CN102351523A - Filter used for filtering soot particulates in diesel engine and preparation method thereof - Google Patents

Abstract

The invention relates to a filter used for filtering soot particulates in a diesel engine and a preparation method thereof, especially to a porous honeycomb industrial ceramic body which uses a mixture of iolite and silicon carbide as a matrix. According to the invention, a mixture of 50% of iolite and 50% of silicon carbide is used as a main raw material, and a pore forming agent, a bonding agent, a lubricant, deionized water and the like are used as auxiliary materials; the above-mentioned raw materials are subjected to crushing by ball milling, uniform mixing and vacuum pugmilling so as to obtain a plastic biscuit which is then subjected to extrusion molding, microwave drying and a special hole sealing process and then to high temperature heat treatment so as to obtain a finished product. Since the mixture of iolite and silicon carbide is used as the main raw material for the product, the product has substantially improved physicochemical performance, and the problems that high temperature resistance and thermal shock resistance of an iolite material can not meet demands for practical application and that industrial production of a silicon carbide material is difficult due to a high thermal expansion coefficient of the silicon carbide material are both overcome. Another characteristic of the invention is as follows: a filtering ratio of soot particulates in a diesel engine is more than 95%, and a part of soluble organic components (SOF) can be also filtered. The filter can tolerate a high temperature above 1500 DEG C and enables a thermal expansion coefficient of a material to be effectively reduced, thereby bringing in great convenience for industrial production and reducing industrial production cost.

Description

A kind of filtering bodies that is used for dovice for diesel engine carbon smoke microparticle filtering and preparation method thereof

Technical field

The present invention relates to a kind of filtering bodies that is used for dovice for diesel engine carbon smoke microparticle filtering and preparation method thereof, particularly this kind filtering bodies is to be the porous honeycomb industrial ceramics body of matrix with trichroite and silicon carbide mixture.Its with 50% trichroite and 50% silicon carbide mixture as main starting material; With pore-forming material, caking agent, lubricant and deionized water etc. as subsidiary material; Form the plasticity biscuit through ball mill pulverizing, uniform mixing, vacuum refining mud; Again through extrusion molding, microwave drying, special hole-sealing technology, after high-temperature heat treatment obtains finished product.Product is mainly used in the filtration, purification of diesel oil engine carbon smoke particulate.

Background technology

From the seventies in last century, along with the aggravation and the CO of global petroleum resources shortage ₂Reduce discharging the increase of pressure, occur the situation of power train in vehicle application dieselization abroad.Europe and the Japanese dieselization that has taken the lead in realizing cargo vehicle and motorbus.At present, 40% has adopted diesel motor in the European car annual production, in countries such as France, Spain more up to more than 50%.And the shared market share ratio of present Chinese diesel-powered car user is very low, this structural constraint further developing of Chinese Automobile Industry '.National departments concerned all proposes to widely popularize modern diesel-powered car in the automobile relevant policies of putting into effect in recent years.Appropriateness increases the ratio of diesel-powered car; Though compare diesel engine with petrol motor is a kind of eco-friendly engine; But comparing with the gasoline car that has assembled three-way catalyst, is that the pollution emission of the diesel vehicle of characteristic becomes its important factor of applying of restriction with oxynitride (NOx) and soot particulate (PM).Particularly soot particulate (PM) is tens times of gasoline car.Therefore developing the qualified diesel engine carbon black particulate filter bodies that is used for becomes essentially, and up to now, the filtering bodies that adopts cordierite material to make still can not satisfy practical application in high thermal resistance and heat-shock resistance, and it can soften in the time of 1400 ℃.And adopt carbofrax material because the too high industrial production difficulty that causes of its thermal expansivity.

Chinese invention patent CN1915520A has reported and has adopted silicon carbide to prepare the technology of ceramic particle capturing device as main raw material(s); But this technology is to prepare the fritter filter core earlier; And then bonding assembly unit obtains finished product after firing, and therefore carrying out scale operation has bigger difficulty.

