Application:

Submersible axial mixing and aerating equipment has been designed to aerate activated basins of biological waste water treatment plants, or as the case may be the ponds, etc. Should there be any request for activation with nitrification and denitrification, the equipment may at the same time perform the function of time-separated function of stirring only with no aeration made.

	Click to magnify

Stainless components to the hydraulic part:

	Click to magnify

Specifications:

- Water and air temperatures
- Sludge concentration and liquid viscosity
- Above-sea level (altitude)
- Water height in activation
- Oxygen concentration in activation and oxygen demand rate
- It has been found out the alpha coefficient may - depending on particular WWTP - move within the range of 0,5 to 0,9

Therefore, the actual and operating yields under various conditions move within the ranges as mentioned in the Table.
Consequently, it is only our Company that makes PAM equipment design of aerating a specific WWTP. The design will be developed based on the results of these extensive measurements carried out within specific WWTPs.
Due to these measurements we assume the actual electric power consumption during aeration of activation is at least 20% lower compared to fine-bubble aeration systems used in Czech Republic. This even under unfavourable conditions for PAMP equipment.

PAM equipment features a rather interesting fact that with increasing slurry concentration the air bubbles diameter gets reduced thus increasing oxygen introduction.Therefore the PAMP equipment seems to be an ideal tool for separated aerobic stabilization of excessive sludge where oxygen yields (recoveries) are higher than the figures given in the Table.
Concerning less concentrated effluents and activation with aerobic stabilization of excess sludge the oxygenation capacity of PAMP equipment is higher than its stirring capability. Therefore, it is required that PAMP equipment is designed in terms of its agitating ability as well.

PAMP equipment leads to the floating device and the reason is to ensure maximal aeration performance even in case there is fluctuation of water level inside activation tank(activated sludge basin). You must anchor the equipment to a chosen spot using the ropes attached over the basin s circumference. If required, these ropes may serve to move the equipment to the basin s wall.Portable swing crane is used either to remove it from inside or fit it in the basin.

Oxygenation capacity of the equipment can be measured solely under viable conditions since in clean water the bubbles several times larger are formed, which quite obviously lowers substantially oxygenation capacity compared to sludge water. It is due to sludge water having higher viscosity. As a result the oxygenation capacities measured under operating conditions (water temperature of 10 °C, air temperture of ca 10 °C, sludge concentration of 3 kg/m 3 , oxygen concentration in water of ca 1 mg/l, elevation of ca 300 above sea level) are simply split by Alpha coefficient that is standard for 0,5 fine-bubble systems. In  USA however, a figure of only 0,4 is recommedned which corresponds to our practical experience. Therefore the theoretical value of standard oxygenation capacity showen in the Table above is only to make comparison with fine-bubble systems.

To mix a required tank a power consumption of 20-30 W/1m 3 of aerated tank (at PAMP-15 the figure of 15-20 W/m 3 would be enough) has to be taken into account. This means that nearly always an aeration performance is significantly higher than its mixing capability. Consequently it seems more convenient to combine this equipment with classical agitator along with turning ON the aeration or mixing alternately depending on the requirement of nitrification & denitrification efficiency.

The design:

ALVEST PROX, s.r.o. will carry out calculations and designing of the equipment.

Example:

It is required to design aeration system for activation WWTP for 5000 EO.
Accurate calculation of oxygen demand is feasible, however the aeration equipment has to be designed to cover the peaks. Therefore, various authors advise the aeration equipment performance to be rated as multiple 2,5 to 3,5 times BOD5 in kg/day. Concerning our example the operational OC = (5000 . 0,06) . 2,5 = 750 kg O2/day = 31,25 kg O2/hour.
When usage of equipment of PAMP-4 magnitude is considered having operating yield under optimal conditions of at least 4 kg O2/kWh, then their required number will be n = (OC/4)/P = (31,25/4)/3,5 = 2,23 pcs.
The suggestion is 3 pcs of PAMP-4 with operation control (ON / OFF) run by EGO sensor (exhaust gas oxygen sensor).

Ilustration of the function after switching ON the equipment.

Terms:

Offering within 3 days. Delivery and installation depending on equipment size and scope of supply, i.e. within 2 months at the earliest.

Warranty and Services:

Waranty for the equipment is 24 months. Services concerning xR and SR equipment malfunctions will be carried out through replacement method, i.e.- within 12 hours from reporting the failure a spare PAMP equipment shall be delivered to secure WWTP operations up until returning the original equipment repaired.

Advantages of the equipment:

• Minimal demands in terms of maintenance. The unit does not contain any mechanical gears that would impair energy transfer and in particular increase the failure and damage hazards.
• Easy and quick to install.
• Minimal noise level - the equipment is submerged completely under water surface.
• Electric power consumption concerning more powerful PAMPs of first generation is roughly 20-30 % lower than with fine bubble aeration systems.
• One single equipment is capable to aerate and agitate simultaneously the activation contents to ensure nitrification and denitrification in one basin - it is recommended with smaller-size treatment units
  up to ca 5 000 EO.
• Simple and cheap control system for electric power consumption - only through frequent switching ON and OFF of the running equipment - recommended for treatment units up to 10 000 EO.
• For most of the treatment plants we recommend to combine PAMP equipment with highly effective agitators along with only the PAMP equipment being switched ON and OFF intermittently.
• When activation mixture passes via the axial impeller the fibrous microorganisms get cut thus substantially limiting fibre sludge bulking - i.e. sludge index lowers and sludge separation characteristics improve.
• The entire equipment is very simple, requiring no construction site for location of pressure air supplies and hence lowering your building costs. When arranged appropriately this treatment unit is capable to reduce your costs rather significantly, especially those incurred to building part - refer to item 2 of this Catalogue.
• Lower investment costs spent on technology when compared to fine-bubble aeration systems.
• Longterm life even when treating chemically agressive effluent water (only stainless materials and fibreglass are applied), where fine-bubble systems are subject to extreme heavy duty stresses and their life gets lowered substantilly.
• When finebubble aeration system is involved, then due to its material construction the ageing and wear of aeration membrane is eminent and will happen relatively very quickly followed by oxygen transfer efficiency being lowered gradually with subsequent rise of electric power consumption. When mechanical aerator PAMP (stainless steel and fibreglass only) is concerned one can expect substantially higher service life (at least two times) compared to finebubble systems due to structure simplicity and material version applied.
• High oxygenation capacity even with shallow basins - significantly higher than with finebubble systems (mixing the air and liquid inside mixing tube at high speed followed by the mixture flowing to the activation basin bottom corresponds to substantilly higher pressure rations and not to the actual geodetic depth of placing under the water level).
• Ideal aerating and mixing equipment for SBR reactor - the least expensive technological arrangement of biological waste water treatment plant possible.
• When operating more WWTPs this PAMP may serve as mobile facility as well in case of emergency when aeration at some of the treatment units breaks down.
  

Cross-section of PAMP equipment

Placing PAMP equipment inside basin

.