Machine train for producing nitric acid

Abstract

A machine train for producing nitric acid includes: a steam turbine having a steam turbine rotor rotating at a first rotational speed; a first compressor having a first compressor rotor rotating at a second rotational speed; a second compressor having a second compressor rotor rotating at a third rotational speed; and an expander having an expander rotor rotating at a fourth rotational speed. The steam turbine drives the first compressor. The rotor of the first compressor drives the second compressor. The expander drives the second compressor. The second compressor is configured and efficiency optimized with respect to its third rotational speed such that during operation of the machine train the first rotational speed of the steam turbine, the second rotational speed of the first compressor, the third rotational speed of the second compressor and the fourth rotational speed of the expander are equal,

Claims

1. A machine train (102) for producing nitric acid, comprising: a steam turbine (10) having a steam turbine rotor (11) configured to rotate at a first rotational speed (n10); a first compressor (20) having a first compressor rotor (21) configured to rotate at a second rotational speed (n20); a second compressor (30) having a second compressor rotor (31) configured to rotate at a third rotational speed (n30); and an expander (40) having an expander rotor (41) configured to rotate at a fourth rotational speed (n40), wherein the steam turbine (10) is configured to drive the first compressor (20), and the rotor (11) of the steam turbine (10) is operationally connected to the rotor (21) of the first compressor (20) via a first coupling (K1), wherein the rotor (21) of the first compressor (20) is operationally connected to the rotor (31) of the second compressor (30) via a second coupling (K2) and drives the second compressor (30). Therein the expander (40) is configured to drive the second compressor (30) and the rotor (41) of the expander (40) is operationally connected to the rotor (30) of the second compressor via a third coupling (K3), and wherein the second compressor (30) is configured and efficiency optimized with respect to its third rotational speed (n30) such that during operation of the machine train (102) the first rotational speed (n10) of the steam turbine (10), the second rotational speed (n20) of the first compressor (20), the third rotational speed (n30) of the second compressor (30) and the fourth rotational speed (n40) of the expander (40) are equal.

2. The machine train according to claim 1, wherein the first compressor (20) is a radial compressor.

3. The machine train according to claim 1, wherein the second compressor (30) is an axial compressor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Exemplary embodiments of the invention are described by way of the description and the figures. Components marked with the same reference numbers have the same functionality. In the drawings:

[0023] FIG. 1 shows a schematic representation of a machine train for producing nitric acid according to the prior art; and

[0024] FIG. 2 shows a schematic representation of an inventive machine train for producing nitric acid.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0025] In EP 0 945 400 B1 the method for producing nitric acid is described. Furthermore, a plant for producing nitric oxide is described in this patent publication and, in addition to this, substantial chemical reaction equations applied during the production of nitric acid are shown.

[0026] The entire content of the patent publication EP 0 945 400 B1 is hereby incorporated by reference in its entirety in this application.

[0027] The description of FIG. 2 relates in particular to the required compressor units. With respect to individual process sequences, reference is made to EP 0 945 400 B1.

[0028] The inventive machine train for producing nitric acid is schematically shown in FIG. 2. The machine train (102) for producing nitric acid comprises a steam turbine (10) with a steam turbine rotor (11), which is configured for rotation with a rotational speed n10, a first compressor (20) with a first compressor rotor (21), which is configured for rotation with a rotational speed n20, a second compressor (30) with a second compressor rotor (31), which is configured for rotation with a rotational speed n30, an expander (40) with an expander rotor (41), which is configured for rotation with a rotational speed n40.

[0029] The steam turbine (10) is configured as a drive unit for the first compressor (20) and its rotor (11) is operationally connected to the rotor (21) of the first compressor (20) via a first coupling (K1).

[0030] The rotor (21) of the first compressor (20) is operationally connected to the rotor (31) of the second compressor (30) via a second coupling (K2) and drives the second compressor (30).

[0031] The expander (40) is configured as a drive unit for the second compressor (30) and its rotor (41) is operationally connected to the rotor (30) of the second compressor via a third coupling (K3).

[0032] The second compressor (30) is configured with respect to its efficiency-optimized rotational speed n30 such that during the operation of the machine train (102) the rotational speeds n10 of the steam turbine (10), the rotational speeds n20 of the first compressor (20), the rotational speeds n30 of the second compressor (30) and the rotational speeds n40 of the expander (40) are equal.

[0033] In a preferred further development of the invention, the first compressor is configured as radial compressor and the second compressor as axial compressor.

[0034] Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.