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Wednesday, February 29, 2012

2. Discharge mechanism


Sludge discharge i s performed as follows. Under centrifugal force acting on pilot valve, packing part is sealed and operating water i s filled in water pressure chamber for closing bowl. Under pressure of the operating water, main cylinder is pushed up to seal main seal ring for purifying operation.


On the other hand, though operating water for closing bowl is constantly supplied to the water pressure chamber for closing bowl, operating water within the water pressure chamber for
closing bowl rotates with the bowl, and therefore pressure generated under centrifugal force and head pressure of operating water to be supplied are balanced to cause water level to be stable at a certain position.



 Operating water for opening bowl is fed for a certain time to the water pressure chamber for opening bowl. Part thereof passes through, but remaining water is filled in the water pressure

Chamber for opening bowl. Under pressure of the operating water, pilot valve slides in counter radial direction.

Seal in the packing part is broken and operating water for closing bowl flows out of the bowl.



If operating water for closing bowl passes through, there is no more force pushing up the main cylinder and the main cylinder i s pushed down by liquid pressure within the bowl.

Seal in the main seal ring part is broken and sludge is instantly discharged out of the bowl.




On completion of sludge discharge, operating water for closing bowl is delivered to the water pressure chamber for closing bowl.

If operating water is filled therein, main cylinder is pushed up to seal the main seal ring part. At this time the packing part is already sealed.





1. Operating water supply equipment


To supply operating water for control of bowl sludge discharge to each water pressure chamber (water pressure chamber for opening bowl, water pressure chamber for closing bowl.), the operating water supply equipment is installed in the lower part of the bowl.
Operating water for opening bowl is supplied from part "A" in Fig. below and enters the water pressure chamber for opening bowl. On the other hand, water for water pressure chamber for closing bowl is supplied from the part "B" and enters the water pressure chamber for closing bowl.
Operating water for closing bowl is normally (when main cylinder is closed) supplied and operating water of water pressure chamber for closing bowl is revolving with the bowl and therefore, pressure generated under its centrifugal force and head pressure from low-pressure operating water tank are balanced and water level is stabilized at a certain position. On the other hand, operating water is, for closing bowl, supplied from the low-pressure operating water tank.
Operating water supply equipment



Tuesday, February 28, 2012

4. Pump


4.1 Gear Pump
This pump is used as a suction pump to feed dirty oil to the purifier.
It is connected via safety joint to the horizontal shaft.
Gear Pump


4.2 Centripetal pump
The centripetal pump is a spiral impeller provided on the top of bowl to transfer light and heavy liquids out of the machine.
Centripetal pump
This pump is provided with a spiral groove or radial hole in a disc with certain thickness, dipped in liquid revolving with the bowl and the liquid will be discharged by its own turning force along groove or hole.


3. Bowl


The bowl is composed of bowl body, bowl hood and bow! nut which form a container. In the inside of bowl, the separation chamber composed of discs and top disc, and distributor leading
dirty oil from bowl inlet to sepration chamber are incorporated. Further. SELFJECTOR has main cylinder sliding up and down hydraulically in order to discharge solids separated and accumulated on the inside wall of bowl during operation.
Further, pilot valve assemblies to control sliding of main cylinder are provided at 2 points on the periphery of bowl body.
Dirty oil led to separation chamber from dirty oil inlet through distributor passes through spaces between discs, with solids and water being separated midway, and thus becomes purified oil which is discharged outside continuously by centripetal pump [impeller ( 1 )] on the upper part of bowl, while separated water is similarly discharged continuously by ceotripetal pump [impeller (2)].




2. Driving system


2.1 Horizontal shaft parts
Friction clutch is installed between motor and horizontal shaft to connect them.
The horizontal shah is supported at two points by bearing housing (3) and bearing houseing (4) with built-in ball bearings and spiral gear is installed between them. Bearing housing (3) and (4) are provided with oil seals, respectively, to prevent leakage of gear oil.
A groove has been cut at the pump side end of horizontal shaft so that the safety joint may enter.

2.2 Vertical shaft parts
The vertical shaft is supported by upper and lower bearing parts and a pinion is provided between them.
The upper bearing parts is provided with flat spring and the lower bearing parts with lower spring so as to absorb vibration in vertical direction. Further. the upper bearing parts is supported by upper springs at 6 points in a radial direction for absorption of vibration in horizontal direction.

