News Archive

Issue 6 June 2008

Your rough guide to choosing the right pump options…
When pumping high viscosity fluids or those with high solids content, as is common for progressing cavity pumps, the pump’s performance is often dependent on the mechanical feed option selected for overcoming poor suction conditions that could easily cause a breakdown to your process and plant.

Use this guide to help evaluate your own plant’s pumping applications and the suitability of installed or quoted pumping equipment.

Your guide-
Viscosity range and typical pump feed aid guide

Viscosity CPS	Suction Feed Option
200,000 to 10,000,000 +	Twin screw feeder
150,000 to 10,000,000	Large top feed auger
75,000 to 275,000	Breaker with auger conrod
20,000 to 100,000	Open throat with auger conrod
10,000 to 35,000	Enhanced feed rotor
1 to 10,000	Standard pump

High Solids range, for municipal waste and typical pump feed aid guide

Solids Content %	Suction Feed Option
18% to 50% +	Twin screw feeder
15% to 22%	Bridge breaker with auger conrod
10% to 17%	Open throat with auger conrod
5% to 12%	Enhanced feed rotor
1 to 7%	Standard pump

If you should have any questions regarding your own applications, or require further information on the mechanical suction devices described, please feel free to call us on Tel (0044) 023 80760000.

Choosing a sanitary pump? Would an industrial stainless steel pump suffice?
A common discussion we have when visiting food manufactures is the specification of pump required. Do you require a full sanitary pump specification or would an industrial stainless steel pump be suitable?

Dairies are easy: 3A and BISSC sanitary specifications have to be strictly complied with; and the pump must be suitable for CIP (Clean in place) procedures to eliminate bacterial growth and possible salmonella poisoning. There is no choice.

However, sometimes there are not clear guide lines for your pumping application: typically, the addition of food additives or flavours. How do you know which is the correct specification?

To help, the main reason to use a sanitary pump is to significantly reduce bug and bacteria traps within the pump and increase your ability to clean the pump to a sterile condition confidently and easily.

If these requirements are essential to your process then you’re going to need a sanitary pump; if not, a standard industrial stainless steel pump could suffice and offer cost savings. But, please, every application needs to be assessed independently so this is a rough guide only.

Here are some of the main features that sanitary pumps give you over an industrial pump:–

• Self-draining discharge port to allow drainage of product and flushing liquid
• DIN and ACME specification flanges, clamp style release, for quick and easy clean; hygienic design
• Clean in place port on pump suction chamber to allow for automated CIP and fluid bypass.
• Material specification 304 or 316 to class No. 4 surface finish

For more information regarding the pump choice for your application please call us.
Remember, if it’s not a progressing cavity pump we will happily recommend whatever design we feel you should investigate. Just call Tel (00) 023 8076 0000 or email sales@robn.com and we will be more than pleased to help.

Very best regards

David Johnson
Business Development Manager

PS
Did you know that progressing cavity pumps are used extensively within the food industry for pumping products like margarine?

This is because this type of product can change viscosity dramatically within the process, the result is often slip and backflow within say a Lobe pump causing shear damage to the product and loss of metering accuracy.

The PC pump has a transitional fit between rotor and stator. There is no change to pumping performance or product quality due to wide changes in a product’s viscosity.