CN100523446C - Ceramic honeycomb filter - Google Patents
Ceramic honeycomb filter Download PDFInfo
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- CN100523446C CN100523446C CNB2006101054254A CN200610105425A CN100523446C CN 100523446 C CN100523446 C CN 100523446C CN B2006101054254 A CNB2006101054254 A CN B2006101054254A CN 200610105425 A CN200610105425 A CN 200610105425A CN 100523446 C CN100523446 C CN 100523446C
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- ceramic honeycomb
- runner
- honeycomb filter
- next door
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Abstract
A ceramic honeycomb filter comprising a ceramic honeycomb structure having porous partition walls defining a plurality of flow paths for flowing an exhaust gas through the porous partition walls to remove particulates from the exhaust gas, the predetermined flow paths among the flow paths being sealed at their ends, a catalyst being carried by the porous partition walls, the porous partition walls having a porosity of 60-75% and an average pore diameter of 15-25 mu m when measured according to a mercury penetration method, and the maximum of a slope Sn of a cumulative pore volume curve of the porous partition walls relative to a pore diameter obtained at an n-th measurement point being 0.7 or more, the Sn being represented by the following formula (1): <DF NUM='(1),'>Sn = - (Vn- Vn-1)/log Dn - log (Dn-1)u </DF> wherein Dn is a pore diameter ( mu m) at an n-th measurement point, Dn-1 is a pore diameter ( mu m) at an (n-1)-th measurement point, Vn is a cumulative pore volume (cm<3>/g) at an n-th measurement point, and Vn-1 is a cumulative pore volume (cm<3>/g) at an (n-1)-th measurement point.
Description
The application is that to be called " ceramic honeycomb filter ", application number be dividing an application of 02154555.3 application for a patent for invention for name that Hitachi Metal Co., Ltd. and Hino Motor Ltd. submitted on September 13rd, 2002.
Technical field
The present invention relates to a kind of particles contained ceramic honeycomb filter of filtering diesel exhaust that is used for.
Background technique
For the particulate that the filtering diesel emission goes out, studying the ceramic honeycomb filter that a kind of use has porous matter next door, make the waste gas that contains particulate by its next door filtering.This filter is commonly referred to as particulate collecting filter (diesel particulate filter).Fig. 2 (a) is that Fig. 2 (b) is this cut-away section side view as the plan view of particulate collecting filter with ceramic honeycomb filter 11, and Fig. 3 is the mode sectional drawing of ceramic honeycomb filter 11 shown in Figure 2.As shown in Figures 2 and 3, be ceramic honeycomb filter 11 cylindraceous approximately and have outer wall 11a and be contained in the porous matter next door 11b of outer wall 11a inboard, end, inflow side 11d and the 11e place, end, outflow side of the runner 11c that surrounds at the porous matter next door 11b of outer wall 11a and porous matter next door 11b or adjacency are alternately sealed by sealing material 12a, 12b.The outer wall 11a of ceramic honeycomb filter 11 is contained in the metal shell 14 under the state fixing by fixed block 13a, 13b.
The waste gas that contains particulate enters runner 11c (being represented by 10a) from open end, the inflow side 11d of ceramic honeycomb filter 11, passes porous matter next door 11b, through the runner 11c of adjacency, discharges (being represented by 10b) from open end, outflow side 11e again.In this process, contained particulate is collected in the pore place of porous matter next door 11b in the waste gas.In a single day the particulate that is collected excessive accumulating occur in ceramic honeycomb filter 11, then can cause the pressure drop of filter 11 to be risen, and engine output descends.Therefore, the particulate that generally adopts external-burning devices such as external electrical heaters or burner regularly to burn and collect makes ceramic honeycomb filter 11 carry out Regeneration Treatment.When this ceramic honeycomb filter 11 is used as the particulate collecting filter, usually adopt dual mode: (a) use a pair of ceramic honeycomb filter, use another filter to replace regenerated way during therein filter regeneration, and (b) when collecting particulate, make particle burning in the cyclic regeneration mode of regeneration filter etc. by catalyst action.