2.3 Brake
The brake is so constructed that the brake is applied by causing brake lining to be pressed against the outside of friction pulley with a spring.
Normally it is desirable to stop without using brake, but only when prompt stopping is desired in case of emergency or for repair and inspection, brake can be applied.
Brake

2.4 Friction clutch
The friction clutch is used to effect slow starting and acceleration so as to prevent motor overload. The motor shah is equipped with friction block and friction boss and the horizontal shaft, with friction pul!ey.
After start-up, the motor attains its rated rotation instantly, friction block lining is pressed under centrifugal force against the inside of friction pulley, slip occurs between friction pulley and lining, and driving force is transmitted to the friction pulley (horizontal shaft side).
The bowl is so designed that normally it attains its rated rotation in about 5 to 10 minutes.
Friction clutch

1. Outline


The outline of structure of SELFJECTOR is as shown below.
Driving power from the motor is transmitted to the horizontal shaft through the friction clutch. And the vertical shaft is accelerated by spiral gear installed on the horizontal shaft and pinion gear on the vertical shaft.
The vertical shaft is supported by upper and lower bearings and further the upper and lower bearings are supported by springs.
The bowl is installed on the top of vertical shaft and revolves at the revolution speed of vertical shaft.
Furthermore. SELFJECTOR is composed of the liquid contact parts such as feed liquid inlet, light liquid outlet, heavy liquid outlet and the chute of discharging sludge, etc. and frame and frame cover.
Also a suction pump (gear pump) feeding dirty oil to SELFJECTOR is connected with the horizontal shaft through safety joint. Further, for discharge of light and heavy liquids, centripetal pumps (impellers) are installed respectively on the top of bowl.
The outline of structure of SELFJECTOR
Vertical shaft parts

Horizontal shaft Parts



2. Definition of terms


Density (p):
Mass per unit volume,
Specific gravity (7):
.
With mass of water per unit volume as 1, ratio of mass of the same volume; the value varies with temperature
Feed rate:

Volume of untreated feed liquid to be fed to a purifier per unit time, being expressed in P/h or.m3/h.
Actual capacity:

Throughput capacity of a purifier as calculated on the basis of SM Standard Specification (exclusive of sludge with specific gravity of more than 1.8 and a diameter of more than 2 microns). (Refer to "Feed rate", above).
Feed liquid
Non-separated oil to be fed to the purifier.
Light liquid
Purified oil as treated with the purifier.
Heavy liquid
Separated water content and heavy content of oil or simply "water".
Sludge
In a narrow sense, solids accumulated within a bowl and, in a broad sense, solids, water and oil mixture as discharged from the bowl.
Interface:

Boundary between heavy liquid and light liquid within a bowl.
Purifying operation:

3-phase (liquid-liquid-solid) separating (Refer to par. "Puri- operation for spearation into oil content, fying operation") water content and solid content. This machine is called "purifier".
Clarifying operation:
(Refer to par. "Clarifying
operation")
Two-phase (liquid-solid) separating operation for separation into oil content and . solid content. This machine is called "clarifier".
Parallel operation:
(Refer to par. "Parallel
operation")
A number of purifiers arranged in parallel and operated with oil fed in dividing specified volume.
Series operation:
(Refer to par. "Series
operation")
Operation of a number of purifiers arranged in series.
Total discharge type:
A purifier so constructed that total quantity within the bowl is discharged
Partial discharge type:
A purifier of the so-called "partial discharge" construction that discharges only water and solid content within the bowl. On the other hand, this machine also has the total discharge function.
E-HIDENS 2 type:
This is a Selfjector with clarifier specification which is incorporated into EHIDENS 2 System and is used in combination with Water Detector. The structure of Selfjector is such that it performs a partial discharge of sludge.




1. Cautions in safety



The bowl of SELFJECTOR revolves at high speed, causing great centrifugal force to act. As erroneous handling causes great danger, handle with due cautions in operation, dismantling, assembling, maintenance and inspection, etc. in accordance with this manual.

Perform assembling perfectly
SELFJECTOR has many parts connected with nuts, bolts
and screws. When assembling it, make sure that they are fully tightened. Extreme care must be exercised to tighten the bowl nut, disc nut, clamp nut, vertical shaft cap nut, frame cover lock handle, etc. positively. Please note thoroughly that it is very dangerous to operate SELFJECTOR without tightening its parts firmly. Wih regard to such parts as bowl, etc. provided with tally mark, be sure to confirm that marks are in coincidence with each other.
On the other hand, if tally marks are misaligned when bowl nut, etc. were tightened, contact us or our service agent.

