Mechanical seal troubleshooting

Mechanical seals employed in machinery with rotating components can be affected by a series of wear issues. The main cause of mechanical seal problems is related to the correct lubrication of the seal itself. These are the main signs and causes of a scarce or wrong lubrication in mechanical seals aiming to a proper troubleshooting.

Dry running
Dry running happens when there is no liquid at all around the mechanical seal. The absence of the liquid film generates friction between the faces of the seal, with a dramatical increasing of the temperature. The typical damage of dry running is the presence of burned elastomeric parts. The damage happens when the O-ring is in direct contact with the over-heated mechanical seal ring.

tenute meccaniche funzionamento a secco

 

Insufficient lubrication
A scarce lubrication can happen when the pumped fluid has a very low viscosity, or when temperature at atmospheric pressure is higher than boiling point, or if there is some air in the circuit. In these cases, the heat caused by the friction can concentrate on small areas on the seal surface, with the result of even extreme heating conditions. Local alternation of heating and cooling of the mechanical seal surfaces can cause small radial cracks due to the thermal shock.

tenute meccaniche risoluzione problemi

 

Absent or scarce flow
It happens when the pump circuit is working with the inlet valve closed. Heat generated by the friction on the shaft seal can generate very high temperatures. The temperature increase can thus damage elastomeric parts of the mechanical seal. In addition, it increases the risk of dry running on the surface of the mechanical seal.

tenute meccaniche troubleshooting

 

Further mechanical seals problems can also be related to installation issues, failure in components or a wrong selection in materials matching. We will dedicate another article to analyze in depth the troubleshooting of these cases.

 

Plates H and L, choosing corrugation in heat exchangers

A new video is up on our YouTube Tempco channel (subtitles option available), dedicated to the kind of plates H and L in plate heat exchangers. H and L plates stands for high and low efficiency, referred to the thermal exchange rate achievable. Thermal transfer efficiency in a plate heat exchanger is indeed a result of the turbulence rate of fluids, depending upon the kind of Chevron angle in the plates corrugation design.

The Chevron angle in H plates is a dull angle, so that when overlapping the plates, rotated by 180° on each other, there will be many contact points leading to a very high thermal transfer rate. By the way, pressure drop will also increase.

That’s the reason why L plates are also available, having a more acute angle in the herringbone design of the corrugation. This goes with less contact points in the plates overlap, reduced pressure drop and also a lower efficiency in thermal exchange.

L plates are suitable for heat transfer applications using viscous fluids, not requiring very high thermal exchange rates.
H plates are suitable to obtain high thermal exchange efficiency with high pressure drop allowed, thus having pressure of a recirculation pump.

How to choose H or L plates in a heat exchanger? The selection is easily done by introducing the design values in a software to calculate a heat exchanger, values such as maximum pressure drop allowed, kind of fluids involved and their inlet/outlet temperatures. The software then determine the kind of plates, often suggesting the right mix between H and L plates in order to achieve the best compromise of heat transfer efficiency and pressure drop for the specific application.

How does a plate heat exchanger work, Tempco VIDEO

We wanted to make this 2019 a new year full of news, starting with a series of tutorial videos aimed to explain in a simple way the main working characteristics of some machinery employed in thermal energy management, such as heat exchangers and heat pumps.

I wanted to be featured in first person, and yes, the one you’ll see in these videos (in Italian language but with subtitles) it’s me, Valter Biolchi, owner and manager of Tempco and behind this Tempco Blog as well.

I wanted to dedicate the first video to the topic of plate heat exchangers, a kind of machinery that I’ve always considered as the most flexible and efficient in terms of heat transfer above all. Heat exchangers ensure indeed higher thermal transfer rates compared to shell and tube heat exchangers. This is due to the fact that fluids are moving inside the exchanger with a turbulent flow, even when the fluids have very low speeds.

