Monday, January 29, 2018

Alfa Laval Hygienic Liquid/Liquid Gasketed Plate and Frame Heat Exchanger

The following video illustrates the working principle of an Alfa Laval liquid/liquid 1-pass gasketed plate-and frame heat exchanger for use in hygienic applications. The hot liquid (shown in red) typically enters through one of the top connections and leaves through a lower connection. The cold liquid (shown in blue) enters through one of the bottom connections and leaves through the connection on top. Heat is transferred from the hot media to the cold media as the fluids pass through the heat exchanger.

The fluids enter the heat transfer plates through the connections and portholes. Highly engineered sealing gaskets between the plates direct the fluids so that the hot and cold fluids pass counter-currently in alternating channels. When the fluid enters between the plates, it passes over the distribution area.  Alfa Laval’s unique design distribution area is one of the most important features of a plate heat exchanger as it ensures an even flow of fluid over the entire plate, maximizes heat transfer efficiency, and minimizes maldistribution and fouling.

Note in the video the distribution area helps the fluids quickly fill up the entire cross section of the plates.

For very heat sensitive media, co-current flow is used in gasketed plate-and-frame heat exchangers allowing the coldest fluid meets the hottest fluid when entering the heat exchanger. This minimizes the risk of overheating or freezing sensitive media. Watching the video, imagine that the hot fluid is reversed, so that both fluids are entering at the bottom connections.

Alfa Laval has an extremely broad range of gasketed plate-and-frame heat exchangers which are used in all types of industries.

For more information about heat exchanger for use in hygienic applications contact Ives Equipment by calling (877) 768-1600 or by visiting https://www.ivesequipment.com.

Monday, January 22, 2018

Measuring Level of Highly Concentrated Sulfuric Acid

SITRANS LR250
SITRANS LR250
For fairly obvious reasons a US chemical company was having a very difficult time finding a process level instrument for a tank containing 93% sulfuric acid. Not many materials can stand up to the corrosive nature of even dilute sulfuric acid, not to mention the concentrated form. Level sensors with special wetted parts would only last a few months and the transmitters would have to be replaced on a regular basis. Downtime was very high and the maintenance was very costly.

Recommendation

SIEMENS recommended the SITRANS LR250 Radar PVDF for the application. The SITRANS LR250 with threaded PVDF antenna is a 2-wire, 25 GHz pulse radar level transmitter for continuous monitoring of liquids and slurries in storage and process vessels including corrosives or aggressive materials.
SITRANS LR250

SITRANS LR250After having the unit installed for a few months, the unit was taken out and inspected. Signal profiles were taken and compared to the signal profiles when the unit was first installed. These profiles demonstrated strong performance by the SITRANS LR250 in that the acid level was being tracked reliably and the inspection of the PVDF encapsulated horn antenna showed no compatibility issues.

Conclusion

The Siemens SITRANS LR250 transmitter with its PVDF encapsulated horn antenna has proven to be the proper instrument for sulfuric acid applications. It provides a lower cost alternative to other instruments requiring exotic and expensive metal alloys. After being in operation for over three years, it has demonstrated a significantly increased life span.

Contact Ives Equipment for more information on the Siemens SITRANS LR250.

Monday, January 15, 2018

Basic Information for the Design and Selection of Heat Trace Products for Pipe and Vessel Heating

Heat Tracing
Heat Tracing Self-Regulating Cable
To specify components for an effectively designed, totally electric heat trace system, it is necessary to understand the basic principles involved. A heat trace system is designed to replace heat lost through the thermal insulation from equipment in the system. In some applications, heat tracing will also be able to provide enough heat to significantly change the process temperature. 

It is always recommended to use thermal insulation since heat loss from bare surfaces is very high and heat transfer between the heater and the pipe/vessel is highly variable. All insulation should be weatherproofed. Wet insulation is ineffectual and heater output is insufficient to dry it.

There are several distinctively different types of electric heaters - self regulating, constant wattage, mineral insulated and tank heating panels. Each type has its own characteristics, often making one more suitable for a certain application than the others.


Self Regulating Heater Cable
Self Regulating Heater Cable will adjust its own output in response to pipe temperature. Available in a variety of temperature and power ratings up to 230°C (450°F) and 65.6w/m (20w/ft.). Product features include:
  • Variable Output
    • Self-Regulating heaters will react to variations in temperature encountered at every point along its length. Colder sections receive more heat output, while warmer sections receive less. This provides greater energy efficiency and more uniform pipe temperatures.
  • Can Be Overlapped Without Damage
    • Because Self-Regulating heaters controls its own output, overlapped sections produce less heat, eliminating “hot spots” and possible burn-through common with other types of cable.
  • Fail Safe
    • Upon reaching the upper limits of its temperature range, Self-Regulating heaters diminishes its own heat output to an insignificant level. This guarantees that maximum temperatures (T ratings) cannot be exceeded no matter what product is used in any application.
  • Easy Installation
    • Because of its infinite parallel path circuitry, Self-Regulating heaters can be cut to any length in the field without affecting the heat output or creating “dead zones”.
Constant-Wattage Heater Cable
Constant Wattage Heat Tracing
Constant Wattage Heat Tracing Cable

