Pneumatic transport is a homogeneous mixture of theoretical science based on engineering, concepts and adjustments developed by the manufacturers of this type of technology; Due to his own experience, OGA agrees with some important pneumatic transport theory writers who indicate that “pneumatic transport is on the dividing line between science and art, where the success of the systems to be implemented is based on the balance between engineering theory and the manufacturer’s experience. ” OGA supports its designs with an engineering personal of considerable size and the more than 1,200 systems designed and manufactured in its 20 years of experience in this field.
- Pressure
- Flow
- Force of gravity
- Differential Pressure Force (DPF)
- Inertia force (fi)
- Speed
- Law of Conservation of Energy
- Law of Conservation of Matter
- Potential Energy
- Pressure Energy
- Kinetic energy
- Perfect Gas Properties
- Properties of Solids
- Density
- Granulometry
- Angle of repose
- Air Quality According to ISO8573 8 (Parker)
Pressure
The pressure is the quotient between the force applied perpendicularly on a
given surface and the area of said surface. (p = F / S) Its magnitude is scalar. Therefore, the greater the force acting on a given surface, the greater the pressure, and the smaller the surface area for a given force, the greater the resulting pressure will be.
Atmospheric pressure
Atmospheric pressure is the force exerted by atmospheric air on the earth’s surface. The atmospheric pressure depends on its state (solid, liquid or gaseous). For gas effects, the pressure is generated all around because the gas occupies all the space on a specific surface.
Measurement units
International System of Units (SI).
Atmospheric pressure is the force exerted by atmospheric air on the earth’s surface.
The atmospheric pressure depends on its state (solid, liquid or gaseous). For gas effects, the pressure is generated all around because the gas occupies all the space on a specific surface.
Pa = Pascal = 1N / m2.
Cegesimal System (CGS).
B = Baria = 0.10 Pa
Cegesimal System (CGS).
B = Baria = 0.10 Pa
Gravitational Technical System.
Kgf / cm2 = Kilogram Strength per Square Centimeter = 98066.5 Pa
Units Technical System.
mm.c.d.a. = Millimeter Water Column = 9.80665 Pa
at = Technical Atmosphere = 98.0665 Pa
English system.
PSI = Pound per Square Inch = 6894.76 Pa
Other Systems of Units.
atm = Atmosphere = 101325 Pa
mmHg = Mercury Millimeter = Torricelli = 133.32 Pa
inHg = Mercury Inches = 3386.38 Pa
Bar = Bar = 100000 Pa
Flow
The flow rate is the amount of fluid that flows through a pipe section per unit of time. It can also be identified as volumetric flow or volume that passes through a given area in the unit of time. Qa = V / T
The forces that must be considered for the calculation of flow in pneumatic transport systems are: Gravity, differential pressure and inertia.
Measurement units
International System of Units (SI).
m3 / s = Cubic Meter Over Second = 1000 l / s = 35.31 ft3 / s.
l / s = Liters Over Second = 0.001 m3 / s = 0.03531 ft3 / s.
Other System
m3 / s = Cubic Meter Over Second = 1000 l / s = 35.31 ft3 / s.
l / s = Liters Over Second = 0.001 m3 / s = 0.03531 ft3 / s.
Force of gravity
The force of gravity is the physical force exerted by the mass of the Plant on the objects that are within its gravitational field. The action of the force of gravity can explain why all bodies remain on the surface and or float through the atmosphere. For this reason in the pneumatic transport this phenomenon is fundamental since it produces sedimentation of the solid inside the pipe.
Differential Pressure Force (DPF)
The differential pressure force is the difference of the pressure measurements between two points of a system, therefore, it is the force that is used to prevent a fluid from expanding. For pneumatic transport, the differential pressure is considered as the resistance that acts in the direction of the flow, towards the lowest pressure.
Inertia force (fi)
The force of inertia is that which acts on a mass when a body is subjected to an acceleration and is only detectable by what is linked to that accelerated system. For him
Pneumatic transport The force of inertia is used to overcome the natural resistance, to the movement of the flow.
Speed
Velocity is a physical magnitude of vector character that expresses the displacement of an object per unit of time.
v = m / s
We can find different speeds in classical mechanics, such as:
Average speed
Also known as average speed, it is the quotient of the space traveled between the time it takes to do it.
v = Δr / Δt
Instant Speed
It is a tangent vector to the trajectory, allowing to know the speed of a mobile that moves on a trajectory when the time interval is infinitely small.
v = dr / dt
Relative Speed
The relative speed is the value of the speed of one observer measured by the other. To which it is alluded that to calculate the relative speed the intervention of two observers is necessary.
vBA = vB – vA
The characteristic speed of pneumatic transport in the diluted phase is
vi = 18 m / s (Minimum) and vf = 46 m / s (Maximum).
The characteristic speed in dense phase is
vi = 1 m / s (Minimum) and vf = 10 m / s (Maximum)
Speed Measurement Units
International System of Units (SI).
m / s = Meter per Second = 0.001 km / s.
Old Metric System.
Km / s = Kilometer per Second = 1000 m / s
Cegesimal System of Units.
cm / s = Centimeter per Second = 0.01 m / s
Anglo-Saxon Units System.
ft / s = Foot per Second = 0.3048 m / s
Mph = Mile per Hour = 0.447 m / s
Law of Conservation of Energy
It is the amount of energy in any isolated physical system, remaining unchanged over time, although that energy can be transformed into another kind of energy. An example of the phenomenon can easily be distinguished when electrical energy is converted into heat energy in a heater.
This law applied in pneumatic transport systems, where there is a constant flow of fluid in a pipe, makes the energy remain constant.
Law of Conservation of Matter
The conservation of matter indicates that matter is not created or destroyed, it is transformed. Therefore, in pneumatic transport systems the mass flowing through any section of pipe is constant.
Potential Energy
Potential Energy is the capacity that this system has to perform a job based exclusively on its position or configuration. It can also be thought of as the energy stored in the system, or as the measure of work that a system can deliver.
For pneumatic transport systems the potential energy is that which has a mass due to its position.
Pressure Energy
It is the energy that has a mass of fluid, due to its pressure above the atmospheric pressure, on the absolute pressure.
Kinetic energy
The kinetic energy is the work necessary to accelerate a body of a given mass from rest to the indicated speed. The body is able to maintain its kinetic energy unless it changes its speed once such energy is achieved during acceleration.
For pneumatic transport systems, kinetic energy is the energy that a mass owes due to its speed.
Perfect Gas Properties
The air or any other gas used for pneumatic transport is compressed and therefore its expansion power possesses an intrinsic energy. The content of air energy for a specific state or conditions is determined by its properties.
The perfect or ideal gas model tends to fail at lower temperatures or high pressures, when the intermolecular size is important.
Properties of Solids
Elasticity
It is the faculty that has a solid to recover its original shape when it is deformed.
Fragility
It is the property of a solid to break into many fragments.
Hardness
It is the property of a solid that does not let itself be scratched by softer ones.
Defined form
It is the property of some solids to maintain their shape, they are relatively rigid and do not flow as gases do, except under extreme pressures of the medium.
Floatation
Some solids comply with this property, only if their density is lower than that of a certain liquid.
Inertia
It is the difficulty or resistance that a solid opposes to changing its resting state.
Tenacity
It is the resistance that opposes a material to propagate fissures or cracks.
Ductility
The difficulty refers to the property of solids being able to obtain threads from it.
Density
Density is a property of matter that measures the amount of material that is compressed in a given space (degree of compaction). In other words, it is the amount of mass per unit volume.
It must be taken into account that each substance has a different density, this depends on the atomic structure that it presents and the disposition of the molecules that make it up.
p = M / V
Apparent density
The apparent density of a material (heterogeneous) is the relationship between volume and dry weight, including voids and pores it contains. This measure applies to porous, granular, pellet materials, among others.
Measurement units
International System of Units
Kilogram per cubic meter (Kg / m ^ 3).
Gram per cubic centimeter (g / cc).
Kilogram per liter (Kg / L).
Anglo-Saxon Units System
Ounce pro cubed inch (oz / in ^ 3).
Pound per cubic foot (lb / ft ^ 3).
Pound per gallon (lb / gal).
Granulometry
The granulometry is the distribution of the sizes of the particles of a solid material in grain.
The simplest granulometric determination method is to obtain the particles by a series of meshes of different widths, which act as filters of the grains that are called commonly column sieve. But for a more accurate measurement a laser granulometer is used, whose beam diffracts in the particles to determine its size.
Measurement units
The units in the international measurement system are micrometers or microns (um)
Angle of repose
It is called the angle of repose of a material in grains, the angle formed between the top or tip of the material cone and the horizontal of the base.
The factors that alter this angle are the humidity of the material, the homogeneity of the cone and the granulometry of the material.
Take into account that the angle of repose can not be greater than 90 °.
Air Quality According to ISO8573 8 (Parker)
In air handling systems, whether at low or high pressure, it is important to consider the quality of air that comes in contact with the product, this classification is specified under ISO 8573