CN101569840A - Method of granulation by spraying melted nicotinamide - Google Patents

Abstract

The invention discloses a method of granulation by spraying melted nicotinamide. The method comprises the following steps: injecting the melted nicotinamide into the spray-granulation tower of a fluidized bed for granulation by a pressure-type spraying nozzle; automatically grading the nicotinamide granules with the granularity being 0.4 to 1.0 mm in the granulation tower by controlling the gas velocity of fluidizing air in the inlet pipe at the lower part of the granulation tower; entering silos through the inlet pipe of the granulation tower of the fluidized bed, and then screening the products within the range of the granularity by a screener; and finally obtaining the nicotinamide granules with the granule size being 0.4 to 1.0 mm. On the one hand, the granular nicotinamide produced by the method of the invention can greatly reduce the dust pollution, moisture absorption and agglomeration occurring to places for packaging, storing, transporting and applying, and on the other hand, the granule sizes of the products are properly distributed so as to ensure the good dispersion of nicotinamide in the following downstream products, such as feed and the like, upon the premise that the following processing technique, such as feed and the like, remains unchanged.

Description

A kind of method of granulation by spraying melted nicotinamide

Technical field

The invention provides a kind of method of granulation by spraying melted nicotinamide, belong to field of fine chemical.

Background technology

Niacinamide (Nicotinamide) is a vitamin B3, chemical name 3-pyridine carboxamide, molecular formula C₆H₆N₂O, molecular weight 122.11,129～131 ℃ of fusing points, white crystalline powder, soluble in water or ethanol.Niacinamide is widely used in medicine, food, the feed industry, is the indispensable nutritional labeling of human body and animal growth.In addition, niacinamide also can be used as plant growth regulator, hair growth promoting agent, hair dyeing growth regulator, polymer stabilizer, electroplate liquid additive and biochemical reagents etc.

At present, the production method of domestic and international industrial niacinamide is a raw material with 3-picoline, 2-methyl-5-ethylpyridine or quinoline mainly, by oxidant direct oxidation or catalytic oxidation, ammoxidation generation nicotinic acid or cigarette nitrile, obtain niacinamide by hydrolysis of cigarette nitrile or niacinamide usp dehydration again.Regardless of adopting above-mentioned which kind of approach, final niacinamide all is to obtain after concentrating (as evaporation), filtration, drying by the aqueous solution, is powdery product by the niacinamide that has explained hereafter now, and its particle diameter is below 0.2mm.Because product cut size is very little, packing, field of employment dust from flying, the workshop dust pollution is serious, causes product loss on the one hand, and even more serious is that workman's health is damaged.And in accumulating, use,, easily reunite because product cut size is very little, and the easy moisture absorption and luming of niacinamide itself, the niacinamide of this reunion caking during as uses such as additive or auxiliary agents dispersiveness bad, have a strong impact on the downstream product quality.

Summary of the invention

The invention provides a kind of method of granulation by spraying melted nicotinamide.By this method, can obtain the granular niacin product of particle diameter at 0.2～0.8mm, reduce the moisture absorption caking phenomenon of production, field of employment dust pollution and storage and transport process, improve niacinamide as the dispersiveness of additive in subsequent product.

The present invention is achieved by the following technical solution:

The fusion in melting kettle of niacinamide powder, temperature are 140～160 ℃, and pressure is normal pressure; The niacinamide of fusion is sent into the nozzle that is installed on fluidized bed spray granulation tower middle and upper part and is atomized into drop by high-pressure pump, spray into fluid bed downwards, the high temperature drop contacts with low temperature niacinamide particle that is in fluidized state and the Cryogenic air that upwards flows that is used for fluidisation in fluid bed, drop attaches on the particle, solidify because temperature reduces, make grain diameter become big; The fragmentation because fluidized particles runs foul of each other simultaneously also can produce the part fine grained and be carried secretly discharge by flow air upwards via granulation tower top gas outlet; The niacinamide powder of discharging enters cyclone separator with AIR MIXTURES and carries out gas-solid the separation, and air is entered by the gas outlet tube on cyclone separator top and enters atmosphere after sack cleaner further separates the niacinamide dust; The niacinamide powder of being discharged by cyclone dip-leg returns fluid bed, is regularly collected by the niacinamide dust that sack cleaner separates, and returns melting kettle again as granulating raw material; The air that is used for fluidized particles enters fluid bed by fluid bed bottom blast pipe, by air velocity in the control blast pipe less than the carrying velocity of niacinamide product minimum particle size particle, realization bulky grain niacinamide separates with the fluid bed small particles, be that the niacinamide particle that carrying velocity is higher than air velocity is separated from the air inlet pipe of fluid bed, drop to the feed bin that links to each other with fluid bed air inlet pipe bottom, send to screening at last, particle diameter returns the thawing still greater than the niacinamide particle of 0.8mm, particle diameter returns the granulation again of mist projection granulating tower fluid bed less than the niacinamide particle of 0.2mm, and particle diameter is sent to packing at the niacinamide particle of 0.2～0.8mm as product;

Described nozzle adopts the pressure type atomizer, and pressure is: 0.1～20MPa, and preferred pressure is 0.5～10MPa;

The invention has the beneficial effects as follows:

(1) adopt the pressure type atomizer, the atomized drop good dispersion degree, liquid-drop diameter is in 35～250 mu m ranges, for guaranteeing that product granularity evenly provides guarantee;

(2) owing to adopt fluidized bed process, the granulation tower endoparticle is in fluidized state all the time, and the bed face particle is brought in constant renewal in, and atomized drop is coated in the niacinamide particle surface equably, and the bed endoparticle can be realized evenly growing up, and particle diameter distributes;

(3), realize the automatic classification of particle by appropriate design fluid bed bottom air inlet pipe gas velocity.Have only after fluid bed endoparticle diameter reaches certain requirement and could separate, enter feed bin, thereby reduced follow-up screening load, cut down the consumption of energy by air inlet pipe.

