Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MK2 > Reverse Osmosis > Flashcards

Reverse Osmosis Flashcards

1
Q

The Village Marine Tec. (VMT) PW400 Seawater Desalinator is a ____

A

Single-pass fully transportable purification system that uses reverse osmosis (RO) as its method of seawater desalination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The Village Marine Tec. (VMT) PW400 Seawater Desalinator produces potable drinking quality water with salt concentrations of _____ from seawater with salt concentrations as high as _____

A

< 500 ppm

35000 ppm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Naturally occurring phenomenon in which a semi-permeable membrane separates a pure and a concentrated solution

A

Osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Preferentially passes a particular substance

A

Semi-permeable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

This potential, referred to as osmotic pressure, increases in proportion relative to ____

A

Concentration of a solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Every fluid has an ____ that is directly related to the type and amount of solids in solution

A

Inherent potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

A concentrated solution has an osmotic pressure that is ____ than that of a pure solution

A

Higher

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

In an osmotic system, the less concentrated solution will attempt to equalize the concentrations of both solutions by ____

A

Migrating across the semi-permeable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Salt water is pressurized on one side of the semi-permeable membrane. The pressure must be high enough to exceed the ___ to cause reverse osmotic flow of water

A

Osmotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Product water

A

Pure water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Feed water

A

Concentrated solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If the applied pressure is increased in an attempt to gain more product water, a point is reached at which the membrane becomes ____

A

Fouled by precipitated salts and other undissolved material from the water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

This RO unit will produce permeate (product water) with a quality of ____ in accordance with World Health Organization (WHO) standards for drinking water

A

< 500 ppm TDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Permeate

A

Drinking water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

With constant salinity and pressure and increasing temperature, permeate TDS ____, Capacity ____

A

Increases

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

With constant temperature and pressure and increasing salinity, permeate TDS ____, Capacity ____

A

Increases

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

With constant temperature and salinity and increasing pressure, permeate TDS _____, Capacity ____

A

Decreases

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If feedwater salt concentration decreases, the product water flow rate should not be allowed to increase more than ___ above rated flow

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Feed pressure may need to be ___ to maintain rated flow in brackish water or fresh water applications

A

Lowered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Experience has shown that operating in waters such as the Chesapeake Bay, system pressure can be reduced from the normal ___ to ___

A

750-800 psi

350-550 psi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

As the salinity of the water is lower, pressure can be ___

A

Decreased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Typical sea water contains about __ salinity whereas in a bay, it is about ___

A

33%

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The RO system can be adjusted to maintain a constant permeate output when feedwater temperature and salinity is other than nominal. This can be down by controlling system pressure manually via ___

A

The back pressure regulation valve located in the system brine piping

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

As permeate flow decreases, the operator can ____ to increase system pressure

A

Throttle the pressure regulation valve closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Throttling the pressure regulation valve closed will ___
Increase the permeate output and mitigate the effect of a decrease in temperature or an increase in salinity
26
Operating the unit at more than 20% of rated capacity in low salinity water can ___
Damage the membranes
27
R/W temperature range (87)
33 - 113*F (1 - 43*C)
28
Minimum R/W inlet pressure (87)
Static suction pressure
29
Maximum R/W inlet pressure (87)
20 psi
30
Design RO element pressure (87)
800 psi
31
Max RO element pressure (87)
1000 psi
32
Max feedwater residual chlorine (87)
< 0.1 ppm
33
pH range (short term for cleaning) (87)
4 - 10 (3 - 11)
34
Membrane type (87)
Thing film composite
35
Minimum product water production (87)
8.3 gpm
36
Seawater that is ship piping supplied to the intake of the Village Marine Tec RO desalination unit will initially flow through the ____
Raw water strainer
37
Once through the strainer, the raw water is supplied to the ____ which ____ of the water in order to
``` Lift pump (low pressure boost pump) Raises the pressure Provide enough positive feed pressure to flow through the filtration system and into the suction of the high pressure pump ```
38
Path of seawater through RO
``` Strainer Lift pump Pre-filter High pressure pump Membrane Drinking water/Reject back to seawater ```
39
Clean and filtered R/W
Feedwater
40
The high pressure pump raises feedwater pressure to between ___
800 - 1000 psi
41
Nominal pressure range required or optimal system recovery
800 - 1000 psi
42
As the pressurized feedwater flows across the membrane it is divided into two streams
Permeate | Brine
43
High purity product stream
Permeate
44
Increasingly concentrated reject stream
Brine
45
After exiting the membrane array, the brine flows through the ___
Back pressure regulator valve
46
Used to control the back pressure through the membrane array
Back pressure regulator valve
47
Membrane array back pressure is directly related to ___
System pressure
48
After passing through the back pressure regulator, the brine flows through the ____ and exits the RO unit
Reject flow meter
49
Provides the operator a means for removing performance degrading organic foulants and scale deposits from the RO membranes
Membrane cleaning system
50
How often should the RO unit be cleaned during constant use?
Approximately every 30 days
51
Components of the membrane cleaning system
5 micron filter housing, LP boost pump, HP pump, cleaning valve, HP bypass valve
52
The filter housing in the membrane cleaning system also functions as a ___
Mixing tank
53
Size of the filter in the membrane cleaning system
5 micron
54
Provides a signal to the Water Quality Monitor
Conductivity sensor
55
TDS
Total Dissolved Solids
56
Permeate TDS > 500 ppm indicates ___
Poor quality water
57
If permeate TDS is > 500 ppm, a signal is sent to a ____ which will ____
3-way product diversion valve | Divert the water away from the tanks to the reject stream
58
If permeate TDS is < 500 ppm a signal is sent to the product diversion valve to ___
Re-position which directs the permeate to a flow meter and then on to the tanks
59
If your product system backpressure approaches ___, you may be unable to deliver rated amounts of product to P/W tanks
40 psi
60
If the product system backpressure approaches 40 psi, it may be necessary to ___
Adjust the setpoint of the pressure relief valve
61
Adjusting the setpoint of the pressure relief valve should only be performed by __
Factory trained service representative
62
Monitors and displays permeate salinity, temperature and accumulated unit operating hours
Water Quality Monitor
63
Provides operational mode control of the system product valve
Water Quality Monitor
64
Water Quality Monitor pushbuttons
Temperature Salinity alarm set point Mode
65
Alloys the operator to display permeate temperature
Temperature pushbutton
66
By adjusting the ___ the temperature can be displayed in F* and C*
Control knob located on the back of the monitor
67
The display normally displays ___
Permeate salinity display
68
How to adjust the salinity alarm set point
Salinity alarm pushbutton and the control knob located on the back of the monitor
69
Allows the operator to bypass the normal automatic operation and manually activate (dump) product valve
Mode pushbutton
70
During normal operation a ___ light is illuminated
Green
71
During dump/cleaning operation a ___ light is illuminated
Yellow
72
The salinity alarm displays a ____ light
Red flashing light
73
Illuminated when the product valve is energized and permeate is flowing through the product valve
Green light
74
Illuminated when the product valve is de-energized and the product valve is closed
Yellow light
75
Indicates that permeate quality is above the salinity set point
Red flashing light on the salinity alarm
76
Provides centralized control and monitoring of all important unit functions and operating parameters
Master Control Center
77
