Removing Odors in a Drycleaning Machine

Almost nothing can run off customers as fast as getting their clothes back and they smell like vomit, stinky feet or just putrid. Removing odors is critical.

This is always caused by free moisture in a lighter than water type solvent that allows bacteria to grow and multiply.  Once the odor begins it can be very difficult to remove; below is an outline on how to methodically remove the odor and then how to prevent it from happening again.

Removing the Odor

All of the solvent must be pumped from the machine and frequently disposed of because it will be impossible to effectively and economically remove the odors.  Remember the solvent is probably a hazardous waste and must be handled according to state and federal regulations.  After the solvent has been removed all of the base tanks must be opened and the build-up of muck, lint and debris must be raked out and removed…ALL of it.

The filters need to be removed and discarded if they are cartridges.  The filter housings can then be closed back up.  If the filter is a spin disk they also need to be drained, removed and cleaned.  After cleaning they can be soaked in a solution of trisodium phosphate (TSP) and water for a half hour or so then rinsed thoroughly with water.  After rinsing they can then be lightly sprayed with a solution of about 1/8 cup of sodium hypochlorite bleach (Clorox) to a gallon of water.  While mixing and spraying avoid breathing the fumes.  Also clean the disk housing thoroughly, rinse with water then spray lightly with the Clorox solution.

Next, fill the base tank with water to cover the bottom with about four inches of water and add one or two pounds of TSP, the idea is to get a high pH cleaner where the tanks and piping are contaminated.  The TSP can be added while the water is being added to the tank.  Cleaning of the tank will be better and faster if the water is heated to about 110 to 120 degrees F.

After the tank has water in it a wand can be made by using a five or six foot section of flexible copper tubing and attaching an air supply to the tubing.  Put the end of the tubing in the base tank and move it all around the bottom and sides of the tank in order to get the water/TSP mixture to all parts of the inside of all the tanks.  If it is possible this mixture needs to be circulated throughout the machine including the piping, pumps and filter housings.  The purpose is to get the water/TSP mixture to all internal parts of the machine that comes in contact with solvent.  Do not forget to also clean the internal parts of the still and piping back to the distilled tank.

Caution, do not take shortcuts by not cleaning even a small part of the internals of the machine as the bacteria can then come back and start all over.

After the machine is internally cleaned the water can be drained back to the base tanks and pumped out into containers.  Then a water hose can be briefly used to rinse the internals of all tanks and piping.  It is not necessary to thoroughly flush the inside as the TSP will not cause corrosion.  Once the tanks and internal piping has been cleaned it should be dried with fans, compressed air or any other means.  The idea is to remove as much of the residual water as possible.

Once the machine is again closed up, including replacing the filters, either cartridges, screens, tubes, bags or cartridges, refill with new or odorless distilled solvent.  Do not add detergent at this time.  Run a load of very slightly damp blankets or other absorbent fabric and this should pick up the remaining moisture.  The solvent can then be charged with approximately ½ to ¾ percent charge of an anionic detergent which will pick up the rest of the moisture.  If there was a slight filter pressure rise this may go back down as the detergent picks up the remaining moisture and holds it in suspension.  Any remaining free moisture will be all removed when the first load of clothing is cleaned.

Remember that all of the liquid that has been on the inside of the machine is probably hazardous waste and must be handled accordingly.

To Prevent Solvent Odors

First remember that most all odors in solvent are from the misuse of moisture or water leaks somewhere into the solvent.  Free moisture will tend to stay in one place of a base tank where there is very little solvent movement.  Some cleaners use their flexible copper tubing with air apparatus to stick in all parts of the base tank while blowing air to thoroughly get the sludge in suspension and then get it onto the filter so it can be removed.  This should be done at least once a week.  Some of the solvent can also be sent to the still after the sludge is in suspension.

It is perfectly OK to use a moisture addition in a drycleaning system without corrupting the solvent.  Moisture must never be allowed to become free moisture by reducing the anionic detergent, allowing water leaks into the system or, overusing moisture either through a moisture addition or spray prespotting spotting.  The quick check for the amount of moisture is to look at acetate jacket linings, after cleaning, for fine wrinkles that tend to go in all directions.  When you see this the solvent is either too hot, undercharged or, there is free moisture in the solvent.  Whenever there is an odor problem in a lighter than water solvent machine it is best to thoroughly clean the inside of the machine rather than add some “miracle cure” in hopes that it will go away.

A small amount of “bound” moisture should be maintained in the solvent by additions to most every load in order to reduce water soluble spotting and body odors, graying and other soils.

For more information on the use of moisture in drycleaning “See Moisture in Drycleaning” under Plant Operations at