dead weight pressure relief valve
DESCRIPTION
dead weightTRANSCRIPT
DESIGN MODIFICATION OFGAS CLEANING PLANT VENT SYSTEM
DEPARTMENT OF
MECHANICAL ENGINEERING
Submitted by :
MALLICHETTI.M (080111804026)
SATHISH KUMAR.C (080111804055)
SRINIVASAN.R (080111804059)
SHANKAR.P (090411804006)
GUIDE: CO-GUIDE:
E.JAMUNA S.MANIKANDAN
Asst. Professor Lecturer
OBJECTIVE
The making of iron in blast furnace, the impure gases coming from this process will
be poisonous. So that impure gases purified in the gas cleaning plant
During the purification of impure gases, the rupture disc on a gas cleaning system
get affected and burst because of top pressure.
The problem will be overcome with the help of pressure relief valve modification.
The pressure relief valve to be designed with materials compatible with many
process fluids from simple air.
The pressure relief valve will be modeled by PRO-E and performance of pressure
relief valve analyzed by ANSYS.
METHODOLOGY
SELECTION OF PROJECT
Company and area of the project chosen
PVT LTD Pottaneri, Mecheri, Salem.
STUDY ABOUT PROJECT
Overall view Blast Furnace plant
EXISTING SYSTEM
RUPTURE DISC
A rupture disc, also known as a bursting disc or burst diaphragm, is a non-
reclosing pressure relief device that, in most uses, protects a pressure vessel,
equipment or system from over pressurization or potentially damaging vacuum
conditions
IDENTIFICATION OF FAILURE
When top pressure of furnace exceeds the rupture disc burst (causes-Furnace slip).
Rupture disc get explode to relieve the excess pressure in the silos of the Gas Cleaning
Plant.
Once rupture disc failed it cannot be reused. New one has to be replaced
Hence we focus to replace the rupture disc into pressure relief valve
PROPOSED SYSTEM
PRESSURE RELIEF VALVE
Pressure Relief Valves is also know as safety valves, which is used to release the
excess steam when the pressure of steam inside the closed vessel exceeds the rated
pressure.
TYPES OF PRESSURE RELIEF VALVE
Hydraulic Pressure Relief Valve
Pneumatic Pressure Relief Valve
Spring Loaded
Dead Weight Pressure Relief Valve
DEAD WEIGHT PRESSURE RELIEF VALVE
DESIGN CALCULATION
1.Counter weight calculation by using free body diagram.
2.Design calculation for
lever
Pin
Shaft
COUNTER WEIGHT CALCULATION
From right angle triangle CDB, shown in fig
tan θ = BD/CD
tan45 = BD/275
1 = BD/275
BD = 275mm
Then using Pythagoras theorem, we get
CD2 + BD2 = CB2
2752 + 2752 = 388.92
Therefore…..
CB = BC = 388.9mm
From right angle triangle ABC, shown in fig
tan θ = BC/AB
tan45 = 388.9/AB
1 = 388.9/AB
AB = 388.9mm
Then using Pythagoras theorem, we get
AB2 + BC2 = AC2
388.92 + 388.92 = 5502
Therefore…..
AC = 550mm
Pressure (P) = Load/Area (Refer [1], P.G - 573)
Load (w) = Pressure × Area
Area (A) = (π/4) D2
= (π/4) × 2502
Area (A) = 49.09×103mm2
Load (w) = 0.13× 49.09 ×103
W = 6381.36 N = 638 Kg
Primary input data’s
Diameter of relief valve (D) = 250mm
Maximum pressure (P) = 1.3bar = 0.13N/mm2
Pin length (Lp) = 600mm
Assuming pin diameter (dp) = 60mm
From the above diagram
From the above diagram is represented by the length of pin = 600mm, then taking
momentum about the center point of the pin
Momentum (M) = 550Sin45×6381.36
= 2.48 × 106 Nmm
From the above diagram is represented by the length of the lever = 1300mm, then taking
moment about the point at P
P×1300 = 2.48×106
P = (2.48×106)/1300
=1909.05
P =190Kg
Finally the counter weight was calculated using above steps as P = 190kg
MODELING & ASSEMBLY
– Bottom reducer
– Seat
– Rubber gasket
– Bottom MS ring
– Top MS ring
– Cover
– Arm
– Arm pin
– Pin
– Lever
– Plummer Block
– Counter weight shaft
– Counter weight
MODELING
Modeling of Dead weight pressure relief valve components was developed by
using modeling software’s Pro-E.
The components are:
BOTTOM REDUCER
SEAT
RUBBER GASKET
BOTTOM MS RING
TOP MS RING
COVER
ARM
ARM PIN
PIN
LEVER
PLUMMER BLOCK
COUNTER WEIGHT SHAFT
COUNTER WEIGHT
ASSEMBLY
Components of dead weight valve was modeled and assembled by
using PRO-E software with proper dimension.
Assembled dead weight valve was developed and indicated with different
views.
Exploded view of dead weight pressure relief valve
3D view of dead weight pressure relief valve
Front view of dead weight pressure relief valve
Top view of dead weight pressure relief valve
Side view of dead weight pressure relief valve
ANALYSIS OF DEAD WEIGHT PRESSURE RELIEF VALVE
A suitable Finite Element was identified and selected.
Then finite element model of Dead Weight Pressure Relief Valve developed with
proper procedure in Ansys.
Finite Element Model of
Dead Weight Pressure Relief Valve
RESULT DISCUSSION
Dead weight Pressure relief valve with diameter 250mm was modified for changing
rupture disc.
The design of Dead weight pressure relief valve will be verified by some design
steps.
The shear stress and bending stress of lever was calculated.
The resultant value was verified with theoretical standard values of respective
material. The material was selected as Mild Steel.
Represents the contour plot of total distribution of von mises stress
S.NO
MECHANICAL
PROPERTIES
OF MILD STEEL
(Theoretical values)
DESIGNED VALUES OF PIN AND
LEVER(Dead weight pr.relief valve)
(as per calculation)RESULT
FOR PIN FOR LEVER
1Shear Stress
= 60Mpa
0.79Mpa
2.11MpaSAFE
2Bending Stress
= 80Mpa26.36Mpa
76.44MpaSAFE
CONCLUSION
Rupture disc in the Gas cleaning plant is affected by blast furnace top pressure
and also by gas reaction during cleaning process.
Once open, they cannot reseal and must be replaced.
Cost of rupture disc high because of shifting every time.
Replacement of rupture disc by Dead weight pressure relief valve will solve
the disc failure problem & replacement time.
When the pressure is high the valve is opened automatically and valve closed
with the aid of self weight, when the pressure is below the set value. So dead
weight pressure relief was selected .
BIBLIOGRAPHY
[1] R.S.KHURMI & J.K.GUPTA, Machine Design (First Multicolor Edition).
[2] R.K.BANSAL, Strength Of Materials (Fourth Edition)
[3] Southern African Pyrometallurgy 2011, Edited by R.T. Jones & P. den Hoed, Southern African Institute of Mining and Metallurgy, Johannesburg, 6–9 March 2011
[4] HARDARSHAN S. VALIA, Scientist, Ispat Inland Inc, Coke Production for Blast Furnace Iron making.
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