DE2837969A1 - TURBO COMPRESSORS - Google Patents

Description

DEMAG Aktiengesellecbaft. M8. August 1978 Wolfgang-Reuter-Placz. (f .. 15898 - C / Schi 4100 Duisburg

Turbo compressor

Turbo compressors are currently driven by turbines (steam and gas turbines) or by electric motors via a gearbox and a clutch.

The turbines are usually directly - without the interposition of a gearbox - coupled to the compressor, whereby there is the possibility of changing the speed to adapt to different operating states of the turbo compressor.

When using electric motors, a transmission with a low-speed or high-speed clutch is usually required interposed, whereby a speed adjustment of the usual electric motor drives with approx. 1500, 1800, 3000 and 3600 min " is possible.

Driving by a steam turbine is fraught with disadvantages, the most common of which are the following: - If no process steam is available cheaply, the power generation is in comparison to the power generation in a large power plant because of the significantly poorer efficiency associated with significantly higher costs;

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- the probability of a failure of the steam turbine system is significantly higher in comparison to the electric motor, so that the operational safety and availability of the entire system is adversely affected;

- In addition to the lubricating oil system, a relatively complex one Control oil circuit required.

When operated by an electric motor with the interposition of a gearbox, inter alia. the following disadvantages:

- a speed change required for process reasons is in the Normally not possible without cumbersome measures (exchange of the gear set). The installation of a fluid coupling is only possible for smaller services.

- The wear of the gearbox as well as additional causes of failure of this component reduce the operational safety and availability of the system.

- Two to five percent of the drive power is converted into losses in the transmission. Since the heat loss with the Lubricating oil must be removed, a significantly enlarged oil system is required.

The object of the invention is to create a motor-driven turbo compressor which avoids the disadvantages indicated, rather it guarantees a wide control range with a high degree of efficiency.

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According to the invention, this object is achieved by the features of the characterizing part Part of claim 1 solved. Advantageous further developments of the invention are in the subclaims contain.

It is true that various embodiments of turbomolecular pumps are known from high vacuum technology. you reach Pressure values in the molecular pressure range, d. H. about between

—2 —9
10 and 10 ~ Torr. Pumps of this type, which z. B. used to generate a hydrocarbon-free high vacuum, work at a speed of about 20,000 rpm. So is z. B. a turbo molecular pump (DE-OS 23 49 033) is known with a vertical rotor which is mounted on a vertical mandrel fixed to the housing. The storage is in the fore-vacuum space overlapped by the hollow rotor. The rotor is mounted opposite the mandrel in a magnetic axial bearing and in at least one magnetic radial bearing, which are located within the space overlapped by the rotor.

In the case of turbo molecular pumps of this type, the pump part is indeed directly coupled to the drive motor, but the structure of the turbo molecular pumps and the turbo compressor is necessary by different purposes as well as parameters - in general fundamentally different. For the turob molecular pumps motors with low powers, on the order of a few hundred watts, are used.

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Furthermore, from DE-OS 26 58 687 a bearing device for a long shaft, in particular for a turbo machine rotor, known. This shaft has two radial bearings in the area of the shaft ends, at least one of which is an electromagnetic one balanced radial bearing is. The bearing consists of a ring armature mounted on the shaft and a den Ring anchor with a narrow gap surrounding the fixed magnetic core. The bearing is in the area between the ends Radial bearings held end portions of the shaft arranged. To regulate the central electromagnetic radial bearing in the sense of supporting the shaft, sensors for the radial position are located in the free axial area between the end bearings the shaft provided.

A blower with smaller powers is also known (DE-AS 20 51 826), in the rotor of which an electric motor is arranged is. The stator of the motor is connected to the fan housing, with the rotor hub on a shaft fixed to the housing is supported at the outer end via a tubular intermediate body connected in a rotationally fixed manner to a bearing bush.

By the arrangement according to the invention, wherein the turbo compressor rotor is directly coupled to the drive motor shaft, it is possible for turbo compressors with the defined speed range to avoid all the disadvantages mentioned at the beginning.

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At high speeds of the motor-compressor train, there is a wear-free, actively damped bearing of the rotor shaft Particularly suitable when avoiding large shaft misalignments. For this purpose, an electromagnetic regulated Radial bearings are used.

The exemplary embodiments of the invention shown schematically in the accompanying drawings are for explanation purposes of the invention described in more detail below.

Show in the drawings

Fig. 1 shows a motor-compressor train according to the invention and 2 shows an embodiment of the motor-compressor train according to the invention with electromagnetic bearings.

As FIG. 1 shows, 1 is a high-speed, speed-controllable Electric motor with a power of 4000 kW and one

Speed n ". = 7000. min ". To the output Mo t, max

The rotor shaft 2 of the motor 1, which is extended on the side, is the rotor of a two-stage radial turbo compressor 3 for compression connected by nitrogen to a final pressure of 35 bar via a coupling 4. The shaft 2 and the rotor shaft run in plain bearings 5. The shaft is axially guided by a hydraulic axial bearing 6, which also provides the axial thrust catches.

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The modified motor-compressor train according to FIG
a high-speed, variable-speed electric motor 10 and a two-stage compressor. The output shaft of the
Motor 10 is directly connected to the rotors and the first and second stages without a clutch. The compressor 12, 13 is thus arranged coaxially with the motor 10. Between the first
and the second stage, a regulated electromagnetic radial bearing 14 is provided which has a magnetic core 15 which surrounds the ring armature 16 connected to the shaft.
The air gap between core and armature is monitored by sensors.

The shaft runs in plain bearing 5. This is for axial guidance Thrust bearing 6 is provided. Instead of plain bearings 5 and axial bearings, electromagnetic bearings can also be provided.

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Claims (1)

15898 - C / Ski 8/28/78 Claims 1. \ Turbo compressor with a drive motor, characterized by the use of a high-speed electric motor for a turbo compressor with a speed range η = χ 10 ⁵ Ί / 1
P. for η> 4000 ü min ^X and
P> 50 kW and
χ (kW ^1/2 min " ¹ ) between 1 and 25, the motor shaft with the rotor of the turbo compressor is directly coupled without the interposition of a transmission. Turbo compressor according to claim 1, characterized in that that a speed controllable electric motor is used. Turbo compressor according to Claims 1 and 2, characterized in that that the coefficient χ for compressors with a casing with a parting line (cup design) running perpendicular to the rotor axis has a value between 3 and 15. 030010/0402 15898 - C / Schi '* "- 28.8.78 4. Turbo compressor according to claims 1 and 2, characterized in that that for turbo compressors for compressing air the coefficient χ has a value between 3 and 12. 5. Turbo compressor according to claims 1 and 2, characterized in that that for turbo compressors for compressing ethylene, propylene or cracked gas the coefficient χ has a value between 3 and 11. 6. Turbo compressor according to claims 1 and 2, characterized in that that for turbo compressors for compressing chlorine and hydrogen chloride the coefficient χ has a value between 2 and 15. 7. Turbo compressor according to claims 1 and 2, characterized in that that for turbo compressors to compress nitrogen the coefficient χ has a value between 5 and 11. 8. Turbo compressor according to claims 1 and 2, characterized in that that the coefficient χ has a value between 5 and 14 for turbo compressors for compressing oxygen. 030010/0482 15898 - C / Schi .3. 8/28/78 9. Turbo compressor according to one or more of claims 1 to 8, characterized in that the shaft of the electric motor and / or the shaft of the The compressor rotor is (is) magnetically supported. 10. Turbo compressor according to claim 9, characterized in that the motor (10) and the compressor (12,13) have a common Have shaft without coupling. 11. Turbo compressor according to claim 9, characterized in that the motor shaft is firmly connected to the compressor shaft is. 030010/0482