Medical diagnostic imaging equipment provides caregivers with advanced tools for diagnosing and treating a full range of medical conditions, from torn ligaments to head trauma. This miraculous equipment provides insight that is invaluable to physicians and surgeon. That performance comes with a caveat, however, as the expensive equipment also generates a tremendous amount of heat that must be dissipated to protect the sensitive equipment from damage.
The primary method for dealing with the heat generated by diagnostic imaging equipment is the use of a chiller. A chiller is a cooling device that can take many configurations and relies on air or water to remove heat from the environment and safely dissipate it. A medical MRI chiller is much like an air conditioner, only instead of cooling the air it is cooling a piece of equipment. Chillers are used in conjunction with several imaging systems, including MRIs, CT scans, PET scans, and linear accelerator machines. Because of the diversity of applications necessary to perform in a demanding medical environment, MRI chillers may take several forms, with each type boasting its own strengths. Read on to learn more about the different types of medical chillers and MRI chillers in use today.
An open-loop system is one of the most commonly used types of chillers in a medical environment because of its simplicity and high level of efficiency. In an open-loop system, water is stored in an external tank that is removed from the heat source. When the imaging equipment is being used, water is circulated from the water tank to the chiller. There, a condenser allows for the chiller to cool the desired equipment. As the water moves through the chiller and back to the tank in a constant loop, it carries the heat away from the equipment and dissipates it into the environment. Most open-loop chillers use water as the coolant rather than air because it’s more efficient and can handle heavier heat loads. Water also allows for a more compact chiller that doesn’t require fans to move coolant. Open-loop systems are ideally suited to the high heat dissipation requirements associated with MRI machines, and are, therefore, common in that application.
Closed-loop chillers operate on the same basic principal as their open-loop counterparts, only instead of utilizing a remote tank to store water, they feature an internal tank. The closed-loop system is more complex than an open=loop system. Whereas an open-loop system depends on heat dissipation of water as it travels back to a remote tank, closed-loop systems incorporate an evaporator that helps to cool the water before it returns to the tank. The evaporator is used to maintain the temperature of the coolant, which maintains the proper operating temperature of the chilled equipment. Coolant temperature is constantly monitored and adjusted within the sealed system. While closed-loop chillers are sometimes used with MRI machines, they are more commonly seen used with PET machines and linear accelerators used in oncology.
In-line chillers combine several key features of closed-loop and open-loop chillers to achieve the same temperature reduction and maintenance standards. They are similar to open-loop chillers in that the coolant is stored in a remote tank that is isolated from the heat source. Like closed-loop chillers, they use an evaporator plate that helps to control the temperature of the coolant. The key difference that distinguishes in-line chillers from their counterparts is that the coolant is put under pressure using a pump. They are sometimes used in conjunction with MRI equipment but are more often used with CT scanners.
Drop-in chillers are unique in the way they perform the task of dissipating heat in a medical environment. They feature an evaporator coil that is embedded in a coolant tank. The chiller itself sits on top of the tank in most cases. Pumps agitate the coolant that surrounds the evaporator, which keeps cool liquid in constant contact with the evaporator. That allows for constant heat dissipation as the coolant circulates within the tank. A sensitive temperature control unit monitors the coolant temperature and can adjust cycling rates in the tank to maintain the desired temperature. Drop-in chillers are ideal in applications where floor space may be limited, or when it may not be feasible to install infrastructure for an open-loop or in-line system. They are used with MRI, CT, and PET scan equipment.
Because the needs of medical imaging equipment are diverse, MRI chillers come in several types that each have their own strengths. If you’re searching for the right way to keep your medical diagnostic equipment cool, visit KKT Chillers, Inc.