Last month we’ve tested a special refrigerating group developed for production lines of tubes to be employed in dialysis plants manufactured by a pharma company.
The tubes for dialysis systems require a very delicate and sophisticated production process, due to the fact that they are employed for blood transport. The tubes are in particular employed with a peristaltic pump, being squeezed in order to pump the blood.
Mechanical and elastic characteristics of the tubes are therefore fundamental, ensuring they are smooth and flexible but at the same time very much resistant.
The system we’ve supplied is a first equipment prototipe that produces a refrigerated air flow at a controlled temperature down to -15° C, with precisions of +/- 0,5° C. The refrigerated air is employed in a patented process which allows to obtain a suitable modification of the dialysis tube.
Previously, the manufacturer employed a venturi effect cooling system, but it failed in obtaining the necessary effect. The results of the test phase of the new refrigerating group totally satisfied the customer, eventually leading to the decision to implement these equipments in all its production lines installed in its facilities globally.
Shell and tube exchangers represent the history of thermal transfer, being the first ones that have been employed for cooling applications both in industry and conditioning.
Each typology has its own advantages and limits. The kind we use the most is the cleanable straight pipe exchanger: in this kind of equipment the two heads can be dismantled showing the straight tubes where the fluid flows, going from one head to the other. Being straight, they can be easily cleaned using a pipe cleaner, taking away the dirt and scaling. The diameter of the tubes depends on the kind of fluid to be treated, on the type of thermal transfer and process. These are usually welded exchangers, so that the tube bundle cannot be extracted. The clean fluid flows therefore inside the shell.
This kind of exchangers is commonly employed in cogeneration, for exhaust recovery on engines. The exhaust fumes flow inside the pipes, that are then cleaned. Another application is in the biogas sector, for biogas dehumidification. The biogas flows inside the tubes, while water glycol flows on the outside, within the shell.
Furthermore they are used for hot water production from vapour. Water flows inside the tubes and the vapour flows within the shell, heating the water that comes out at a higher temperature.
The limits of straight pipe cleanable shell and tube exchangers is related to their length, so that if long thermal transfers with long thermal gaps are required it is necessary to install multiple exchangers in series. The passage in series is possible, but in this case the construction of the heads becomes much more complicated.
The other classic typology is the U tube bundle exchangers. This kind of shell and tube exchanger has a bundle of U shaped pipes, welded upon a unique head. In this case, the section that can be cleaned is the shell, thus the external one, because the pipe bundle can be extracted. The pipes cannot be cleaned instead, because the curve cannot be reached using a pipe cleaner.
The dirty fluid usually flows inside the shell, even if when having bundles with a high amount of pipes, and very packed, cleaning operations can become very difficult to achieve.
This kind of exchanger allows to better leverage the thermal length, because here the thermal length of pipes doubles the overall length of the exchanger.
In terms of construction materials, shell and tube heat exchangers can employ mostly every kind of materials, from stainless steel to copper and iron. The selection depends on the kind of fluid to be treated, on the kind of process and the temperatures involved.
As a follow up to our past august’s intervention for the complete regenaration of heat exchangers for a customer that manufactures plastics for the manufacturing sector, the company contacted us again asking for a re-engineering and update of their cooling plant for the production lines.
The messy growth on the facility during the years has generated indeed a series of great issues within the cooling water distribution circuit.
After a preliminary study, the customer accepted the proposal we’ve deployed in modular steps, divided by areas of problems. The aim is not to generate production downtimes, thus implementing the intervention in a non invasive way in order to ensure operations continuity. The intervention schedule will therefore follow these three steps:
Intervention to solve water distribution problems
Once the water will be properly supplied to all of the utilities, analysis of temperatures required and fulfillment of them, in order to implement wherever is necessary new cooling solutions or proceeding with a boosting of the existing ones
Let’s talk about Chocolate pattern, which in our sector means talking about plate heat exchangers. One of the mostly asked questions we receive is what is the best configuration of the connections distribution on plate heat exchangers.
