Dust control system

Abstract

A road cleaning or sweeping machine ( 10 ) fitted with a dust control system using a water atomiser ( 42, 60 ). The atomiser ( 42, 60 ) creates water particles of a similar size to dust, and by entraining atomised water through the road sweeping machine's dust handling systems, i.e. from the brushes ( 14 ), through a suction pipe ( 20 ) and into a hopper ( 16 ), dust control is established. A method of improving dust separation in a hopper ( 16 ) of a road sweeping machine ( 10 ) using a water atomiser to reduce dust or a spray to wet the walls of the hopper ( 16 ).

1 - 41 . (canceled) 
     
     
         42 . A road cleaning machine comprising a suction pipe and a hopper for collecting dirt sucked up by the suction pipe, and a dust control system comprising a water atomiser arranged to dispense a cloud of atomised water droplets into the air in front of the suction pipe so as to be entrained with dust particles in dust-laden air being sucked into the suction pipe. 
     
     
         43 . The machine of  claim 42 , wherein water particles from the water atomiser are at least as small as the majority of the dust particles of the dirt being sucked up. 
     
     
         44 . The machine of  claim 42 , wherein the machine does not significantly wet the dirt on the road in front of the machine. 
     
     
         45 . The machine of  claim 42 , wherein the atomised droplets from the water atomiser include a majority of droplets having a diameter of less than 200 μm. 
     
     
         46 . The machine of  claim 45 , wherein the atomised droplets from the water atomiser include a majority of droplets having a diameter of less than 100 μm. 
     
     
         47 . The machine of  claim 45 , wherein the atomised droplets from the water atomiser have an average diameter of between 40 μm and 70 μm. 
     
     
         48 . The machine of  claim 42 , wherein the dust control system is provided with a water tank, or water tanks, having a volume of about 20% of the volume capacity of the hopper. 
     
     
         49 . The machine of  claim 42  comprising one or more road-sweeping brushes. 
     
     
         50 . The machine of  claim 49 , wherein two counter rotating brushes are fitted to the front of the road sweeping machine. 
     
     
         51 . The machine of  claim 50 , wherein the atomiser is fitted so as to provide the cloud of droplets between the brushes. 
     
     
         52 . The machine of  claim 42 , wherein another water atomiser is positioned in the hopper. 
     
     
         53 . The machine of  claim 42 , wherein the machine recirculates air which has passed through the hopper back into the hopper. 
     
     
         54 . The machine of  claim 53 , wherein the recirculated air is directed to a location in front of the suction pipe for recirculating to the hopper. 
     
     
         55 . The machine of  claim 42 , wherein the or a said water atomiser comprises a rotary spray head. 
     
     
         56 . The machine of  claims 42 , wherein the or a said water atomiser is a nozzle. 
     
     
         57 . The machine of  claim 42 , wherein the average water droplet size from the atomiser is controllable. 
     
     
         58 . The machine of  claim 42  comprising a dust sensor, the dust control system being adapted to be switched on automatically upon the sensor sensing dust. 
     
     
         59 . The machine of  claim 42  comprising a water sprayer at the exit of the suction pipe or within the hopper for wetting the inside of the hopper. 
     
     
         60 . The road cleaning machine of  claim 42 , wherein the hopper comprises a cyclone separator. 
     
     
         61 . A retro-fit kit for a road cleaning machine, comprising a water atomiser and mounting means for fitting the water atomiser to the machine so as to dispense a cloud of atomised water droplets into the air in front of a suction pipe of the machine so as to be entrained with dust particles in dust-laden air being sucked into the suction pipe. 
     
     
         62 . A method of dust control in a road cleaning machine having a suction pipe and a hopper for collecting dirt sucked up by the suction pipe, the method comprising dispensing a cloud of atomised water droplets into the air in front of the suction pipe so as to be entrained with dust particles in dust-laden air being sucked into the suction pipe. 
     
     
         63 . The method of  claim 62 , wherein the atomised water is treated to reduce its surface tension. 
     
     
         64 . The method of  claim 63 , wherein the treatment is the addition of one or more of the following: a soap, a detergent or an antibacterial agent.