Stop immediately when vibration is great.
Though the vibration of Selfjector will differ depending on the effect of imbalance and besides the vibration of hull or the installing condition of Selfjector, the undermentioned Table shall be complied with Stop SELEFJECTOR immediately when vibration has become great. In that case, do not perform sludge discharge.
After confirming complete stop, proceed to dismantling, cleaning and inspection.

Table 1.1 Standard of Vibration AUowanoe

Condition of
ooeration
When engine
Has stopped
operation
When engine
is operating
Operation or action
to be taken
Excellent
Below 30
Below 40
Operation or action
to be taken
Good
31~49
41~59
Continuous operation
permissible
Passable
50~69
60~79
Continuous operation
permissible
Very Poor
Avobe
Above 80
Inspection will be made at once

Vibration measurement shall be conducted in the frame part of SELFJECTOR (at point "A).
 
After confirming complete atop, loosen the parts.
After confirming that the bowl completely stopped revolving, loosen the parts and dismantle.
On the other hand, whether or not revolution has stopped completely can be confirmed at the gear pump and horizontal shaft conciliation (safety joint) or motor fan.

Handle parts carefully.
As SELFJECTOR is a precision machine, take due cautions in handling of the parts, etc. so as to avoid impact and high heat.
Take caution against corrosion and erosion periodically check for damage, if any, due to corrosion o,r erosion. With regard to unidentifiable points, contact us or our service agent.

Others
(1) Before dismantling, be sure to switch off power to starter.
(2) When treating liquid different from the liquid originally planned to be treated please contact us or our service agent.
(3) Since the bowl has been adjusted in balance, it is preferrable to avoid replacement of bowl parts even in the case of the same model.


Monday, February 27, 2012

Other hazards

Injury may be caused by:

● Slipping, tripping or falling
● Improper treatment of water additives and treatment products
● Touching the insulation box, turbo-charger, pipes, exhaust manifold, or other unprotected parts without protection during engine operation
● Dropping parts during maintenance work
● Starting maintenance work too early, thus, causing burns when handling hot components
● Neglecting use of cranes and/or lifting tools
● Not using proper tools during maintenance work
● Not using correct protecting outfits when handling hot parts, thus, causing burns
● Contact with fuel, lubrication oil or oily parts during maintenance work
● Exposure to high noise levels
● Touching or removing turbocharger insulation too soon after stopping the engine
● Ejection of preloaded springs when dismantling components.



Electrical hazards

● Fire or sparks due to damage or short circuit in electrical equipment
● Contact with electricity during maintenance work if power not disconnected
● Hazards due to incorrect grounding of electrical equipment
● Electrical shocks because electrical cables or connectors are damaged
● Electrical shocks because electrical equipment is dismantled with the power connected
● Incorrectly wired or disconnected emergency stop switch
● Overload of a control system component due to incorrect electrical connections, damaged control circuitry or incorrect voltage
● Engine out of control due to a failure in the shutdown circuitry
● Unexpected start-up or failed stop
● Crankcase explosion if:
 
- engine not safeguarded at high oil mist levels, due to energy supply failure
- engine not (fully) safeguarded at high oil mist levels, due to failure in oil mist detector circuitry
- engine not (fully) safeguarded at high oil mist levels, due to an incorrect electrical connector or leakage in a pipe connection.

Hazards due to leakage, breakdown or improper component assembly


● A fuel or gas pipe bursting and spraying fuel or gas
● A control oil pipe bursting and spraying oil (Common Rail)
● VIC housing bursting and spraying oil (if variable inlet close valve used)
● Leakage of:

- fuel at joints on the low and/or high pressure side
- lube oil
- high pressure water on DWI engines
- HT water
- charge air
- exhaust gas
- pressurised air from air container, main manifold or pipes
- high pressure gas and sealing oil on GD engines

● Fire or explosion due to leakage from a fuel or gas line
● Fire or explosion due to flammable gas/vapour (crude oil) leaking into the insulation box
● Inhalation of exhaust gases or fuel gases due to leakage
● Failure of pneumatic stop
● Ejected components due to:

- breakdown of hydraulic tool
- breakdown of hydraulic bolt
- breakdown of turbocharger
- high firing pressures
- major failure

● Ejection of:

- pressurised liquids and gases from the engine block or piping
- high pressure fluid due to breakdown of hydraulic tool
- gas due to high firing pressures
- pressurised gases from high pressure gas system
- high pressure fluid due to breakdown of HP sealing oil pipe
- high pressure air from compressed air supply pipes during maintenance of pneumatically operated equipment
- cooling water or fuel/lube oil if sensor is loosened while the circuit is pressurised
- leaks during maintenance work

● Oil spray if running without covers
● Ejection of fuel injector if not fastened and:

- the turning device is engaged and turned
- the engine turns due to closed generator breaker or coupling.

