Bissoy.com
Doctors Medicines MCQs Q&A

In condensation from mixtures, with or without a non-condensing gas, then the assumptions underlying the logarithmic mean temperature difference (LMTD) are valid.

In condensation from mixtures, with or without a non-condensing gas, then the assumptions underlying the logarithmic mean temperature difference (LMTD) are valid. Correct Answer False

In condensation from mixtures, with or without a non-condensing gas, the variation of the equilibrium temperature with enthalpy is not linear and in the thermal design of condenser, it is impossible to assign a single demanding temperature difference and an overall heat transfer coefficient to the exchanger based on it, and hence we need a zonal or stepwise calculation of the surface area which is far more complicated than a HE.

Related Questions

In condensation from mixtures, with or without a non-condensing gas, the assumptions underlying the logarithmic mean temperature difference (LMTD) are invalid, so what is the method that we can adopt to cope with this problem?
If the coolant is not in multiple-phase, and if the overall heat transfer coefficient is constant, then the assumptions underlying the logarithmic mean temperature difference (LMTD) __________
The following question has three statements. Study the question and the statements and decide which of the statement (s) is/are necessary to answer the question. The percentage of milk in three mixtures A, B, and C is 60%, 75%, and 80% respectively. Find the quantity of water in the resultant mixture. I)  All three mixtures A, B and C are mixed in the ratio of 1 : 3 : 2 respectively. II) Quantity of resultant mixture of three mixtures is 60 liters. III) The ratio of water quantity in three mixtures is 8 : 15 : 24.
Which are the correct statements? (a) Film condensation usually occur on oily surface. (b) Temperature of condensate gradually increases towards the liquid-vapour interface. (c) Suitable coating is used to promote dropwise condensation. (d) Dropwise condensation gives lower heat transfer rate than film condensation.
In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is
In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is
Consider the following statements (i) If a condensing liquid does not wet a surface, then drop wise condensation will not take place on it (ii) Drop wise condensation gives a higher transfer rate than film wise condensation (iii) Reynolds number of condensing liquid is based on its mass flow rate (iv) Suitable coating or vapor additive is used to promote film wise condensation Identify the correct statement
Statement 1: Film-type condensation has a higher heat transfer co-efficient than drop-wise condensation. Statement 2: Drop-wise condensation is easier to maintain than Film-type condensation
Propositions are
1. Gift made during marz-ul-maut to a heir is valid without the consent of other heirs under Sunnite law
2. Gift made during marz-ul-maut to a heir is valid without the consent of other heirs under Ithna Ashari law
3. Gift made during marz-ul-maut to a heir is valid only with the consent of other heirs, under Sunnite law
4. Gift made during marz-ul-maut to a heir is valid only with the consent of other heirs under the Shia law.
Which amongst the following is correct
There are two mixtures of alcohol and water. In 48 L of the first mixture 32 L is alcohol while in 32 L of the second mixture 20 L is alcohol. If these mixtures are mixed in a large container in such a way that per cent of water in the final mixture becomes 36.8%, then find that in what ratio these two mixtures are mixed to form the final mixture?