Apparatus and method for spraying a mixture of a binder and a volatile liquid.

摘要

One particular application of the invention is in spraying a foamed binder such as bitumen or tar onto a road surface. As shown in Figure 2 the apparatus comprises a binder tank (22) and a pump (23). The binder is transferred using a pump (23) and passes to a spray bar (25) having a number of spaced branches (26). Volatile liquid in a tank (27) passes through a pump (23A), and needle valves (42) to a manifold (31) which has a number of spaced branches (32). The supply of binder, from spray bar (25), through a typical branch (26) passes through a control valve (33) to a mixing chamber (35). A series of mixing chambers (35) are equally spaced along the liquid manifold (31) and spray bar (25) which are close to each other. The volatile liquid passes through the branches (32) to control valves (36) and non-return valves (37) and then into the same mixing chambers (35). Thus each mixing chamber (35) receives a controlled supply of binder from the tank (22) and a controlled supply of volatile liquid from the tank (27). The control valves (33 and 36) are synchronised either pneumatically or mechanically.