11 water purifying units, air purifying units for industrial use; sewage treatment units, rotary sludge furnaces, industrial water filtering units, water and waste water filters; water purifying units for industrial air filters; filtration equipment for industrial use; dry particle dust collectors; fume scrubbers; odor control filters; industrial fans; blowers; air handlers; exhaust fans for industrial use; ventilation ducts; recovery systems comprising reservoirs, pumps, filters, and cleaners; heaters, filters, and pumps sold in combination for use in filtering applications