Drawing number 100502 (copyright Practically Green Environmental Services.)
This valve distributes compressed biogas to the base of a digester via 12 ports. About 50 square meters of floor area is thus kept in motion for optimum bacterial contact with the feedstock. The boiling action at the surface prevents scum formation. The main advantage of this system is the low energy cost. Typical propellor based mixing systems use between 5 and 20 kw motors. A kilowatt-year of energy costs about 500 - 600 UK pounds (almost $1000). Savings in purchased energy of about one thousand pounds per year can be expected for an RV1 over other stirring systems. The average energy consumption of an RV1 and its associated gas compressor is about 250 watts for a 2.5 meter hydraulic depth.
We have over 500,000 valve-hours of successful operation on these units in Sub-Arctic environments on high H2S / CO2 digesters. One RV1 is capable of stirring a maximum of 40 -50 square meters of floor area at 1.5-5 meter hydraulic depth. The smallest digester fitted with one of these units has a volume of 60 cubic meters . Where two stirring heads are used in one tank we suggest 'crossing over ' (interleaving) 50% of the stirring pipes to enable full tank stirring when one rotary valve is being cleaned. Depending on the depth, each unit will require 1-2kW of gas compression at installation with a 15-25% duty cycle.
Very long life, continuously rated,
Normally supply 240v single phase (other voltages by request)
Preselected speed - normally supplied 15 minutes per revolution +/- 3
Specification for wet condensing environments
Optional : Fail-Safe remote warning signal for shear pin failure (to be integrated to PLC or timer - not supplied).
Easy clean design for both inside and outside of valve - quick release connections to gain access to the inside of the stirring pipes. Stirring pipe cleaning has never been this easy!!
Suitable for continuous driving rain with motor cover in place.
Highly tolerant of H2S in the local atmosphere.
High Quality Finish to enhance the look of a digester.
This really looks the part, a very easily installed unit complete with non return valve (easily accessible for cleaning), 12 ports, tested and boxed with instructions. 'Old Faithful' will not let you down and will fail safe during foaming and sludge -in - line incidents. The motor is protected against jamming and the shear pin failure warning will alert the operator to loss of stirring incidents.
You can compress gas for this unit in one of our biogas compressor packages for small digesters.