The processing industry today is facing increasing demand for maintaining product safety, improved quality, efficiency and profitability. The cleaning of equipment is an important parameter in achieving some of these objectives and hence more attention is paid to the optimisation of Cleaning in Place systems (CIP).
Efficient CIP is central to quality and efficiency particularly, when it comes to the tanks and storage vessels on which so many processes depend. Properly planned and executed tank cleaning, does more than maintaining specified hygiene level. It improves process performance; reduces water, energy and chemical consumption; and consequently, boosts performance.
The cleaning process
The various ways of cleaning processing equipment depend on the degree of sophistication and the level of automation. This is categorised as follows:
- Cleaning with hand and brush
- Cleaning with high pressure spray lances
- Cleaning by filling the vessel with cleaning liquid for washing/boiling; fill-boil-dump
- Cleaning with static spray balls
- Cleaning with reaction-driven rotary spray heads
- Cleaning with media and motor-driven indexed rotary jet heads.
Cleaning is normally automated and a large number of tanks and vessels are cleaned by one of the above-mentioned methods.
Cleaning a tank manually can take days and involves high labour costs. Even cleaning with static spray balls takes hours. Large amount of water, detergents and energy is consumed and large volumes of waste generated. Worst of all, the cleaning process involves extended periods of downtime that reduce the overall output of the plant. Flexible and efficient production with rapid and smooth change between different types of products with minimum waste is a requirement. Cleaning tanks with rotary equipment makes a valuable contribution to quality and also lesser use of detergent & chemicals and smaller volumes of waste, thus lowering environmental impact.
The high impact rotary jet tank cleaning equipment is an ideal solution for cleaning tanks throughout the process where high cleaning standards are required to ensure a strict bacteriological standard.
Bioethanol
The tank cleaning technology enables ethanol producers to make radical changes to their cleaning procedures, for better results. All the processing systems and tanks used in the ethanol production industry need regular cleaning to prevent contamination during the fermentation process. In particular, cleaning of the fermenters after each batch – with or without the use of biocide – is part of the normal cleaning procedure.
By installing rotary jet heads inside the fermenters, it is now possible to carry out such tank cleaning both rapidly and automatically which earlier took longer time to clean by using spray ball technology. This rapid and highly impacted technology removes the last traces of savage yeast from the tanks by eliminating downtime and saving money on antibiotics.
Similarly, in pulp and paper industry, the high impact cleaning of process tanks, towers, bleaching and filtrate tanks saves money and increases product quality & longevity of the paper machines. Automatic cleaning can be performed regularly at shorter intervals without stopping the process.
In the speciality chemical industry, the high impact cleaning of inner tank surfaces, related pipework and fittings between each batch avoid cross-contamination and reduces the risk of reject batches. It also contributes to personal safety by preparing the tank for human entry after cleaning.
The rotary cleaning machines also streamline every stage of the brewing process, from brew house, yeast cellar and fermentation to bright beer.
In food industry, it removes burnt food residues & biofilm and cleans tanks equipped with agitators and baffles.
The scrubbing head of the rotary is ideal for removing stubborn residues such as yoghurt or fresh cheese. Fast and efficient cleaning of silo and storage tanks is provided by the rotary heads. Where permanent cleaning machines are unsuitable, the retractable systems are the ideal solution.
In both, the pharmaceutical and personal care markets, Alfa Laval’s Toftejorg products meet the hygienic standards of EHEDG, FDA and other approval authorities and are suitable for wide range of viscous, foaming and thixotropic products.
Case Study
A large Japanese steel manufacturer uses the rotary cleaning equipment to clean used process oil from its cold-rolling mills. Automatic, high impact cleaning with Toftejorg rotary jet units has reduced the amount of flammable sedimentation scum and cut cleaning time between milling operations thus saving time & money and making the mill operation safer.
“We tried conventional cleaning equipment from other suppliers,” says the company spokesman, “but the heads often ran to a standstill, the nozzles became clogged and cleaning results were unsatisfactory. After conducting tests with the rotary cleaning equipment, we realized that Toftejorg automatic rotary jet heads were clearly superior to conventional solutions.”
Altogether the customer purchased more than 80 Toftejorg TZ-67 high-impact rotary jet heads – 20 units for fixed installation in each of its four mills. The equipment cleans the mill automatically after each operation. During the cleaning process, blinds are rolled down around the mill to avoid spraying cleaning fluid into other areas of the plant.
Submitted by Alfa Laval (India) Ltd