Plate heat exchangers of latest generation have for the majority parallel connections, which means primary fluid on the right and secondary fluid on the left, or viceversa. Since a few years ago there were also exchangers with crossed connections. We are then very often asked if crossed connections, on the perspective of the distribution of the fluid within the plate, is not better than parallel ones.
In fact it can be natural to think crossed connections are better than parallel ones, when looking at the design of a plate and at how plate heat exchangers do work. Just because, especially with large sized plates and maybe with lower flow rates of the fluids, the distribution doesn’t happen on the overall thermal transfer surface of the plate but only on the side where connections are.
Clearly, having crossed connections it doesn’t happen, because the fluid gets automatically distributed upon the whole surface of the plate.
This kind of implication has been studied indeed, leading to the famous Chocolate pattern design. Looking carefully to photographs of the triangular area between the nozzles, it is possible to observe a very peculiar design that reminds the one of chocolate bars, from which it gets its name. This system has been designed and engineered in order to allow a uniform distribution of the fluid upon the whole surface of the plate.
Looking with further attention, one can see that the channels that distribute the fluid upon the whole width of the plate have differentiated passage sections. This allows to foster the correct distribution of the fluid upon the whole width of the thermal transfer surface. And finally, see also how this kind of distribution design is equally applied to small size plates.
The growing adoption of robotic automation systems within the industrial sector increases the efficiency in production processes. The Tempco Infographic we are presenting here showcases a reached value of 62,75 billion of dollars in 2020 for the worldwide robotics market, with an interesting growth trend for collaborative robots, or cobots, which enable the safe interaction without protection fences between humans and robots in any kind of industrial application.
The concept of efficiency in the enhancement path of industry is a cornerstone here, establishing a strong connection between the world of industrial automation and Tempco, committed in the development of solutions for temperature control in industrial processes aimed to implement energy efficiency approaches and savings on energy consumption.
The implementation of robots and automated systems increases the efficiency of production processes, enabling a more smart and efficient employ of resources, evolving at the same time working methods and human skills, placing operators at the core of the Industry 4.0 transformation. Energy, and thermal energy in particular, is therefore one of the most precious resources to safeguard, by adopting waste reduction approaches but also leveraging energy recovery.
Cooling, heating and thermoregulation are strongly linked to the robots sector, where a number of Tempco solutions provide the temperature control and hydraulic oil cooling in order to ensure excellent operational conditions of actuators and motion control devices of robots and automation systems along the production lines.
In a growing market of robotics, which lead to a constant improving of efficiency toward a more smart and sustainable industrial production built upon a more responsible employ of energy.
Following the administration last year of the Covrad company, a historical manufacturer of cooling systems and heat transfer equipment based in Coventry, UK, recently in Tempo we have received several requests from manufacturers that are looking for similar solutions to those once supplied by the British company.
In particular, the company used to provide thermal modules to be combined with power generation groups for cooling of jackets and after coolers, radiators, heat exchangers, engine cooling modules and remote cooling kits in a near-to monopoly regime of the market.
Since a few months now, in Tempco we are therefore working to develop similar solutions to those that Covrad provided since last year, opening the opportunity to offer systems aimed for this kind of application. Three first projects are already being defined, in an advanced engineering step in order to further optimize the construction and quotation of the solutions.
Another interesting use of TCOIL dimple jacket exchangers, of which we often talk about for immersion cooling applications, is using them for contact cooling applications, as if they were a jacket. A very interesting characteristic of TCOIL exchangers is in fact the capacity to be shaped to fit the shape of the equipment to be thermoregulated.
It is then possible to use TCOIL dimple jacket exchangers for application on the outside of equipments employed in the chemical industry, such as mixers and reactors, or generally on the outside of tanks or furthermore on the outside of electric batteries. The metal sheets of the plates of a TCOIL exchanger are in fact easily made into a cylindrical shape, to fit the shape of cylindrical objects to be cooled or heated. Otherwise, it is also possible to use flat plates to cover the external surface of a machinery.
