SPECIFICATIONS
The Sand Hand has been engineered to safely handle the task it has been designed for. The Sand Hand is considered open ended. With 3.14sq inches of inlet (2” 1502) for max line volume and pressure to enter and a total of 17 sq inches of outlet (6” pipe) for max working volume and pressure to exit. There is 784.8 cubic inches of area inside the Sand Hand (10” schedule 40 pipe) to allow the max amount of sand and water slurry, slurry with a displacement of gas or straight gas, from the dump line to enter the sand hand and be instantly reduced to working pressure. The pressure drops as it enters the sand hand but the slurry still maintains momentum, it then comes into contact with a curved ware plate. The curved ware plate diverts a straight flow into a cyclonic flow creating a vortex in the center of the Sand hand, this allows the gas to separate from the slurry into the vortex and discharge through the gas discharge tube, located at top center of the Sand Hand. The momentum of the slurry will quickly be reduce as it rotates downward and hits the cyclone breakers that are mounted vertically to the inner Sand Hand walls.
The Sand hand can be used on an upstream or downstream SKO rated up to 20,000 psi, with a 2” 1502 dump line with or without an automated dump valve after the adjustable choke, over a long period of time.
An SKO can hold around 20 gallons of sand. The filter sock holds about 4.5 gallons of sand. The max sand and liquid slurry volume that pushed through the 2” 1502 dump line varies. The pressure is drastically less than the SKO pressure as it enters into an open ended 2” dump line. When the SKO has retained a lot of sand, it starts the discharge very slow due to the fact that the sand is very dense and flows at a low flow rate. When this happens the dense sand falls through the sand hand as it enters. Only at the very end as the water to sand ratio becomes higher the discharge volume becomes higher. The higher water to sand ratio the less chance of sand compaction. The velocity of the slurry coming out of the inlet will carry the high volume of slurry through the sand hand.
We have two Sand Hands one has a max working pressure of 33 psi. For wells under 5,000 psi WP and the other sand hand has a working pressure of 800 psi for wells above 5,000 psi WP. There are vertical baffles to slow the momentum of the slurry before it discharges from the sand hand but does not restrict the discharge volume. Our field flow analysis has proven this. When the SKO is depleted of sand water and oil and only gas reaches the sand hand the sand hand can handle the mass volume of the gas.
The gas flows through the dump line at a much higher pressure and volume, it does maintain momentum as it flows through the sand hand but only builds a nominal amount of pressure. In our field flow analysis 4500 psi in an SKO blown down to the sand hand with the discharge valve wide open there was not enough pressure built up to move the needle on a 100lb gage mounted on the lid of the sand hand. There is a pressure release valve mounted on the lid of the sand hand directly across from the inlet as an extra precaution if the sand hand was too over pressure, which should never happen even under extreme conditions.
With low pressure and low momentum the slurry enters the filter sock until the sand subsides or the sock is full of sand, then the valve between the SKO and sand hand is closed, the sock is tilted to release the trapped water in the filter sock, the scale is zeroed and the sand is dumped, the empty weight will then show a negative number on the scale, this is the amount of sand dumped out. The filter sock holds up to 76 lbs of sand. The carriage that holds the filter sock is built out of 5/8” diameter rod, it is strong enough to sufficiently support the weight of the sand and force created by the momentum of the sand entering the filter sock. The Sand Hand is mounted on a hardened 1’ shaft sufficient to support the weight of the Sand Hand, carriage and 76 lbs of sand. Hoppers that weigh sand on automated sand mitigation systems retain water. The sand hand is able to remove the water before weighing and works well with automated valving systems.
The weighing system is considered intrinsically safe. The load cell that is mounted over the tank in class 1 div. 1 falls below the amperage and voltage threshhold allowing it to be considered intrinsically safe. The digital processor is mounted in an explosion proof box on the working deck in class 1 division (2) There is a sand buster that breaks up the sand as it dumps out of the filter sock, eliminating fluid from splashing back on to the operator. A sturdy deck mounts to the tank to work from with handrails and individually mounted steps with hand rails that meet OSHA standards. They custom fit to any size open top tank with adjustable stands on the base step that contour to the landscape.
