Answer / m.elangovan

NPSH = Hp + HZ – Hvp – Hf

Hp = Absolute pressure at surface of liquid
in ft
Hz = Height in ft of liquid above or below
centerline of pump.
Hvp = Vapor pressure head of liquid in ft.
Hf = Friction loss head between surface of
liquid & pump
suction pipeline in ft.
NPSH = Net Positive Suction Head in ft.
NPSHa = NPSH available + of the system.
NPSHr = NPSH required + by pump manufacturer.
NPSHa > NPSHr
As good engineering practice provide NPSHa-NPSHr = 1.5
m of liquid.

Answer / lokesh singh

above answer is quite good but ,Hvp is vapor pressure of
pumping fluid at the fluid temperature in the suction line.

secondly Hf is the friction losses from the outlet of the
suction side liquid holding tank to the eye of the pump
impeller.

Why do we apply on iron articles?

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Dielectric materials in static fields

0 Answers   HCL,

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.21 : The cost of building a biochemical processing plant is increasing due to inflation. Let I = inflation rate, R = nominal interest rate, r = real interest rate. According to Fisher Equation, (1 + r)(1 + I) = (1 + R). According to General Inflation Equation, R = r + I. (a) By assuming that both r and I are fairly small, prove by mathematical calculations that complicated Fisher Equation could be simplified into the General Inflation Equation. (b) By using 2 first order Taylor expansions in the linear approximation, namely 1 / (1 + x) ≈ (1 - x), (1 + x)(1 + y) ≈ 1 + x + y, show by mathematical calculations that (1 + r) = (1 + R) / (1 + I) could be approximated by r ≈ R - I.

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Question 49 - According to rules of thumb in chemical process design, consider the use of an expander for reducing the pressure of a gas when more than 20 horsepowers can be recovered. The theoretical adiabatic horsepower (THp) for expanding a gas could be estimated from the equation : THp = Q [ Ti / (8130a) ] [ 1 - (Po / Pi) ^ a ] where 3 ^ 3 is 3 power 3 or 27, Q is volumetric flowrate in standard cubic feet per minute, Ti is inlet temperature in degree Rankine, a = (k - 1) / k where k = Cp / Cv, Po and Pi are reference and systemic pressures respectively. (a) Assume Cp / Cv = 1.4, Po = 14.7 psia, (temperature in degree Rankine) = [ (temperature in degree Celsius) + 273.15 ] (9 / 5), nitrogen gas at Pi = 90 psia and 25 degree Celsius flowing at Q = 230 standard cubic feet per minute is to be vented to the atmosphere. According to rules of thumb, should an expander or a valve be used? (b) Find the outlet temperature To by using the equation To = Ti (Po / Pi) ^ a.

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Chemical Engineering Unit Operation - Which of the sequence below represent a feasible flows of ethanol processing plants using cellulose as starting material? A. raw material --> heat exchanger --> distillation column --> reactor. B. reactor --> distillation column --> raw material --> heat exchanger. C. heat exchanger --> raw material --> distillation column --> reactor. D. raw material --> heat exchanger --> reactor --> distillation column. E. distillation column --> raw material --> reactor --> heat exchanger.

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.12 : You, as an engineer, buy a piece of biochemical instrument to start a servicing business. The instrument has a useful life of 3 years, that costs $60k. The instrumental business generates $100k per year. The labor costs $50k per year. The $60k new instrument depreciates in its value evenly up to 3 years, thereafter the old instrument needs to be replaced by another piece of new instrument. (i) In the first year of this engineering business : (a) what is its starting cash? (b) calculate the depreciation value of the instrument. (c) find the operating profit generated. (d) what is the capital expense of the business? (e) calculate the cash from operation. (f) calculate the ending cash. (ii) Based on the income statement of the business in the second year : (a) find the capital expense of the business. (b) what is its starting cash? (c) calculate the depreciation value of the instrument. (d) find the operating profit generated. (e) calculate the cash from operation. (f) calculate the ending cash.

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is extractive distillationӞH

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How can one quickly estimate the additional pressure drop to be introduced with more tube passes?

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What are some of the consequences of an undersized kettle type reboiler?

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What is % of piping & equipment cost for a chemical plant having batch process?

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ENVIRONMENTAL ENGINEERING - QUESTION 22.1 : In order to predict the wastewater production, the population number has to be understood. The population data is : 72000 (for year 1961 or P-1961), 85000 (for year 1971 or P-1971), 110500 (for year 1981 or P-1981). (a) Find the average population increase, or [ (P-1981 - P-1971) + (P-1971 - P-1961) ] / 2. (b) Find the average percentage population increase, or [ (P-1981 - P-1971) / P-1971 + (P-1971 - P-1961) / P-1961 ] / (2) X 100. (c) Find the incremental increase or P-1981 - 2 (P-1971) + P-1961. (d) Let Po = P-1981. After 2 decades or n = 2, the population is P-2001. By using arithmetical increase method, find P-2001 = Po + n (Answer for a). (e) By using incremental increase method, find P-2001 = (Answer of d) + n (n + 1) (Answer of c) / 2. (f) By using geometrical increase method, find P-2001 = Po [ 1 + (Answer of b) / 100 ] ^ n where ^ is power sign, or 1 ^ 2 = 1 x 1 = 1. (g) If the actual P-2001 = 184000, which method of estimation is more accurate, based on your answer in (d), (e) and (f)?

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