When unit is in standby mode it will display ___
STANDBY MODE
78
When LP boost pump is running (only) it will display ___
LP PUMP ONLY
79
When HP pump is running (only) it will display __
NOTE: HP PUMP ON ONLY (NO LP PUMP)
80
When both low and high pressure pumps are running it will display ___
RO MODE
81
When automatic fresh water flush it will display ___
0 FLUSH 2 | <<<<<<<<<
82
When unit has high salinity it will display ___
CHECK PRODUCT WATER
83
When unit has low inlet pressure it will display ___
CHECK FILTRATION
84
After every 500 hours of operation it will display ___
CHANGE HP PUMP OIL
85
After every 2000 hours of operation it will display ____
CLEAN MEMBRANES
86
After every 50 freshwater flushes it will display ___
CHANGE FLUSH FILTER
87
Accumulated operating hours for membrane cleaning should be multiplied by ___ to get actual hours
10
88
Master Control Center pushbuttons
LP pump HP pump Flush Reset
89
Controls the operation of the LP pump and energized a light that indicates when the pump is running
LP pump
90
When the raw water pump is running the ___ signals the MCC to display the message LP PUMP ON
LP pump
91
Controls the operation of the HP pump and energizes a light that indicates when the pump is running
HP pump
92
When only the HP pump is running, ___ signals the MCC to display the message NOTE: HP PUMP ON ONLY. NO LP PUMP
HP pump
93
Opens the automatic flush valve. Activates an internal time that will automatically run the LP and HP pumps for every 2 minutes.
Flush
94
Completion of each successful flush cycle will be recorded on the ___
Flush counter
95
What is considered a long term shutdown?
7 days
96
What valves must be open to turn on the RO unit?
``` Sea chest Supply to RO unit Brine OVBD discharge RO unit discharge Discharge to tank ```
97
What valve must be closed to turn on the RO unit?
RO unit flush water cut off
98
How to start the RO
``` Verify valves Verify power Start the LP pump Start the HP pump When flow through the reject discharge flow meter is free of air bubbles, place the high pressure bypass valve in the RO position ```
99
Pressure on the HP gauge should never exceed ___
1000 psi
100
After starting the unit, if the green lamp does not light within ___, sample the product water
5 minutes
101
Normally a drop of ___ in the product water product water production rate indicates the need for RO membrane cleaning
10 - 15%
102
The product flow meter indicates in ___
Gallons per hour
103
When the water product quality reaches ___, the green lamp will light
500 ppm TDS
104
The brine flow meter indicates in ___
Gallons per minute
105
Short term shutdown procedure
Release pressure by turning high pressure bypass valve to Cleaning position Secure HP pump Secure LP pump Perform fresh water flush
106
Bacterial contamination of the RO unit can be avoided by ___
Flush with non-chlorinated fresh water for 2 minutes weekly Flush the RO unit by operating the system for 5 minutes every 7 days Flush with a preservative solution every 3 months
107
Flush the unit with ___ water only
Non-chorinated fresh
108
Do not exceed ___ flushing water pressure
30 psi
109
The ___ must be in place while flushing
Carbon filter
110
The drive belt should not deflect more than 1/2" when a force of ___ is applied
6 - 9 lbs
111
Adjust the ___ to obtain proper belt tension
Base plate
112
When flushing with preservative, allow the chemical solution to circulate for ___
10 minutes
113
What chemical is used for flushing?
Preservative chemical #3
114
Preservative chemical #3 is a ____
Food-grade preservative
115
The preservation procedure should be repeated every ___. In colder climates, the interval between preservation may be ___
3 months | 6 months
116
The filter should be replaced when ___
The inlet pressure gauge reading drops below 0 psi
117
The PW400 uses a ____ filter
Single 5 micron, 30 ft2 filter
118
Filters can be washed and reused ___ times
2 - 3 times
119
VMT filter cartridges are specifically designed for RO applications and constructed from ____
An oil attractive sulfone
120
HP pump plungers should have ___ applied to them any time it is inspected or installed
Ceramic lubricant
121
How much oil does the HP pump take?
Approximately 32 oz
122
Basic cleaning used to remove oil, grease, biological matter, and grime from the surface of the RO membranes
Cleaning chemical #1 Alkaline detergent
123
Used to remove mineral scale deposits
Cleaning chemical #2 Acid cleaner
124
Used to prevent formation of microbiological slimes
Cleaning chemical #3 Food grade preservative
125
How much of each chemical is used in cleaning the membranes
1 cup #1 3/4 cup #2 1/6 cup #3
126
___ may need to be added during the duration of the cleaning cycle to maintain the pH = 2
Cleaning chemical #2
127
R/W temperature range (87)
33 - 113 degrees F
128
Minimum R/W inlet pressure (87)
Static suction pressure
129
Maximum R/W inlet pressure (87)
20 psi
130
Design RO element pressure (87)
800 psi
131
Maximum RO element pressure (87)
1000 psi
132
Maximum feedwater residual chlorine (87)
133
pH range (short term for cleaning) (87)
4 - 10 (3 - 11)
134
Membrane type (87)
Thin film composite
135
Minimum product water production (87)
8.3 gpm

MK2 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions