Water Chillers and Recirculators

Vibration elimination feature:

This is a unique damping device that smoothes out the small pulsations in water flow, eliminating a source of image instability and resolution loss in the final image.

Safety interlock feature:

This feature is critically important to protect the valuable scientific equipment in our customer's laboratories and to reduce the chances that they will be facing some day a large and otherwise unexpected repair bill that could run into the thousands of dollars, all because their water cooling failed. There are three major parameters that are important for a water chiller: water temperature, water level, and water flow. All SPI Supplies chillers have built-in and as standard equipment this safety interlock feature. Because of the variety of different instrumental configurations, the chiller has a contact closure signal, which the customer can use in conjunction with the microscope interlock systems to shut down the instrument in case of cooling failure and prevent damage from occurring.

Noise and sound considerations:

The issue of noise levels is perhaps one of if not the most important concerns of prospective customers contemplating the purchase of a water chiller. This is especially true of any electron microscope application because the unit often times must go into the same room as the microscope and operator. After spending a day working in the presence of a noisy water chiller, even the most sane of minds can start to go a bit crazy. We know that from our own experience. And that is why the SPI Supplies chillers have been designed for low noise levels, which is accomplished by a combination of the use of extra sound proofing materials on the metal cabinets and the water pump (major source of noise). Another source of noise is the fan needed for cooling, and other than selecting fans that are designed for low noise operation, there is not much we can realistically do about such fan caused noise.

In-line particle filter:

There are a number of reasons why an in-line filter is useful. For one thing, if the filter starts to suddenly start collecting large amount of particulate debris particles, this could be indicative of an electro chemical reaction occurring somewhere in the system, something that if not followed closely or stopped could end up ruining the microscope or other instrument being cooled. Secondly, it removes particles from the cooling water stream that could otherwise cause harm to the microscope.

Pressure and flow control and monitoring:

One normally does not appreciate the importance of this standard built-in feature until they start the installation and find that without these features, they don't have the slightest clue as to the pressure or flow rate, or how close the pressure and flow rate come to meeting the manufacturer's specifications for the microscope. On the SPI Supplies chillers, it is always possible to independently control and monitor the pressure as well as the flow rate. Our customers tell us these features reduce dramatically the time needed to perform the installation and get the microscope up and running.

Large fill-ports:

Ease of filling the reservoir is another advantage of the SPI Supplies chillers over competitive units. Many other units has fill-ports that are only 1" in (25.4 mm) diameter but the SPI Supplies chillers have diameters of 3" (76.1 mm).

External reservoir drain port:

Most users of other chillers find it incredibly inconvenient to change coolant fluid for periodic preventative maintenance programs and consequently, as a result, preventative maintenance programs tend to be either put off or forgotten, with the end result of premature chiller failure and/or possible damage to the microscope. We have studied this phenomenon and have concluded that the best way to help our customers is to build in an external reservoir drain port. This makes changing out the cooling fluids easy and convenient, and without the need for disconnecting the chiller from the microscope, and we also find that there is a higher level of performance of preventative maintenance programs, resulting in longer unit life.

Summary of standard built-in features not found generally in other chillers without special-ordering it as an option item:

We want to stress that all of these build-in "features" mentioned above, in general, are not "standard" in any other line of chillers and while some can be special ordered, the cost to get them in a system will be significantly higher than the prices of SPI Supplies.

Voltage conversion considerations:

All cooling capacities are based on operation at 60 Hz. For operation at 50 HZ, the cooling capacity has to be reduced by 17%. We are assigning the chillers on the assumption of 220v or 240v 50 Hz operation which would mean that the chiller for 60Hz operation would in fact be slightly oversize. But this also leaves the flexibility for adding some other instrument to the cooling line such as a vacuum evaporator.