The turbulent flow is obtained thanks to the design of the plates, which are then coupled each-other rotated by 180° in order to create tiny flowing channels with 2,5 – 3 mm width, depending on the kind of heat exchanger, forcing the fluids through the plates in a continuously interrupted and non-linear flow.

scambiatori a piastre corrugate moto fluidi

Another advantage offered by plate heat exchangers is the compact design and smaller size achievable with this kind of solutions, and most of all the possibility to obtain crossing temperatures between warm and cold fluids.

Data center, how liquid cooling is gaining ground

Let’ start the New year on the sign of continuity within innovation… We further go on indeed on the topic of cooling in data center, that we have already covered in our last year’s post. And we welcome you in the 2019 with a new Tempco logo, to be properly focused on in a future post of our blog.

data center cooling

Talking about cooling in data centers, we recently found an interesting article online that explains how the power increase in data center’s racks is becoming a problem for traditional air cooling systems, promoting the growth of liquid cooling, a topic we’ve already faced in the past months. A Gartner statement reported affirms that the air cooling is no more able to achieve the necessary heat dissipation in data centers where the electrical consumption is increasing by 16 up to 20 kilowatt for each rack. An increase in energy intensity that affects all data centers around the world, with liquid cooling solutions growing at a rate of 25%.

The higher efficiency ensured by liquid cooling solutions is naturally due to the fact that fluids can carry heat better than air, offering an efficiency in heat transfer 50 to 1.000 times higher. Liquid cooling offers a range of solutions, including water and special non-conductive fluids, and also the new groundbreaking innovations in nanofluids, special thermal fluids on which R&D around the world is very committed, able to increase conductivity and heat transfer capacity of common thermal fluids by the addition of metallic nanoparticles.

raffreddamento a liquido data center

In liquid cooling for data centers, heat exchangers can be installed on the rear of the racks or by direct contact with hardware components, properly using non conductive fluids. A trailblazing and growing application is the direct immersion of racks in dielectric fluids, or even the construction of underwater data centers, such as the Natick project of Microsoft or the data center Green Mountain as well.

The trend raises new challenges for IT staff, traditionally scared by possible leaks of water and fluids in the presence of electrical devices. Elsewhere, the increase in computational power required from data centers is forcing to find new cooling solutions for servers and racks, employing water and liquids that are developed offering high security and protection for electrical components. A cultural change is thus necessary for IT administrators, with training programs aimed to prepare them to the technical transformation happening in the cooling systems for IT infrastructures.

Happy Holidays warmly by Tempco!

We would like to wish you all Happy Holidays, a Warm and Merry Christmas and a Joyful and Thrilling New 2019, from all the Tempco team!

Looking forward for all the new and challenging applications related to thermal energy management, and to the many news and innovations we’re working on… soon to be revelead! But in the meantime, Merry Christmas and Happy New Year to Everyone!

 

Tempco - Best wishes

 

 

 

Dimple jacket and free cooling in data center against global warming

Cooling in data centers is often achieved by direct expansion chillers. This kind of systems, in addition to being highly energy-intensive, employ refrigerants that are pollutants, and thus more and more banned or limited by regulations. The increase in the computational power, due to the global adoption of artificial intelligence, big data analytics and cloud computing, machine learning and blockchain, has an effect increasing the impact of data centers upon the global warming.

If actually the increase of working temperatures of computers is reducing the need of mechanical cooling in data centers, regulations are pushing to a drastic reduction in the employ of refrigerants, responsible of greenhouse gas emissions.

Data center cooling green

 

Different HFC (hydro-fluorocarbon) refrigerants are employed in data centers, the most commonly being the R13a (in big plants) and the R410A (in small-medium size data centers). Their control imposed by regulations around the world is making their prices getting higher, pushing operators to find out new technologies and green cooling strategies for data centers.

Among green solutions for data centers, there is the employ of TCOIL dimple jacket exchangers for liquid cooling of the servers. Possibly also leveraging cold water available in the environment (as achieved in the Green Mountain installation in Norway). Getting rid of chillers, in addition to eliminating the use of HFC refrigerants, also would allow low energy consumption in data center operations.

