Centrifugal smoke exhausters of unilateral absorption like DN and D are intended for suction of combustion gases from fire chambers of the boiler units equipped with effectively operating systems of a zoloulavlivaniye and also for suction of combustion gases from fire chambers of oil-gas boiler units.
Smoke exhausters are calculated on a long operating mode indoors and in the open air in the conditions of a temperate climate (a climatic modification At, categories of placement 1, 2, 3 and 4, GOST 15150 — 69). Start of smoke exhausters is allowed at a temperature in a snail not below -30 °C. The maximum temperature of combustion gases on an entrance to the smoke exhauster should not exceed +200 °C.
A series of smoke exhausters consists of the DN and D types: DN-21, DN-19, DN-17, DN-15, DN-13, DN-12,5, DN-11,2, DN-10, DN-9, DN-8, DN-6,3, DN-5, D-3,5 and D-15,5.
For various erosive properties of the transported combustion gas smoke exhausters are manufactured in two executions:
- DN smoke exhausters with antiwear protection of internal surfaces of snails and shovels of driving wheels - basic execution;
- DN-GM smoke exhausters without antiwear protection for oil-gas boiler units.
Each standard size of smoke exhausters is made the right and left rotation with a console arrangement of the driving wheel. Rotation of a rotor clockwise is considered right if to take a detached view the electric motor. The main knots of smoke exhausters are the driving wheel, a running gear, a snail and the directing device.
The driving wheel of smoke exhausters consists of a krylchatka and a nave. Krylchatka represents the welded design consisting from 16 sheet back bent or forward the bent shovels located between the main (radical) and conic (covering) with disks. It should be noted that during the work on ozolenny combustion gases driving wheels of DN smoke exhausters differ in the increased wear resistance and are self-cleaning. So, in comparison with smoke exhausters of D type DN smoke exhausters in identical service conditions (i.e. at identical dust content of combustion gases and abrasivity of ashes) have almost doubled service life.
The running gear of smoke exhausters consists of a shaft, the connecting elastic vtulochno-manual coupling and bearings located in the cast case having the horizontal socket.
Smoke exhausters of the DN-12,5, DN-11,2, DN-10, DN-9, DN-8, DN-6,3, DN-5 and D-3,5 types are carried out without special running gear with direct landing of the driving wheel to an electric motor shaft. For protection of bearings of a rotor of the electric motor against an overheat heat which is transferred on a shaft from the driving wheel to electric motor bearings to smoke exhauster operating time, the driving wheel of smoke exhausters of this group has a special nave. Normal functioning of smoke exhausters (without overheat of bearings of the electric motor) is ensured at a temperature of external air which is not exceeding +40 °C.
Snail of smoke exhausters welded of sheet and profile steel. For creation of necessary rigidity of a wall amplify fins from squares and strips. The internal surface of a snail on forming is protected by the armored sheets replaced in process of wear.
For a vyem of a rotor of smoke exhausters (a running gear with the got driving wheel) on snails the removable sector is provided.
The snail of smoke exhausters No. No. 5-13 is delivered by manufacturer with a corner of a turn of a pressure head branch pipe from r =0 ° to r =270 ° through everyone 15 °, at the same time the edges of a snail preventing installation are cut.
For removal of the case of smoke exhausters on the soaking-up party it is necessary to have a removable site of the gas pipeline length not less:
- for the DN-9, DN-8, DN-6,3, DN-5 smoke exhauster - 400 mm;
- for the DN-10 and DN-11,2 smoke exhauster - 450 mm;
- for the DN-12,5 smoke exhauster - 550 mm;
I will eat away a rotor of smoke exhausters (the electric motor with the got driving wheel) it is carried out through an opening in a wall of the snail located between the main disk of a krylchatka and the electric motor. In working order this opening is closed by a removable diaphragm.
The operating mode of DN and D smoke exhausters is established by the axial directing device.
Shovels of the axial directing devices of smoke exhausters can turn from a corner 90 ° (the soaking-up opening is completely blocked) to 0 lakes. The directing devices of smoke exhausters are calculated on the drive from the electroexecutive MEO mechanism, are carried out manually. Smoke exhausters have to be installed on the base.
Metalwork of smoke exhausters has to become covered outside by a layer of thermal isolation.
The design of smoke exhausters is not calculated on perception of loadings from weight and thermal expansion of the bringing and taking away gas pipelines. The drive of smoke exhausters is carried out from asynchronous electric motors.
Productivity, total pressure, power on a shaft and efficiency of smoke exhausters of the DN series are defined on various operating modes.