Process control, Chemical Engineering

Assignment Help:

1.      In the system shown schematically below, water is supplied to a spray nozzle by a gear pump with a constant output of 20 US gpm. The flow rate of water discharged through the nozzle is controlled by manipulating the flow of water re-circulated around the pump using a proportional-plus-integral controller. The set point of the controller is normally 14 US gpm but can vary between 9 and 18 US gpm. The flow sensor has a range of 0-20 US gpm and responds instantaneously to flow variations. The control valve has a CV of 3 US gpm/psi1/2, a time constant of 2 seconds, a linear installed characteristic and is current-to-close.

(a) What should be the action of She controller (reverse or direct)? Why?

(b) Would it be better to eliminate the recirculation loop and install the control valve immediately downstream of the pump? Why?

(c) If the pump discharge pressure is 100 psig when the control valve is closed, show that the flow rate across the nozzle is 8 US gpm when the control valve is wide open,

Notes: The valve and nozzle are the only significant flow resistances in this system. You may also assume that the pump suction port and the spray leaving the nozzle are at atmospheric pressure. The nozzle behaves as an orifice.

(d) What are the outputs of the controller and flow transmitter (in %) when the set point is 12 US gpm and steady-state has been achieved?

148_Process Control.png


Related Discussions:- Process control

Explain eddy current losses, Explain Eddy Current Losses Eddy Current...

Explain Eddy Current Losses Eddy Current Losses The core of a generator armature is made from soft iron, which is a conducting material with desirable magnetic sort. Any con

Separation process, develop a process schematic which will yield separation...

develop a process schematic which will yield separation process streams

Refractoriness under load (rul), Refractoriness under load (RUL): This rep...

Refractoriness under load (RUL): This represents the resistance of a refractory material to the combined efforts of heat and load. RUL is the temperature at which the deformation

Explain projection printing, Projection Printing Projection printing, k...

Projection Printing Projection printing, keep away from mask damage entirely. An image of the patterns on the mask is projected onto the resist-coated wafer, which are many cen

Explain soft magnetic materials, Soft magnetic materials  Soft magnetic...

Soft magnetic materials  Soft magnetic materials are majorly utilized in those applications in which the soft material has to amplify the flux occured by the electrical current

Concentration gradient , Mass transfer coefficients can be of either local ...

Mass transfer coefficients can be of either local or overall type. a. Describe carefully what the local and overall mass move coefficients show. b. How does the concentration

Assignment, can you help with process control questions

can you help with process control questions

Axon, Ask queswhat is axontion #Minimum 100 words accepted#

Ask queswhat is axontion #Minimum 100 words accepted#

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd