A hash pump is used to transport trichome laden water from an agitation tank to a collection vessel in the bubble hash extraction process. A pump is needed whenever gravity drain is not possible (i.e when the agitation tank is not raised above the collection vessel). The Hashtek 25t and Hashtek 65t units use gravity drain for trichome rich water and centrifugal pumps for recirculating trichome rich water.
There are certain situations when gravity drain is not possible. The most common limitation is height in your solventless lab. The 65t unit comes in at 96″ (8 feet or 2.4 meters) total height and not every hash lab is going to have that amount of height to dedicate. This is where something like our horizontal extraction skid makes more sense.
Centrifugal vs Diaphragm Hash Pumps
Centrifugal pumps – move a fluid by means of the transfer of rotational energy from one or more driven rotors, called impellers. Fluid enters the rapidly rotating impeller along its axis and is cast out by centrifugal force along its circumference through the impeller’s vane tips. The drawback of using centrifugal pumps for moving trichome rich water is that they have high sheer forces which can damage sensitive trichome heads. Centrifugal pumps should only be used to recirculate filtered water which no longer has any trichomes in it.
Diaphragm pumps – use a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable valves on either side of the diaphragm (check valve, butterfly valves, flap valves, or any other form of shut-off valves) to pump a fluid. The animated gif below shows the action of a diaphragm pump.
Hashtek manufactures a diaphragm hash pump that can be used to retrofit existing systems with a gentle hash pump for moving trichome rich water.
Diaphragm Hash Pump Vs Gravity Drain
The advantage of using diaphragm pumps is that they do not have shearing forces that can crush trichome heads. As an example other industries use diaphragm pumps to transport whole strawberries, boiled brocolli and other sensitive products without crushing them into a pulp.
The disadvantage of diaphragm pumps is how loud they are. A guiding design principle at Hashtek is that the hash making process should be an enjoyable one. There is nothing particularly enjoyable about listening to a diaphragm pump. As they are pneumatic (air driven) on every stroke you have a loud air exhaust that fills the room. Although this is accepted in many industries as the cost of doing business, we prefer to avoid it. This is why when customers ask me which system I would buy for myself- the answer is always a gravity drain system like the Hashtek 65t.
As you can hear in the video above diaphragm hash pumps are anything but enjoyable to be around.
Happy hash making!