1. A fluid valve assembly comprising:
a generally hollow cylinder coupled to an axially aligned piston chamber, the cylinder defining an internal void extending from one side of the cylinder to another side of the cylinder, wherein the cylinder includes at least one fluid inlet path and at least one fluid outlet path;
a shuttle arranged within the internal void of the cylinder, the shuttle being slidable between a first position and a second position around an axially located piston rod of the piston chamber, wherein a sealed chamber exists between a portion of the shuttle and the cylinder and when the shuttle is in the second position, the chamber is fluidly coupled to the fluid inlet path and the fluid outlet path to provide a controllable fluid flow into and out of the cylinder.
2. The fluid valve assembly of claim 1, wherein the fluid configured to flow into and out of the cylinder is compressed gas.
3. The fluid valve assembly of claim 1, wherein the valve functions as a pilot valve to actuate a larger fluid flow control valve.
4. The fluid valve assembly according to claim 1, wherein the axially aligned piston chamber is at least a portion of a pole saw.
5. The fluid valve assembly according to claim 1, wherein axial movement of the piston rod moves the shuttle between the first position and the second position.
6. The fluid valve assembly according to claim 1, further comprising:
a first biasing mechanism and a spring holder positioned adjacent the shuttle within the internal void, wherein when the shuttle is in the second position, the first biasing mechanism is at least partially compressed between the spring holder and the shuttle.
7. The fluid valve assembly according to claim 1, further comprising at least one o-ring configured to seal the chamber.
8. The fluid valve assembly according to claim 1, further comprising at least one elastomeric diaphragm configured to seal the chamber.
9. The fluid valve assembly according to claim 1, wherein the piston rod includes a biasing member adjacent a free end, the biasing member being in contact with the shuttle and applying a force thereto when the shuttle is in the second position.
10. The fluid valve assembly according to claim 1, wherein the cylinder includes a vent hole configured to reduce backpressure within the cylinder.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A slow and controlled-release polymeric fertilizer having the general formula of (I):
wherein n is in the range of from 50 to 200, m is in the range of from 0 to 5, and for each repeat unit, M is same or different and is independently selected from the group consisting of K, NH4, NHCONH2 and the like.
2. The slow and controlled-release polymeric fertilizer according to claim 1, based on the total mass of the slow and controlled-release polymeric fertilizer, comprising:
27.9% K2O, 42% P2O5 and 16.6% N when m is 0 and all M is K;
12% K2O, 18.2% P2O5 and 28.7% N when m is 3 and all M is K; and
8.2% K2O, 12.5% P2O5 and 29.4% N when m is 5 and all M is K,
wherein the amounts of K, P and N are calculated as that of K2O, P2O5 and N respectively.
3. The slow and controlled-release polymeric fertilizer according to claim 1, based on the total mass of the slow and controlled-release polymeric fertilizer, comprising:
48.4% P2O5 and 28.6% N when m is 0 and all M is NH4; and
19.5% P2O5 and 34.5% N when m is 3 and all M is NH4,
wherein the amounts of K, P and N are calculated as that of K2O, P2O5 and N respectively.
4. The slow and controlled-release polymeric fertilizer according to claim 1, wherein the contents of nutrients K, P and N are adjusted respectively in the preparing process of preparation according to the requirements of crops and soils, with the content of the nutrients being in the adjustable range of 16\u02dc35% by mass of nitrogen, 13%\u02dc48% by mass of phosphorus and 6%\u02dc27% by mass of potassium.
5. The slow and controlled-release polymeric fertilizer according to claim 1, wherein M is further selected from the group consisting of Fe, Cu, Zn, Mn, Mg and other microelements which the crops and soils demand, with the content of each microelement being in the range of 0.1% to 1% by mass.
6. A process for the preparation of a slow and controlled-release polymeric fertilizer of claim 1, comprising the steps of:
(1) adding reactants and phosphoric acid into a reactor and heating to generate dihydric phosphate, wherein said reactants are chloride, hydroxide or carbonate of potassium;
(2) adding carbamide and formaldehyde into another reactor and adjusting the pH value to generate methylene urea oligomer at a suitable temperature;
(3) adding the dihydric phosphate obtained in step (1) and the product of step (2) or carbamide sufficient to provide enough nitrogen into aher reactor (4) heating to start the polycondensation reaction, and continuing the polycondensation reaction under the action of the reaction heat; granulating the melted polycondensation product.
7. The process according to claim 6, wherein the reactants are further selected from the group consisting of oxides or hydroxides of Fe, Cu, Zn, Mn, Mg and other metal elements that are needed.
8. Use of the slow and controlled-release polymeric fertilizer of claim 1, wherein said fertilizer is applied independently or in combination with farmyard manure.