For this particulate collecting filter, the collecting efficiency of pressure drop and particulate and may acquisition time (begin acquire a certain degree time) from particulate collecting to pressure drop the most important.Collecting efficiency and pressure drop are reciprocal relationship, and collecting efficiency high pressure drop more is big more, and collecting efficiency can decrease when pressure drop reduces.For satisfying this characteristic that the filter of reciprocal relationship is arranged, the porous matter next door porosity and average pore size how to control ceramic honeycomb filter were being studied in the past.And to how satisfying the particulate that to collect with the efficient combustion ceramic honeycomb filter, and can not study because of the necessary condition of the thermal stress damage that produces in the combustion process etc.
Based on this present situation, the special pore that discloses a kind of next door for fair 3-10365 number by the aperture be that the aperture of 5-40 μ m and macropore that the aperture is 40-100 μ m are formed, little hole count is big hole count 5-40 times exhaust emission control filter, and it is a kind of high collection rate that keeps in the early stage, the lower exhaust emission control filter of pressure drop simultaneously.Pore average pore size on this filter next door is greater than 15 μ m, and the accumulation pore volume is preferably in 0.3-0.7cm
3In/g the scope.Though special fair 3-10365 patent is not put down in writing the porosity P (volume %) in next door, if the density p of employed steinheilite is 2.5g/cm among the embodiment
3, then can be according to accumulation pore volume V (cm
3/ the formula of g) deriving calculates the porosity P in next door.
Described formula is as follows:
P(％)＝100Vρ/(1+Vρ)
By above formula, the optimum range (0.3-0.7cm of the accumulation pore volume of pore will be had on the next door
3/ g) be converted into the porosity of 42.8-63.6 volume %.
Disclose by the control porosity and average pore size for special public clear 61-54750 number, can finish design from high collection rate to low collection rate type filter.As the public clear 61-54750 of spy number best instantiation, Fig. 8 has provided the porosity and the average pore size that connects in 1,5, the 6 and 4 each point zones.The porosity and the average pore size of each point are as follows.
| The point | The porosity (capacity %) | Average pore size (μ m) |
| 1 | 58.5 | 1 |
| 5 | 39.5 | 15 |
| 6 | 62.0 | 15 |
| 4 | 90.0 | 1 |
Te Kaiping 9-77573 number a kind of honeycomb molded body is disclosed, it has the average pore size of the porosity and the 25-40 μ m of 55-80%, the pore in next door is that the aperture of 5-40 μ m and macropore that the aperture is 40-100 μ m are formed by the aperture, little hole number is 5-40 a times of big hole number, and this honeycomb molded body has high collection rate, low pressure loss and low-thermal-expansion rate.
Yet, though the optimization in the porosity, average pore size and aperture, next door by ceramic honeycomb structure, the pressure drop that to a certain extent can the balance filtration device and the collecting efficiency of particulate, but in case add all apertures of macro porosity peace, the intensity in filter porous matter next door must reduce.This mainly is because the intensity in porous matter next door and its porosity and average pore size are reciprocal relationship.Particularly in order to obtain the filter of low pressure loss, when the porosity more than 60% or average pore size when 15 μ m are above, the intensity in its porous matter next door can significantly reduce.Therefore, be difficult to obtain the strong ceramic honeycomb filter of durability, this filter has low pressure loss and high collection rate, and the mechanical stress of the fastening and vibration generation when it can be because of the thermal stress that produces during with filter as the collection particulate of diesel engine and thermal shock and by assembling etc. is damaged.
When making the regeneration of honeycomb filter in the past after collecting particulate, as shown in Figure 3, because waste gas passes the runner of next-door neighbour's outer wall 11a, the ignition heat that therefore is collected particulate can be dispersed to metal shell through outer wall 11a and fixed component 13a, 13b.Therefore,, thereby cause breaking, and because of external temperature is difficult to rise, so problems such as particle burning is not thorough can occur because of filter appears in the thermal stress effect because the central part of filter 11 is excessive with outside temperature gradient.
