Centrifugal blower type 540-41-1 is designed to compress nitrous gas and supply it to the production line for the production of weak nitric acid.
Brief description of the design. The unit consists of a supercharger and a built-in turbo-expander, a step-up gear, a drive motor and systems: oil, heat engineering control, control, protection and signaling.
A longitudinal section of a 540-41-1 gas blower is shown in Fig. 52, installation drawing _ in FIG. 53, and its gas-dynamic characteristics are shown in Fig. 54.
The blower is a single-cylinder, four-stage, single-suction machine with labyrinth end seals.
The turboexpander is a two-stage turbine of the active type and serves to reduce the power consumption for the compression of nitrous gas in the supercharger. The turboexpander uses the energy of tail gases - waste in the production of weak nitric acid.
The parts of the supercharger and the turboexpander are made of special alloy steels, which ensure their corrosion resistance.
The end seals are labyrinth type, with an intermediate chamber on the turbo expander side. The tail gas / air mixture that has leaked into the intermediate seal chamber is discharged into the suction of the blower.
The blower casing has a high temperature, therefore it is covered with a special casing that allows ventilation of the casing.
Reducer type Р2100 / 2.83 with double-sided helical gearing is designed to increase the rotational speed of the supercharger rotor from 2980 to 3455 rpm.
The supercharger is driven by an asynchronous electric motor with a squirrel-cage rotor, type 2АЗМП-1600/6000-U4 with a power of 1600 kW, a voltage of 6000 V, and a rotational speed of 2980 rpm.
The supercharger with the gearbox and the electric motor are connected by means of gear couplings.
The oil system of the unit provides forced lubrication of the “bearings of the unit, as well as the supply of oil to the gear train of the reducer, gear couplings and protective devices.
The supercharger, having a constant mode of operation, is not equipped with a device for automatic regulation. The performance of the blower is maintained by constantly changing the ratio of nitrous gases and additional air.
The heat engineering control, protection and alarm system provides for control of the blower two panels: local and remote.
A local panel with devices for starting the unit is located directly at the blower. The remote control and monitoring board is equipped with emergency and warning, as well as technological light alarms, "devices for remote measurement of operating parameters and shutdown of the unit.
The unit is equipped with protection devices against axial displacement of the blower rotor, lowering oil pressure in the lubrication system and gas pressure by; suction of the blower, temperature rise in the bearings of the unit.