Why is maximum pipe size advantageous?

a shell and tube heat exchanger with four shells passes and eight tube passes uses 3kg/s of ethylene glycol in the shell to heat 1.5kg/s of water from 20 to 50 C.The glycol enters at 80c , and the overall heat transfer coefficient is 900W/m2C.Determine the area of the heat exchanger?

please slove it step by step .

1. Consider a simplified one-dimensional laminar flame, such as that discussed in the classroom. The earliest description of a laminar flame is that of Mallard and Le Chatelier in 1883. Assume that:

a. 1-D, constant area, steady flow,

b. kinetic and potential energies, viscous shear work, and thermal

radiation are neglected,

c. pressure is constant,

d. diffusion of heat and mass are governed by Fourier’s and Fick’s laws

and binary diffusion is applied,

e. Lewis number is unity,

f. individual specific heats are all equal and constant,

g. fuel and oxidizer form products in a single-step exothermic reaction,

h. fuel is completely consumed at the flame with oxidizer in

stoichiometric or excess proportion.

By applying suitable boundary conditions, please derive the expressions for laminar flame velocity and flame thickness. (Simplified solution can be found in most of the combustion textbook, such as the one by S.R. Turns(1996) or the one by I. Glassman (1993 or newer edition).)

Describe how an industrial hygienist evaluates a potential hazard from a chemical agent.

Explain the difference between an aerosol and a fume.

One way to remove harmful “NO_x” (NO and NO₂) atmospheric pollutants from flue gas is the “thermal deNOx” process, in which NH₃ is used to reduce the NO to N₂:

__4__ NO (g) + __1__ O₂ (g) + ____ NH₃ (g) → ____ N₂ (g) + ____ H₂O (g)

The research lab has several gas cylinders available for studying this reaction, including one cylinder containing a mixture of 3.0 wt% NO and 15 wt% O₂ in an N₂ diluent, and a second cylinder containing a mixture of 4.5 wt% anhydrous ammonia in N₂ diluent. Assume that all the gases behave ideally.

Balance the thermal deNOx reaction.

You introduce 8.0 g from the NO cylinder and 3.5 g from the NH₃ cylinder into an isothermal, constant volume (20 L) batch reactor. What are the initial molar concentrations of NO, NH₃, and O₂?

What are the initial NO, NH₃ and O₂ mole fractions?

What is the total initial reactor pressure (in bar) at 250°C? What are the partial pressures (in bar) of NO, NH₃, and O₂?

What is the limiting reagent and the final partial pressures of NO, NH₃, and O₂, assuming the reaction goes to completion? Note: the limiting reagent is the reactant that, due to stoichiometry, limits the extent to which the reaction can proceed.

What molar concentrations of NO and NH₃ remain when 75% of the limiting reagent is consumed (i.e., 75% conversion)?

Consider a rigid, thick-walled tube that is filled with H2O liquid and vapor at 0.1 MPa. After it is sealed, it is heated so that it passes through its critical point. What fraction of the mass in the tube is liquid?

A microbial cell may be modeled as a well-mixed reactor in which nutrients (“corn steep liquor”) diffuse into the cell and are converted to products (including penicillin) which diffuse out of the cell. Write unsteady-state material balances on the nutrients (A) and on the products (B) in terms of the rate of consumption of A (rA), the yield of B (YB/A) defined as the mass of B produced per mass of A consumed, a mass-transfer coefficient (kA) for transport of nutrients into the cell, a mass-transfer coefficient (kP) for transport of product out of the cell, the surface area of the cell (A), the volume of the cell (V), the concentrations of nutrients outside and inside the cell (CAo, CA), and the concentrations of products outside and inside the cell (CPo, CP).

Steam at a temperature of 280 DegreeC flows in a steel pipe (k=70 W/m K) having an inner and outer diameter of 5 cm and 5.6 cm. The pipe is covered with glass wool insulation (k=0.05 W/m K) to a thickness of 4 cm. On a windy day heat is lost from the lagging surface with a convective heat transfer coefficient of 50 W/m² K. The surroundings are at a temperature of 5 DegreeC and the internal heat transfer coefficient for heat transfer between the steam and the steam pipe is 600 W/m² K.

What are the rate of heat loss from pipe per unit length and the outer surface temperature of the lagging?

Ethanol can be produced commercially by the hydration of ethylene:

C2H4 + H2O -> C2H5OH

Some of the product is converted to diethyl ether in the side reaction:

2C2H5OH -> (C2H5)2O + H2O

The feed to the reactor contains ethylene, steam, and an inert gas. A sample of the reactor effluent gas is analyzed and found to contain 43.3 mol% ethylene, 2.5 mol% ethanol, 0.14 mol% ether, 9.3 mol% inerts, and the balance water.

a. Take as a basis 100 mol of effluent gas, draw and label a flowchart, and do a degree of freedom analysis based on an atomic species balance.

b. Calculate the molar composition of the reactor feed, the percentage conversion of ethylene, the fractional yield of ethanol, and the selectivity of ethanol relative to ether.

Question 3 Steam enters an adiabatic turbine at 800 psia and 900oF and leaves at a pressure of 40 psia. Determine the maximum amount of work that can be delivered by this turbine.

1.) what are electron levels? Please describe.

2.) explain how the number of protons, electrons, neutrons and electron energy levels are related on the periodic table.

Determine the thermodynamic state of 1,1,1,2-Tetrafluoroethane (R-134a) at 102 °C and 1000 kPa. Critical Pressure= 4.059 MPa, Critical Temperature = 101.06°C.

*I keep getting stuck with a quadratic equation and two volume values, when using the van der Waals equation of state (P=(RT/(V-b))-(a/V^2))....I am determining the thermodynamic state by finding if the compressibility factor (z) is less than or greater than 1, to find if attractive or repulsive forces dominate.