1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
stiv31 [10]
3 years ago
14

Evaporation in Double-Effect Reverse-Feed Evaporators. A feed containing 2 wt % dissolved organic solids in water is fed to a do

uble-effect evaporator with reverse feed. The feed enters at 100°F and is concentrated to 25% solids. The boiling-point rise can be considered negligible as well as the heat of solution. Each evaporator has a 1000-ft2 surface area and the heat-transfer 700 btu/h -ft2-°F. The feed enters evaporator number 2 and steam at 100 psia is fed to number 1. The pressure iin the vapor space of evaporator number 2 is 0.98 psia. Assume that the heat capacity of all liquid solutions is that of liquid water. Calculate the feed rate F and the product rate Li of a solution containing 25% solids. (Hint: Assume a feed rate of, say, F 1000 lbm/h. Calculate the area. Then calculate the actual coefficients are U1 500 and U2- feed rate by multiplying 1000 by 1000/calculated area.) Ans. F- 133 800 lbm/h (60 691 kg/h), L,- 10700lb»/h (4853 kg/h)

Engineering
1 answer:
Ne4ueva [31]3 years ago
5 0

Answer:

472,826 lb/hr

Explanation:

As per the given data:

Solids in feed= 2%

Solids in concentrate= 25%

HTA1 = HTA2 = 1000 ft^2

U1 = 500 Btu/ h ft^2 F & U2 = 700 Btu/ h ft^2 F

Overall material balance: Feed= Distillate + concentrate ----> Eq-1

Component balance: Feed * 0.02 = Distillate * 0 + concentrate * 0.25

Feed = 12.5 * concentrate ---> Eq-2

Boiling point rise = negligible, so solution & solvent vapor temperature will be same.

Assumed that the 1st effect is operating under atmospheric pressure (Boiling point - 212F).

As per the data:

Latent heat 212F = 300 Btu/lb

Latent heat 100F = 320 Btu/lb

As per material balance:

Vapor flowrate * latent heat = Overall HT coefficient * HTA * DT

1st effect: M-1= (500 * 1000 * (326-212)) / 300 = 190,000 lb/hr

2nd effect: M-2= (700*1000 * (212-100)) / 320 = 245,000 lb/hr

Distillate = M-1 + M-2 = 190,000+245,000 = 435,000 lb/hr

Substituting the above in Eq-1

Feed = 435,000 + concentrate

Substitute Eq-2 in the above

12.5 * concentrate = 435,000 + concentrate

Concentrate, L1 = 435,000/11.5 = 37826 lb /hr

Feed, F = 435,000 + 37826 = 472,826 lb/hr

1st effect operating pressure is not given, That may be the reason we are not getting the given answer. But procedure is right.

[ Find the figure in the attachment ]

You might be interested in
How to draw the output voltage waveform rectifier
tatyana61 [14]

Answer:

Half-wave rectifier converts an AC signal into a DC signal. It's called a half-wave because it only rectify the positive part of an AC signal.

AC Signal = An electrical signal that alternates between positive and negative voltage.

DC Signal = An electrical signal that only has positive voltage.

Rectify = A fancy word for converting something.

Adding a capacitor helps the positive part of the signal stay on longer. This work because the capacitor stores energy kinda like a battery. During the negative part of the AC signal, the energy stored in the capacitor will be drained and used, then the cycle repeats.

The load resistor is just there to prevent a short circuit from happening.

7 0
2 years ago
⦁ An ideal Otto cycle has a compression ratio of 8. At the beginning of the compression process, air is at 95 kPa and 27°C, and
Anon25 [30]

Answer:

<u><em>note:</em></u>

<u><em>solution is attached in word form due to error in mathematical equation. furthermore i also attach Screenshot of solution in word due to different version of MS Office please find the attachment</em></u>

Download docx
8 0
3 years ago
You work in a furniture store. You receive a
spin [16.1K]

Answer:

18 pieces of furniture

Explanation:

Since you receive $120.93 per furniture piece and a the month's commission is $2,176.74 you divide the commission by the furniture price.

  • 2176.74/120.93
3 0
3 years ago
Read 2 more answers
What is a system that performs different functions according to a fixed schedule?
geniusboy [140]

<u>I'm pretty sure your answer is B, because Sequential Control operates during order like a schedule</u>

Sequential Control=A control system in which the individual steps are processed in a predetermined order, progression from one sequence step to the next being dependent on defined conditions being satisfied.

Tell me if I'm incorrect but, Hope this helps!

4 0
2 years ago
Read 2 more answers
6.
zhenek [66]
The answer is b i did the same thing and i got it right
5 0
2 years ago
Read 2 more answers
Other questions:
  • Consider the following program:
    15·1 answer
  • What does basic levels of competence involves??​
    13·2 answers
  • A pressure cylinder has an outer diameter 200 mm, maximum external pressure 4 MPa, and maximum allowable shear stress 27.5 MPa.
    13·1 answer
  • 6. PVC boxes are primarily used in new construction because it is simple to
    11·1 answer
  • The line voltage of a balanced three-phase transmission line is 4200 V rms. The transmission line has an impedance of 4 6 Z j l
    12·1 answer
  • What is the base unit in standard measurement
    13·2 answers
  • Air at 7 deg Celcius enters a turbojet engine at a rate of 16 kg/s and at a velocity of 300 m/s (relative to engine). Air is hea
    7·1 answer
  • A motor cycle is moving up an incline of 1 in 30 at a speed of 80 km/h,and then suddenly the engine shuts down.The tractive resi
    11·1 answer
  • - If you overload the rear portion of you vehicle &amp; it's raining out, your car could easily:
    14·1 answer
  • All these are returnless fuel systems EXCEPT ?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!