A safe portable sprayer, of the type comprising a clean water tank that can be carried on the back of the user or hang from the shoulders by straps attached to the tank by handles. The tank is provided with a large mouthpiece on the top surface, a smaller mouthpiece with a water pump fitted thereto and a small neck with a lid through which water is supplied. At least, a lid (5) is screwed onto the mouthpiece (3) and a container (7) fitted to the mouthpiece (3) and extending up to close to the bottom of the tank (1)is provided inside the tank (1). The water-tightness between the lid (5), the mouthpiece (3) and the container (7) is ensured by seals (48, 49 and 50) arranged therebetween, and the lid (5)has a plurality of vertical bores (15) that extend through a single horizontal channel (8) inside the top wall of the lid (5). The bores (15) are provided with an inner thread above the channel (8) for receiving corresponding valves (17) with lower conical ends for closing the bores (15) below the channel (8) when they are moved to the lower end of course thereof. Flexible tubes (19) containing a concentrated chemical product are attached each to one of the bores (15)inside the container (7) by means of hydraulic fittings (16), and are kept immersed and under the pressure of a water volume inside the container (7)supplied by a pump (20)located next to the container (7)inside the water-filled tank (1), such as to cause a check valve (25) of this pump (20)to communicate with the container (7) through a hose (26), and to cause the pressure generated inside the container (7) by the water pumped into the tank (1) to inject water and chemical product into the channel (8) in the lid (5), forming a mixture that flows into a spike (9) connected to the spraying gun (11) by the hose (10).