In order to increase the thermal transfer efficiency of a TCOIL exchanger in contact cooling applications, it is therefore necessary to have a flat sheet on the side at direct contact with the equipment. This is achieved using metal sheets having different thickness. When inflating the plates of the TCOIL exchanger, only the external sheet with lower thickness will blow up, taking the typical dimpled look of a TCOIL exchanger, while the internal side with greater thickness, aimed for direct contact with the object to be cooled or heated, will remain flat.
A further trick to increase even more the thermal transfer rate in TCOIL exchangers contact cooling applications is to rub a thermal conductive paste on the flat side aimed for direct contact with the outside of the equipment to be thermoregulated.
This kind of contact cooling application of TCOIL dimple jacket exchangers is triggering a high interest for employ in electric battery cooling, as well as for cooling of electrical and electronics machinery that clearly cannot be cooled using a direct flow of cold water.
We’ve been recently involved in a very peculiar and complicated project for a temperature regulation unit aimed to an automotive test bench for radiators and fans, which required quite a huge deployment of resources. It is enough to say that the whole development and commissioning took 18 months.
The unit works using water/anti-freeze solution in a temperature range between 20° C and 130° C. The power capacity of the system is 240 kW, with an adjustable flow rate between 10 and 200 lt/min, with cooling capacity of 120 kW.
The complexity of the plant is in the fact that it can work at 130° C, thus with pressurized water. And the customer need to avoid leakages of non-freezing solution inside the tunnel test during the substitution of parts. Therefore we’ve had to install a system with quick connections on the mounting/dismantling section of the tested parts. The substitution is made prior the complete draining of both the radiator and the related pipes, using actuated valves and logic managed through a PLC.
Each time a radiator has to be replaced, the plant gets cooled, de-pressurized and secured for the operators, in order to proceed with the draining of the pipes connected with the radiator.
When mounting a new part for the testing procedure, the plant has to be re-filled and pressurized, always through logic, automated valves and pressure transducers.
The overall plant is managed by a dedicated software developed in close collaboration by Tempco and the customer, leveraging both expertise in respective fields of activity. Code writing and the test procedures of the PLC alone took several days.
The evaluation of the thermal duty to be dissipated is fundamental in order to properly size both heat exchangers and chillers and other cooling systems employed to achieve cooling and thermostatation of the anodic oxidation bath.
Anodic oxidation is an electro-galvanic event, which means it involves a direct current at a certain voltage that passes through the anodizing bath. The evaluation of the amount of kW to be dissipated is therefore easy to do, being it directly proportional to the current employed to achieve the anodic oxidation and the voltage of it.
Temperature levels of the galvanic bath then vary depending on the kind of anodic oxidation. In case of hard anodic oxidation plants, the required temperatures are quite low, between 10° C and 15° C. Traditional anodic oxidation processes require instead temperatures between 20° C and 25° C.
Cooling at these temperatures, unless huge amounts of artesian well water at temperatures of 10-12° C are available, leave not too many options. Chillers and refrigerating groups are indeed required, even because the secondary circuit of the exchanger must be fed with water at a temperature of 10-15° C, depending on the type of anodic oxidation.
Among our customers in Tempco, in addition to the CERN in Geneva with the supply of a cooling system for the testing of IGBT equipments, we’ve also had the pleasure to collaborate with the LNGS-INFN Gran Sasso Laboratories in nuclear physics.
Once again, the provided solution consists in a cooling system, in this case complete with a temperature control module. Quite important for this prestigious commission was the flexibility and the rapidity during the deployment and the commissioning of the system to the customer, which is actually involved in a series of activities requiring a very high precision levels of temperature control.
Eventually, in just 10 days we’ve then been able to supply the integrated solution.