Description of drawings

Fig. 1 is a granulation by spraying melted nicotinamide process chart of the present invention.

The specific embodiment

The present invention is further described below in conjunction with accompanying drawing.

Embodiment 1

With reference to Fig. 1, a kind of method of granulation by spraying melted nicotinamide, this method step comprises:

The fusion in melting kettle (1) of niacinamide powder, temperature is 140-160 ℃, pressure is normal pressure; The fusion niacinamide is sent into the nozzle of fluidized bed spray granulation tower (3) middle and upper part and is atomized into drop by high-pressure pump (2), spray into fluid bed downwards, the high temperature drop contacts with low temperature niacinamide particle that is in fluidized state and the Cryogenic air that upwards is used for fluidisation in fluid bed, drop attaches on the particle, solidify because temperature reduces, make grain diameter become big; The fragmentation because fluidized particles runs foul of each other simultaneously also can produce the part fine grained and be carried secretly discharge by flow air upwards via granulation tower top gas outlet; The niacinamide powder of discharging enters cyclone separator (4) with air mixture and carries out gas-solid the separation, and air is entered by the gas outlet tube on cyclone separator top and enters atmosphere after sack cleaner (5) further separates the niacinamide dust; The niacinamide powder of being discharged by cyclone dip-leg returns fluid bed, is regularly collected by the niacinamide dust that sack cleaner separates, and returns melting kettle (1) again as granulating raw material; The air that is used for fluidized particles enters fluid bed by fluid bed bottom blast pipe, by air velocity in the control blast pipe less than the carrying velocity of certain particle size particle, realize the separation of bulky grain niacinamide, be that the niacinamide particle that carrying velocity is higher than air velocity is separated from the air inlet pipe of fluid bed, drop to the feed bin (6) that links to each other with fluid bed air inlet pipe bottom, send to screening machine (7) screening at last, particle diameter returns thawing still (1) greater than the niacinamide particle of 0.8mm, particle diameter returns the granulation again of fluidized bed spray granulation tower (3) bottom fluid bed less than the niacinamide particle of 0.2mm, and particle diameter is sent to packing at the niacinamide particle of 0.2～0.8mm as product.

Embodiment 2

According toembodiment 1 production craft step, niacinamide melt pelletization production capacity can reach 200 kilograms/hour, and product order number is between the 30-80 order, and product need not further drying, and directly packing gets final product.

The present invention proposes a kind of method of granulation by spraying melted nicotinamide, can produce particle diameter 0.2～0.8mm graininess niacinamide, greatly reduce the dust pollution and the moisture absorption caking of packing, accumulating and use occasion on the one hand, do not changing under the production technology prerequisite such as follow-up feed on the other hand, suitable product cut size distributes and has guaranteed the good dispersion of niacinamide in subsequent downstream products such as feed.

Claims (5)

1, a kind of method of granulation by spraying melted nicotinamide, it is characterized in that: spray into the stratum granulosum in the granulation tower after the atomizer atomizing of fusion niacinamide through being installed on fluidized bed spray granulation tower middle and upper part downwards, atomized drop attaches to the niacinamide particle surface that is in fluidized state and solidifies and make particle grow up; The air that is used for fluidized particles enters the fluidized particles layer by granulation tower bottom blast pipe, realizes the automatic classification of bulky grain niacinamide and fluid bed small particles by air velocity in the control blast pipe less than the carrying velocity of niacinamide product minimum particle size particle.

2, the method for a kind of granulation by spraying melted nicotinamide as claimed in claim 1 is characterized in that: described atomizer is the pressure type atomizer, also high-pressure pump need be set before the described atomizer.

3, the method for a kind of granulation by spraying melted nicotinamide as claimed in claim 1 is characterized in that: the bulky grain niacinamide of separating through the fluidization air air inlet pipe also needs through screening, thereby obtains the niacinamide product that desired particle size distributes.

4, the method for a kind of granulation by spraying melted nicotinamide as claimed in claim 3, it is characterized in that described screening is particle diameter and returns the thawing still greater than the niacinamide particle of 0.8mm, particle diameter returns the granulation again of mist projection granulating tower fluid bed less than the niacinamide particle of 0.2mm, and particle diameter is sent to packing at the niacinamide particle of 0.2～0.8mm as product.

5, the method for a kind of granulation by spraying melted nicotinamide as claimed in claim 1 is characterized in that: because the fluidized particles fragmentation that runs foul of each other, also can produce the part fine grained and be carried secretly discharge by flow air upwards via granulation tower top gas outlet; The niacinamide powder of discharging enters cyclone separator with AIR MIXTURES and carries out gas-solid the separation, and air is entered by the gas outlet tube on cyclone separator top and enters atmosphere after sack cleaner further separates the niacinamide dust; The niacinamide powder of being discharged by cyclone dip-leg returns fluid bed, is regularly collected by the niacinamide dust that sack cleaner separates, and returns melting kettle again as granulating raw material.

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