Build-up of sludge in various locations in the system can wreak havoc with the operation of the booth itself. Sludge build-up on the flood sheets will lead to poor water distribution and open gaps where live paint overspray can make its way into the scrubbing chamber and up the stacks. Booth balance will also be affected potentially impacting paint finish quality. Sludge in the piping will clog off water flow and have a similar effect. Paint sludge getting up the stacks is a huge signal that booth balance is off – with the potential for the sludge to exit the stacks and go out to the parking lot.
Wet paint booth systems can require significant care and attention to ensure they run smoothly. Operational knowledge of the equipment and improper/out of balance chemical treatment will lead to declining booth performance and poor final paint quality. Booth system maintenance costs will increase and the resulting issues/challenges could potentially interfere with continuing operation of the booth system.
Some challenges that can present themselves to the booth operation are listed below. Case Studies are linked below the challenges where a study has been written.
Sludge build-up in booth sumps, holding tanks, and pits can go unnoticed until it’s time for a cleanout – or the system starts to experience ramping up of suspended solids; and proliferation of bad odors from anaerobic bacteria that get stirred up during Monday morning start-ups. The key to resolving this buildup is running the process so that the detackification “detack” chemistry and paint sludge removal equipment are working in sync. If either one gets out of whack, sludge will build up in the system. Ultimately the plant will need to shut down the system, clean out the sludge and haul it off for disposal. This costs money and adds to the overall cost to run the paint system. Of course, over extended periods of time all systems will require sump/pit clean-outs.
All industrial equipment requires maintenance. The key question to ask is what is a reasonable frequency and what will that cost in lost production and manpower/resource costs. Every system is different so there is no magical answer – and most plants learn through experience what their schedule should be. Having said that, a poorly run chemical treatment program coupled with system inattention is a formula for disaster. Both need to be managed and run properly to keep plant costs to a minimum.
Being more “green” can mean a variety of things – such as a more environmentally-friendly detack program, creating a drier sludge reducing disposal costs and impact on the waste processing facility, using less water for conservation reasons or to reduce the impact on the waste treatment plant, or creating a sludge that can be receptive to a fuels blending program. Galaxy can work with the plant to come up with a plan to deal with any or all of these challenges.
Foam in the booth can interfere with booth balance and impact the painting operation. Foam in the pit/sump can lead to sludge removal problems. Foam getting out the stacks can lead to paint deposits on surfaces outside the plant. Sources of foam are many – but a few include high dissolved and suspended solids, increased organic loading, solvent dumps, chemical treatment that is improper or out of control, and highly aerated situations, such as pump cavitation. Galaxy understands the sources of foam and also has products to control it.
Wet sludge is a sign that the sludge conditioning/dewatering process is not working as well as it should. This could be the result of an out of balance chemical treatment program, poor functioning sludge separation equipment, or some combination of both. Wet sludge adds undesired volume prior to disposal and can add extra expense. Wet sludge may also not be accepted at the landfill – adding more costs to condition it.
Odors in wet paint booth systems are typically the result of anaerobic bacteria activity – primarily due to paint sludge build-up in low flow areas, especially the pit or sump. Staying on top of the sludge removal process can minimize the potential for this – so the bacteria have nowhere to hide out. In some cases, a chemical biological treatment program will also be required to keep biological odors under control.
High or increasing suspended solids levels are a signal that sludge deposition could follow, leading to poor booth performance. Some reasons for increased/high suspended solids include improper or out of balance chemical treatment, paint/solvent dumps, changes in production levels, sludge handling equipment not running to spec (change in flow rate, etc.), system was recently “cleaned” and some solids were left behind, and more.
Reduced booth water flow and inadequate distribution across the flood sheets can occur for a variety of reasons – sludge/paint build-up that is interfering/blocking the water pathways, booth water flow rate valved back in an attempt to balance the booth, and pumps that are not functioning properly due to worn impellors or blockage, to name a few.
Nothing is more important than a properly functioning paint booth. The key to this is having a booth that is balanced and in-spec so the highest quality paint job can be assured. Most people believe that booth balance is strictly related to proper air flow and distribution. While air flow is very important, full booth balance will not occur unless the water flow and distribution is also in spec. Deposition of live paint or paint sludge in the booth proper will upset this balance quickly and the paint job will begin to suffer either with air flow that is blowing by the paint job or “fogging” when the air flow is too low, depositing paint overspray onto the job.
