Overview of World Markets
Road sweeping began in North America and Western Europe hundreds of years ago. As a result of climate and infrastructure differences between the two regions, street sweeper markets developed differently in each area to better suite their specific applications.
Western Europe has a mild climate, good road quality, and very frequent sweeping operations. These conditions inspired the development of the vacuum type sweeper, which is suited for such applications and currently monopolizes most the Western European market. There are two regions in Europe, Scandinavian countries with snowy winters and the Italian Alps, where mechanical sweepers are present in a meaningful capacity.
North America has quite different conditions. In the hot and dry Southern States of the U.S., sand blows from the beaches in Florida and California or in the desert areas in Nevada and New Mexico. Further North in Canada and the North U.S., snowy winters and sand spraying are a common. These conditions require a more robust sweeper that is capable of conveying more material, more efficiently. These heavy-duty conditions created a need for a more efficient way of moving materials from the road surface to the hopper than vacuum sweepers and ultimately resulted in the modern mechanical sweeper, which currently dominate this market. In these conditions vacuum sweepers typically handle light day-to-day requirements while mechanical sweepers are in high demand due to their versatility in handling any type of sweeping. In the USA and Canada mechanical road sweepers make up approximately 70% of the market, air based sweepers hold the remaining 30%.
The primary difference between mechanical and vacuum sweepers is the way in which they move/convey materials from the street to the hopper or debris tank.
Mechanical sweepers use the main brooms bristles flicking effect to throw material from the ground to the mechanical conveyor. The conveyor is approximately 1500 mm wide and is located just in front of the broom. To conceptualize this, it is similar to sweeping a floor, the operator has a broom and dust pan to flick material into pan. Almost every piece of material moved by the main broom is successfully moved onto conveyor and transported to the hopper. If some material doesn’t reach the conveyor it drops in the front of the main broom and broom has another “try” to locate it on the conveyor. It is much more efficient system than any air moving process.
Vacuum sweepers use a large fan located in the front of the chassis to create a vacuum while a pick up nozzle sucks up debris. The pickup nozzle is located in front of the rear wheels and is approximately 300 mm wide, it rolls on the surface with a set of caster wheels. Debris is shifted to the pickup nozzle using a main broom and side broom. Debris is picked up by the nozzle and carried by the air stream to the hopper, through a fan, and then is released into the atmosphere. The main issue is separating debris from the air stream. The way of separating debris is by saturating debris with water and slowing down the air stream once it enters the large volume hopper. The most efficient way of separating debris is by using an additional filtration system.
Due to the nature of this system, vacuum sweepers require approximately twice the power of mechanical sweepers and use significantly more water.