A Filling Machine for the Flammable Chemical Industry – Hazardous Location Systems
Inline Filling Systems has built many systems over the years for producers of inorganic and organic solvents, flammable petroleum products, solvent based paints, explosive compounds for munitions and high proof ethanol and liquors for distilleries. We build both simple pneumatically operated hazardous location machines for semiautomatic operation and also more sophisticated high speed, electrically operated machines with all of the versatility of our standard filling systems.
The choice of how a hazardous location filling machine is designed and applied and what product it is being used for depends greatly upon the interpretation of the various insurance, national and local regulatory agencies and inspectors as well as applicable standards in the National Electrical Code. Inline Filling Systems always takes the most conservative approach as to avoid any conflicts with any regulatory entities.
About the Design and Construction of Hazardous Location Electrical Systems for Filling Machines
These systems use intrinsically safe electrical enclosures for class I division I group D explosion hazard locations. The entire operating system including 40 character visual display is available to the operator for user friendly control of all conventional filler operations. Panel enclosures and piping are designed to contain and cool explosive gases in the event of auto-ignition inside the electrical system housing and conduit. All connective components of this system are UL listed and conform to the National Electric Code as well as requirements of major insurance carriers.
The primary difference between a filling machine used for flammable products and one that is non flammable is the use of intrinsically safe components of the operating system so that auto ignition of these products is avoided. This can be accomplished with all pneumatic components or an electrically isolated control panel or a combination thereof. One disadvantage of purely pneumatic systems is the use of pneumatic logic control components that are subject to timing errors if the user’s system air is not supplied at consistent rates and pressure. Electrically operated systems installed in intrinsically safe control panels of these filling machines are more functionally reliable and offer greater elegance of operating controls. These systems can be installed in an overflow filling machine, a time gravity filling machine and piston filling machine depending on the flow characteristics of the products being filled.
Overflow Filling Machine for Thin and Flowable Flammable Chemicals
Flammable chemical products with thin viscosities that are filled into narrow opening bottles, cans and canisters and be filled on either the Overflow Filling Machine or the Time Gravity Filling Machine. The overflow filling machine is the filling machine of choice for distilled products filled in glass and plastic bottles in the liquor industry. The primary reason for this is that the fill height of the containers are visible to the consumer and the overflow filling machine guarantees that all bottle fill heights will be the same within 1/16″. This is particularly important in the case of liquor filled into glass bottles where the manufacturing variances of the glass can be significant. Solvents such as acetone and methanol that are filled in semi translucent bottles are also best filled on this type of filling machine since the fill height in the bottle is also readily apparent to the consumer.
Some flammable products should not be pressurized because the flashpoint of the product may be lowered to a level that makes it unsafe for commercial filling operations. Also, continued recirculation of the product in an overflow filling machine could increase vaporization of the product to unsafe levels depending on the operator’s control and design of the hazardous location filling area. In these cases, we would not recommend an overflow filler but more commony, a time gravity filling machine.
Time Gravity Filling Machine for Non Recirculated Thin and Flowable Flammable Chemicals
Like the overflow filling machine for flammables described above, the Time Gravity Filling Machine is also useful for flammable chemical products with thin viscosities into narrow opening bottles, cans and canisters. It is also useful for filling large containers of solvent based chemicals where the top of the container cannot be sealed and where it is not practical to pressurize or recirculate the product for safety reasons.
Although there are inherent accuracy issues with time gravity filling machines, they are relatively cost effective machines and the producers are generally not as concerned about precision of filling accuracy of these commodity based products. Also, since these machines are often used for bulk filling applications of flammable products, the accuracy errors produced by timing errors become relatively small as a percentage of total fill volume.
Please note that proponents of time gravity filling systems as the primary choice for flammable products ignore some important marketing and operational considerations. As discussed above, precise cosmetic fill heights are extremely important for some products like distilled spirits filled in glass and this is simply unattainable in a time gravity machine even with constant operator attention. Furthermore, a system that requires constant attention by an operator to meet certain quality control parameters raises some fundamental questions about its fitness for that purpose. Inline Filling Systems understands these tradeoffs intimately and can help you make the best economic and operations decision for your hazardous location products.
Piston Filling Machine for Flammable Chemicals
The most common types of flammable products filled in a piston filling machine are solvent based coatings and paints into cans and to a lesser degree, into bottles. Coatings and paints by nature are thicker viscosity and require a positive displacement delivery system to fill a precise quantity of product under pressure regardless of viscosity changes. Products like paint would be too thick to recirculate in an overflow filling machine or flow out of a time gravity filling machine.
Many piston fillers on the market use pneumatic only logic control for operation because the piston filling machine operating system is quite simple; only manual adjustments are made to change the fill volume. Although pneumatic/mechananical piston fillers do have a disadvantage in longer setup times, this is generally not an issue for paint producers since the generally accepted fill sizes are limited and therefore changeovers are not frequent. Inline Filling Systems can offer both pneumatic logic controlled systems as well as electrically operated piston fillers for hazardous location operations. It is our experience that electrically operated systems are more trouble free over the period of ownership. There is also an advantage in operator training and setup when using digital controls instead of pneumatic analog controls.
Servo Pump Filling Machine for Flammable Chemicals
This type of filling machine is the most costly machine to build especially in a hazardous location configuration but for some applications, it is ideally suited. Because the servo filling machine is easy to clean, it is typically used for high value flammable products in large fill sizes , that require multiple changeovers, or have a particularly challenging cleanup after use. An example of this would be a solvent based, food grade flavor operation requiring frequent and thorough cleanups between flavor batches to avoid cross contamination. Another example is thick viscosity specialty or anaerobic epoxies that require a hazardous solvent such as MEK to clean the machine after each run so as to avoid hardening of the product in the machine’s fluid path. If you have even a more obscure product that requires hazardous location installation, Inline Filling Systems has a breadth of industrial application’s experience that is unmatched by any of our competitors.