US1496770A

US1496770A - Hydraulic turbine

Info

Publication number: US1496770A
Application number: US502268A
Authority: US
Inventors: John S Carpenter
Original assignee: Worthington Pump and Machinery Corp
Current assignee: Worthington Pump and Machinery Corp
Priority date: 1921-09-21
Filing date: 1921-09-21
Publication date: 1924-06-10
Anticipated expiration: 1941-06-10

Description

June 10, 1924. Y EAQQWQ J. 5. CARPENTER HYDRAULI C TURBINE Filed Sept. 21. 1921' a wwawto'a Patented June 10, 1924..

,MFT Z JOHN s. CARPENTER. or 'IRVI-NGTON, NEW JERSEY. nssienon TO WORTHINGTON PUMP AND MACHINERY VIRGINIA. 7

Application filed September 21, 1921.

T 0 all whom it may concern:

Be it known that I, JOHNS. CAnrEN'rER'. a citizen of the United States, residing at Irvington, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Hydraulic Turbines, fully described and represented in the following specification and the accompanying drawings,'forming a part of the same.

This invention relates to improvements in hydraulic turbines and particularly to high speed turbines.

It has been common heretofore to provide mixed flow turbines having outer bands and crowns, wherein the water guiding or inner surface of the outer band was flared out:- wardly in the direction'of the water flow, but in such cases generally the outward flare was either too great for the normal speed for which the runner wasdesigned, or was too small a slope for a high speed runner. Where in a fewexceptional' cases the angle of the outward flare was proper for the normal speed of the turbine, there was either no inner band'or it was either straight,-that is, had no flare,or was flared the wrong way, namely, with a slope toward the axis of the runner in the direction of the water flow. I have discovered that with such runners there are appreciable losses due to ed dies or whirls. to provide a runner in which these losses will be avoided.

With this object in view the invention consists in a hydraulic turbine having a runner provided with an inner as well as an outer band whose water guiding surfaces are sloped outward in the direction of the water-flow, and having the angle of slope so related to the normal speed of the runner that no eddies are formed, as will be more fully explained hereinafter.

The invention will first be described in connection with the accompanying drawings and then more particularly pointed out in 4 the claims.

Inthe drawings,

Fig. 1 is a vertical section through one form of hydraulic turbine embodying the invention; and

Fig. 2 is a halt plan part1 in section of the same.

Referring to the drawings. the runner comprises the blades'A, the outer band B and the inner band C suitably mounted for VH'YDRAULIC TURBINE.

The object of my invention is CORIEOERATI ON, YORK,-N. Y., A CORPORATION OF rotation. the present example the run? ner has a hub D which is advantageously formed integral with the inner band, this hub being mounted on a turbine shaft E which is suitably hung from a suitable suspension beariug (not shown) and-journaled in a bearing carried by the casing, as indicated at 1. The casingis arranged to conduct thepwater to the runnerin the general direction of the axis of the runner. In the present example the water enters in a radial direction :and then is deflected by-the casing so as to flow' in the axial direction when it strikes the runner. The c'asing'showncomprises an annular cover-plate F and a coent example the supports comprise column bolts I. Suitable gates are provided for controlling the water.'- These-are indicated atK and in the bestforin of the'invention are arrangedso that their inner ends, when the gates are open, overhang the runner, as will be clear from-the drawings. The overhanging cornershavetheir sides formed as stream line surfaces in thedirection'of the water flow downward, as, for example, by beveling or gradually reducing the thickness of the corner. f

Any suitable gatebperating' mechanism may be employed. In the present example, the gate spindle 7c is provided with an-arin L connected by a link Z to a ring M angularly movable on an upward projecting hub N carried by the casing.

Beneath the runner is a curb-ring P which is provided with an upward-extending por' tion 7) flanged at its upper part, this flanged portion serving to support the interior part of the bottom ring. The curb-ring Pis carried by the foundation.

A draft tube R of annular form is joined to the curb-ring, the profiles of the sides sloping away from each other as shown in the drawing. It is advantageous, however; to give the interior wall of thedraft tube greater slope than the outer wall.

A most important feature of the invention is the provision of proper profiles for the water-guiding surfaces of the inner and outer bands of the runner. If the outward slope of the profiles of these bands is too great or too'small for the predetermined normal speed of the runner, eddies will be set up and there will be an appreciable loss in ethciency. 7

An important feature of the invention consists in giving the Water-guiding surfaces of the bands profiles which will slope away from the runner axis of rotation at an angle substantially equal to that of the resultant tan Q= In this formula Q:angle of slope. Lzlength of the water of the runner. gzacceleration, due to gravity.

Hzhead of water (in feet) acting on the runner.

wzangular velocity in radians per second at the normal speed.

'r zradius in feet of the inlet end of the water-guiding surface of the band. r zradius in feet of the outlet end of said surface.

By giving thewater-guiding surfaces of the bands profiles having slopes substantially as fixed by the formula, the saving becomes very important with runners working at high speeds.

It will be understood that r, and r represent the radii of the'inlet and outlet ends respectively of the water guiding surface of either the inner band or ofthe outer band, according to which is being calculated. If the profiles of the water-guiding surfaces of the bands are not straight lines but are curved between the inlet and outlet as may sometimes be desirable then the angle of guiding surface slope determined by the formula is the slope of an imaginary line drawn on the profile from the inlet end to the discharge end.

It will be seen that in a hydraulic turbine constructed in accordance with the specific form of the invention where both the inner and the outer band are sloped outward, the water is discharged from the runner in an outwardly sloping direction, rather than in a truly axial direction. I

The blades of the runner may be designed both as to number and as to profile at the different sections in any Well known way.

It is to be understood that the invention is not to be limited to the particular turbine shown, as it may be embodied in other forms \Vhat is claimed is:

1. In a hydraulic turbine, a runner having bands formed to provide water-guiding surfaces having profiles sloping away from the axis of the runner in the direction of the water-flow, the angle of the slopes being substantially equal to that of the resultant of the vertical and centrifugal forces acting, under normal operating conditions, upon the water contacting with said surfaces of the bands, substantially as described.

2. In a hydraulic turbine, a runner having an inner and an outer water-guiding surface, each of said surfaces having. such a profile that a line drawn on each profile from the inlet to the discharge end will slope outward away from the axis of the turbine, the tangent of the angle of slope being substantially that given by the formula In, Q 11 substantially as described.

JOHN S. CARPENTER.