Model 625 HDPBHD Hand Dredge with the Experimental Gravity Trap GOLD Concentrator
With a single elongation stroke of the HG Power Plant, the M625 hand powered suction GOLD dredge is capable of producing enormous suction at the intake nozzle attributable to it's sealed chamber construction. Pulling the handle can more than double the mechanical force of the incomming water when compared to siphoning and improves the potential for gold recovery from cracks and crevices. See Video
The Model 625 was tested using a vacuum gage and regularly achieved and held a -10 in/hg, that's more than 1/3 of an atmosphere. It was equipped with 24" of class 200 1 1/2 in. PVC pipe, yielding 55 cubic inches or 30 1/2 fluid ounces.
Atmospheric formula
1 atmosphere (29.92 inches mercury) = 14.695948775 pounds per square inch
1/3 of 14.695948775 = 4.898
1.71 I.D. /2 = .855r
(.855r x .855r) x 3.14159 (pi) = 2.29658
4.898 psi x 2.29658 sq. in. = 11.24866lbs.
If this calculation is right that 11.2487 lbs.would be a lot of weight that could be held to the end of the 1.71 I.D. nozzle. Compare that to the world famous TV vacuum cleaner commercial that used a 16 pound bowling ball to prove their product and that was with a 6" cone so that created a larger area to apply vacuum over, still experts place the water lift of that vacuum at 65", so the model 625 is twice as powerful.
During the pump down phase, the slurry of sand, gravel, and gold that was on the way up the intake pipe may loose momentum and begin to fall back, but a rapid succession of pump strokes will keep it moving towards the pump virtually walking the dredged material all of the way up and into the pump. Model 625's can pump over 25 gallons of water per a minute.
On average, siphons 1625 gallons per hour (27+ gallons per minute), and simplifies siphon dredging by serving as the priming device to keep the siphon alive. Adding extra hose is recommended, or upgrading to 2" hose to minimize 1 1/2" plug ups.
The Model 625 Hand Dredge, works like a typical recreational suction dredge, only the suction is direct and not dependent upon a power jet venturi that seeks to produce a more constant vacuum. The convoluted cylinder bellows "HG Power Plant" is reinforced from inside and out making the operation more like a "rocking" piston pump. Best of all, it's ported to effortlessly pass 1 1/2" diameter cobbles, or attach the large 3 1/2" inner diameter, 1/2" mesh seive nozzle for suctioning and pumping massive amounts of pre-classified dredge material with fine gold into a free flowing sluice or the EGTC Gold Concentrator and a side loading bucket. Effortless operation makes all day GOLD hand dredging possible.
The EGTC eliminates the need to build a miners dam or struggle to get the angle and water flow inside the sluice set right! Once the angles set, the intermittent pumping action insures maximum efficiency with the EGTC Gold Concentrator. Find a rock and secure the concentrator using the cargo lashing kit (extra) then stretch and shape this flex pipe so that the material is being pumped "UP HILL"! A rise of 7" calculates to about a 45 degree angle.
Pump a few cubic feet of the dredge material in and as it's crossing over the Deep-V surface, the heavier values will tend to settle as the the lighter over burden flushes out. The concentrator serves as a low pressure area for black sand and gold to settle which becomes quite obvious with any users first clean out after hand dredging in gold bearing streams, creeks and rivers.
The key is the intermittent pumping action and flushing out excess material accumulating in the concentrator during the hand dredging operation. Never have another boring clean out, ever again!
See these You Tube Video Demo @ https://youtu.be/lf0cz9f6r4M ,
Great way to conduct on the go prospecting operations when looking for black sand gold bearing deposits while hand dredging.
Go To: D.I.Y. Gravity Concentrator's and see all of the You Tube Video's as the gravity concentrator was being tested for it's efficiency by sluicing hand dredged tailings.
Includes:
1) Model 625 HDP Basic Hand Dredge (Intake port is deflector plate protected 3 ply cloth inserted rubber and discharge valve is Buna- N rubber)
1) EGTC Gravity Trap Concentrator/Submersible Sluice Assembly
1) 3 1/2" I.D. White PVC Seive Nozzle w/ 1/2" mesh
1) 1 1/2" X 18" Thin wall PVC Pipe
1) 1 1/2" X 36" Cuffed (2) wire reinforced dredge hose (standard length, add extra hose from options below).
1) Sand Bag
1) Teflon Tape
YouTube Video available CLICK ON PICTURE ABOVE
Available now.......New Side Loading Bucket Lid fixture for the EGTC GOLD Concentrator. The window allows the EGTC to snap right in. Fits most 3, 5 and 7 gallon buckets.
The EGTC was discovered trying to design a "Picker Trap" while serving as a Header Box for the sluice in hopes that it would give a preview of what to expect from the sluice cleanout. Each cleanout of the EGTC built anticipation as to how much GOLD could be expected, except that on each occasion, the GOLD never escaped the EGTC. So, the sluice cleanouts were without any GOLD, not even any color!
Select from the list below to redesign this dredge. NOTE: - negative values delete features and revise price.
