# Classification of Rotating Equipment 1. Driven Driven 2. Driver 3. Transmission Transmission devices devices 4. Auxiliary Auxiliary equipment equipment # Driven equipments; + compressor - dynamic, centrifugal, axial and integral. - positive displacement pumps. + pump - dyamic, dyamic, centrifugal, centrifugal, axial and integral. integral. - Positive Positive displac displacement. ement. # Driver equipments; + ac motor + steam turbine + engine # Transmission devices; + gears + clutches + couplings # Auxiliary equipments; + lube & seal systems. + buffer gas system. + cooling system. # Similarities between pump and compressor; + moves fluids from one energy to another energy. + pump moves incompressible liquid. - Liquid volumes does not change with temperature and pressure. + compressor moves compressible fluid. - Gas volumes volumes change with pressure and temperature. # positive displacement – compressor + not self limiting. + variable pressure @ head. + flow is fixed. + not sensitive to system changes. + not sensitive to specific gravity. + constant volume. + capable pumping airlock. + flow not sensitive to the gas density. # how reciprocating works; + piston moves and constant volume displaced. + discharged pressure developed will be the same @ the discharged flange caused by process pressure and system resistance. + that’s why gas in cylinder will not exit until pressure developed in cylinder greater than pressure @ compressor discharge flange. # dynamic compressor;
+ increase the pressure of a gass by using rotating blades to increase the velocity of gas. # types include; + axial - Used for high flow. + centrifugal # dynamic + self limiting. + heavy duty. + sensitive to system changes. + sensitive to specific gravity. + variable flow. + fixed head capacity (for certain flow). # compressor in a process system; + compromised of - Suction system and - Discharge system. # objectives of a compressor; + remove flow from suction vessel at d same rate that enter d vessel. + pressure reduced from suction vessel to compressor flanges. + discharge system - to push d required amount of flow through the system resistance to achieve d final discharge system terminal pressure. # d operating point; + equilibrium condition that exists between the head produced by d equipment and the head required by the process system. + and always depends on system resistance, gas characte ristics and compressor condition. # Pump types and applications; + pumps divided into 2 types. - positive displacement - dynamic action. # comparison of positive displacement and dynamic. + positive displacement, - definition : increase pressure in a fixed volume (confined space). -types : screw, gear and reciprocating. - characteristics : constant volume, variable differential head, insensitive to liquid properties, insensitive to system changes and not self limiting. +dynamic, -definition : increase pressure by using rotary blades to increase fluid velocity. - types : centrifugal axial. - characteristics : variable volume, constant differential load, sensitive to liquid properties, sensitive to system changes, self limiting.
# pump similarities; + hydraulic and mechanical ends regardless of pump type. # types of positive displacement pumps; + reciprocating pumps. -increase liquied energy by pulsating action. -i.e power pump, direct acting pump, diaphragm pump and metering pump. - anti pulsation devices required in order to prevent damage which caused by pulsation. i.e volume bottles, orifice and pulsation bottle. # power pump. + used for high pressure. + low flow application. + either vertical @ horizontal. + termed because driven by external power source such as motor, internal combustion engine and steam turbine. # Diaphragm pump. + has good suction lift characteristics. + effective to used for low pressure with low flow rates. + capable to pump against pressure. + pressure of the motive fluid. + used for metering pump. + can handle sludge and slurries. + good also for dry running. + low shear. + good self priming capabilities. + cause pulsating flow @ water hammer. # rotary pump. + PD type that do not cause pulsation. + inherent high efficiency and versatility. + suitable for lube oil, seal and other high viscosity. # metering pump. + the pump itself is pressuring device. + not self limiting. + and need relieve valve in between shut off valve to prevent over pressuring of the tubing or piping in line in case shut off valve or stop valve inadvertently shut while the pump is running. + not good at pumping gasses. + and before start up this pump need to be primed first. + Prime = the pump head filled with liquid to be pumped. + vapor lock – gas enter the pump and the pump hardly to push the gas out to solve this problem chromatography solvents are often degassed before pumping. # screw pump. + fluid flow carried axially between the threads if two or more close clearance rotor so that affixed volume if fluid is displaced in each revolution. + frequently used for lube and seal service.
