When we first approached Wastewater engineers with the design nearly 30 years ago, it was recommended that the Brush System for Clarifier Cleaning be made of stainless steel for durability and corrosion resistance. Stainless steel has become even more prominent in the Wastewater field and Ford Hall Company has upgraded all system components to 304 and 316 stainless steel. This will allow us to maintain our leadership in the industry and guarantee our customers the highest quality in the highly corrosive wastewater field.
Aluminum is not as sturdy as Stainless steel. We also found that in colder climates the weight of the system combined with the weight of snow and ice causes an aluminum system to bend; thereby, causing damage to the system, the skimmer arm and/ or even the clarifier drive. A stainless steel system is sturdier and more reliable, giving a customer years of trouble free service.
Many people think that if they cover the effluent launders on their clarifiers, they will eliminate algae growth and accumulation on these surfaces. In reality, algae blooms start in the center of the clarifier where the "nutrient rich" water and sunlight meet. However, it is where the water exits the clarifiers (i.e. the weirs and launders) that the algae particles accumulate and build up. Launder covers usually only cover up the problem. Algae and non-algae debris will still accumulate on these surfaces; weirs, baffles and launders will still require manual cleaning; Total Suspended Solids (TSS) and Biological Nutrient (BN) sample readings will continue to be high or out of compliance. Furthermore, with the addition of launder covers, one creates access and compounds confined space issues and eliminates the ability to see the weirs, launders and your clarifier's flow which allows or may assist in diagnosing other problems at the Wastewater Plant. Lastly, Launder Covers are very expensive; usually 3 times the cost (material and labor) of a fully installed system.
Ford Hall completed vigorous research on automated spray systems in the early 1990's but with less than pleasing results. We found that a spray systems would need multiple nozzles to be effective. With multiple spray nozzles being fed from one water line, a booster pump (and monthly energy consumption) would be required to adequately supply enough PSI to each nozzle to be effective. We also found the nozzles quickly clogged with debris and mineral build up. But most importantly, the nozzles cannot clean below the water's surface where much of the algae accumulation takes place (i.e. like between the baffle and weir and in the effluent channels or launders of the clarifiers and thickeners). Additionally, automated spray systems have to be drained off or go unused in the winter months in colder climates due to freezing, but clarifiers and thickeners still need to be cleaned during these months due to continued algae accumulations and non-algae accumulations such as grease, debris and solids which continue to build up.