As shown in Figures 2 and 3, in existing ceramic honeycomb filter, because the exterior edge face of the sealing material of waste gas inflow side is the plane, so particulate can be deposited in the exterior edge face of inflow side sealing material.And because the cohesive force of particulate is very strong, so the accumulation body of particulate can increase gradually.If it is big that the accumulation body of particulate becomes, then cause the inflow side runner to diminish, the pressure drop of filter is risen.Finally the particulate collecting time can be shortened, loaded down with trivial details filter regeneration must be carried out.
Summary of the invention
Therefore, the object of the present invention is to provide a kind of have superior mechanical strength and durability, the while can prolong the particulate collecting time and reduce the ceramic honeycomb filter of pressure drop.
In view of described purpose, the inventor waits by rationally limiting the pore size distribution range in the porous matter next door of ceramic honeycomb structure after deliberation, and improvement encapsulating method, found that pressure drop is low, collection rate is high and the high optimization regeneration efficiency of intensity, thereby obtained to collect for a long time the ceramic honeycomb filter of particulate.
Promptly, ceramic honeycomb filter of the present invention is made of the ceramic honeycomb structure with porous matter next door of dividing many runners, waste gas passes the particulate in the described porous matter next door filtering waste gas, wherein, seal the end of defined runner in the described runner, under the situation of measuring described porous matter next door by mercury penetration method, its porosity is that 60-75% and average pore size are 15-25 μ m, the maximum value of the gradient Sn of the accumulation pore volume distribution curve in the described next door of the fine pore of relative n test point is more than 0.7, and the gradient of described accumulation pore volume distribution curve is represented by following formula (1):
Sn＝-(V
n-V
n-1)/[logD
n-log(D
n-1)] (1)
(in the formula: Dn is the fine pore (μ m) of n measuring point,
D
N-1Be the fine pore (μ m) of n-1 measuring point,
Vn is the accumulation pore volume (cm of n measuring point
3/ g),
Vn-1 is the accumulation pore volume (cm of n-1 measuring point
3/ g),
And the material of described ceramic honeycomb filter is made of steinheilite, mullite, alumina, silicon nitride, silicon carbide, aluminium nitride, lithium alumina silicate, aluminium titanates or zirconium oxide,
The maximum value of the gradient Sn of the accumulation pore volume distribution curve of described porous matter fine pore is more than 0.9, the porosity in described porous matter next door is 65-70%, described porous matter next door average pore size is 18-22 μ m, and its Main Ingredients and Appearance is in fact by the SiO of 42-56 quality %
2, 30-45 quality % Al
2O
3And the chemical composition of the MgO of 12-16 quality % formation, the main composition of crystallised phase is a steinheilite.
Also have, ceramic honeycomb filter of the present invention is made of the ceramic honeycomb structure with porous matter next door of dividing many runners, waste gas passes the particulate in the described porous matter next door filtering waste gas, wherein, seal the end of defined runner in the described runner, described porous matter next door maintains catalyzer, under the situation of measuring described porous matter next door by mercury penetration method, its porosity is that 60-75% and average pore size are 15-25 μ m, the maximum value of the gradient Sn of the accumulation pore volume distribution curve in the described next door of the fine pore of relative n test point is more than 0.7, and the gradient of described accumulation pore volume distribution curve is represented by following formula (1):
Sn＝-(V
n-V
n-1)/[logD
n-log(D
n-1)] (1)
(in the formula: Dn is the fine pore (μ m) of n measuring point,
D
N-1Be the fine pore (μ m) of n-1 measuring point,
Vn is the accumulation pore volume (cm of n measuring point
3/ g),
Vn-
1Be the accumulation pore volume (cm of n-1 measuring point
3/ g),
And the material of described ceramic honeycomb filter is made of steinheilite, mullite, alumina, silicon nitride, silicon carbide, aluminium nitride, lithium alumina silicate, aluminium titanates or zirconium oxide.
Promptly, ceramic honeycomb filter of the present invention is made of the ceramic honeycomb structure with porous matter next door of dividing many runners, waste gas passes the particulate that contains in the described porous matter next door filtering waste gas, wherein, seal the end of regulation runner in the described runner, and near the runner the periphery wall seals with sealing material at two end part, the length that described sealing material begins from the filter end face is at below 8.2% of filter total length, and the described runner of sealing both ends be present in from outside in the radial direction length range of maximum 5x next door, thoughtful center spacing.
