boiler supply fan and boiler induced draft fan respectively, 6 is the pressure coefficient at the highest efficiency point multiplied by 10 and rounded, 51 is the specific speed, 1 is the first design, N18 represents the impeller diameter of 1800mm, and 90° is the outlet angle.

Features

1. The design of this series of fans is based on aerodynamic diagrams finalized after more than a year of model tests and adopts patented technology of "adjustable inlet"; advanced proprietary technologies such as high-strength wear-resistant impellers, oil-proof bearing housings, and self-aligning axial adjusting doors.

2. Wide range of high-efficiency operating conditions, dense arrangement of model numbers, easy to select high-efficiency operating points.

3. Patented technology of "adjustable inlet centrifugal fan".
This patented technology is adjusted to the ideal position during fan installation.
If there is friction during fan operation, the inlet can be adjusted to the ideal position. During fan maintenance, the inlet is adjusted axially to disengage from the impeller, and the rotor can be vertically lifted out.

4. High-strength wear-resistant impeller. The impeller adopts a near-diameter, backward single-plate blade, which reduces airflow impact, improves stability, and prevents motor overload. It overcomes the shortcomings of the original 4-73 type airfoil hollow blade, such as ash entering the interior after wear, ash causing vibration due to non-working area, etc. The easily worn parts of the induced draft fan blades are welded with wear-resistant welding wire for fans, greatly extending the service life of the fan. This type of fan has high pressure coefficient, low peripheral speed, and low noise, thus good practicality.

5. Oil-proof bearing housing

It adopts a lap-type oil thrower ring to throw the oil brought up by the high-speed rotating bearing to the inner wall of the bearing housing and flow back to the oil sump; the semi-open aluminum oil seal, in addition to facilitating maintenance and preventing friction accidents, can increase the resistance along the axial direction to intercept some thin oil back to the oil sump; the outer pressure packing is to block a small amount of thin oil; the top of the bearing housing is equipped with a vent plug to reduce the slight positive pressure in the bearing housing, ensuring no oil leakage and good dust prevention performance.

6. Self-aligning axial adjusting door
The pivot points of the guide vanes of this adjusting door are equipped with self-aligning bearings. There is no "dead" point during operation and adjustment, so the adjustment is flexible, labor-saving, safe and reliable, ensuring that the actuator is not overloaded, and it can also be used outdoors.

7. This fan is assembled in a whole or in parts. This series of fans N O The transmission group, motor, and coupling cover below 16D are assembled on a complete base before leaving the factory; the casing, inlet, and adjusting door are another base. Small-sized fans are assembled into two bases before leaving the factory, and large-sized fans are disassembled and assembled into three bases (the motor is another base).

8. This fan is fully equipped
Adjusting door, coupling cover, inlet and outlet flange, foundation bolts for the whole machine, inlet and outlet flexible connection, and vibration measuring instruments for medium and large-sized models. According to the needs, it can also be equipped with a complete set of actuators, vibration dampers, and silencers, etc.

10. Complete relevant parameters provided
Main component weight, static and dynamic loads, rotor flywheel torque, resistance torque curve during fan start-up, resistance torque of the adjusting door, and external dimensions, etc. With the sample of this series of fans, construction design can be carried out.

11: This fan is convenient for installation and maintenance
This fan has two complete bases, casing and transmission group. The casing has a central dividing surface or vertical dividing surface, which is particularly convenient for disassembly and assembly; the rotor can be vertically lifted out, and if only the impeller needs to be replaced, it can also be disassembled and assembled axially.

12. Key quality assurance measures for products
(1) Design and manufacture according to national and industry standards.
(2) Fan performance is obtained by similar conversion based on fan model tests.
(3) Non-destructive testing is carried out according to the standard when the fan impeller diameter is greater than 2m or the peripheral speed exceeds 100m/s. (4) Reinforced blades are used when the impeller peripheral speed is high, and wear-resistant welding rods are used for welding on the easily worn parts of the induced draft fan blades. Users can weld them themselves after on-site wear.
(5) Flexible connections are provided at the inlet and outlet of the fan to prevent stress interference caused by deformation of the pipeline and fan. (6) SKF imported rolling bearings are used for ventilation fans from №14D to 29.5D.
(7) N O Above 16D, vibration protection devices are provided to prevent damage to the unit due to vibration.

Operation

I. Fan operating procedures:
Before starting the fan, the following preparations should be made
1. Close the regulating valve.
2. Check the clearance dimensions of each part of the fan, and whether there is any scraping or collision between the rotating parts and the fixed parts.
3. No one is allowed to stand near the impeller radius or the coupling.
4. Check if the bearing box oil level meets the standard.
5. Check whether the electrical circuits and instruments are correct. 6. Check whether the cooling part is normal. After the fan starts and reaches the normal speed, gradually open the regulating valve until the specified load is reached. During operation, the bearing temperature rise must not exceed 40℃, and the surface temperature must not exceed 80℃. If the temperature rise is too high, water cooling can be used. Generally, 0.5~1m³/h is considered. If the effect is not good, the water flow can be appropriately increased.

II. Emergency stop of the fan:
Emergency stop must be performed under the following circumstances:
1. The fan has a loud noise.
2. The bearing temperature rises sharply.
3. The fan vibrates violently or there is an impact sound.

Maintenance

1. The fan must not be operated with any problems.
2. The fan must be shut down and the power must be cut off before debugging and repairing.
3. Regularly remove dust, dirt, water and other impurities from inside the fan, and prevent rust.
4. Regularly check the sensitivity of the thermometer and oil level gauge.
5. In addition to replacing the lubricating oil after each disassembly and repair, the lubricating oil should be replaced every 3 to 6 months under normal circumstances.

Single-unit supply scope

1 set of ventilation fan
1 complete set of foundation bolts
1 set of coupling cover
Thermometer N O Nos. 8D~16D are 2 bimetallic temperature switches with electrical contacts, N O 17D~29.5D are 2 bimetallic thermometers and 2 platinum resistance thermometers. N O Vibration meter is equipped for 17D and above. (As per contract)
Inlet and outlet soft connection.
One motor (without electrical equipment) (subject to the order contract).
Random drawings (provided with the product) Fan general drawing parts list: 1 copy Fan general drawing: 1 copy Instructions or sample 1 copy