Past boards Flashcards
Histogram Definition
a graph used to represent the frequency distribution of a few data points of one variable. Histograms often classify data into various “bins” or “range groups” and count how many data points belong to each of those bins.
Pioneered the use of zeolites in water softening
Robert Gans
Earth Wax
Ozocerite
Kailan hindi ginagamit ang log mean temperature
Pag constant value ang U (overall heat transfer coefficient
Debye Huckel Theory
This theory was proposed by Peter debye and Eric huckel to explain the departure of electrolytic solution from ideality, because the electrolytic solution shows the deviation from the ideal behavior. Colligative properties of ideal solutions are directly proportional to the concentration of solute.
Used for low pressure and viscous fluids
Flowmeter
Kerogen
Oil shale
Used in cement production
ESP and Venturi
Difference between set point and experimental value
error
O2 needed per 100 m3 of CO & H2
Producer gas
part of turbulent velocity profile where v is constant
viscous sublayer
Lang factor for fluid processing
5.12
Lee/Kesler correlation is only applicable for
nonpolar and slightly polar
Measurement for low flow rate and high viscosity
Flowmeter
Alloy for standard definition of kilogram
Platinum/Iridium
Theoretical something
Transfer function
Collective term for disturbances in control
Perturbation
Producing heat from low temperature source
Heat pump
Difference of agitation from blending/mixing
agitation refers to forcing a fluid by mechanical means to flow in a circulatory or other pattern inside a vessel. Mixing usually implies the taking of two or more separate phases, such as a fluid and a powdered solid or two fluids, and causing them to be randomly distributed through one another.
Gravity Decanter
A gravity decanter is a vessel or stage in which two liquids of different densities are allowed to separate by gravity.
The feed is sent to a gravity decanter where the n-butanol phase separates from the aqueous phase and rises to the top.
A gravity decanter is used for the continuous separation of two immiscible liquids of differing densities.
A gravity decanter is a vessel or stage in which two liquids of different densities are allowed to separate by gravity.
If the membrane is broken and the gases diffuse, what is the change of entropy of the system if the gases act ideally?
delta S = Cpln T2/T1 - RlnP1/P2 = 0-1.986ln(4/2) = +1.376 Btu/moleR
(coulson) A forward feed double effect evaporator, having 10 m3 of heating surface in each effect, is used to concentrate 0.4 kg/s of caustic soda solution from 10 to 50 percent by mass. During a particular run, when the feed is 328 K, the pressures in two calandria are 375 and 180 kN/m2
(a) the load on the condenser
(b) the steam economy
(c) overall heat transfer coefficient in each effect
(a) 0.15 kg/s
(b)1.57 economy
(c) 2.53 kW/m2K and 1.84 kW/m2 K
(coulson) 1.4 m and of cross-sectional area 0.0045 m2, the concentrations measured at the inlet and outlet of the column are as shown in the figure
Determine the overall transfer coefficient and the height of the transfer unit
1.63 m
(coulson) Cool 100,000 kg/h of methanol from 95ŽC to 40ŽC, duty 4340 kW. Cooling water inlet
temperature 25ŽC and outlet temperature 40ŽC.
(a) Area required
(b) Channel velocity of Methanol
(c) Channel velocity of Brackish water
(a) 72.92
(b) 0.51 m/s
(c) 0.96 m/s
(himmelblau)
A limestone analysis:
CaCO2 92.89%
MgCO3 5.41%
Unreactive: 1.70%
(a) how many pounds of calcium oxide can be made from one ton of this limestone
(b) how many pounds of CO2 can be recovered per pound of limestone
(c) how many pounds of limestone are needed to make 1 tone of lime
(a) 1041 lb CaO/ton limestone
(b) 0.437 lb CO2/lb limestone
(c) 3550 lb stone/ton lime
(Coulson)
A packed tower is used for absorbing sulphur dioxide from air by means of a caustic
soda solution containing 20 kg/m3 NaOH. At an air flow of 2 kg/m2
s, corresponding to
a Reynolds number of 5160, the friction factor R/ρu2 is found to be 0.020. Calculate the mass transfer coefficient in kg SO2/s m2 (kN/m2
) under these conditions
if the tower is at atmospheric pressure. At the temperature of absorption, the diffusion
coefficient SO2 is 1.16 × 10−5 m2/s, the viscosity of the gas is 0.018 mN s/m2 and the
density of the gas stream is 1.154 kg/m3
.
7.56x10-4 kg SO2/m2s
(Coulson)
In an absorption tower, ammonia is absorbed from air at atmospheric pressure by acetic
acid. The flowrate of 2 kg/m2s in a test corresponds to a Reynolds number of 5100 and
hence a friction factor R/ρu2 of 0.020. At the temperature of absorption the viscosity of
the gas stream is 0.018 mN s/m2, the density is 1.154 kg/m3 and the diffusion coefficient
of ammonia in air is 1.96 × 10−5 m2/s. Determine the mass transfer coefficient through
the gas film in kg/m2s (kN/m2).
2.70x10-4 kg/m2s
you are asked to recommend, with reasons, the most suitable type of equipment for carrying out a gas-liquid reaction between a gas A and a solution of a reactant
(a) find Beta numerator
Beta numerator = 1.5x10-5
Bubble dispersion range (0.075 to 0.038)
Beta range (0.3 to 0.15)
liquid water in equilibrium with its vapor.
Total number of phase P = 2 (liquid and vapor) Total number of components C = 1( water) So degree of freedom F = C - P +2 = 1-2+2 = 1 Degree of freedom liquid water is equilibrium with its vapor
liquid water in equilibrium with a mixture of water vapor and nitrogen
2
a liquid solution of alcohol in water in equilibrium with its vapor
2
1.4 M3/S Flowrate From A Tank Is To Be Delivered To Another Tank. Using Parallel Flow, D1=0.6m And D2=0.4m
(a) velocity in d1=0.6
(b) velocity in d2=0.4
(c) what is the diameter if one pipe
(a) 3.636 m/s
(b) 2.97 m/s
(c) sqrt 0.891/D^2V
What element is used in the standard 1 kg measurement
Iridium
A hollow-fiber permeator with do=300 micros and d1 = 200 micron gives a water flux of 10 gal/day with 0.1M and the salt rejection is 97 percent. Feed solution flows normal to the fibers at an average superficial velocity of 0.5 cm/s. Is concentration polarization
0.068 since it is less than 1 then it might have significant polarization
A certain toaster has a heating element made of Nichrome wire. When the toaster is first
connected to a 120 V source (and the wire is at a temperature of 20.0C), the initial current is
1.80A. The current decreases as the heating element warm up. When the toaster reaches its final
operating temperature, the current is 1.53A. Find the power delivered to the toaster when it is at
its operating temperature.
P = VI = (120x1.53) = 183.6 W
When 1.61 x 10-3 moles of phenolphthalein indicators in dissolved in one liter of water plus
ethanol. Estimate the the concentration at equilibrium of [Hphth], [H3O+] and [phth-].
(pKa = 9.3 | Ka = 5x10-10 memorize K value of phenolphthalene)
ANS: [Hpth] = 1.599 x 10-3 M; [H30+] = 8.0 x 10-7 M; [phth-1] = 8.0 x 10-7 M