Steam Desuperheaters

Diagram of one type of steam desuperheater
Schutte & Koerting

Steam has been a preferred means of delivering energy for many decades. Whether used for propulsion, as when driving a turbine, or delivery of heat, steam has proven to be an acceptably reliable and safe means of energy transfer.

Steam can exist in a saturated or superheated state. When saturated, molecules are at the minimum energy level needed to maintain a gaseous state. Superheated steam is essentially steam that has additional sensible heat content beyond what is necessary to create saturated steam. Some processes, such as turbines, will operate best with superheated steam. Heat transfer processes will often provide their best efficiency with saturated steam. Whatever the case, there can be instances where it is preferential, or necessary, to reduce the superheat level of process steam.

Desuperheaters reduce the sensible heat content of steam through a number of methods, most that involve adding finely atomized water to the steam flow. The document included below outlines various construction methods and principles of operation for steam desuperheaters. The illustrations, diagrams, and explanatory content will provide a useful overview of this common industrial process, including application examples.

Types of Steam Desuperheaters from Classic Controls, Inc.

When to Use a Globe Valve for Fluid Process Control

Heavy duty industrial globe valve with pneumatic actuator
Masoneilan brand of GE

Industrial process control often involves the regulation of fluid flow. There are almost uncountable types and variants of flow control valves, each with a particular set of attributes that can make it the advantageous choice to meet certain applications.

When the process calls for controlling flow over a range of possible values, known as throttling, a globe valve may be a good candidate for the application.

Globe valves are characterized by the change in direction of fluid flow as it passes through the valve and the plug or disk positioned in an opening through which fluid must pass. The plug is connected to a stem extending to the exterior of the valve body through the bonnet. Movement of the stem will reposition the plug in relation to the opening, providing a successively larger or smaller opening area through which fluid can pass.

Simple globe valve diagram
Courtesy Wikipedia

Globe valves are available in tee, angle, and wye configurations, as well as an enormous range of special configurations to suit specific applications.

What are some potential advantages of globe valves?

• Good throttling and shutoff capability
• Comparatively easy maintenance
• Comparatively short travel of plug from open to closed position
• Seats can usually be resurfaced when worn

What are some limiting factors for globe valves?

• Higher valve pressure drop than some other designs
• No straight through fluid path
• Comparatively higher actuator torque requirements to operate valve

When flow throttling capability is the overriding concern for an application, a globe valve could be a good candidate for consideration. Share your flow control challenges with product specialists. Combining your process knowledge with their product application expertise will produce effective solutions.

Fuel Air Ratio Controller for Combustion Efficiency

Combustion efficiency reaps substantial cost savings

Steam and hot water use is prevalent throughout industrial processes. Production of these two media is most commonly accomplished with a boiler, many of which are heated by combustion of fossil fuel. Fuel fired boilers of a certain size become the focus of regulatory requirements for emissions. All boilers consume what would be construed by their owners as large amounts of costly fuel. Because of their high pressure and temperature, and the presence of a controlled combustion within an occupied facility, safety is a paramount concern.

There, fortunately, is a single solution that can help to attain useful goals with the three concerns of safety, fuel cost, and regulatory compliance. Applying an efficiency controller to manage the fuel to air ratio of the combustion system will deliver benefits far in excess of the cost to incorporate the necessary devices. The three basic goals for the fuel air controller are:

• Maximize fuel efficiency
• Minimize regulated emissions
• Maintain safe operating condition

A good portion of all three goals can be accomplished through careful concerted control of combustion air supply and fuel supply. The fuel air ratio must be subject to continual adjustment in response to current air conditions (which can vary on a daily basis) and the level of O2 in the flue gas. Controlling the air fuel ratio supports the following goals:

• Preventing excess fuel vapors from entering the flue and creating an unsafe condition
• Providing the correct amount of air to effectively combust the fuel supplied to the burner
• Preventing excess air flow from reducing net heat transfer to the feedwater
• Maintaining regulated emissions within required limits
• Limiting fuel consumption to the minimum necessary to meet demand

Fireye® is a leading manufacturer of flame safeguard controls and burner management systems for commercial and industrial applications throughout the world. Their products, the first of which was developed in the 1930's, enhance the safety and efficiency of all fuel fired burners.

