CN101973798B - Method for producing compound fertilizer by melting urea fertilizer with heat conducting oil heated cyclically and granulating in high tower - Google Patents

Abstract

The invention discloses a method for producing a compound fertilizer by melting urea with heat conducting oil heated cyclically and granulating in a high tower, wherein urea fertilizer meltwater is used as a fluid carrier, is intensively mixed with powdery monoammonium phosphate, potassium chloride or lemery salt, and auxiliary materials in a mixing tank to form slurry, the slurry is dispersed into small liquid drops by a granulating device at the top of a granulating tower, the small liquid drops drop under the effect of the gravity and the buoyancy force, reversely contact cold air from the bottom of the granulating tower to be cooled and solidified and finally freely drop to form compound fertilizer particles by cooling and solidifying. The main point of the method is that the preparation of the urea fertilizer meltwater comprises the following steps of: adding the urea fertilizer into a urea fertilizer melting pot, adding 150-160 DEG C heat conducting oil in the coil pipe of the urea fertilizer melting pot to heat and melt the urea fertilizer, wherein the heat conducting oil coming out from the coil pipe of the urea fertilizer melting pot returns a heat conducting oil boiler to be heated for cyclic using. The method resolves the technical problems of low energy efficiency, waste of water resource and environmental pollution existing in the traditional technology.

Description

Conduction oil circulation heating and melting urea high-tower granulation is produced the fertile method of compound

Technical field the invention belongs to the production of compound fertilizer technical field, relates to a kind of conduction oil circulation heating and melting urea high-tower granulation and produces the fertile method of compound.

It is fertile that the high-tower granulation of background technology prior art is produced compound; Be to utilize urea melting liquid to make fluid carrier, in mixing channel, fully mix forming slip with powder ammonium phosphate, potassium chloride or potassium sulfate and auxiliary material, the prilling granulator through the granulation cat head is separated into droplet; Landing under gravity and buoyancy; With reverse contact of cold air that gets into from the granulation tower bottom, the cooling curing free-falling is a compound fertilizer granule, and the preparation of urea melting liquid wherein is that urea is added in the urea melting jar; Utilize the steam pipe coil in the urea melting jar to heat, abandon it from the steam condensate (SC) that fusion jar steam pipe coil comes out with urea melting.The mode of operation of prior art exists that energy utilization rate is low, the technical problem of water resource waste and environmental pollution.

Summary of the invention the objective of the invention is to solve that prior art exists that energy utilization rate is low, the technical problem of water resource waste and environmental pollution; Provide a kind of conduction oil circulation heating and melting urea high-tower granulation to produce the fertile method of compound, to overcome the deficiency of prior art.

To achieve these goals; Conduction oil circulation heating and melting urea high-tower granulation of the present invention is produced the fertile method of compound, is to utilize urea melting liquid to make fluid carrier, in mixing channel, fully mixes forming slip with powder ammonium phosphate, potassium chloride or potassium sulfate and auxiliary material; Prilling granulator through the granulation cat head is separated into droplet; Landing under gravity and buoyancy, with reverse contact of cold air that gets into from the granulation tower bottom, the cooling curing free-falling is a compound fertilizer granule; Its main points are that the preparation of urea melting liquid is that urea is added in the urea melting jar; The conduction oil that in the coil pipe of urea melting jar, feeds 150～160 ℃ is the urea heating and melting, and the conduction oil that comes out from the coil pipe of urea melting jar returns the heat conducting oil boiler heat cycles and uses, and the concrete operations of urea melting are following:

1), carry out oiling to high tank, observes the high tank liquid level, confirm that oiling puts in place, then igniting heating heat-conducting oil furnace through the low level oil groove;

2), the ON cycle pump, make fully circulation of oil;

3), slowly heating makes oily temperature rise in the boiler to 60-80 ℃, make the water evaporates 20～30 minutes in the oil, persistently overheating then to 150～160 ℃ of coil pipes that get into the urea melting jars, with urea melting;

4), in the thermal process, keep the liquid level of high tank, in time replenish when oil starvation occurring, the low level oil groove keeps half the oil level.

