Cannon Artes has developed Zerogas Spray Smart, the compact degasser for the CO2 and O2 removal from steam generator feed water
April 4, 2019
We talked about it with Ivan Davide Borriello, Riseria Gariboldi Operations Director.
Riseria Gariboldi 1889
Since 1955, for about 30 years, Franco Gariboldi has worked as a FAO consultant, a specialized ONU agency, directing rice process assistance programs for developing nations. During this time, He also produced FAO handbooks and manuals to define technical process standards.
Riseria Gariboldi was founded in 1889 in Assago (MI), by the homonymous family, and in forty years it became one of the largest Italian companies for the production and market of the paraboiled rice.
At the beginning of the 2000s the company moved in the Lomellina Valley (Pavia), in the heart of the rice fields: this position guarantees direct contact with the raw material and the possibility of choosing the best varieties of Italian rice.
In February 2019 Riseria Gariboldi became part of the Euricom group, an Italian company, one of the world leaders in the rice sector.
With a turnover of over 40 million euros/year (strongly growing after the implementation of a recent industrial development plan), and with around 64 permanent employees, the company is one of the Italian leading companies in the rice production and marketing.
Riseria Gariboldi treats about 100,000 tons of rough rice – raw rice produced from threshing and drying, still wrapped in glumette – from which rice is extracted and processed according to two production processes: white rice, and that of parboiled rice, which constitutes 60% of the volumes.
Steam: the key of the element of the parboiling process
Through the parboiling technology, rice is treated with hot water and steam, then is dried, in order to obtain shiny, slightly amber-coloured granules, rich with vitamins and minerals and more resistant in cooking.
For this process, the continuous availability of steam is a fundamental element (and critical at the same time): in case of steam missing, in fact, the rice would suffer serious damage, also becoming unusable. Losses for the company would be significant.
This is why boilers must work correctly. One of the main causes of anomaly and fallowing of the boiler in the steam production phase is the deterioration of the generator’s tube bundles due to the oxidation of the material.
A feed water boiler rich with oxygen can cause serious damage to the pipes which, over time, lead to boiler stops and costly maintenance work to replace it.
In this case, a food water treatment, for the elimination of excess oxygen and for the improvement of the water quality, drastically reduces the risk of corrosion of the pipes (and therefore of plant fallowing) and allows the steam generator to work more efficiently.
The costumer requests
“The main need was to reduce the oxygen levels [in feed water], so that the boiler oxidation could be totally negligible and the risk of fallowing for sudden boiler malfunction caused by corrosion reduced”
In the long term, oxidation could spread to other parts of the boiler, making necessary a complete replacement of it.
The aim of Riseria Gariboldi was therefore to reduce the oxygen level present in the boiler feed water; consequently, to limit the use of reducing chemical products – according with European and American standards (FDA) – for the oxygen removal in water.
The company has therefore chosen a thermophysical deaerator (much more efficient than chemical degassing in eliminating the gases dissolved in water), which must be of limited size, in order to be installed in a small space, and integrated into an existing steam circuit.
Cannon Artes solution
After having examined several proposals, Riseria Gariboldi chose Cannon Artes ZeroGas® Spray Smart deaerator, thanks to which the company was able to significantly reduce the presence of oxygen in the feed water.
ZeroGas® Spray Smart deaerator guarantees an output concentration of O2 dissolved less than 20ppb, as established by the standard EN12953 – 10: 2003 for the feed water of fire tube boilers. Moreover, thanks to the integration of the degassing section inside the tank, this deaerator is more compact and lighter and fitted perfectly into the existing plant, to which it has been interconnected through a dedicated PLC.
Riseria Gariboldi commercial evaluation had considered the “Total costs awarnership“: the sum of the installation and management costs over time. Evaluation that rewarded Cannon Artes product: the ease of installation and management, and the reliability of the Spray Smart deaerator reduce start-up and maintenance costs. The deaerator without tower, then, allows the recovery of excess steam, which is used to preheat the boiler feed water, and which results in a significant recovery of the thermal energy used.
“Since we installed the deaerator, we did not need to contact Cannon Artes again, as it is a highly reliable machine that does not require further intervention”
Cannon Artes supported Riseria Gariboldi throughout the development of the project, by offering its technical and commercial support, to provide the customer with a product modelled on his needs.