There are numerous capabilities built in to the company's PPC4000 series of fuel air ratio controllers. Some of the more notable include:

• Precise fuel air ratio attained using parallel control of servos to regulate fuel and air supplies.
• User selected burner profiles
• Alarm contacts
• PID operation
• An array of inputs and outputs to accommodate sensors and devices needed to monitor and control boiler operation
• Compatible with other products that provide additional flame and burner monitoring safety
• Multiple boiler sequencing and cold start thermal shock protection
• On board boiler efficiency calculation
• User interface, optional larger touchscreen interface

Glance through just the first two pages of the document below to get a full description of the capability of this compact and comprehensive controller. You can get more detailed information, or get a professional evaluation of your current system efficiency, by contacting the combustion experts at Classic Controls.

Fuel Air Ratio Controller for Combustion Equipment from Classic Controls, Inc.

Solenoid Valve Operating Principle

One of many solenoid valve variants
Courtesy Burkert

A solenoid is an electric output device that converts electrical energy input to a linear mechanical force.

At the basic level, a solenoid is an electromagnetic coil and a metallic rod or arm. Electrical current flow though the coil produces a magnetic field, the force of which will move the rod. The movable component is usually a part of the operating mechanism of another device. This allows an electrical switch (controller) to regulate mechanical movement in the other device and cause a change in its operation. A common solenoid application is the operation of valves.

A plunger solenoid contains a movable ferrous rod, sometimes called a core, enclosed in a tube sealed to the valve body and extending through the center of the electromagnetic coil. When the solenoid is energized, the core will move to its equilibrium position in the magnetic field. The core is also a functional part of valve operation, with its repositioning causing a designed changed in the valve operating status (open or close). There are countless variants of solenoid operated valves exhibiting particular operating attributes designed for specific types of applications. In essence, though, they all rely on the electromechanical operating principle outlined here.

A solenoid valve is a combination of two functional units.

• The solenoid (electromagnet) described above.
• The valve body containing one or more openings, called ports, for inlet and outlet, and the valve interior operating components.

Flow through an orifice is controlled by the movement of the rod or core. The core is enclosed in a tube sealed to the valve body, providing a leak tight assembly. A controller energizing or de-energizing the coil will cause the valve to change operating state between open and closed, regulating fluid flow.

Share your control valve requirements and challenges with a valve application specialist. Combining your process application knowledge with their product expertise will produce the most effective solutions.

Comparison of Three Lightning Protection Approaches

Lightning strikes pose a substantial hazard
to the operation of electrical equipment

Protection from lightning strikes is an essential part of securing the safe and continuous operation of any commercial or industrial process or facility. Systems and equipment selected, purchased, and installed to protect against lighting strikes will likely be in place for a long time, so it is important to make a sound decision at the outset.

Dehn Inc. has been providing lightning protection and related equipment since 1910. They have provided a white paper comparing blunt rod lightning protection to other methods, including early streamer emission (ESE) and lightning dissipation array (LDA). The paper also provides some historical background of efforts at lightning protection and avoids overly technical jargon.

Browse the white paper. It is not lengthy and provides useful insight into the lightning protection field. Share your lighting protection requirements and challenges with application specialists and work together to formulate effective solutions.

Blunt rod lightning protection advantages over nonconventional approaches from Classic Controls, Inc.

Data Acquisition - Precursor of Control and Decision Making

Models DX1000 and DX2000 Data Acquisition Units
Courtesy Yokogawa Corp.

