Flue Gas Stacks
Flue gas stacks vent the flue gas produced as part of the
combustion process of the burners to the atmosphere. They are typically located
directly above the heater or boiler or located nearby and connected to them by
ductwork. Flue gas stacks are generally constructed of carbon steel and
internally lined with refractory. The stack may have an organic coating to
protect the steel from internal corrosion beneath the refractory lining. Stacks
may be either self-supporting or guyed, and their height should be above that
of nearby platforms.
UNIVERSAL JOINT
To
couple two shafts in different planes, you need to use a universal joint.
Universal joints have various forms. They are used in nearly all types and
classes of machinery. An elementary universal joint, sometimes called a Hooke
joint consists of two U-shaped yokes fastened to the ends of the shafts to be
connected. Within these yokes is a cross-shaped part that holds the yokes
together and allows each yoke to bend, or pivot, in relation to the other. With
this arrangement, one shaft can drive the other even though the angle between
the two is as great as 25° from alignment.
It is merely a slight modification of the old Hooke joint. Automobile drive shaft systems use two, and sometimes three, of these joints.
.jpg)
The Bendix-Weiss universal joint provides smoother torque transmission but less structural strength. In this type of joint, four large balls transmit the rotary force, with a smaller ball as a spacer. With the Hooke type universal joint, a whipping motion occurs as the shafts rotate. The amount of whip depends on the degree of shaft misalignment. The Bendix-Weiss joint does not have this disadvantage; it transmits rotary motion with a constant angular velocity. However, this type of joint is both more expensive to manufacture and of less strength than the Hooke type.
It is merely a slight modification of the old Hooke joint. Automobile drive shaft systems use two, and sometimes three, of these joints.
The Bendix-Weiss universal joint provides smoother torque transmission but less structural strength. In this type of joint, four large balls transmit the rotary force, with a smaller ball as a spacer. With the Hooke type universal joint, a whipping motion occurs as the shafts rotate. The amount of whip depends on the degree of shaft misalignment. The Bendix-Weiss joint does not have this disadvantage; it transmits rotary motion with a constant angular velocity. However, this type of joint is both more expensive to manufacture and of less strength than the Hooke type.
SCADA - Typical diagram representing the flow of data
SCADA (Supervisory Control and Data Acquisition) is normally associated with telemetry and wide area communications, for data gathering and control over large production sites, pipelines, or corporate data from multiple facilities. With telemetry, the bandwidth is often quite low and based on telephone or local radio systems the SCADA system is often optimized for efficient use of the available bandwidth. Wide area communication operates with wideband services, such as optical fibers and broadband internet.
Remote Terminal Units (RTU) or local controls systems on wells, wellhead platforms, compressor and pump stations are connected to the SCADA system by mean dot the available communication media. SCADA systems have many of the same functions as the control system, and the difference mainly comes down to data architecture and use of communications.
Ref: Oil & Gas Handbook
Subscribe to:
Posts (Atom)