Intelligent Peristaltic Dosing Pump for Ceramic Slurry Liquid Filling Machine

Application Background

Ceramic slurry has been an important part of our history, for centuries we have used this clay slurry to create pottery and moulds for other materials such as metal, plastic, and rubber. Also referred to as slip, Barbatine and slip casting, this mixture is poured into a mould and heat is applied to harden it, either for a mould to create other items like tools or to create pottery, for example plates and cups.

It is common for a deflocculant such as sodium silicate to be added to the slip, this is a sticky solution and dries hard. It acts as a glue that helps bind ceramic and aggregate particles together, it then forms a ceramic bond during firing. A huge benefit of the sodium silicate is that it reduces the amount of water required and allows a higher solid content to be used, this means that drying shrinkage is reduced and creates a superior and stronger product.

Having a drier mixture with a higher solids content does have benefits as mentioned above, however the dry and high viscosity slip creates issues that require careful consideration when pumping. This is exactly the problem our customer was facing, a specialist manufacturer of semi-automated liquid filling machines. This particular project involved the design of a bespoke filling machine being supplied to a manufacturer of architectural precast facades.

Precise Dosing Requirement

Semi-automated liquid filling machines allow the production of complex designs and patterns in various colours and materials. Once a 3D mould is created, the machine dispenses precise amounts into various size casts, this can then be reproduced countless times and is a huge cost saver compared to manual inputs. A pump is one of the main components of the machine, this must be the correct type to cope with the fluid while also being correctly sized to dose the exact quantity needed for the mould.

This client required a unit capable of producing a wide range of low flow rates but also precise and repeatable, budget was also a challenge as they did not have the flexibility to spend tens of thousands for other automated solutions on the market. We had the perfect solution for this application, a highly intelligent peristaltic pump that is excellent for ceramic slurry dosing but also cost effective.

How the AMP16 Control provides Precise Repeatable Metering

The AMP16 Control is an intelligent peristaltic metering pump with built in variable speed drive. It has all the benefits of less sophisticated peristaltic hose pumps; however, it has a lot of additional features that enable the dosing of precise amounts of product. The specialist design allows the pumping of highly viscous, gaseous, solids laden and shear sensitive fluids, the absence of seals and valves removes the risk of clogging and rapid wear that is experienced with other types of pump. The unique construction also permits self-priming, dry running and reversible flow making it an extremely versatile pumping unit.

Due to the peristalsis action, the unit ensures precise, linear, and repeatable dosing whatever the fluid characteristics. With a programmable flow range of 5.5 to 410 l/h and pressure capabilities up to 8 bar, this unit is excellent for filling casts that require very small and precise volumes. There are several operating modes including one off batching, repeatable metering, and continuous running. A one of batch can dispense volumes as low as 700ml and repeated metering has a ±2% accuracy after 500 revolutions of the rollers.

The unit comes with a 3” LED display to provide feedback and control the various functions. The built-in menu is controlled via a click wheel and keys, it also facilitates control via BUS (profibus, profinet, cenbus) and is additionally IOT capable. The intelligent interface can learn from how it is used and anticipate hose failures, hose life can therefore be increased, and downtime can be significantly reduced by following the recommended maintenance periods.

The installed hose leakage detector senses if the internal hose has ruptured and will stop the pump and warn the operator that maintenance is required. The user interface has a programme that guides the operator through the process of replacing the hose with step-by-step instructions, the pump head automatically rotates into the correct position through this process to make it as simple as possible.

Despite having a wide range of useful features, the unit is compact making it ideal for installation onboard liquid filling machines. The plant now has an easy-to-use pumping solution that can handle the highly viscous and dry ceramic slurries while metering the exact amounts required for filling their moulds. It is a simple process for them to change the output flow rate when the mould sizes change depending on the project in hand.  

An Example of Manually Dosing Ceramic Slurry

Typical Liquids for the AMP16 Control: 

Sulfuric acid, hydrogen peroxide, chlorine, sodium hypochlorite, flocculants, coagulants polymers and other chemicals. 

Typical Applications for the AMP16 Control:

Chemical – Metering & Injection of Chemicals
Food and Beverage- Enzymes, Flavourings, Colourants, & Shear Sensitive Liquids
Mining –Polymers, Additives, Antifoam, Flocculants and Coagulants
Paint – Metering of Solvent, Oils, Tint, Resin or Pigment
Paper –Additives & Polymers
Plastic – Additives & Polymers
Potable Water –Disinfectants, Flocculants & Coagulant
Wastewater industry - High viscosity products, Polymers, Flocculants & Coagulants 

Below is the specification of the ceramic slurry pump that was installed: