An important issue for the food processing industry is the necessity to cleanse food stations and large containers after a food or product has left that particular stage of processing. Maintaining sanitation is imperative in the food industry, and so is a reliable pumping system to pump water to properly clean the containers on a regular basis. This washdown system, as it is known in the industry, is similar to that of the washing wands often seen at self-service car washes, in the sense that there are several high-pressure wands all connected to a ring attached to a main system and a central pumping system.

The Washdown Process
Currently, washdown systems employ a centrifugal pump to keep water pressurized in the system. In turn, centrifugal pumps must run constantly in order to maintain this pressure, impairing the energy efficiency of the system as a whole. A technology known as the UNiGY PhD™ (Pump-modeling hydraulic Drive), developed by Kadant AES, a global provider of fluid process solutions to the pulp and paper industry, is able to significantly increase efficiency over the existing centrifugal pump system by halting the motor when there is no demand for flow. This “on-demand” pressure is a significant advantage because it prolongs pump and motor life, increases efficiency, and decreases operating costs and energy needs.

How it Works: UNiGY Technology for the Food Service Industry

The UNiGY PhD system is able to increase efficiency drastically through its ability to maintain pressure in the system when the pump’s motor is not in operation. For these pumps, the motor’s RPM is directly related to flow rate and torque is related to pressure. UNiGY operates the pump only when there is a demand for flow, such as when a worker is using a high-pressure wash wand. This on-demand water pressure is the result of the UNiGY technology precisely operating the pump only when needed: in order to maximize efficiency, it holds torque to sustain pressure, or has the ability to step down to a lower pressure when there is no flow.

In addition, running the pump only when needed has the added benefit of minimizing wear and tear on hoses, fittings, and other critical parts of the pump system. It also eliminates the need to waste-gate the excess fluid in order to manage the pressure as a centrifugal pump needs to.

UNiGY technology has shown success in several operations such as hydraulic rams in the metal forging industry, precision chemical metering, another more complex washdown process for the paper industry, as well as many other applications. UNiGY technology results in significant increases in energy efficiency, thus lowering costs, helping to decrease noise levels of the pump, and making diagnostics and maintenance much easier.  

The Benefits of UNiGY Technology

In today’s energy-conscious world, energy efficiency is of utmost importance. For instance, in a cheese factory where UNiGY technology was integrated in its everyday processes, an 84 percent savings in energy was reported.  


UNiGY is able to use very little power in order to maintain pressure even as the flow rate approaches zero. The pump speed has a direct correlation to flow rate, but with UNiGY, the pump can hold the torque of the motor to keep constant pressure during periods of no flow when the motor is not spinning or is spinning slowly. Power is simply the product of torque and motor speed, so the motor is not producing much power during periods of no flow, because of the low speed of the motor. The UNiGY system achieves maximum efficiency when hooked up with a Hydra-Cell® pump, but can also be retrofitted to other positive displacement pumps that have been certified to work with the UNiGY PhD system. In the case of the cheese factory, the reduction in power consumption worked out to about $24,000 savings in energy costs over the course of a year. Other companies that have integrated UNiGY with their pump systems have obtained a return on investment typically within one or two years.

UNiGY’s many advantages in washdown systems are a result of its software.  UNiGY employs proprietary software which models the performance characteristics of the pump, or pumps, attached to it. This model then dictates how the pump motor should operate in order to achieve a particular flow rate and pressure. The programming enables it to protect the system by detecting any leaks, should these occur. As an example, if the pressure drops but flow rate is maintained, the system “knows” that a leak has occurred and shuts down right away in order to prevent damage.  An added benefit is that the streamlined design of UNiGY is simpler and easier to use, and as a result, it is able to lower maintenance and downtime costs. UNiGY eliminates sensors and additional instrumentation because it monitors only the speed and torque of the motor to manage pressure and flow rate. Also, because UNiGY is so efficient, there is no need for overflow valves to compensate for too high a flow rate. UNiGY’s software also includes a reliable diagnostic system which knows when a problem is beginning to form, should there be a discrepancy between its readout and the actual flow rate.

The technology is capable of controlling more than one pump and motor in order to achieve a redundancy system, thus keeping downtime maintenance to a minimum. In this redundancy system, one pump is used to handle the bulk of the flow needs of the washdown system, but should the flow rate increase to a certain point that one pump cannot handle the load, the second pump begins operation and both pumps share the load. UNiGY makes the whole system extremely flexible in that the end user is able to configure at what load percentage the first pump should be operating  before the second pump begins operation to ease the load. When one pump is taken off-line for maintenance, the other pumps are able to keep the washdown system working.

Centrifugal pumps currently used in the food industry washdown process have to be rebuilt because they are constantly running, even when there is no flow out of the wands. Such centrifugal pumps last an average of one to one and a half years. As previously stated, UNiGY only runs the pumps when there is a need for flow from the high pressure wands, and therefore the pump system connected to the UNiGY technology has, in many cases, “gone three or four years without needing any type of maintenance” as Bilal Mehmood, business manager for UNiGY, explains. This increased span, without any user intervention, helps to reduce related maintenance costs, because the technology either lowers the motor rpm or stops it altogether while still maintaining pressure.


The UNiGY PhD system has proven to be a much improved system in the food washdown process when compared to conventional centrifugal pump systems, mainly because of the more efficient use of the pump motor. UNiGY does not require the pump to operate when there is no flow in order to maintain pressure, and this sustained pressure uses very little energy when no flow is needed, thus helping  minimize maintenance. At the end, its greater efficiency translates to energy savings, as well as operational cost savings.