Skip to main content

Homogenizer


 
  •  The homogenizer (Vickers Type: See figure above) provides an alternative solution to the problem of water in high-density fuels. It can be used to emulsify a small percentage for injection into the engine with the fuel. This is in contradiction to the normal aim of removing all water, which in the free state can cause gassing of fuel pumps, corrosion and other problems. 
  • However, experiments in fuel economy have led to the installation of homogenizers on some ships to deal with a deliberate mixture of up to 10% water in fuel. 
  • The homogenizer is fitted in the pipeline between service tank and engine so that the fuel is used immediately.
  • It is suggested that the water in a high-density fuel could be emulsified so that the fuel could be used in the engine, without problems. 
  • A homogenizer could not be used in place of a purifier for diesel fuel, as it does not remove abrasives such as aluminium and silicon, other metallic compounds or ash-forming sodium which damages exhaust valves.
  • The three disc stacks in the rotating carrier of the Vickers type homogenizer are turned at about 1200 rev/min. Their freedom to move radially outwards means that the centrifugal effect throws them hard against the lining tyre of the homogenizer casing.
  • Pressure and the rotating contact break down sludges and water trapped between the discs and tyre, and the general stirring action aids mixing.

Comments

Popular posts from this blog

Manganese bronze is not typically used as a propeller material .Why

1. High cost: Manganese bronze is a costly alloy, making it less economical for large propellers. 2. Low strength-to-weight ratio: Compared to other propeller materials like nickel-aluminum bronze or stainless steel, manganese bronze has a lower strength-to-weight ratio. 3. Susceptible to corrosion: Manganese bronze can corrode in seawater, especially when exposed to high velocities and turbulence. 4. Poor cavitation resistance: Manganese bronze is more prone to cavitation damage than other materials. 5. Difficult to cast and machine: Manganese bronze is challenging to cast and machine, making it less desirable for complex propeller geometries. 6. Limited weldability: Manganese bronze has poor weldability, making repairs and modifications difficult. Nickel-aluminum bronze or stainless steel are commonly used for propellers due to their: - High strength and durability - Excellent corrosion resistance - Good cavitation resistance - Ease of casting and machining - Weldability

MAN B&W MC Engine VIT Pump

The pump is basically a jerk type with a plunger moving in a matched barrel, using two helical grooves machined in the plunger to control the end of injection by uncovering spill ports and causing the discharge pressure to drop rapidly, thus causing the needle valve in the injector to close. Oil is supplied to the barrel via the spill ports and a suction valve. The suction valve, situated at the top of the barrel opens when the pressure in the  barrel falls below the supply pump pressure; i.e. during downward stroke of plunger, while spill ports are covered by plunger. Replaceable erosion plugs  are fitted in the pump housing opposite the spill ports. The high pressure oil, spilling back, as the edge of the helix uncovers the s...

Main engine interlocks

Interlocks are provided so that the engine can be started or reversed only when certain conditions have been fulfilled. When there is a remote control of engines, it is essential to have interlocks. This reduces the possibility of engine damage and any hazards to the operating personnel. Turning gear Interlock . This device prevents the engine from being started if the Turning gear is engaged. Running Direction Interlock . This prevents the fuel from being supplied if the running direction of the engine does not match the Telegraph. Starting Air Distributor in end position . This prevents starting from taking place if the shifting of the Distributor has not been completed. Main Lube. oil pressure, Piston cooling pressure, Jacket water pressure, and important parameters must be above the required minimum. Auxiliary Blower Interlock . The Auxiliary Blower is provided in case of Constant pressure turbo charging. Air Spring pressure Interlock . In case of the present generation...