Paint booths never remove 100% of the paint overspray, so light build-up over an extended time frame is to be expected. However, live paint that makes its way out the stacks and onto cars in the parking lot is never a good thing. Bottom line is that somehow paint overspray is getting past the scrubbing chamber and suggests that 1) paint deposition there or on the flood sheets is allowing paint to bypass it, and/or 2) booth balance is upset and the scrubbing efficiency is less than design. A third possibility is the booth may be above its capacity due to increases in paint loading/production.
Water is a valuable resource and should never be intentionally wasted. By design, booth systems are supposed to recirculate the contained water over and over again, using fresh make-up water to replace that lost through evaporation and sludge removal. A well run recirculating booth system will recycle the water as much as possible until water chemistry limits begin to exceed values set by the chemical treatment company. Unknown or undesired losses of excessive water can sometimes be traced to a system mechanical issue – such as a broken level control or booth start-up procedures that cause excess water to flood the system. Water unnecessarily going to drain is the same as $ leaving the plant’s pocket.
The last thing most industrial waste treatment plants (WTP) need is higher volumes of waste streams they can’t handle. Potential issues at the WTP can include the inability to process the total volume delivered to them – causing the refusal to take more from a given process; to not being able to meet plant discharge limits, which could lead to fines. Tied closely to high water consumption, the plant needs to make every effort possible to treat water like any other plant raw material or resource – as paying for water supply and treatment costs the plant $ at both ends.
Water chemistry is an extremely important facet of any paint booth detack and sludge consolidation program. Aside from applying the right chemistries in the right place, in the right amounts, and at the right times, the water constituents need to be watched closely. As the booth water “cycles up” due to evaporation, the conductivity and the ions that contribute to it (along with cycled up organics) will continue to rise to the point where the chemical treatment begins to suffer, results degrade, and system corrosion risks increase. How much water to blow down or when to replace the booth water should be reviewed carefully. Galaxy has the know-how to help the plant in setting water chemistry limits.
Every painting facility has its own set of paints, production volumes, and process equipment that defines the challenges unique to them. Even the best chemical programs can fail, however, if the process equipment is not functioning to design or is the wrong equipment for the job that needs to be done. A well designed chemical treatment program takes into account all of these variables to match the best chemistry with the paints and equipment on site. When it’s appropriate Galaxy will recommend paint sludge processing equipment that could enhance the overall performance. Simply said, the paint detackification “detack” program costs should match the demands for that particular process along with tight control of usage, feed methodology, and results tracking.
No paint detack and sludge conditioning program will be successful if the sludge removal equipment is not working properly. Whether it’s a flotation/dewatering device, centrifuge, gravity filter, etc., the equipment must be maintained regularly and operated to its design specs. Some key aspects of running the equipment within design include proper flow rates, solids loading levels matched to the equipment, and correct filter media and processing cycles, to name a few.
What to do with the resulting paint sludge is a challenge presented to all painting facilities. Each plant may have its own issues with the sludge – whether it’s dealing with a sludge that is too wet to landfill, trying to avoid landfilling completely, or coming up with a solution where the sludge could potentially be recycled or used as a fuel. As a working partner, Galaxy can assist your plant to come up with a solution that best matches your sludge disposition needs.
There are many types of sludge consolidation equipment out there – including skimmers, gravity and vacuum filters, flotation/dewatering units, centrifuges, sludge dryers, home-made devices, and more. Some equipment requires dispersion of paint solids in the booth while others require flotation – and in some instances, the plant needs to sink the sludge. Galaxy can tailor the paint detack and sludge conditioning chemistry to best match with the equipment you have through lab screening and on-site tests.
Although Galaxy is a chemical treatment company, we have decades of experience dealing with all kinds of sludge consolidation equipment. When your back is up against the wall with increased production and the sludge equipment appears to be maxed out – Galaxy can assess your equipment to determine if additional output is possible or if additional/new equipment will be required. We have professional relationships with the best sludge consolidation equipment companies in the industry and can bring them into assist with your approval.
Nothing is more important than having a safe production work place. Paint booth systems are wet and as such, present safety challenges that could potentially result in personal injury. Although many safety issues can be controlled through good housekeeping practices, there are instances where the support of Galaxy expertise can be brought in to gain better control of a wet or foaming situation.