The honeycomb ceramic filter that the employing cordierite material of U.S. Corning company invention makes; In invention is a contribution with milestone character at that time really; But the phenomenon that this cordierite bodies in use scorification often occurs or hardening cracks illustrates that the resistance to elevated temperatures of cordierite material still can not satisfy the demand of practical application.

In sum, the large-scale popularization use of dovice for diesel engine carbon smoke microparticle filtering body needs to solve the problem of two aspects, and an aspect is to want to be fit to the condition of large-scale commercial production, and another aspect is to satisfy the technical indicator of practical application.

Summary of the invention

It is low that the present invention aims to provide a kind of production cost, the production technique environmental protection, and production process is quick, adapts to the large-scale commercial production condition, and various technical indicators can meet wall-flow type soot particle filtering bodies product of practical application and preparation method thereof again simultaneously.Adopting trichroite and silicon carbide mixture is that matrix makes the porous honeycomb filter body; Its with 50% trichroite and 50% silicon carbide mixture as main starting material; With pore-forming material, caking agent, lubricant and deionized water etc. as subsidiary material; Form the plasticity biscuit through ball mill pulverizing, uniform mixing, vacuum refining mud; Again through extrusion molding, microwave drying, special hole-sealing technology, after high-temperature heat treatment obtains finished product.Owing to adopt the main starting material of the mixture of trichroite and silicon carbide as product; The physical and chemical performance of product greatly improves; Both solved cordierite material and still can not satisfy the problem of practical application request, solved the too high problem that causes the industrial production difficulty of carbofrax material thermal expansivity again at high thermal resistance and heat-shock resistance.Product of the present invention reaches more than 95% the dovice for diesel engine carbon smoke microparticle filtering rate; Solubility organic composition (SOF) also can partly obtain filtering; And can anti-high temperature more than 1500 ℃; Effectively reduce the thermal expansivity of material simultaneously; Bring convenience to industrial production, reduced the industrial production cost.

Technical scheme

Filtering bodies with 50% trichroite and 50% silicon carbide mixture as main starting material, with pore-forming material, caking agent, lubricant and deionized water etc. as subsidiary material.

2. filtering bodies is made up of the following materials based on weight proportioning: trichroite and silicon carbide 1; Activity charcoal powder (pore-forming material) 0.01～0.08, methylcellulose gum (caking agent) 0.05～0.1, water glass (caking agent) 0.02～0.04; Paraffin (lubricant) 0.025～0.15, deionized water 0.3～0.5.

3. soot particle filterability>=95% of filtering bodies product, filtration area>=95kg/L, porosity is 75%, working temperature>=1500 ℃, thermal expansivity is 1.2 * 10 ^-6

4. the preparation method of filtering bodies adopts following steps:

(1) raw materials such as trichroite, silicon carbide and gac of certain proportioning are distinguished ball milling, and screening is 200,300 and 400 orders respectively.

(2) press claim 2 described weight proportions and add methylcellulose gum, water glass, paraffin and deionized water, carry out wet ball grinding and mix.

(3) put into vacuum pugmill mixing 2～3 hours, form the plasticity moulded pottery not yet put in a kiln to bake.

(4) put into extrusion machine, under the guiding of mould, form the ceramic honeycomb biscuit of 64 hole/square centimeters.

(5) put into the microwave drying oven drying and shaping then, intersect sealing of hole again.

(6) move and be put in the high-temperature roasting stove, be warmed to 1510 ℃ with 6 ℃/minute heat-up rates, be incubated 50 hours, naturally cool to 100 ℃ then, kiln discharge promptly obtains required finished product.

