RU65138U1 - SEALING A TURBINE FROM FLUOR POLYMERS - Google Patents

Abstract

The utility model relates to power engineering, in particular, to turbine engineering.

A useful module solves the problem of creating a turbine seal, characterized by high operational reliability of the seal and the simplicity of its manufacture and operation.

To solve the problem in a turbine seal containing a housing in which at least one annular groove is made, in which an inner casing is placed and a fluoroplastic ring is rigidly fixed, having a protrusion and ribs on the outer surface, and antennae having an inclination on the inner surface .

Description

The utility model relates to power engineering, in particular to turbine engineering.

State of the art

Turbines, like all rotating units in the places where the shaft exits the housing, have seals between the shaft, the housing and the diaphragms. Depending on the installation site, three types of seals are distinguished: end, over-band and diaphragm. External seals are designed to reduce leakage of the working fluid (steam, gas) at a pressure above atmospheric, or to prevent the penetration of outside air into the body at a pressure below atmospheric.

All known labyrinth seals are characterized by design complexity, determined by safety conditions due to the impact of the rotor shaft by the seal. At the same time, the problem of deflection of the shaft in operation when the rotor is touched by the seal remains unsolved. In this case, the seal segments and the shaft surface fail.

The complication of seal designs, on the one hand, the use of various materials in them to reduce gaps, is sometimes negated by the practice of installation, adjustment and repair of seals, when, due to insufficient qualifications of specialists, the gaps are set to maximum instead of the minimum, which sharply reduces the turbine's efficiency. When tightly installed seals on the shaft, the sealing antennae wear out the shaft surface.

A labyrinth seal is known, consisting of a body having recesses, in which there are usually six (three by half) segments of the Christmas tree type, where the antennae are machined for high and medium pressure cylinders along with the rings, and in low pressure cylinders brass antennae are made from sheet brass.

The principle of operation of a seal of any design is to ensure a minimum vapor pass through a series of small gaps, therefore, the requirements for the reliability of the seal are quite high, and the main task of the developer of such seals is to provide a seal having radial clearances, characterized by ease of assembly, ease of repair, and ease of disassembly with minimal labor costs for both the manufacture of the seal and its repair.

Existing seals are characterized by rather complicated manufacturing methods.

All of the above disadvantages are solved by the improved seal described below.

For the prototype of all analogues, we select the turbine seal described in the description of the utility model for application No. 98119014/20 certificate No. 10422 of July 16, 1999

In this utility model, according to the formula, the seal comprises a housing in which at least one annular groove is made, in which a ring is provided that has a protrusion on the outer side and an antenna on the inner surface, and the protrusion and antennae are made of the same material that the ring is based on fluoropolymer and has a radial cut. We take this model as an analog and, naturally, as a prototype.

A useful prototype model has a straight antennae, which is a weak design factor.

Utility Model Disclosure

The utility model shows the operability of all operational factors inherent in it, the main of which is the absence of medium flow in both directions: the density of the sealing ring was achieved by chaotic curvature of the antennae on the uneven surface of the existing shaft.

The curvature and undermining of the pointed antennae is also observed in the shaft processed according to the drawing conditions.

Thus, in all cases of installation of the ring, even taking into account the coefficient of linear expansion F-4, there is a negative factor of the incorporated design. Namely, in case of deviation of the rotor vibration above the nominal, there is a natural wear of the straight antenna.

In the proposed utility model, antennae having a certain slope are performed.

This seal does not have a decrease in its level of technology, but exclusively increases it by an order of magnitude.

It is known that the most applicable in the practice of this unit and used in the working order fluoroplastic-4 has low thermal conductivity, which gives a wide opportunity to vary by various technologies and implementation methods.

The essence of the utility model as a technical solution is expressed by one sign sufficient to achieve the technical result provided by the utility model. A feature of the utility model is the inclination of the antennae. The causal relationship of the sign is determined by the technical effect, a property that manifests itself after manufacture, installation, operation. The technical result is expressed as a decrease in the coefficient of friction, wear of the antennae, minimization of gaps. The antennae are processed easily, which is characteristic of fluoroplast-4 with virtually no clearance on the shaft.

In this embodiment, the seal remains in operation for all overhauls.

Brief Description of the Drawings

The utility model is illustrated by an example implementation. The figure 1 shows a radial section of a fluoroplastic ring mounted in a cage and representing the end seal.

The device has a shaft (pos. 1), an internal cage (pos. 2), a housing (pos. 3), a PTFE-4 ring (pos. 4) with antennae (pos. 5). As can be seen in figure 1, the sealing antennae (pos. 5) have a straight shape.

Figure 2 also shows a seal having a shaft (pos. 1), an internal cage (pos. 2), a housing (pos. 3), a fluoroplastic ring F-4 (pos. 4) with antennae (pos. 5), which differs from figure 1 the fact that a number of antennae (pos. 5) are made inclined.

In accordance with the claimed utility model, the fabricated seal shown in Figure 2 eliminates all the above-described disadvantages; a complete test was passed at one of the CHPPs of the Sverdlovsk Region. The test results and the operation of the seal are positive, fully consistent with the above technical result.

Literature:

1. Certificate No. 10422 for the utility model "Turbine Seal".

Claims (1)

A turbine seal of fluoropolymers for low-pressure cylinders, comprising a housing in which a cage with external and internal processing is made and installed to place it in the housing and rigidly fix the fluoropolymer ring in it, having one radial section with antennae cut on the inner surface, characterized in that the antennae are made oblique.