The present invention's beneficial effect compared with prior art: use the heating of conduction oil Automatic Cycle; The inlet temperature of fusion jar is 150～160 ℃; Outlet temperature then is 130～140 ℃, returns and can realize recycle after boiler heats 20 ℃ of temperature difference, and only this item is energy savings in a large number.In addition, conduction oil circulation heating can be practiced thrift the water of a large amount of usefulness because conduction oil heating capable of circulation, heat loss seldom, steam boiler then need consume a large amount of water.The invention solves that prior art exists that energy utilization rate is low, the technical problem of water resource waste and environmental pollution.

Specific embodiment conduction oil circulation of the present invention heating and melting urea high-tower granulation is produced the fertile method of compound; Be to utilize urea melting liquid to make fluid carrier; In mixing channel, fully mix to form slip with powder ammonium phosphate, potassium chloride or potassium sulfate and auxiliary material, the prilling granulator through the granulation cat head is separated into droplet, under gravity and buoyancy, lands; With reverse contact of cold air that gets into from the granulation tower bottom; The cooling curing free-falling is a compound fertilizer granule, and wherein the preparation of urea melting liquid is that urea is added in the urea melting jar, and the conduction oil that in the coil pipe of urea melting jar, feeds 160 ℃ is with the urea heating and melting; The conduction oil that comes out from the coil pipe of urea melting jar returns the heat conducting oil boiler heat cycles and uses, and the concrete operations of urea melting are following:

1), carry out oiling to high tank, observes the high tank liquid level, confirm that oiling puts in place, then igniting heating heat-conducting oil furnace through the low level oil groove;

2), the ON cycle pump, make fully circulation of oil;

3), slowly heating makes the oily temperature rise to 80 ℃ in the boiler, make the water evaporates 20 minutes in the oil, persistently overheating then to 160 ℃ of coil pipes that get into the urea melting jars, with urea melting;

4), in the thermal process, keep the liquid level of high tank, in time replenish when oil starvation occurring, the low level oil groove keeps half the oil level.

The heating of prior steam boiler makes urea melting, and the inlet temperature of fusion tank is 150～160 ℃, becomes discharge of wastewater after the outlet and abandons it; Heat conducting oil boiler Automatic Cycle heating of the present invention makes urea melting; The inlet temperature of fusion tank is 150～160 ℃, and outlet temperature then is 130 ℃-140 ℃, and its residuals temperatures heat energy is capable of using; After 20 ℃ of temperature difference of heating, realized recycle again, only this item is energy savings in a large number.In addition, conduction oil circulation heating can be practiced thrift a large amount of water, because conduction oil heating capable of circulation; Heat loss seldom; Steam boiler then need consume a large amount of water, and producing the fertile device of 400,000 tons of compounds per year with a cover is example, disposes 10 tons of steam boilers; 10 tons of steam boilers per hour consume about 10 side's water, calculate about water consumption 72000 sides according to producing 300 days per year.

Claims (1)

1. a conduction oil circulation heating and melting urea high-tower granulation is produced the fertile method of compound; Be to utilize urea melting liquid to make fluid carrier; In mixing channel, fully mix to form slip with powder ammonium phosphate, potassium chloride or potassium sulfate and auxiliary material, the prilling granulator through the granulation cat head is separated into droplet, under gravity and buoyancy, lands; With reverse contact of cold air that gets into from the granulation tower bottom; The cooling curing free-falling is a compound fertilizer granule, and the preparation that it is characterized in that urea melting liquid is that urea is added in the urea melting jar, and the conduction oil that in the coil pipe of urea melting jar, feeds 160 ℃ is with the urea heating and melting; The conduction oil that comes out from the coil pipe of urea melting jar returns the heat conducting oil boiler heat cycles and uses, and the concrete operations of urea melting are following:

1), carry out oiling to high tank, observes the high tank liquid level, confirm that oiling puts in place, then igniting heating heat-conducting oil furnace through the low level oil groove;

2), the ON cycle pump, make fully circulation of oil;

3), slowly heating makes the oily temperature rise to 80 ℃ in the boiler, make the water evaporates 20 minutes in the oil, persistently overheating then to 160 ℃ of coil pipes that get into the urea melting jars, with urea melting;

4), in the thermal process, keep the liquid level of high tank, in time replenish when oil starvation occurring, the low level oil groove keeps half the oil level.