User talk:Ahmad ali alinejad tayyebi

INNOVATION & TECHNICAL MUTATIONS IN RECIPROCATING PUMP INDUSTERIES. PERMISSION TO PRESENT THIS TECHNICAL ARTICLE TO THE LATE MOHAMMAD BAHMANBEIGI DECEASED DID A GREAT SERVICE FOR THE EDUCATION OF IRANIAN TRIBAL PEOPLE. (http://ghashghayi.mihanblog.com/) TITLE: Innovation in pump Industry and prevention from the damages resulting from EMERGENCY SHUT DOWN in high-pressure plunger pumps. author: ahmadali alinejad tayyebi Organization: mechanical engineering department Email: ahmad.tm2009@yahoo.com Phone: 00989171021635

INTRODUCTION: world industries has a lot of high-pressure plunger reciprocating pumps. According to research done, there are also a considerable number of the pumps above in world Ministry of Oil and other industries. Energy transfer to the fluid of the aforesaid pumps is done periodically while the moving force is supplied by powerful electrical motor. Revolution of electrical motor is transferred to the crankcase after being decreased in the gear box. Then, the rotary Revolution of the crankshaft is changed into reciprocating one in plungers Returning of the plunger through the inside of cylinder makes a vacuum condition and consequently ,the liquid enters the cylinder through a suction check valve and the movement of the plunger makes the suction close completely which discharge opens and the liquid is transferred towards a Discharge vessel .there are two main technical rules in plunger pumps: 1-they must never be started while the discharge valve is close. 2-they must never be shut down while having operated with an operational pressure. Considering that the most permits of repairing activities have been issued for the pumps above (due their high output pressures), and that they have expensive mainly foreign parts, it requires a special attention to starting, stopping, and maintenance of the pumps.

DISCUSSION: The pumps above have a standard safe instruction for starting and stopping, in which a manual valve is considered beside the pump by the pump designer and manufacturer. This valve, indeed, acts as a connector between input and output surge tank, which after opening the valve above, the pump pressure will reduce from high pressure to approximately suction pressure, consequently being balanced. According to the manufacturer's recommends, the manual connecting valve should be open at the time of starting or stopping; and the pump specialists are very sensitive to pressure unbalance at the time of starting and stopping, due to awareness of its destructive consequences and irreparable damages on the pump and electrical motor parts. But in some causes, the plunger pumps above will be out of service in unwanted manner, including Emergency shut down (due to such factors as high temperature oil alarm and low pressure oil alarm,…). When operating the switches above, the pump will be out of service in very high pressure with sudden stoppage. According to the investigations conducted, most of repairs and failures in the pumps which have the most unwanted disabling, including, Broken crankshaft in several stages, Broken plungers or deviation from standard path, crushed moving parts such as bearings, couplings and gears, Continual abnormal sounds, Repetitive leakages from fluid seals and packing, Broken glands and internal rings.

METHOD&RESULT: The existing pump technology is related to nearly 3 decades ago. So the considerable changes will be created in amount of productivity and increase in maintenance of the pumps above through designing and installing a PLC system .one xcv valve is installed parallel to the manual valve balancing output and input pressure of the pumps, which will transfer all shut down signals of the pump to the xcv above. After the xcv is opened, instantaneous pressure discharge balancing will be done; and then according to the manufacturer offer, the electrical motor will continue several seconds to move in a descending manner, normal safe manner around the pressure discharge will be done;, normal safe manner around the direction of total stop; and the pump will consequently continue to move with several reciprocating cycles of the plunger (having descending rate) and then will be stopped. The pump starting and stopping will be done by(on/off) buttons of the electrical motor. Therefore, to have more safety and prevent from unintentional mistake by operators of the pump above in the industries, we consider timer delay on in (on button) of the electrical motor so that as soon as the operators presses on button to start pump, xcv will be immediately opened, and pump pressure is dropped, if existed (i.e. the related manual valve is closed), will be occurred, and then electrical motor and pump will be in service. We also consider timer delay off in off button, so that similar operation can be done at the time of pump stopping. After permanently installing the plc system above, trip of the pump under load will be prevented (high pressure), whose consequences include, increased productivity, preventing from the above-mentioned damages to pump and electrical motors, No need for expensive spare parts. Preventing from severe damages of plunger to seals which causes frequent leakages of the pumped liquid(that are economically a lot of expenditure for buying and transporting the liquid).for example crankshaft of plunger pumps for injecting glycol weighs 895 kilogram, power=75 KW, Revolution=1450 RPM, weight of motor=533 KG, 380 volt,144 amp and 3 phase whose rotation speed is 68 revolutions per minute (rpm). At the time of emergency stopping, the whole of a 7000-kilogram equipment will be stopped in an instant, due to lack of the system above in plunger pumps. Above pumps Have 3 reciprocating plungers and move in 3 cylinders separately in each pump .that plungers function are periodic and transfer extremely energy to liquid(DEA glycol).we consider And use analysis of limited element on moment. All of once a one of plungers move forward in to cylinder and that cause transfer pressure Energy to liquid(suction is full close and discharge is full open and pressure is high in cylinder).another plunger return inside cylinder and Intake fluid (suction is full open and discharge is full close).the third plunger is between two operation in above. In emergency shut down (Suddenly stopped) very quickly all thinks stopped. In fact that plunger go forward in cylinder can not do anything and Immediately stopped hard.because resistance high pressure and plunger don't energy for continue ,it can not move but two plungers don't have problem for continue move. But that is critical point for crank shaft and what took place is completely unexpected and crank shaft put under torque (angular momentum) All technical expert Understand That torque is very heavy and the tragic consequences of that operation many years in world industries. all pumps have a leakage liquid permanent. cost of liquid (buying and transferring) is high in price. we use a new packing(high technology and self lubricate). don't need a oil for lubrication. Collect all leakage from every side Glands, Plungers and Air sealing line is simple and directly transfer to nearest sump in unit. Another suggestion: Many pumps have a PCV valve in discharge line for control extra pressure and we can use that PCV .but that need a some mutations. as an example must be replacement PCV suction line to before check valve and add ON/OFF mode to percentage mode.

CONCLUSION: I expect to install the PLC systems above or do mutations on pcv (control extra pressure) and use new technology packing (sealtek brand) on all pumps available in the oil, gas, petrochemical and other industries world, which can be examined and considered in the technology of high-pressure plunger pumps in the all factories manufacturing pump. ACKNOWLEDGEMENT: Special grateful to the all persons to teach ,training me and my technical colleagues that they prove by experience full of science.

Warmly thank, Any questions?