Data acquisition, like an equipment acquisition, is the procurement of an asset. Data is an asset. It helps an operator evaluate process or business conditions and make decisions that impact the success of the organization. Let’s define data acquisition as the sampling of signals that represent a measurement of physical conditions and the conversion of those signals into a numeric form that can be processed by a computer. A data acquisition system will generally consist of sensors, transmitters, converters, processors, and other devices which perform specialized functions in gathering measurements and transforming them into a usable form.

Industrial process operators and stakeholders benefit from the collection and analysis of data by enhancing performance of valuable facets of the process or activity. Data acquisition, commonly known as DAQ, is widely employed throughout industry where there is a true need to know current conditions and analyze trends, patterns, or events. A desire for increased profit drives the need for increased process output and efficiency. A desire to reduce risk of loss drives the need for reduced downtime and improved safety. Today, there are likely many useful applications for data acquisition that are not being tapped to their fullest potential. The modest cost and simplicity of putting a data acquisition system in place, compared to the benefits that can be derived from a useful analysis of the data for your operation or process, makes the installation of a data acquisition system a positive move for even small and unsophisticated operators in today’s market.

Other examples of industrial data acquisition equipment

Courtesy Yokogawa Corp.

What we call DAQ today started in the 1960’s when computers became available to businesses of large scale and deep pockets. By the 1980’s, personal computers employed in the business environment could be outfitted with input cards that enabled the PC to read sensor data. Today, there is an immense array of measurement and data collection devices available, spanning the extremes of price points and technical capability. For a reasonable cost, you can measure and collect performance data on just about anything. You can get an impression of the simplicity, modularity, and compactness of a modern system with a quick review of this product from Yokogawa, a globally recognized leader in the industrial data acquisition equipment field.

Data acquisition has an application anywhere an operator or stakeholder can benefit from knowing what is occurring within the bounds of their process or operation. Here is a partial list of the many physical conditions that can be measured in industrial settings.

• Temperature
• Pressure
• Level
• Flow
• Force
• Switch Open or Closed
• Rotational or Linear Position
• Light Intensity
• Voltage
• Current
• Images
• Rotational Speed

Consider your industrial process or operation. Are there things you would like to know about it that you do not? Would you like to increase your insight into the workings of the process, how changes in one condition may impact another? Do you know what operating condition of each component of your process will produce the best outcomes? Is reducing maintenance, or heading off a failure condition before it occurs something you would like to have in your operation? Applying your creativity, ingenuity and technical knowledge, along with the help of a product expert, will help you get the information you need to improve the outcomes from your industrial process or operation.

Yokogawa Data Acquisition Station DX1000 & DX2000 from Classic Controls, Inc.

A Step Forward in Non-contact Radar Liquid Level Measurement

VEGAPULS 64 80 GHz Radar Liquid Level Sensor

Employing non-contact level measurement in a process control operation has many potential benefits. Radar level measurement has gained acceptance as an accurate and reliable method of liquid level measurement. The process measurement instrumentation manufacturers have continually made strides in the evolution of their product offerings, providing more effective lower cost solutions.

VEGA, a global leader in the manufacture of level and pressure instrumentation for the process industry, has introduced a new radar liquid level sensor. The VEGAPULS 64 operates at 80 GHz, a substantially higher frequency than previous models. The higher radar frequency, along with some other improvements, deliver operational benefits.

Tight beam focus accommodates
vessel internal fixtures
Courtesy VEGA

• Measurement is unaffected by condensation or buildup on the antenna
• High measurement certainty with product deposits on vessel walls
• System is quickly available for operation after cleaning cycles
• Tight focusing of the radar beam on the liquid surface provides easier setup and commissioning with complex vessel internal fixtures.

The radar level sensor is available with a number of connection fitting sizes, extending down to 3/4", which enable retrofitting of this improved technology to smaller vessels without extensive modification. There is also an encapsulated antenna variant that is suitable for hygienic or chemical applications.

There is more to learn about the advances in radar level sensors. Reach out to product specialists for more information. Share your level measurement challenges with the product specialists, then combine your process expertise with their product knowledge to produce effective solutions.

VEGAPULS 64 Encapsulated Version