Rotating Scraped Surface Heat Exchangers – HRS R Series
The HRS R Series is a scraped surface heat exchanger designed for the most difficult heat transfer applications, for example where very high viscosities and highly fouling fluids need heat treatment.
Unlike the HRS UNICUS Series, where the scraper movement is back and forth, the HRS R technology uses a rotary scraper rod. This scraper rod can reach velocities up to 300 rpm resulting in very high levels of shear and mixing at the heat transfer surface; this dramatically increases the heat transfer rate.
The R Series has been developed for both hygienic and industrial applications. Each inner tube contains a scraper bar fitted with a helical screw which rotates at high speed and enhances flow through the tube whilst reducing pressure drop. In addition, the continuous scraping action eliminates fouling on the inner tube wall, ensuring that the heat transfer area is clean at all times.
Some of the unique features of the HRS R Series include:
- Gearbox system designed to reduce noise levels
- Unique scraper bar system to reduce pressure drop
- Unique baffle placement
- Removable inner tubes with multiple tube option
- Expansion bellows
Unlike other rotating scraped surface heat exchangers, the HRS R Series can use one or several heat transfer tubes in a single unit. This is made possible using a uniquely engineered gearbox system which transfers the energy of a single electrical motor to the scraper rods in each individual heat transfer tube. In this way, a greater surface area can be fitted in a single system. The gearbox design also gives the benefit of a low noise level during operation due to the materials of construction.
UNIQUE SCRAPER BAR SYSTEM
A spiral blade is fitted to the scraper rod. The rotating movement of this blade helps to push the fluid forward. This way, high viscous fluids are pumped through the HRS R more easily resulting in less back pressure.
UNIQUE BAFFLE PLACEMENT
The design of the HRS R Series allows one or multiple heat transfer tubes to be fitted into one single heat exchanger shell, increasing the size of the shell-side cross section. If the liquid shell-side flow is limited then velocities, and therefore heat transfer, are reduced on the shell side. To improve this longitudinal baffles are fitted to separate the fluid paths in the shell; acting as an individual compartment for each heat transfer tube. The flow cross section is reduced and velocities increase, maintaining heat transfer rates. For multi-pass designs, complete counter-current flow between the shell side fluid and tube side fluid can be obtained.
In case of condensing (for example steam heating) or evaporating (for example ammonia cooling) fluids, the units can be designed without longitudinal baffles for better performance.
REMOVABLE INNER TUBES
The HRS R Series is fitted with removable inner tubes; ensuring easy inspection and maintenance. This significantly reduces operational costs.
HRS R SERIES: A SCALABLE SOLUTION
The HRS R series comes in three versions, each version in tube lengths of one or two meters:
- HRS R 1: Tube in tube version: heat transfer areas from 0.35 to 0.7 m².
- HRS R 3: Three tube version: heat transfer areas from 1.05 to 2.1 m².
- HRS R 6: Six tube version: heat transfer areas from 2.1 to 4.2 m².
The HRS R Series is suitable for heat transfer applications on a wide range of products and situations:
- Viscous food products: Dairy and vegetable concentrates (condensed milk, tomato paste, purees, juice concentrates, honey, butter, margarines)
- Convenience foods: Chocolate-based dressings, ketchup, cheese sauce, spreads
- Protein: Egg-based products, minced meats
- Cosmetics: Lotions, cream, gels
Materials: Shell side: AISI 304 stainless steel; Tube side: AISI 316L stainless steel
Connections: Shell side: flange; Tube side: clamp
External Finish: Satin or Polished: Product side <0.8 microns
Design conditions: Shell side: 7.5 bar(g) / 185 oC; Tube side: 21 bar(g) / 185 oC
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