laporan praktikum sedian semi solid dan liquid. lotio vit EDeskripsi lengkap
Deskripsi lengkap
Full description
Deskripsi lengkap
anemia defisiensi vitamin b 12
r
vit b1Deskripsi lengkap
kak sweeping vit aDeskripsi lengkap
Kontrol kualitas sediaan sterilDeskripsi lengkap
Full description
Deskripsi lengkap
fhgggggggf
fhgggggggfDeskripsi lengkap
kak sweeping vit a
Fisika FarmasiDeskripsi lengkap
(1) Conve Conventional VI V IT system – V IT is a form of fue f uel pum pump control control enabli bling an engine to operate operate with with the desi designe gned maxim aximum firing ri ng or combusti combustion on pressure pressure from from approx. 75% 75 % power output to maxim aximum power. power. This his im improves thermal rmal eff efficie ciency & lowers fuel consumption. Varia riable timi timing max. pressure pressure a rox rox. 12 125 bar
Fixed timing
Fuel cons
approx
160g/kwh
LOAD%
Cylinder pressure plotted against engine load The The fuel fuel con consu sum mption for an engine ine at any load oad will ill be relat lated to the expansion ratio of the combustion gases from their maximum pressure to the pressure at the commencement of exhaust blowdown. In case of the ‘conventional VIT’ system (i.e. the profile-plunger principle, as used on GB, L35MC & L42MC engines) the break-point is fixed in relation to the pump index – that is to say, the “break” “break” always autom automatica atically lly occurs occurs at at the the predetermined pump index. The The fuel fuel cam cam is use used d to adj adjust the timing of the com commence encem ment of inje inject ctio ion n in a normal manner so that the max. allowable firing pressure is reached @ 75% of full load. The timing of the commencement of injection will then be retarded as the quantity of fuel injected is increased. The amount of retardation necessary to hold the cylinder pressure constant at the desired max. value will be designed into the control system.
(2) Super VIT system – The ‘super VIT’ system is developed to fulfil the requirement of maintaining the MCR P max under part load conditions, in order to save fuel. This is achieved by a mechanism which automatically adjusts the commencement of fuel injection, such that the MCR P max is kept constant as the engine load is reduced from 100%, down to a certain pre-specified part load, known as the ‘break point’. In the super-VIT configuration, employed on the larger L/K/S MC engines, the fuel pump plunger is not profiled (i.e. has no extra oblique cut) but instead, the start of fuel injection timing is freely determined by altering the vertical position of the pump barrel, whereby in this system the break point is fully adjustable. The pump barrel is moved up and down (relative to the plunger) by means of a rack and pinion, in combination with a double thread. The VIT-rack setting itself is controlled via the regulating shaft position - i.e. according to the engine load. When running at the break point, the pump cylinder will be at a low position, i.e. giving early injection and the specified design P max (MCR P max ) for the engine in question. Although it is the regulating shaft which determines the VIT-rack positions, two forms of intermediate adjustments are available. A) Individual P max adjustments (at each fuel pump) B) Collective P max adjustments (simultaneously for all pumps) Both of these adjustment modes can be utilized while the engine is running. (3) FQs : As all fuels are different, they differ in their ignition quality. Some fuels have a reduced ‘ignition delay’ period, & are considered to have a better ignition quality. Reducing ignition quality increases the delay period. A high ignition quality fuel will have high paraffin content. The large and rapid heat release, associated with paraffin fuels, usually counteracts the effect of reduced fuel mass at ignition, due to reduced ignition delay period. The result is an increased peak pressure & better thermal efficiency. The FQs on the engine takes care of the differences in ignition quality, by advancing or retarding the fuel timing.
