Tuesday, September 27, 2016

Multivariable Flow Measurement For Liquids, Gases, and Steam

Insertion flow meter for steam, liquids, or gases
RIM 20 Rotor Insertion Flowmeter
Courtesy Spirax Sarco
Combining multiple measurement capabilities into a single instrument is generally advantageous over installing separate devices to cover an array of parameters. A simple reduction in fittings and connection complexity can bring enough benefit to justify a selection of an instrument with expanded functionality.

Spirax Sarco provides a multivariable rotor insertion flowmeter, available in four configurations to match a broad range of flow measurement needs. All are based on a turbine rotor which is inserted in the fluid flow path. The instrument detects passage of the turbine blades by a sensor, using the measured frequency to determine flow velocity. Further processing with other measurements can provide volumetric and mass flow.

One version of the instrument delivers only volumetric flow rate. A second variant adds a temperature sensor and is capable of providing a temperature compensated mass flow reading. This model is often applied for measuring saturated steam.

A fuller featured version incorporates a pressure sensor along with the temperature sensor and can function as a flow computer, providing instantaneous readings of mass flow rate for gases, liquids, or steam. Several output signals can be configured to provide a selection of mass flow rate, volumetric flow rate, pressure, temperature, or density.

There is also a product version specifically intended for energy monitoring in applications involving steam, chilled water, or hot water. This multivariable version provides energy usage readings in selectable units, as well as supply and return temperatures, delta T, mass total and energy total.

The unique insertion design measures liquids, or gases, including steam, and can be installed without line shutdown. The unit is suitable for applications on line sizes from 2" to 80". More detail is found on the data sheet included below. Contact an instrumentation specialist and share your flow measurement requirements and challenges. The combination of your process knowledge and their product application expertise will produce effective solutions.

Tuesday, September 20, 2016

Replacing Heat Exchanger Tube Bundles

heat exchangers outdoors at oil refinery
Heat exchangers of many sizes are used throughout industry
Heat, a well recognized energy component of countless industrial processes. Heat exchangers are employed to move or transfer heat between two media, and are available in a wide variety of designs and configurations. They are manufactured from materials and in forms to accommodate the specific performance requirements of each process, machine, or operation.

The shell and tube heat exchanger is one common type of this heat transfer device that can be found in many commercial buildings and industrial plants. The unit is comprised of a vessel, or shell, with an array of tubes contained within. One fluid will flood the shell, encompassing the tubes through which a second fluid passes. The contact between the fluid within the shell and the outer surface of the tubes facilitates the transfer of heat energy between the two media. Applications for shell and tube units typically involve two liquids or one liquid and steam. They are not suitable for applications involving air streams.

Eventually, all heat exchangers need either major overhaul or replacement. Tubes tend to deteriorate faster than the shell, so replacement of the tube bundle can breathe extra life into a heat exchanger. Original documentation provided with the unit, plus a physical inspection, should provide all the information needed to have a new tube bundle manufactured. Numerous sources are available for replacement tube bundles, with the original manufacturer being only one potential source.
The replacing of a heat exchanger is also a good time to examine the performance delivered by the existing unit. Was it a limiting factor in the operation of the process? If so, perhaps this may be an opportunity to build in some headroom. Whatever the case, recognize that bringing in a product specialist with experience and knowledge will provide the beneficial leverage you need to get the job done right and finished on time.

Monday, September 12, 2016

New Anti-microbial Cooling Tower From Delta Cooling Towers

Delta Cooling Towers, globally recognized leader in the manufacture of corrosion resistant cooling towers, has added a new dimension to their product line. Cooling towers for industrial and commercial applications are now available with construction features and materials that significantly inhibit the growth of microorganisms in the tower fill and shell.

Microbial growth has long been a concern of cooling tower operators. The environment within a tower, continuously wet and warm, provides ample opportunity for microbial propagation. The new anti-microbial cooling towers make use of HDPE resin that is fully compounded (not just on surface) with an anti-microbial agent to provide the corrosion protection for which Delta is known, along with resistance to biofilm growth. The fill in the tower also provides the same level of resistance to microorganism growth. The corrosion resistant materials used in the construction of Delta towers allows the use of more aggressive chemical treatment than would be recommended with metal cooling towers.

The new Delta Cooling Towers have some distinct advantages for health and safety, as well as extended operating lifetime. Reach out to a product application specialist. Get all the details on the new anti-microbial cooling towers and share your HVAC and industrial cooling challenges to get solutions.

Wednesday, September 7, 2016

Severe Service Valves - Application Targeted

severe service flanged plug valve lined Fluoroseal
Sever Service Plug Valve
Industrial process control applications can be associated with some very stringent and challenging performance requirements for the physical equipment and components that are part of the process chain. In fluid based operations, the control and shutoff valves can be a significant impact point of extreme fluid conditions, requiring careful design and selection consideration to assure proper performance and safety levels are predictably maintained.

Industrial valves that are intended for application at the extremes are generally referred to as severe service valves. While there are plenty of published and accepted standards for industrial valves, one does not exist to precisely define a severe service valve. There is, however, some movement toward the development of severe service standards in some industry segments.

So, how do you know when to focus valve selection activities on severe service valves, as opposed to general purpose valves? There are a number of basic criteria that might point you in that direction:
  • Very extreme media or environmental temperature
  • High pressure drop operation that may cause cavitation
  • Rapid and extreme changes to inlet pressure
  • Certain types or amounts of solids contained in the fluid
  • High number of mechanical operations
  • Thermal cycling
Certainly, any of these criteria might be found in an application serviceable by a general purpose valve, but their presence should be an indicator that a closer assessment of the fluid conditions and commensurate valve requirements is in order. The key element for a process stakeholder is to recognize when conditions are in evidence that might overrun the capabilities of a general purpose valve, leading to premature failure in control performance or catastrophic failure that produces an unsafe condition. Once the possibility of a severe service condition is identified, a careful analysis of the possible operating conditions will reveal the performance requirements for the valve.

There are numerous manufacturers of severe service valves, each seeming to concentrate on a particular niche. Fluoroseal, a globally recognized manufacturer of lined valves for corrosive applications, has their own entry in the severe service arena that is based upon one of their popular general purpose valves. The focus for the FE Series valve design appears to be thermal cycling, excessive number of mechanical operations, and fugitive emissions.

I have included a technical bulletin that describes and nicely illustrates (with a cutaway view) the various features incorporated in the valve design.

You can always get more information, or discuss your special requirements, with a product application specialist. They have access to technical resources that can help with selecting the right valve configuration to meet your severe service applications.