Automating a Tedious but Necessary Task
Anyone who works in a lab quickly learns the value of labware washers. Today washers are almost as common in laboratories as they are in kitchens. Any lab that uses glassware for analysis, science, or engineering is a potential user. Washers are found in schools, research institutions, pharmaceutical companies, and water and wastewater analytical labs, and are used in many industries such as public health, forensics, chemical R&D, petrochemicals, electronics, medical devices, optics and cosmetics.
Washers are usually specified according to their capacity. Under-counter models sport about 4.5 cubic feet of wash chamber, medium-capacity models range from about 5 to 10 cubic feet, and larger capacities have above 10 cubic feet. Another way to categorize washers is by where they are located: in centralized cleaning rooms or at the point of use. Organizations with a central washer often hire a technician to pick up and deliver glassware. The downside, observes Jenny Sprung, product manager at Labconco (Kansas City, MO), is lack of control over wash scheduling and conditions, not to mention breakage and loss.
Still another way to break down washers’ capabilities, notes James A. Espiritu, Western regional sales manager at Miele (San Dimas, CA), is by type of contaminant removed, which differs significantly for various lab types.
For example, inorganic chemistry or forensics labs require removal of trace metals and other contaminants to part-per-billion levels; organic chemistry labs demand removal of oily and tarry residues; and glassware used in biochemistry and microbiology labs should be free of enzymes, proteins, or inhibitors of microbial growth. Dozens of other industries demand cleaning of small parts or implements made of plastic, stainless steel, ceramics, and other materials. In short, any contaminant that affects or biases results of subsequent work needs to be eliminated.
“The circulation rate and temperature of water in the wash chamber, the type of detergent used, and basket design are important parameters in these applications,” Espiritu notes.
Somewhat like kitchen dishwashers, the value proposition for lab washers is their capability for critical cleaning of glassware of various shapes, sizes, and durability. Design of the washer’s basket system is critical in terms of how it handles such items as narrownecked glassware, pipettes, biochemical oxygen demand (BOD) bottles, and microtiter plates.
One of the most significant trends in washer technology has been programmability. “Manufacturers have designed models with programming capability to address every conceivable application,” Espiritu says. “Some incorporate sensors, such as conductivity meters, to ensure proper cleaning and enable automatic repetition of the wash cycle if required cleanliness is not achieved.” To conform with environmental regulations, some washers have either a cool-down capability to reduce the temperatures of effluents sent to drain, or certain mechanisms to adjust effluent pH.
An emerging market for new lab washers, Espiritu tells Lab Manager Magazine, is high school and college labs, which frequently incorporate washers as part of their design. “This is great not only for the lab washer business but [for] teaching future scientists that these areas the company has initiated numerous changes in how it manufactures chillers. For example, under reliability, Thermo partnered with a plumbing systems company to provide leak-free chillers, customer-configured preventive maintenance reminders, and an indicator of when the condenser clogs with dust. “The latter occurrence taxes the refrigeration unit in much the same way that a clogged filter taxes home air conditioners,” says David Lamprey, global process product line manager at Thermo Fisher Scientific.
Perhaps the most notable change occurred under “flexibility.” According Lamprey, Thermo created a modular chiller design that allows customers to check off the features they want and purchase only those.
User-friendliness and unobtrusiveness are additional desirable features in chillers.
“Recirculators are supporting actors in a lab,” says Philip Preston, president of PolyScience (Niles, IL). “People might get excited about a new laser, but the chiller is just there, cooling it.”
The chiller may be cooling the process or application, but it is simultaneously heating the room and generating noise, two related problems. Heat is generated when the condenser fan—by far the main source of noise—blows heat harnessed from the application into the room. The problem is exacerbated when applications operate at less than full throttle and users over-specify chilling requirements.
PolyScience engineers noticed that the heat-noise relationship was not linear: A 20 percent reduction in fan speed results in a 50 percent reduction in noise. So they designed a noise reduction system based on four proportional integral differential (PID) control loops. When the chiller turns on it quickly determines the cooling requirement and ramps up to full operation (and noise). Afterward, it senses how much heat is actually being removed and adjusts the fan speed downward to compensate.