Described trichroite self-control; Form by silicon, aluminium, magnesium

Described silicon carbide is commercially available

Described activity charcoal powder is commercially available

Described methylcellulose gum is commercially available

Described water glass is commercially available

Described deionized water self-control

The practical implementation method

Below in conjunction with embodiment the present invention is described further

Embodiment 1

Filtering bodies is a raw material with trichroite, silicon carbide, activity charcoal powder, methylcellulose gum, water glass, paraffin, deionized water, and the raw materials in part by weight proportioning consists of: trichroite 0.5; Silicon carbide 0.5; Activity charcoal powder 0.01; Methylcellulose gum 0.05; Water glass 0.02; Paraffin 0.025; Deionized water 0.3; Put into ball mill after taking by weighing in proportion and carry out the wet ball grinding mixing; Put into vacuum pugmill then and formed the plasticity moulded pottery not yet put in a kiln to bake in mixing 2 hours; Put into extrusion machine then; Under the guiding of mould, form the ceramic honeycomb biscuit of 64 hole/square centimeters; Put into the microwave drying oven drying and shaping then; Intersect sealing of hole again; Move and be put in the high-temperature roasting stove; Be warmed to 1510 ℃ with 6 ℃/minute heat-up rates; Be incubated 50 hours, naturally cool to 100 ℃ at last, kiln discharge promptly obtains required finished product.

Embodiment 2

Filtering bodies is a raw material with trichroite, silicon carbide, activity charcoal powder, methylcellulose gum, water glass, paraffin, deionized water, and the raw materials in part by weight proportioning consists of: trichroite 0.5; Silicon carbide 0.5; Activity charcoal powder 0.08; Methylcellulose gum 0.1; Water glass 0.04; Paraffin 0.15; Deionized water 0.5; Put into ball mill after taking by weighing in proportion and carry out the wet ball grinding mixing; Put into vacuum pugmill then and formed the plasticity moulded pottery not yet put in a kiln to bake in mixing 3 hours; Put into extrusion machine then; Under the guiding of mould, form the ceramic honeycomb biscuit of 64 hole/square centimeters; Put into the microwave drying oven drying and shaping then; Intersect sealing of hole again; Move and be put in the high-temperature roasting stove; Be warmed to 1510 ℃ with 6 ℃/minute heat-up rates; Be incubated 50 hours, naturally cool to 100 ℃ at last, kiln discharge promptly obtains required finished product.

The technical indicator of table one, product

Trichroite content	≥40％
		Silicon carbide	45％
The hole length of side	1.1mm
		Wall thickness	0.2
Porosity	75％
		Laterally resistance to compression	2.4Mpa
Vertically resistance to compression	19Mpa
		Filterability	≥95％
Volume density	～0.80Kg/L
		Working temperature	≥1500℃

Claims (5)

1. filtering bodies that is used for dovice for diesel engine carbon smoke microparticle filtering.It is characterized in that this filtering bodies is is the porous honeycomb industrial ceramics body of matrix with trichroite and silicon carbide mixture.

2. filtering bodies as claimed in claim 1 it is characterized in that its with 50% trichroite and 50% silicon carbide mixture as main starting material, with pore-forming material, caking agent, lubricant and deionized water etc. as subsidiary material.

3. filtering bodies as claimed in claim 2 is characterized in that being made up of the following materials based on weight proportioning: trichroite and silicon carbide 1; Activity charcoal powder (pore-forming material) 0.01～0.08; Methylcellulose gum (caking agent) 0.05～0.1; Water glass (caking agent) 0.02～0.04; Paraffin (lubricant) 0.025～0.15, deionized water 0.3～0.5.

4. filtering bodies as claimed in claim 1 is characterized in that filterability>=95%, filtration area>=95kg/L, and porosity is 75%, working temperature>=1500 ℃, thermal expansivity is 1.2 * 10 ^-6

5. the preparation method of filtering bodies as claimed in claim 1 adopts following steps:

(1) raw materials such as trichroite, silicon carbide and gac of certain proportioning are distinguished ball milling, and screening is 200,300 and 400 orders respectively.

(2) add methylcellulose gum, sodium silicate water glass, paraffin and deionized water by the described weight proportion of claim 2, carry out wet ball grinding and mix.

(3) put into vacuum pugmill mixing 1～3 hour, form the plasticity moulded pottery not yet put in a kiln to bake.

(4) put into extrusion machine, under the guiding of mould, form the ceramic honeycomb biscuit of 64 hole/square centimeters.

(5) put into the microwave drying oven drying and shaping then, intersect sealing of hole again.

(6) move and be put in the high-temperature roasting stove, be warmed to 1510 ℃ with 6 ℃/minute temperature rise rates, and be incubated 50 hours, naturally cool to 100 ℃ then, kiln discharge promptly obtains required finished product.