Propeller and Nozzles

Product catalog summary

Overview
This document discusses the propulsion systems designed by Eliche Radice, specifically focusing on propellers and nozzles suitable for working vessels such as tow-boats, fishing boats, river barges, and pusher tugs. The document outlines the types of nozzles, their geometric parameters, advantages, and calculation parameters for selecting the appropriate propeller.

Nozzle Types and Geometric Parameters
Nozzles are categorized into two types: Fixed and Rotating (Steering Nozzles). Key geometric parameters include:

L/D Ratio: Ratio of nozzle length (L) to internal diameter (D).
Contraction Ratio: Ratio between water entry and exit areas.
Section Geometry: Naca type.

Advantages
The use of nozzles offers several benefits:

Reduction in propeller and shaft diameters.
Decreased vibrations and noise, especially with wide sterns.
Reduced ship pitching in rough waters.
Increased propeller thrust and potential 15% speed increase.
Improved performance in shallow waters.
30% reduction in engine power requirements, leading to cost savings.

Calculation Parameters
To determine the most suitable propeller, data on the vessel's dimensions, displacement, motorization, and reduction ratio are required. A technical questionnaire is provided to customers for clarity. Calculations can provide:

Propeller and thrust data at maximum speed.
Thrust calculations at various RPMs and speeds.
Bollard-Pull calculations with absorbed engine power.

Nozzle Types and Applications
Nozzles are divided into different styles based on their characteristics and uses:

Nozzle 19A: Suitable for heavily loaded propellers, offering 2-3% improved performance in forward gear. L/D = 0.5.
Nozzles 22 and 24: Used where Bollard-Pull is crucial, with L/D ratios of 0.8 and 1, respectively.
Nozzle 37: Symmetric shape, used for strong Bollard-Pull in both forward and reverse gears, offering 7-10% better performance in reverse compared to K19A. L/D = 0.5.

Nozzle type 19A is the most commonly used, but other types can be prepared for specific applications or customer requests.

Mechanical Characteristics of Alloys
The document also provides mechanical characteristics of the alloys used, such as ultimate tensile strength, yielding, and elongation percentages.

Contact Information
For further inquiries, Eliche Radice can be contacted via their website or through the provided contact details.

Catalog excerpts

ELICHE RADICE ELICHE E MANTELLI Propeller and Nozzles www.elicheradice.com

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Q uesto tipo di impianto propulsivo, è particolarmente adatto per imbarcazioni da lavoro (rimorchiatori, pescherecci, chiatte fluviali, spintori) impiegate nei mari e sui fiumi. T his type of propulsion system is particularly suited to working vessels (tow-boats, fishing boats, river bargers and pusher tugs) in the sea and on rivers. I mantelli possono essere di tipo “Fisso” o “Girevoli (Mantelli Timone)”. The nozzles can be of two types: “Fixed” or “Rotating” (Steering Nozzles). I parametri geometrici più importanti, sono i seguenti: The main geometric parameters are the following: – Rapporto...

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LINEA D’ASSE CON MANTELLO TIMONE 19A Tail Shaft with Steering Nozzle 19A type LINEA D’ASSE CON MANTELLO FISSO 19A Tail Shaft with Fixed Nozzle 19A type

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Mantello fisso Tipo 19A - POSIZIONE ELICA E MANTELLO Fixed nozzle 19A type - Propeller and Nozzle Position CARATTERISTICHE MECCANICHE DELLE NOSTRE LEGHE Mechanical characteristics of our alloy RESISTENZA MECCANICA - Ultimate Tensile Strenght OT.MAN (N/mm2) RESILIENZA - Yelding (N/mm ALLUNGAMENTO - Elongation A5(%) 2 MIBRAL 535 650 220 260 25 22

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La forma della sezione del mantello è di tipo Naca. I Mantelli si suddividono in diversi tipi, con caratteristiche ed impieghi ben definiti: The shape of the nozzle section is Naca type. The nozzles are divided into different styles, with considerably different characteristics and uses: Mantello 19A Nozzle 19A È adatto per eliche molto caricate e quando è richiesta un’ottima manovrabilità. In condizioni di marcia avanti, ha un rendimento superiore del 2-3%, rispetto a tutti gli altri mantelli. L/D = 0,5 This nozzle is suitable for very heavily loaded propellers and when excellent manoeuvrability...

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ottobre 2007 www.elicheradice.com [email protected] Via Valtellina, 45 - 20092 Cinisello Balsamo - Milano - Italia - (T) +39-02.660 493 48 - (F) +39-02.612 7688

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Propeller and Nozzles

Propeller and Nozzles

Catalog excerpts

All Eliche Radice S.p.A. catalogs and brochures