The Batch (discontinuous) process for liquid detergent production is based on a stainless steel reactor mounted on a load cell with a high-efficiency stirrer and heat exchanger for accurate and fast temperature control.
The design principle of the batch operation ensures high flexibility and extended automation in performing the production cycle. The high flexibility allows quick and frequent product changeover with the possibility to modify the range and the quantity of the components. Proper automation of the batch-cycle, supported by field-instrumentation, will ensure high production yields and optimised equipment utilisation.
A number of reactors can be installed in parallel whenever required by the production program so as to dedicate each reactor to specific/similar compatible product formulations.
Independently of the size and plant configuration, the Batch Process operates as follows:
- The main components like anionic surfactants, non-ionic surfactants, solvents and neutralizing agents are dosed in a predetermined ratio to the stirred reactor by on/off valves actuated by the weight control of the reactor.
- Depending on the selected product formula, the sequence of components addition is automatically prepared by the Computer Control System that also determines and sets the optimum stirring speed in the reactor.
- This stirred reactor is designed and powered to avoid product aeration and to intimately mix fluids with a viscosity in the range of 100-5000 mPa.sec
- The addition of minor components is made in the same manner or, depending on the required quantity, by pre-weighing and adding them by automatic or manual loading to the reactor.
- Once all the components have been added, the control system checks the temperature, pH and viscosity of the fluid mixture. If needed, additional components are fed into the reactor to correct the physical characteristic of the product or to stabilise the temperature at the desired value.
- Upon completion of all the components addition and chemico-physical stabilisation, the product is transferred to an intermediate storage vessel. This tank is complete with an ejector and external recirculation pump to ensure additional mixing without air entrainment. From the intermediate storage tank, the product is then finally transferred through a finishing filter (designed to remove insoluble particles larger than 50 microns) to the storage tanks from where it is sent to filling lines.
- Usually, the batch-cycle lasts for 2-3 hours and the size of the stirred reactor may vary between 3 and 25 m3, resulting (for each production line) in equivalent hourly production capacity in the range of 1 to 7 tons/hour.