South East Mill Realizes True Water Savings

It’s a known fact that we all use too much seal water in pumps equipped with Mechanical Seals or Mechanical Packing. Regardless of the sealing mechanism the volume of Seal Water consumed has long reaching economic impact.

Every excess gallon or liter of flush water that is fed into the process streams is just one more gallon that needs to be either evaporated out of the product or clarified before it flows out in the effluent stream back to the body of water from whence it came. NOTE: It takes 1000 lb of steam to evaporate 1 lb of water.

The challenge becomes how much seal water is required to adequately lubricate the sealing device while reducing the inherent temperature rise caused by the process and the dynamic sealing assembly. In most applications we default to “more is better than not enough”. But the actual flow rate is seldom if ever measured. We just know it is in excess or not.

North America is facing increased demands for water that is becoming a rare commodity. The continent wide drought continues to create concerns for all of us.

A Pulp and Paper mill in the southern USA has addressed this issue. One section of the plant decided to measure the flow rates in 40 Goulds Pumps .The pumps ranged in size from 3196 MTi’s ANSI Pumps  to 3175 Stock Pumps.The total flow for the 40 pumps was 154 USGPM . Not much you may think, except that flow rate translates to 80,942,000 USG per Year. Typical examples would be the following:

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As a proactive measure, the Mill Maintenance team decided to install SealRyt Corporation’s patented close-clearance stuffing box bearing known by many in the industry as the PackRyt BLR. In addition the mechanical packing incorporated with the BLR was sized and selected to suit the application. In many cases the packing used is selected by the actual cross-section rather than cross-section coupled with proper process application. (It should be noted that the packing selection is critical to greater MTBF and contributes greatly to the life of the shaft and/or shaft sleeve.)

The PackRyt BLR’s and the 3 die-formed packing rings were installed as per the recommended procedure. Furthermore, care was taken to adjust the packing over time, as is required to create effective process sealing.

The pumps were started and the resulting Seal Water flow rates were measured. Referring to the 3 example pumps above the new and improved flow rates were:

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The resulting reduced Seal Water demand is 9,723,600 USG/year.

So, the bottomline is the bottomline. There is an 88% reduction in water consumption or 71,218,400 us Gal/Yr

In a pulp mill 1000 pounds of steam are required to evaporate 1 lb of water.

With a saving of  71,218,400 USG/year X 8.33lb/galX 1000lb of Steam/lb.

Results in 5.93 x 10 (11) lb of steam /year.

You do your own math.