19 November, 2016

Sample pumps and pipes

 

Boxray Flowstand, secondary sampling tank for onstream elemental analyzer

Sample pumps and pipes

We recommend pumping the samples to the secondary sampling tank, Boxray Flowstand. In our experience this gives the most consistent flow to the secondary sampling tank. It also give the least risk of segregation in the pipes taking the sample out of service. Some sites use flow by gravity to transport the sample from the primary samplers to the secondary sampling tank. But as the flow from the primary sampler is proportional to the process flow there is risk of segregation and clogging if flow or pressure in the process occur.

Choose a suitable pumping system

The choice is between a slurry pump or a peristaltic pump. Slurry pumps work well but peristaltic pumps have become more popular over recent years. Peristaltic pumps will produce a pulsating sample flow. This means that the sample pipes must be securely fastened so they don’t wear against their supports. The pulsating flow appears to reduce the risk of segregation in the pipe.

Dampeners increases the durability

To reduce the pulsations pulse dampeners can be fitted behind the pump. There are several types of designs; horizontal, vertical, oil filled, air filled. There is not one solution that is better than the other. What is working on one sample stream may not be as good on another stream. The air filled dampeners have the advantage that the pressure inside them can be adjusted by filling more or less air into them.