# Gear pump. + fluid is carried between the teeth of two external gears and displaced as they mesh. + used for small volume lube oil services and liquids of very high viscosity (asphalt or polyethylene and etc. # Dynamic pump. + centrifugal pump. + use centrifugal force for pumping liquid from low level to higher level of pressure. + liquid enters the center if the rotating impeller which imparts energy to the liquids before centrifugal force discharges the liquids thru pump volute. + widely used in fluid handling especially in refinery and petrochemical. # Type of dynamic/centrifugal pump. + Single stage overhung pump. -Its construction incorporates an impeller affixed to the shaft. - Its center of gravity located outside the bearing support system. + Single stage inline. - Increased usage in applications if low head, flow and horsepower. - Advantage of this pump, it can be mounted inline or vertically between pipe and flanges and does not require a baseplate but concrete grouted support plate however strongly recommended. - Do not incorporate bearing in pumps and rely on a rigid coupling to maintain pump and motor alignment. - Acceptable shaft assembled runout limited to 0.001”. + Integral gear centrifugal (sundyne pump). -used for low application requiring high head. - mounted in vertical and inline with piping. - incorporate pump bearings and integral gear to increase impeller speed and can reach above 30000RPM. + Single stage double flow suction between bearing. - double suction impeller are mounted on between bearing rotors. - commonly used when flow and head requirements make it necessary to yield low values of NPSH required. - Net Positive Suction Head; parameters shows the difference between the actual pressure of a liquid in a pipeline. - the liquid vapor pressure at a given temperature. - important parameter to take into account when designing a circuit whenever the liquid pressure drops below vapor pressure liquid boiling occurs and final effect will be cavitation. Vapor bubble may reduce or stop the liquid flow as well as damaging system. +Multistage horizontal split. - this pump will mostly used when hydraulic limits of a single stage pump are exceded. - easy to remove the casing. - impeller configuration cab be either inline or opposed. - limited to working pressure if approximately 2000psi and temperature to 600F. - opposed impeller arrangement has the advantages of not requiring a thrust balancing device which is not required for the inline configuration. + Multistaging barrel. - used for service condition exceeding those normally considered acceptable for horizontal split case design.
- thrust balance device always required because most of this pump type the impeller configuration are inline type. - the circular mounted end flange results in excellent repeatability for a tight joint as compared to a horizontal split case design. + Vertical canned pump. - this pump is designed for low available NPSH. - to provide the adequate NPSH characteristics, the first stage impeller can be lowered. - the multistage canned pump is comprised of a number of bowl assemblies and all contain within a can. - reduce the risks of hydrocarbon leakage to atmosphere. - lubrication to the sleeve bearings located throughout the length if shaft is provided by the pumped liquid. - bearing material vs. product compatibility must always be considered. - to prevent leakage at the location of shaft passes through the can to connect the driver, sealing is normally used to prevent the leakage and usually mechanical seal is the solution. + Submersible pump. - An electric motor driver is coupled directly to the impeller and bowl assembly. - all components are designed to be submerged in the pumped fluid. - increasing environmental restrictions cause this pump become more f requently used in the refining and petrochemical. + Sump pump. - designed for handling run off streams of rain water and non-corrosive or corrosive liquids. - setting limitation is approximately 10ft. - design incorporates and enclosed line shaft with external lubrication to the bottom bearings. - the pump shaft and impeller are coupled to the driver which is supported by the motor support bracket bolted to a cover plate. +Magnetic drive pump. - due to stringent environmental constraints and regulations. - design motor shaft is attached to power frame of the magnetic driver pump by means of flexible or rigid coupling the outer magnet and shaft assembly is supported by its own bearings. - alignment requirements for this type of pump are similar to that for horizontal mounted centrifugal pumps fitted with mechanical seals or packaging. - sealess pump is generally applied when there is a need to contain toxic or hazardous fluids. *Centrifugal pump are particularly vulnerable especially when pumping heated solution bear the vapor pressure. *Positive displacement pump are less affected by cavitation as they a re better able to pump two phase mixture (gas and liquid)
# Centrifugal pumps. + Advantages. - variable capacity control over operating range at constant speed. - can handle liquid containing catalyst and dirt solids. - can pump liquid with poor lubricity. - weight, size, initial cost and installed cost is lower that PD pump with same hydraulic condition. - liberal clearances, no rubbing parts and minimum wear higher availability. - does not normally require overpressure protection over operating range at constant speed. + Disadvantages. - flow rate is affected by specific gravity. - viscosity effect performance and require priming. - develop limited head over operating range at constant speed. - low to moderate efficiencies. # Positive displacement pumps. + Advantages. - not limited to delivery pressure for given capacity. - can handle high viscosity liquids efficiently. - higher efficiencies than centrifugal. - flow rate is not significantly affected by specific gravity. + Disadvantages. - require overpressure protection. - flow control with bypass or speed. - pulsations associated with reciprocating PD pumps.
