We are working through the issues on installing 1000 volt motors on well pumps at about 350 metres (1100 feet ) below ground. We have to go to 1000v because of the cable size required to limit the voltage drop at 400volts is so large that we cant fit the pump and the cable down the well. These...
I am setting up a pressure decay test (PDT) on a UF plant. In simple terms a PDT involves pressurizing with compressed the feed side of the membrane to about 5psi ,locking off the valves and looking at how quickly the pressure decays. This assumes that if a lumen is broken the pressure will leak...
Would it be normal to put an isolation valve before a rupture disc to allow maintenance etc. to occur without shutting the plant down. I am talking about a water treatment installation where the rupture disc is installed as a last line of defense if all else fails on a pressure manifold.
My gut...
One of our nearby Utilities dug this up during a water main replacement program in the city CBD. It is believed to be circa 1933 but no one knows for sure. Some of the water mains in the historic CBD were laid in the late 1800s and are largely CICL construction. Some upgrades occurred when...
I am undertaking pilot trials on an iron removal process as pre-treatment for an RO plant treating brackwish water from a very deep well.
The water comes out of the ground at about 55C.
One of the options i have been trialling is oxidising the iron with sodium hypochlorite and then dosing with a...
I have a 1 million USG drinking water reservoir constructed of Glass Fused Lined steel panels with mastic sealant along all the bottled joints. The tank is only a couple of years old and the mastic has failed twice due to the chlorine levels in the water which can be as high as 9mg/l near the...
I have a Glass fused lined steel tank that is bolted construction and holds potable water at a water Treatment plant. The joints between the steel sections are curreently mastic sealed. The mastic cannot handle the chlorine in the water. The tank is only a couple of years old but has some rust...
We have a Glass lined steel tank as a clear water storage at awater treatment plant. The tank is made from bolted panels with mastic sealant over every joint. Because of the chlorine contant in the water the mastic has oxidized and is vey soft and sticky and has lost its consistency in many...
Gents,
I have a wastewater plant where most of the motors are controlled by VSDs or they are well loaded. Those on VSDs run generally between 75 and 100% speed and at full speed would be about 90% loaded.
Our local power utility is reporting the whole plant power factor as 0.51 and showing it...
I typically do most of my work in an around the treatment plants the utility i work for owns/operates so this is not generally my area of concern. But we have recently had a couple of near incidents where the network guys have had valves in the wrong position during upgrades and maintenance...
I want to seek your opinion on the grade of citric acid for CIP in a potable water UF plant.
I have taken the line with our supplier that the liquid citric acid should be food grade citric powder mixed with food grade water(potable) with records and standards to a HACCP standard.
They are...
I am in the middle of a debate regarding short circuiting on water storage reservoirs.
Do high inlet and outlet velocities encourage short circuiting or reduce short circuiting? Do high velocities increase or reduce stagnant areas in the tank?
To give you an idea of the magnitude of the tanks...
I am looking for some evapotransporation rates for reed beds processing wastewater.
I know there are many variables but i am looking for some approximate ranges (or even a % of pan rate evaporation) as a starting point to see if this technology would be appropriate for one of the treatment...
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To all who responded last time i sought advice on the roof of this reservoir.
I finally got the froofing sheets replaced and lapped the correct way. However i could not get a win on the screws being in the valleys rather than the ridges. Apparently some engineer somewhere...
I work for a Water Utility doing process engineering and water quality control. 12 months ago we commissioned a new treated water reservoir at one of our water plants. It is a Glass lined steel panel construction of about 1million USG capacity and stores potable water. The water is not unusually...
At one of our plants we are regularly seeing a pink tinge or worse in our sodium hypochlorite solution. The chemical is tankered in from a supplier , but the same supplier and often the same tanker goes to our other plants and the problem is not apparent there. The solution in the tank has a...
I am having trouble with a potassium permanganate dosing system. The system is operating from a solution batch tank that has a concentration of 25kg/1000 liters with a water temperature of about 20 degrees C. This should be well under the solubility limit at this temperature which is about...
Over the last 10 years the utility that i work for has been trying to operate and progress to AMR for over 12000 meters. This has been expensive and such a disaster that as the electronic meters come up for replacement we are going back to old style manually read meters.
This is not in my...
I have been looking at some ISO container tankers for the possibility of storage of 47% aluminium sulfate (alum) and 30% calcium chloride.
I am getting some really mixed information with regards to the compatibility of the tanks with these chemicals. The tank supplier gave me a chemical...
We are getting an above ground concrete tank built at one of our wastewater plants to store treated effluent. Its about 50000 USG capacity with a wall height of 9 foot and a wall thickness of about 6 inches.
We have a number of pipes to go through the wall , two four inch and two 10 inch. These...
