US 5,823,740 A · Dissolved gas augmentation with mixing chambers

Abstract

A shrouded turbine for enhancing the levels of dissolved gas such as oxygen in water flowing therethrough. The turbine comprises a rotatably mounted runner, a stationary discharge ring and a band seal. The runner includes a crown, a band, and a plurality of blades extending between the crown and the band. The discharge ring is concentric with the band and spaced therefrom to permit relative rotation of the band and discharge ring. The band seal is disposed near an upstream edge of the band between the discharge ring and the band to limit water leakage into a band mixing chamber formed therebetween. The seal and the chamber are configured such that the band mixing chamber remains substantially flooded during turbine operation. A gas admission aperture allows gas to be injected into the mixing chamber. The mixing chamber is configured to promote mixing of the gas with the water leaking into the chamber during turbine operation. An additional mixing chamber may be provided above the crown.

Claims21

Dependent claims

A Francis turbine used to increase a level of dissolved gas in water passing through a casing provided with an upstream inlet port and a downstream outlet port, the turbine comprising:

a rotatably mounted runner having a crown, a band substantially concentric with the crown, and a plurality of blades extending between the crown and the band at spaced intervals along the crown, the band being bounded by spaced apart and oppositely facing inner and outer surfaces, an upstream edge and a distal downstream edge, each blade fixedly secured to the crown at an inner edge and to the inner surface of the band at a distal outer edge;
a stationary discharge ring substantially concentric with the band and spaced outwardly therefrom;
a band seal disposed adjacent the upstream edge of the band between the discharge ring and the band to limit water leakage into a band mixing chamber formed therebetween, the seal and the chamber being configured such that the chamber remains substantially flooded during turbine operation;
and
a gas admission aperture for injecting a gas into the chamber, the band mixing chamber being configured to promote mixing of the gas and water leaking into the chamber during turbine operation, thereby increasing the level of dissolved gas in the water being discharged from the downstream port.

2 more elements

A Francis turbine installation configured to improve dissolved oxygen level in water passing through the turbine, the installation comprising:

a stationary casing for containing turbine components and extending from an upstream inlet port to a downstream outlet port, the casing including a head cover, a discharge ring and a draft tube;
a runner rotatably disposed in the casing so that water flowing therethrough impinges on the runner, the runner including a crown, a band substantially concentric with the crown, and a plurality of blades extending between the crown and the band at spaced intervals along the crown;
and
a first annular seal disposed between the runner and the casing to limit water leakage into a first mixing chamber formed between the runner and the casing, the first seal and the first mixing chamber being configured such that the chamber remains substantially flooded during turbine operation;
wherein the runner includes a first gas admission passage extending from the crown to the first mixing chamber for injecting an oxygen containing gas thereinto for mixing with water leaking into the first mixing chamber during turbine operation, thereby improving the level of dissolved oxygen in the water being discharged from the downstream port.

2 more elements

Dependencies are inferred from the claim text.

Dissolved gas augmentation with mixing chambers

Life of this patent

Dissolved gas augmentation with mixing chambers

Life of this patent

Abstract

Claims21