G4-73 Y4-73 Steel Centrifugal Blower Induced Draft Fans For Boiler Ventilation

G4-73 Y4-73 Steel Centrifugal Blower Induced Draft Fans For Boiler Ventilation

1. Overview

G4-73 Y4-73 Steel Centrifugal Blower and Induced Draft Fans are suitable for ventilation and induced draft fan systems of steam boilers with a capacity below 670t/h in thermal power plants. When there are no other special requirements, G4-73 can also be used for mine ventilation and general ventilation.
The medium transported by the ventilator is air, and the maximum temperature shall not exceed 80°C; the medium transported by the induced draft fan is flue gas, and the maximum temperature shall not exceed 250°C.
In front of the induced draft fan, a dust removal device must be installed to reduce the dust content of the flue gas entering the fan as much as possible. According to general power plant usage conditions, the dust removal efficiency shall not be less than 85%.

2. Feature

(1) The Centrifugal Ventilator and Induced Draft Fans are made of single suction, each with a total of 12 machine numbers N28~28.
(2) The fan has two rotation directions: left and right. Viewed from one end of the motor, the impeller rotating clockwise is called a right-hand fan, represented by "right"; the impeller rotating counterclockwise is called a left-hand fan, represented by "left".
(3) The outlet position of the fan is expressed by the angle of the air outlet of the casing.
(4) The transmission mode of the fans is D type, and they are all driven by elastic couplings.

3. Specification

4. Structure

The Centrifugal Ventilation Fans are mainly composed of impeller, casing, air inlet, regulating door and transmission part.

(1) The impeller consists of 12 backward-inclined airfoil beveled blades welded between the conical arc-shaped front disk and the flat-shaped rear disk. The use of airfoil-shaped blades ensures high efficiency, low noise, and high strength of the fan. The impeller has been calibrated by static and dynamic balance, so it runs smoothly. The impeller structures of the ventilation and induced draft fans of the same machine number are the same.

(2) The casing is a volute body welded with ordinary steel plates. The casing of the single suction fan is made into three different forms (Ng8~12 casing is made of an integral structure and cannot be disassembled, N214~16 casing is made of two-opening type, and N218~28 casing is made of three-opening type). The induced draft fan and scroll plate are appropriately thickened to prevent wear.

(3) The convergent and streamlined air inlet is made into an integral structure and fixed on the inlet side of the fan with bolts.

(4) The device used to adjust the flow rate of the fan is installed axially in front of the air inlet. The adjustment range is from 0° (fully open) to 90° (fully closed). Adjust the door's lever position, looking at the right side from the direction of the air inlet. For a right-hand cyclone fan, pushing the lever from bottom to top will change the direction from fully closed to fully open; for a left-hand fan, pulling the lever from top to bottom will change from fully closed to fully open. to full open direction.

(5) The main shaft of the transmission part is made of high-quality steel, and this fan uses rolling bearings. There are two types of bearing boxes: N28~16 use an integral cylindrical bearing box; N218~28 use two independent pillow-type bearing boxes. The bearing box is equipped with a thermometer and oil level indicator (only for induced draft fans). The lubricating oil is L-AN46, a total loss system oil. The amount of oil added is in accordance with the requirements of the oil level mark. If grease is used in the N28~16 integral cylindrical bearing box, an oil baffle should be added to the ball side of the bearing box, and its fixing groove has been prefabricated. The induced draft fan is equipped with a water cooling device, so a water pipe must be installed. The water consumption varies with the temperature, and is generally considered to be 05~1m²/h.