Constant Wattage Heater Cable is a parallel resistance heater that produces the same watts-per-foot of heat along its entire length.
  • EasyInstallation
    • Constant-Wattage heaters can be cut to length and terminated in the field. 
  • Economical 
    • Provides good power densities and exposure temperatures with parallel circuit cable capabilities at economical prices. Exposure Temperatures to +204°C (+400°F). Ideal for maintaining many process temperature applications. 
Mineral Insulated Heater Cable
MI Cable
MI Cable

Mineral insulated Cable is a series conductor, high temperature heater cable with a special, thin metal sheath. Some of MI advantages are:
  • Corrosion-Resistant
    • Alloy 825 sheath provides excellent corrosion resistance and immunity from chloride stress corrosion - a common problem with stainless steel. 
  • Ideal for High Temperature Applications
    • Mineral Insulated heaters can withstand exposure temperatures up to 593°C (1100°F). Exposure temperatures can be increased to 750°C (1400°F) with special components. 
  • Ratings To 600V
    • Mineral Insulated heaters are available in a variety of voltages to match the available power supply. 
  • High Heat Output 
    • Mineral Insulated heaters have heat output ratings up to 10 times higher than most other cables, reducing the amount of cable required. 
  • Rugged Construction
    • A durable metal sheath provides greater mechanical protection.
  • Thin Wall Construction
    • A unique manufacturing process allows thin wall cable construction for easier field installation. 
Tank Heating Panels
Heating Panel
Heating Panel

  • Low Cost Installation
    • Flexible silicone construction allows panel to conform to tank wall. No bonding or heat transfer aids are required. 
  • High Temperature 
    • Tank Heating Panels maintain temperatures up to 79°C (175°F) and can withstand exposure to 204°C (400°F).

Saturday, December 30, 2017

Happy New Year from Ives Equipment

With 2017 coming to a close, all of us at Ives Equipment wanted to reach out and send our best wishes to our customers, our vendors, and our friends! We hope that 2018 holds success and good fortune for all of you.


Friday, December 29, 2017

How New Lead-Free Regulations Will Impact Your Selection Of Potable Water Valves

Potable Water Regulations
Bottom line: Get the lead out.
Recent legislation in several states has tightened regulation of lead content in the components of potable (drinkable) water treatment systems. Other states may well be considering similar moves. This pace of regulation seems unlikely to slacken.

This report examines the choices facing specifiers and purchasers of small solenoid valves for potable water systems. It weighs the advantage and disadvantages of brass, plastic, and stainless steel designs. Finally, it suggests the solutions that smart planners should consider for current and future use.

You can download the full report (courtesy of ASCO Valve) here, or you can view it below in the embedded viewer.

Saturday, December 23, 2017

SIEMENS Process Instrumentation by Ives Equipment

Siemens brings you an innovative portfolio of process instruments for flow, level, pressure and temperature measurement, as well as a wide range of continuous weighing products. Pneumatic valve positioners, process controllers and recorders, and process protection devices complete the package.
  • Belt Scales and Weighfeeders
  • Communications and Software
  • Flow Measurement
  • Level Measurement
  • Pneumatic Regulators and Relays
  • Pressure Measurement
  • Process Controllers and Recorders
  • Process Protection
  • Remote Displays
  • Temperature Measurement
  • Valve Positioners and Accessories
https://www.ivesequipment.com
877-768-1600

Saturday, December 16, 2017

Increasing Safety in Chemical Waste Water Treatment Plant

Waste water treatment and location of the measurement
Waste water treatment and location of the measurement.
Purified Terephthalic Acid (PTA) is the preferred raw material for the most common plastic products of daily life. The PTA production process generates various waste water streams which are high in organic content.

Purification of Process Waste Water

In the waste water treatment plant, the water treatment starts with aeration. The last step is an anaerobic bio reactor where the treatment is done in a controlled atmosphere. Micro organisms purify the water and produce biogas. Biogas roughly consists of 60 % methane and 40 % Carbon dioxide. This biogas is compressed and used as a fuel to reduce the net energy supply.

Although production or intrusion of oxygen into the reactors or pipes is highly unlikely, safety systems are installed. In case air enters unexpectedly into the process this first may result in a non-supporting atmosphere for the microbes and in the worst case the gas mixture may lead to an explosion.

Safety Guaranteed Using Siemens LDS 6

To ensure that oxygen never exceeds the maximum accepted concentration, the customer chose an in-situ measurement with the Siemens Laser Diode Spectrometer LDS 6. LDS 6 performs a continuous monitoring of the oxygen concentration in the biogas produced.
Measurement path and the two LDS 6 sensor heads
Measurement path and the
two LDS 6 sensor heads.

The response of the system is in three levels:
  1. In case the oxygen level exceeds 5 % an alarm is triggered.
  2. The threshold of 7 % causes an automatic nitrogen injection and the closure of a valve preventing the gas mixture from entering into the compressor.
  3. When the limit of 9 % is exceeded, this automatically shuts down the compressor.
The in-situ measurement leads to a fast and reliable measurement.

The stability and availability of the LDS 6 system is ensured by the integrated reference cell which provides a lifetime calibration. To be absolutely on the safe side, the customer operates a weekly safety check which involves opening a valve that allows a controlled air intake into the LDS 6 sensor heads. As the sensor heads are physically separated from the process by process windows, no oxygen may enter into the process. The reaction of the system shows in any of these tests once more the reliability of the measurement method used.

For more information about this application, or for any analytical instrument requirement, contact Ives Equipment by calling (877) 768-1600 or visiting https://www.ivesequipment.com.

Reprinted with permission from Siemens Case Study.