Process chillers for precision cooling of low viscosity industrial fluids are routinely used in hospitals and laboratories to control the temperature in a variety of applications including rotary evaporation, reaction vessel jacketing, diffusion pumps, laser systems, electron microscopes and linear accelerators. Two of the most prevalent applications of this technology include heat load management in magnetic resonance imaging (MRI) and computed tomography (CT) scanners.
This blog explores how process water-chilling technology is applied to these critical applications.
MRI (magnetic resonance imaging) is a non-invasive scanning technology that produces cross-sectional images of the body. It is used in a range of medical fields including:
MRI scanning can differentiate soft tissue structures in any plane, making it an invaluable diagnostic tool. MRI scanners generate a strong magnetic field that is used in conjunction with radiofrequency currents to stimulate specific molecules in the body. The behavior of the molecules can be used to generate a three-dimensional image of body tissues. Example MRI images are shown below:
All MRI scanners contain superconductive magnetic coils. These coils must be cooled to approximately -296° celsius to promote superconducting properties in the metal alloys. The low cooling temperature is achieved by circulating liquid helium around the magnetic coils.
An average-sized MRI scanner contains approximately 1,700L of helium. A mechanical device called a “cold-head” is used to minimize the loss of helium. The device re-condenses gaseous helium back to a liquid state after contact with the magnets.
Below is a diagram of the cold-head circuit:
In addition to controlling the ambient temperature around the MRI scanner, heat must be removed from several processes during machine operation. These include:
Chillers can be integrated into the MRI system to provide cooling capacity in several ways. In most instances, the chiller is used in conjunction with a heat exchange cabinet (HEC) located in the equipment room (kept separate to the magnet room). The HEC utilizes heat exchangers that can be connected to the water supply from the chiller.
Below is an example layout of the HEC:
Computerized tomography (also referred to as computerized axial tomography, CAT) is a scanning technique that uses x-ray to produce cross-sectional images of the body. The images provide more detail of body structures when compared to a standard x-ray. Hospitals have a high demand for CT scans due to the range of diseases and conditions that can be diagnosed.
The CT scanner uses motorized x-ray tubes that move around the patient. The x-ray that passes through the patient is picked up by detectors that send the data to a computer for processing.
The Parker Hyperchill Water Chiller has a proven track record of performance with all the major manufacturers of MRI and CT scanner systems. Key benefits include:
The selection of the most reliable and efficient water chiller will help assure the uninterrupted use of MRI and CT scanners in diagnosing patient conditions. Parker Hyperchill Chillers offer state-of-the-art components and systems that protect these valuable assets from heat-related failures, improve efficiency and assure consistent, trouble-free performance.
After more than a century of experience serving our customers, Parker is often called to the table for the collaborations that help to solve the most complex engineering challenges. We help them bring their ideas to light. We are a trusted partner, working alongside our customers to enable technology breakthroughs that change the world for the better.
This post was contributed by James Brown, compressed air and gas treatment/analytical gas sales manager and Filippo Turra, product manager, Parker Gas Separation and Filtration Division EMEA