Page 35: of Maritime Reporter Magazine (April 1994)

(Continued from page 34) which is higher than the mean exhaust gas backpressure even at part load. Thegreat share of fresh air in the cylinder permits not only a favorable torque, but also keeps the combustion chamber compo- nents cool. The exhaust valves and piston rings have a higher service life, because they are working un- der favorable operating conditions.

Particularly favorable is the low tem- perature before turbine also at part load when driving a fixed-pitch pro- peller. This significantly reduces the frequency of turbine cleaning.

The six-and nine-cylinder en- gines are working according to the ideal three-pulse process. Three cylinders at a time at afiring angle distance of 240 crank angle send their respective pulse energy through a pipe, each to the corre- sponding section of the turbine sur- face. The MaK eight-cylinder en- gines combine the impulses of two cylinders each in one exhaust gas pipe. The four pulse pipes end in a special pulse rectifier. The collected pulse energies then act on the full turbine surface. Both pulse charg- ing systems permit permanent en- gine operation on the propeller curve.

As an option for particularly dif- ficult applications, the M32 in-line engine can be equipped with a con- trol of the turbine surface accord- ing to the MaK VMP-system. The pulse rectifier here is used for all three cylinder numbers. An adjust- ment mechanism permits to uti- lize the concentrically divided tur- bine surfaces either in only one ring or in two rings together. By reduc- ing the turbine surface at part load the air admission to the engine is significantly increased. Particu- larly fast acceleration, lowtempera- tures as well as high part load torques are possible.

On the M32 the pressure differ- ence between charging pressure on one side and exhaust gas pressure on the other side is mainly for the benefit of scavenging and efficiency of the engine. The speed energy after compressor is converted into pressure energy before charge air cooler by diffusers. In an even ad- mission flow the charge air then flows through the amply dimen- sioned charge air cooler with low differential pressure. Out of the cast- in air duct the air then flows via convolutions favorable for the flow and an even continuity of surfaces to the inlet valve. The inlet as well as the exhaust duct are optimized in terms of flow characteristics and in their tandem conduits they show excellent flow coefficients. The ex- haust gases flow through diffuser ducts up to the exhaust gas pipes to transmit their pulse energy then directly onto the turbine.

The turbocharging efficiency, which is kept at a high level by many minute measures, has a very positive influence on consumption, heavy fuel capability and part load behavior of the engine.

Latest orders won by Krupp MaK include: • eight 6 M 552 C units as propul- sion engines for two ferries for TT-

Line/Germany, building at

Finnyards, Finland;

April, 1994 • six 6 M 552 C units as propulsion engines for three special transport

Gorthon, Sweden, building at AESA,

Spain; • six main and 10 auxiliary engines of the series M 552 C and M 20 for four product tankers and two con- tainer vessels for Bomta, China, building at Lindenau, MTW and

Brand; • 36 x 6 M 20 units as propulsion engines, including gear box for 18 sea-going river tankers for Liko

Promarket, Russia, building at

Rousse Shipyard, Bulgaria; • two 6 M 20 units as propulsion engines including gear box for a sea-going river tanker for the Min- istry of the Republic ofTatarstan, building at Gorkowo, Tatarstan.

This is the firstvessel of a series of three; • 12 x 6 M 20 units as auxiliary engines for four container vessels for Dohle, Dauesberg, and

Interorient all in Germany, build- ing at Kvaerner Werft, Germany; • eight engines of the series M 453 C for the state-owned company PLN for public supply in Indonesia; this is part of a total number of 76 engines for 19 power stations and a total output of more than 200 MW has been or will be delivered respec- tively.

For more information on Krupp

MaK,

Circle 116 on Reader Service Card

PV SERIES

Double-Acting

Torque to 50,000 IN-LB @ 3000 PSI

PS SERIES

Spring Return

Torque to 9,500 IN-LB @ 1500 PSI •Ultra-compact configurations • Fully adjustable •Mounts directly to valve flange • No backlash • Maintains position without drift • For most quarterturn rotary valves

PfflWa 1-800-327-2589 206/825-1601

CORPORATION FAX: 206/825-1603 225 BATTERSBY AVE • ENUMCLAW, WA 98022

US Pals 4741250,4881419,5027667 S corresponding intersat'l patents.

ATTENTION

ELLIOT LIFERAFT OWNERS

If you have an Elliot Liferaft manufactured between January 2, 1992 and January 31,1994, please contact your nearest United States

Coast Guard approved Elliot service station as soon as possible. Corrective action by an authorized service technician may be required on your raft. You can find the date of manufacture on the metal nameplate which is affixed to the raft container.

We regret any inconvenience this may cause you, but your safety is our primary concern. If you have any questions or need the name of your nearest authorized Elliot service facility, please call 1-800-531-7238 on the East Coast or 1-206-575-2660 on the West Coast. We urge you to contact your service station as soon as possible.

ELLIOT

INFLATABLE RAFTS

ELLIOT INFLATABLE RAFTS 3874 Fiscal Court

Riviera Beach, FL 33404 (800) 531-7238

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CLEATS • ALUMINUM • STEEL

Weld-on and bolt-on types for every application - choose from one of the largest inventories of marine equip- ment and supplies in the U.S.

SAVE MONEY - CALL

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FAX (206) 621-9834

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