Data center cooling free

 

Free cooling is another green cooling strategy for data centers, that stands out, as well as dimple jacket exchangers, for cooling efficiency and sustainability. The free cooling employs cold environmental air where it’s available, representing an efficient solution combined with cold water cooled systems. Moreover, the option of an adiabatic boost, which extends the dissipation efficiency of the free cooling systems, makes this green cooling solutions feasible in a wider range of geographical areas.

Evolving electrical thermoregulation in pharma industry

Leveraging a solid know-how built by Tempco in more than 15 years in thermoregulation applications in the pharma sector, we are introducing an improvement in the engineering of our TREG thermoregulating units.

termoregolazione pharma TREG

The new electrical heating units dedicated to chemical, industrial and pharma fields meet the need of these sectors to regulate the temperatures in their processes, with increasing precision and programming functionalities.

In addition the pharma sector requires a constant monitoring of all process’ steps, thus including a continuous monitoring of temperatures and cycle times of all the heating/cooling/temperature maintaining cycles.

termoregolazione settore farmaceutico TREG

These requirements must be fulfilled providing compact machinery, ensuring easy and fast installation and commissioning. Tempco’s solutions portfolio offers a broad constructive range of power capacities, with different temperature control levels.

termoregolazione pharma Tempco TREGOn the side of equipments we held our decisions, at the beginning not always accepted but nowadays representing a very appreciated and required standard:

  • Stainless steel heating armored resistances
  • Stainless steel internal pipings
  • Stainless steel plate heat exchangers
  • Flanged connections
  • Process and utilities connections on the upper side, making installation easier
  • Electrical panel in watertight box with thermoregulation unit interface and remote set point
  • ALL-IN execution complete with fairing, allowing a ‘clean’ installation without external components

Norbornadiene, thermal fluid for solar energy storage

Coming from Sweden is a new thermal fluid for solar energy storage, called Norbornadiene. The innovation arrives from a study of the Chalmers University of Technology in Göteborg, Sweden, dedicated to a new solar thermal fuel mostly composed by carbon, hydrogen and nitrogen molecules.

The Norbornadiene solar thermal fuel is indeed able to capture solar radiation, and to storage solar energy at low cost for years, without discharging in opposition to what happens with traditional batteries. The stored energy can be released on demand in form of heat, by activating the fluid through a catalyst.

Norbornadiene stoccaggio solare termico

When hit by the sunlight, the molecules of Norbornadiene get excited so that some of the bonds between atoms are rearranged to a higher energy level structure (quadricyclane). The energized version of the molecule is stable, with strong chemical bonds, enabling the molecule to sit for nearly two decades without losing the stored energy.

Passing through a catalyst, the chemical bonds are rearranged releasing quite a lot of heat. By inserting a heat exchanger between the thermal fuel and water in the circuit, is it possible to transfer the thermal energy to heat the water at a temperature of approx. 65° C, to be employed for domestic heating or to obtain sanitary hot water.

stoccaggio solare termico norbornadiene

The researchers are actually further developing and optimizing the process, aiming to lower the costs of both materials and the process to take the norbornadiene-based solar thermal storage technology to the market within the next 8-10 years.

Thermal energy and industrial processes, a guide

Tempco operates since many years in the field of thermal energy management in industrial processes, with a solid know-how and expertise and several applications in all kind of industrial sectors. Every day we are committed in solving heating, cooling, dissipating, thermoregulating and heat recovery matters.

We wanted to collect and share our know-how in a Manual, Energia termica and industrial processes (Italian language only), aiming to offer a first guide to engineers and designers helping them in the choice of the best suitable thermal machine for their specific application.

Energia termica e processi industriali Tempco

The Manual offers a wide description of all the main thermal machines, heat exchangers, chillers, cooling towers, thermoregulating units, dissipators and free coolers. Each solution is described in its characteristics and related advantages, completed with a series of case histories developed by Tempco along the way.

 

manuale Tempco energia termica indiceA section is in particular dedicated to the evaluation of thermal capacity of a machine, essential step in order to choose the machine itself and the kind and dimensions of heating/cooling components.

Flexibility and customization capacity complete the ability to suit the best thermal energy management solution in order to fit any customer’s production process need and requirements.