Automated chemical drum cleaning and decontamination system

01

Choose a wash head that fits the drum opening

Spraying Systems describes its AA190E electrically motorized tank washer as fitting into a 3 in (76 mm) diameter opening and ideal for cleaning drums, totes, tanks and reactors; multi-axis rotation of its solid-stream nozzles covers the internal surfaces, and the nozzle turret's rotational speed is independent of cleaning-liquid pressure and flow. [1]

The manual lists 500 psi (35 bar) maximum liquid pressure and 200 °F (93 °C) maximum liquid temperature, and says the unit may run on plain water or chemicals compatible with 316 stainless steel; when chemicals are used it should be flushed with clean water at the end of the day, and a liquid line strainer ahead of the unit is recommended. [1]

Its AA190E-EP version carries a NEMA 7 explosion-proof motor for process areas where electrical sparks may be hazardous, with the motorized drive mounted outside the tank. [1]

Editorial calculation: 35 bar is 3.5 MPa. [1]

Give the supplier the drum types (steel, plastic, tight-head or open-head), opening sizes, residues and their hazard class, wash and rinse chemistry, pressure, temperature, throughput, drain and drying needs, effluent handling, hazardous-area classification, power and air supply, and floor space.

02

Set the cleanliness end point before buying

Under US rule 40 CFR 261.7, a container that held non-acute hazardous waste is empty when everything that can be removed by pouring, pumping, aspirating or similar practices has been removed and no more than 2.5 centimetres (one inch) of residue remains, or no more than 3 percent by weight of total capacity remains for containers of 119 gallons or less (0.3 percent above 119 gallons). [2]

For acute hazardous waste the container is empty only if triple rinsed with a solvent capable of removing the product, cleaned by another method shown in the scientific literature or by the generator's tests to achieve equivalent removal, or, for a lined container, the inner liner that prevented contact has been removed. [2] State which rule or customer specification the cleaned drums must meet so the supplier can size the rinse stages and verification.

03

Compare the machine cycle with the label rinse procedure

US rule 40 CFR 156.146 sets the container-cleaning instructions that labels of dilutable pesticides in rigid nonrefillable containers must carry. Triple rinse: empty the contents, fill the container 1/4 full with water and close it; for containers too large to shake, roll it on its side for 30 seconds with at least one complete revolution, then tip it on each end; empty the rinsate and repeat two more times. For containers small enough to shake, the instruction is to shake for 10 seconds and drain for 10 seconds after the flow begins to drip. [3]

The pressure rinse instruction has the container held upside down over the application equipment or mix tank while the rinsing nozzle is inserted through the side. Rinsate goes to the application equipment or mix tank, or is stored for later use or disposal. [3]

Editorial calculation: for a 208 L (55 US gal) drum, 1/4 full is about 52 L per rinse, about 156 L for a triple rinse; 40 psi is about 2.8 bar. A machine cycle can be checked against these figures for water use, pressure and contact time.

Ask the supplier whether the machine's rinse programme meets the label rinse method for your products, and for water use per drum, nozzle pressure and rinse time.

04

Match washing to the transport rules for reusing and reconditioning drums

US DOT hazardous materials rule 49 CFR 173.28 says a packaging used more than once must be inspected before reuse and may not be reused unless free from incompatible residue, rupture or other damage that reduces its structural integrity. For metal drums, reconditioning means cleaning to the base material of construction with all former contents and internal and external corrosion removed, restoring shape and chimes, replacing non-integral gaskets, and inspecting after cleaning but before painting, rejecting drums with visible pitting, significant thickness loss, metal fatigue or damaged threads or closures. [4]

Editorial note: a wash line that ends at the 40 CFR 261.7 empty-container point does not by itself make a drum ready for refilling with hazardous materials; under 49 CFR 173.28 the drum also needs inspection and, where it is subject to the air leakproofness test, a passed retest and “L” marking. Ask the supplier whether the line includes post-wash drying and visual inspection, and whether a leak-test station at 20 kPa or 48 kPa can follow the wash. [4] [2]

Editorial calculation: 48 kPa is 2.4 times the 20 kPa retest pressure, so a leak-test station serving Packing Group I drums needs a regulator and gauge range that covers both settings. [4]

05

What to ask any drum-washer bidder: head, pressure, cycle time, effluent and area rating

Ask any supplier for drum sizes handled, wash head type and opening size, pump pressure and flow, wash temperature, wetted materials, cycle time, water and chemical consumption per drum, effluent volume, hazardous-area rating, installed power, footprint and weight.

06

Wash head, NEMA 7 drive, pump and strainer, wash liquid and rinse stages

All rows but the last come from the AA190E manual; the drain and rinse stages are sized by the end point the drum must reach under 40 CFR 261.7, not by the wash head. [1] [2]

07

Cycle time, drum size, wash pressure, temperature and rinse method for a drum washer

Nine of the fifteen rows have no published value. Pressure, temperature, drive rating and wetted material describe one wash head, the AA190E, rather than a complete washing line. [1]

08

Send the drum, residue and end-point data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Drums: [steel; plastic; tight-head; open-head; sizes]
Residue: [product; hazard class]
Wash: [chemistry; pressure; temperature]
End point: [40 CFR 261.7; customer spec]
Throughput: [drums per hour]
Area: [hazardous classification]
Utilities: [power; water; air; effluent]

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