Centrifugal Pumps

A centrifugal pump converts the input power to kinetic energy in the liquid by accelerating the liquid by a revolving device - an impeller. The most common type is the volute pump. Fluid enters the pump through the eye of the impeller which rotates at high speed. The fluid is accelerated radially outward from the pump chasing. A vacuum is created at the impellers eye that continuously draws more fluid into the pump.


The energy created by the pump is kinetic energy according the Bernoulli Equation. The energy transferred to the liquid corresponds to the velocity at the edge or vane tip of the impeller. The faster the impeller revolves or the bigger the impeller is, the higher will the velocity of the liquid energy transferred to the liquid be. This is described by the Affinity Laws.

Pumping Philosophy

Pumping Philosophy

• Pumps transfer liquids from one point to another by converting mechanical energy from a rotating impeller into pressure energy (head)
• The pumping system designer must consider fluid properties, determine end use requirements, and understand environmental condition.
• The fluid properties being pumped can significantly affect the choice of pump, includes;         -Acidity/ Alkalinity (pH) and chemicals composition
         - Operating temperature
          - Solid concentration/particle size
          - Specific gravity
          - Vapor pressure
          - Viscosity

• End use requirement – system flowrate and head: The design pump capacity is needed to accurately size of the piping system, determine friction head loss, construct a system curve, and select a pump and drive motor.

•Process requirement can be met by providing a constant flowrate, or using a throttling valve, or variable speed drive to supply continuously variable flow rate

Heat Balance Diagram for Power Plant

An application of the first law of thermodynamics to a process in which any work terms are negligible.
For a closed system, one that always consists of the same material, the first law is Q + W = ΔE, where Q is the heat supplied to the system, W is the work done on the system, and ΔE is the increase in energy of the material forming the system. It is convenient to treat ΔE as the sum of changes in mechanical energy, such as kinetic energy and potential energy in a gravitational field, and of internal energy ΔU that depends on changes in the thermodynamic state of the material. Because the rates at which any changes occur are usually of interest, heat balances are often written in terms of heat flow rates (heat per unit time), sometimes denoted by a dot over the symbol, , so that for a process with negligible work, kinetic energy and potential energy terms, , the rate of change of internal energy with time.

efficiency boiler

The efficiency of a boiler is quoted as the % of useful heat available, expressed as a percentage of the total energy potentially available by burning the fuel. This is expressed on the basis of gross calorific value (GCV). ASME Standard: PTC-4-1 Power Test Code for Steam Generating Units This consists of • Part One: Direct method (also called as Input -output method) • Part Two: Indirect method (also called as Heat loss method)

SEPARATOR

Separation of Heterogeneous mixtures which Heterogeneous mixtures consist of two or more phase (part) which have different compositions that do not react chemically. The separation can be done physically by the differences in the density between the phases such as: gas-liquid, gas-solid, liquid-liquid, liquid-solid and solid-solid. Separator vessels can be classified based on its functions: 1) Two phases separator:  Gas/ vapor-liquid separator, Liquid-liquid separator, Gas – solid separator, and Liquid – solid separator and 2) Three phases separator :Gas-liquid-liquid separator.

MASS AND HEAT BALANCE DIAGRAM

Mass and Energy balance is to assure the input, conversion efficiency, output and losses. Mass and Energy balance is powerful tools for establishing the basis for improvement and potential savings. Materials quantities, as they pass through process operations can be describes by material balance. Such balances are statements on the conservation of mass. Similarly energy quantities can be describes by energy balance, which are statements on the conservation of energy. If there is no accumulation, what goes into a process must come out. Material balances are fundamental to the control of processing, particularly in control of yields of the product. Energy balances are use in the examination of various stages of process, over the whole process.

Process Flow Diagram

Process Flow Diagram (PFD) is an engineering diagram to indicate the general flow of plant processes and equipment. The PFD shows the relationship between major equipment of a plant facility as per process requirement. Generally, a PFD shows only the major equipment and doesn't show details. The PFD is the most effective way of communicating information about a process. The PFD contains the bulks of the chemicals engineering data necessary for the design of a chemical process. The symbols used in PFD vary somewhat from company (plant) to company (plant). So you may see several different symbols that all represent a pump. PFD is used by process engineers for detail engineering purposes such as prepare P&ID. However, PFD can be used for “visitor” information, and employee/ operator training. On the other hand P&IDs are used by process technicians and instrument and electrical, mechanical, safety, and engineering personnel. PFD is used by process engineers to prepare DCS Graphi.