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Showing posts from May, 2020

Secondary NOx Reduction Measures

These are measures designed to remove NOx from the exhaust gas by downstream cleaning technique. The most common secondary measures are – SCR ( Selective catalytic reduction) :- In this system the exhaust gas is mixed with ammonia before passing through a layer of special catalyst at a temperature between 300 deg Celsius to 450 deg Celsius. The NOx is reduced to gaseous and harmless by-products of water and nitrogen. SNCR( Selective non-catalytic reduction) :- In case of SNCR, the reaction between ammonia and NOx takes place in a gaseous phase in a temperature window of between 800 and 900 deg Celsius. The most effective method of NOx reduction is a secondary measure.  The advantages are:- Secondary measures reduce NOx in case of SCR of up to 80- 95% and in case of SNCR 30-50%. Whereas primary measures average Nox reduction is up to 25- 35%. Possible side effects of primary measures are lower overall energy efficiency, increased carbon mono-oxide, and soot formation and hydrocarbon emi

Primary NOx Reducing Measures

These are measures aimed at reducing the amount of NOx formed during combustion by optimizing engine parameters with respect to emission. Some of the methods are listed below – A. Water addition:- Direct water injection:- Greater heat capacity is utilized to reduce high peak temperatures as the water evaporates immediately upon injection. Rapid evaporation of injected water also helps to create a homogeneous fuel-air mixture. Emulsified fuel or fuel-water emulsion:- It is favored by some manufacturer claiming a clear reduction in NOx emission at low cost with no significant design changes. B. Altered fuel injection:- Delayed fuel injection:- Retarded fuel injection timing retards the  combustion process. Nitrogen oxide formation occurs later and with lower concentration. Common rail control:- It has proven to be a very effective way in combating  NOx reduction techniques. NOx optimized fuel spray pattern:- Different fuel nozzle types and model  injection also has an influence. C. Combu

Differentiate between third party liability and contractual liability. When may the ship seek to limit his liability? List the persons entitled to limit liability and claims entrusted.

An insurance policy is a contract. The insured is referred to as the first party to the contract. The insurer i.e. the insurance company is who issues the contract is the second party. A stranger to the contract who makes a claim against the insured is known as the third party. Third-party liabilities: It is an obligation to compensate another person harmed or injured or suffered a loss due to negligence or mistake or wrongful act of first party. Third-party liabilities are those liabilities which are caused to any other persons or his property not included in any contract. The contract takes place between two parties hence any third person not a member of this contract is a third party or person. When the insured – first party causes a loss then the second party assumes the insured liability up to the policy limit. Examples of third party liabilities are collision, third party injury or death claim, oil pollution liability, cargo claim, crew claim, unrecoverable general average contri