Fire extinguishing appliance adjustable in foam expansion ratio

1. A fire extinguishing appliance adjustable in foam expansion ratio comprising:

a main body;

the main body comprising an agent chamber;

the agent chamber forming an interior of the main body;

a pressure within the agent chamber being higher than a pressure of an outside;

a non-toxic agent;

the non-toxic agent being received within the agent chamber;

a connecting pipe;

the connecting pipe being coupled with the main body;

the connecting pipe being communicated with the agent chamber;

a spray-head seat;

the spray-head seat comprising two axial ends;

the two axial ends being respectively defined to be a first end face and a second end face;

the first end face comprising a first accommodating groove and a through jet orifice;

the first accommodating groove comprising a first inner ring surface and a bottom surface;

the first inner ring surface being assembled with the connecting pipe;

the through jet orifice being bored on the bottom surface;

the second end face comprising a second accommodating groove;

the second accommodating groove comprising a second inner ring surface;

the second accommodating groove being communicated with the first accommodating groove via the through jet orifice;

a damping piece;

the damping piece being mounted on the second inner ring surface;

a water guide member;

the water guide member being received in the first accommodating groove;

the water guide member comprising a seat and a protruding ring;

the protruding ring extending from one side surface of the seat;

the protruding ring being smaller than the seat in diameter;

the seat comprising a plurality of through insert holes axially bored therein;

the plurality of through insert holes being spaced apart from each other at an outer side of the protruding ring;

the protruding ring comprising a free end;

the free end surrounding the through jet orifice;

the protruding ring comprising an inner surface and a volute chamber;

the volute chamber being formed by the inner surface;

the volute chamber corresponding to the through jet orifice;

the protruding ring comprising a plurality of flow passageways cut thereon;

the plurality of flow passageways being spaced apart from each other and communicated with the volute chamber;

the first inner ring surface comprising a female thread;

the seat comprising an outer circumferential edge and a male thread;

the male thread being correspondingly disposed on the outer circumferential edge;

the seat being threadably fixed in the first accommodating groove via the female thread and the male thread; and

the female thread being longer than the male thread.

2. The fire extinguishing appliance adjustable in foam expansion ratio as claimed in claim 1 comprising:

the first inner ring surface comprising another female thread;

the connecting pipe comprising an outer surface and a combining thread;

the combining thread being formed on the outer surface; and

the connecting pipe being fixedly combined with the spray-head seat via the another female thread and the combining thread.

3. The fire extinguishing appliance adjustable in foam expansion ratio as claimed in claim 1 comprising:

the first end face comprising a recessed groove;

the recessed groove being formed on the bottom surface;

the recessed groove surrounding the through jet orifice; and

the free end being positioned to face the recessed groove.

4. The fire extinguishing appliance adjustable in foam expansion ratio as claimed in claim 1 comprising:

a gas supply unit; and

the gas supply unit being connected with the main body.

5. The fire extinguishing appliance adjustable in foam expansion ratio as claimed in claim 1 comprising:

the damping piece being a screw or a bulging block.