Hazards due to incorrect operating conditions

● Overspeed or explosion due to air-gas mixture in the charge air
● Overspeed due to air-oil mist mixture in the charge air
● Malfunction of crankcase ventilation
● Crankcase explosion due to oil mist mixing with air during inspection after an oil mist shut down
● Crankcase safety explosion valves opening due to a crankcase explosion.



Hazards due to moving parts

● Running the engine without covers and coming in contact with moving parts
● Touching pump parts during unintentional start of electrically driven pump motor
● Turbocharger starting to rotate due to draft if not locked during maintenance
● Thrusting a hand into the compressor housing when the silencer is removed and the engine is running
● Unexpected movement of valve or fuel rack(s) due to a broken wire or a software/hardware failure in the control system
● Unexpected movement of components
● Turning device engaged during maintenance work
● Accidental rotation of the crankshaft if the turning device is not engaged during maintenance work, for instance, because it has been removed for overhaul
● Mechanical breakage (for example of a speed sensor) due to incorrect assembly of the actuator to the engine or faulty electrical connections.

Fluoride rubber products


Precautions when handling fluoride rubber products

Normal sealing applications
In normal sealing applications the use of fluoride rubber products does not cause any health hazards. The products can be handled without any risk provided that normal industrial hygiene is maintained.

When changing O rings of valve seats
Always wear protective rubber gloves when changing the O rings of the valve seats.
Contents, instructions, terminology
When handling the remains of burnt fluoride rubber
When handling the remains of burnt fluoride rubber, for instance, when changing O-rings after a valve blow-by, wear impenetrable acidproof gloves to protect the skin from the highly corrosive remains.
Appropriate glove materials are neoprene or PVC. All liquid remains must be considered to be extremely corrosive.
The remains can be neutralized with large amounts of calcium hydroxide solution (lime water). Used gloves must be disposed of.

Grinding dust
Dust and particles originating from grinding or abrasion (wear) of fluoride rubber may when burned form toxic degradation products. Smoking must therefore be prohibited in areas where fluoride rubber dust and particles are present.

In case of fire
When burned fluoride rubber can cause the formation of toxic and corrosive degradation products, for example, hydrofluoric acid, carbonyl fluoride, carbon monoxide, and carbon fluoride fragments of low molecular weight.
Operators handling the remains of burnt fluoride rubber must wear impenetrable acid-proof gloves to protect the skin from the highly corrosive remains. Appropriate glove materials are neoprene or PVC. All liquid state remains must be considered extremely corrosive. Burning (incineration) of fluoride rubber is allowed only when approved incinerators equipped with gas emission reduction systems are used.

Use of fluoride rubber products at temperatures above 275°C (527°F)

Fluoride rubber can be used in most applications (up to 275°C) without any substantial degradation or health hazard. Use or test of fluoride rubber at temperatures above 275°C must be avoided. If the material is exposed to higher temperatures, the temperature may get out of control.

Personal protection equipment for fluoride rubber products

Hand protection: Use impenetrable acid-proof gloves (neoprene or PVC).
Inhalation protection: Use breathing mask.

First aid measures for accidents with fluoride rubber products

Inhaling: Move the victim from the danger zone.
Make the victim blow his nose.
Seek medical advice.
Eye contact: Rinse immediately with water.
Seek medical advice.
Skin contact: Rinse immediately with water.
Put a 2 % solution of calcium gluconate gel on the exposed skin.
If calcium gluconate gel is not available, continue to rinse with water.
Seek medical advice.

Lead in bearings


Lead has valuable lubricating properties and is therefore incorporated into many bearing alloys.
The bearings in Wärtsilä engines contain lead and are therefore toxic. Bearings that are to be scrapped and contain lead must be disposed of according to the local authority regulations.

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