13 Dec Case 1 – Belgium
Used in combination with the right technique, cleaning with solvents allows to fulfill the cleanliness requirements, it’s reliable and environmentally compatible. There are different areas within which advantageous cleaning results are obtained with solvents. One of these cases is when heavily oiled parts are concerned and need to be cleaned efficiently and effectively. In this area the implementation of an aqueous cleaning system would necessitate an extensive conditioning of the medium and a high cleaning agent consumption.
Lesage has already been an important supplier of copper, brass, aluminum and stainless steel pipes for 50 years. The company produce copper draw tubes customized to customers specifications.
At the start of June Lesage brought a new, fully automatic degreasing machine into operation to be able to serve its customers even better. Until recently the pipes and pipe sections we produce were degreased in open baths. This is no longer allowed under environmental law.
Because of high consumptions and due to the strict solvent regulations, Lesage had to invest in a closed solvent machine, because alternatives as aqueous systems were not possible due to their oily and heavily contaminated parts. To invest in a closed machine gave them the possibility to immerse the chamber and to lift the parts to drain the solvent. Drying take place under vacuum.
As the company also have small sawed parts to customers request (with a lot of swarfs), they recently invested in a small closed degreasing machine with the possibility to rotate the basket.
CSI 4800 V – operating with super stabilized perchloroethylene
The machine supplied by Cemastir allows the elimination of the different types of pollutant from metals or other different alloys (such as brass, iron, aluminum, etc.) compatible with the solvent and machined with oil or emulsified oil, without altering the material features and color with the following main characteristic:
- at each cycle to clean with the best possible solvent, fundamental condition to get a constant, long lasting quality of washing independently from the quantity of the material and from the type of pollutant involved
- to perform cycles of cleaning with hot and cold solvent, as well as rinsing with solvent vapors with pre-arranged times and sequences. The cycles are studied in function of each single different type of part to be cleaned
- drying under vacuum with final phase through carbon adsorptions unit.
The CSI 4800 V solvent degreasing machine is steam heated with a central treatment-chamber manufactured in stainless steel and thermally insulated. The machine features the following components:
- Hot solvent tanks: situated on top of the distillation tanks they contain the heated solvent used in the first phase of cleaning (pre-cleaning). Heating comes from vapors from the distillation unit.
- Distilled solvent tank: it contains the distilled solvent, normally used during the second phase of cleaning (fine cleaning).
- Immersion tank: it contains the hot solvent which is needed for the immersion phase in the cleaning chamber.
- Solvent boiler or distillation tanks: during each cycle it distils the solvent used during the pre-cleaning phase thus granting an excellent quality of solvent at every cycle and a consequent stable cleaning level. A safety thermostat located inside the still chamber checks the solvent temperature and prevents any damage during the distillation phase. Cleaned solvent vapors can be directed by the still unit through a three way valve either to the inside of the cleaning chamber (vapor rinsing) or to the heat-exchanger (to heat the solvent used during the pre-cleaning phase). The final stage is the condensation via stainless steel water-cooled condenser.
- Water Cooled Solvent Condenser: during the distillation process, the solvent is condensed by a water-cooled coil and discharged into a water separator. This water passes through an independent and insulated circuit, never getting in contact with the solvent.
- Water-separator: capable of separating, by specific weight, the solvent mixed with water coming from the humidity collected in the cleaning chamber during the loading and unloading phase.
Ecosystem device: able to reduce solvent concentration contents in still residues. This system also allows a significant reduction in solvent consumption and consequently a reduced emission of toxic residues with lower solvent content; fully automatic and programmable.
To improve the safety, a centrifugal pump discharge the solvent residues coming from the distillation unit to a external barrel. A protection pump filtering unit (3) (filtration level of 200 μm) is capable of collecting particles removed from the parts during cleaning cycle. This filter is located at the outlet of the cleaning chamber and allows a first drying of the residues. Then a secondary micro filter unit (3) improves tremendously the cleanliness of the machine when parts are contaminated by very small particulars.
To control the whole system the machine is equipped with a PLC of Siemens S7-200. The machine has an automatic
loading door pneumatically controlled with safety device to prevent any opening during the cleaning cycle. A safety micro switches on all doors and pneumatic locks keep all doors safely closed during the operation.
Oversized solvent Pump – improves the cleaning performance and insure the necessary solvent pressure through all filtration systems, the machine is fitted with 3 oversized pump.
Active Carbon Unit is an activated carbon recovery unit consisting of a double container containing 75 kg of active coal each, complete with a system of forced ventilation inside the containers, of a condensation system). Before the opening of the door, It allows the removal (adsorption) of the vapors of solvent still presents at the end of the cycle inside the treatment-chamber. The regeneration takes place by a forced circulation of hot air, thus avoiding problems of polluted contact-water. The whole process is totally independent and does not need the stop of the machine during the various working shifts.
Solvent Concentration Measuring Device (3 channel): monitoring computer to control the solvent-gas concentration inside the treatment chamber, in the working area and outside of the carbon unit complete with display and preset of alarms, check the concentration level in to the drum, and prevent any opening of the chamber within the levels of solvent concentration is below the pre-set value (eg. 2 g/m³), ensure that on the working area the concentration remain below the limit and advise when one of the two carbon unit mast be switched with the other one.
- Pre-cleaning phase: after collecting the hot solvent from the tank (60 – 80°C / 140 – 176°F) the jets at the top of the backside of the washing chamber inject the solvent onto the parts and remove up to 90% of the polluting material which is drained into the still together with the solvent. The washing cycle time are pre-programmed and memorized in the computerized control system.
- Immersion: the third phase, consisting in the immersion of the parts by means of the very hot solvent (80 – 90°C / 176 – 194°F) contained in the steam-heated tank; during this phase the cleaning action can be reinforced injection flooding.
- Vapor rinsing phase: during the vapor phase, the washing chamber and the still are connected. Because of the difference in temperature between the parts to be treated and the vapors, the solvent condenses on the minute details. This ensures a final complete rinse and raises the temperature of the parts before the drying phase begins.
- Vacuum drying phase: the pressure inside of the chamber is reduced (up to 50 absolute mbar) thus accelerating the evaporation of the solvent. The air/solvent combination, which is drawn into the washing chamber, is forwarded to a condensing unit and afterwards to an active carbon unit before being sent to the chimney of the machine with concentration levels of just a few PPMs.
- Carbon Activated Absorption phase: once the cooling cycle is completed, the air left in the washing chamber is sent to an active carbon unit which absorbs the residual solvent concentration.
- Loading and unloading phase: when the loading door is opened a suction system is activated which intakes air from the outside and (according to local regulations) sends it to the chimney of the unit which, conforming to the VOC directive on solvents, guarantees emissions below 100 gr/h. This device allows the user to accurately determine the levels of concentration present in the area surrounding the washing unit.
During all steps in the programs it is possible to move the trolley with the parts up and down to improve the cleaning and the drying.
Unique In Belgium
Lesage took this big step forward to be able to maintain its growth. The closed degreasing machine can degrease pipes with a length up to 7500 mm, and the closed nature of system means the 4,000 liters of perchloroethylene cannot evaporate outside. After the degreasing process the residual content of 2 mg/3m is negligible.
the new machine is also the first such version to be brought into use in Belgium. and now the company offers a degreasing service to third parties .