At this, the length that begins from the end face of the sealing material that seals near the runner the described periphery wall at two end part is at below 3.3% of ceramic honeycomb filter length overall, near the runner the sealed periphery wall in two ends be from the periphery wall of honeycomb filter end face towards the center of honeycomb filter end face, be present in the runner of the length range of maximum 3x (next door spacing).
Also have, preferably, the periphery wall of described ceramic honeycomb filter is that the colloidal silica by steinheilite particle and existence betwixt constitutes.
In the end that utilizes sealing material sealing runner, after the opening portion of one distolateral regulation of honeycomb molded body utilizes resinous mask to cover, the degree of depth of dipping regulation in sealing material powder slurry is removed resin system mask, and is fired sealing material after powder slurry drying.
The manufacture method of ceramic honeycomb filter of the present invention, its can plasticization pottery quantitatively the mixture extrusion molding be cellular and fire, and become ceramic honeycomb structure, and the two end part of the runner of described ceramic honeycomb structure are alternately sealed, it is characterized in that, from outside circumferential center, the two end part of the runner of existence seal from the length below 8.2% of filter end face with the filter total length in the scope of the radial direction length of maximum 5 * next door spacing.
Preferably, seal from the length below 3.3% of filter end face with the filter total length, in addition, from outside circumferential center, the two end part of the runner of existence seal in the scope of the radial direction length of maximum 3 * next door spacing.
The next door that sealing material has the honeycomb molded body of said structure has high porosity and distinct pore-size distribution, and is more near the pore proportion of average pore size.Therefore, ceramic honeycomb filter of the present invention has low pressure loss and high strength.
Description of drawings
Fig. 1 (a) is an embodiment's of expression honeycomb molded body plan view;
Fig. 1 (b) is the partial cut away side views of honeycomb molded body among Fig. 1 (a);
Fig. 2 (a) is the plan view of an embodiment in the filter of expression use honeycomb molded body;
Fig. 2 (b) is the partial cut away side views of Fig. 2 (a) middle filtrator;
Fig. 3 represents that waste gas flows into the section sketch map of ceramic honeycomb filter;
Fig. 4 is a plotted curve of representing the relation of fine pore of being tried to achieve by mercury penetration method and the gradient Sn that accumulates the pore volume distribution curve;
Fig. 5 is the contract plotted curve of relation of intensity of the gradient Sn maximum value of expression accumulation pore volume distribution curve and A axial compression;
Fig. 6 for expression embodiment 1 and 2 and reference example 1 in the plotted curve of fine pore and the relation of the gradient Sn of accumulation pore volume distribution curve of honeycomb molded body;
Fig. 7 is the side view of another example in the expression ceramic honeycomb filter of the present invention;
Fig. 8 is the A-A sectional drawing of Fig. 7;
Fig. 9 (a) is another embodiment's of expression ceramic honeycomb filter of the present invention partial cut away side views;
Fig. 9 (b) is the partial cut away side views of another embodiment in the expression ceramic honeycomb filter of the present invention;
Fig. 9 (c) is the partial cut away side views of another embodiment in the expression ceramic honeycomb filter of the present invention;
Fig. 9 (d) is the local end face side view of another embodiment in the expression ceramic honeycomb filter of the present invention;
Figure 10 represent embodiment 1 and 2 and the accumulation pore volume of the honeycomb molded body that obtains of reference example 1 and mercury penetration method setting value between the plotted curve that concerns;
Figure 11 is the particle size distribution figure of pore creating material.
Embodiment
Among the present invention, by following formula (1) about the accumulation pore volume curve (with the transverse axis is the aperture, is the curve of the graphical representation of accumulation pore volume with the longitudinal axis) in the next door of honeycomb molded body:
Sn＝-(Vn-V
n-1)/[logDn-log(D
n-1)] (1)
(in the formula: Dn is the fine pore (μ m) of n measuring point,
D
N-1Be the fine pore (μ m) of (n-1) individual measuring point,
Vn is the accumulation pore volume (cm of n measuring point
3/ g),
V
N-1Be the accumulation pore volume (cm of (n-1) individual measuring point
3/ g),
Sn is the gradient of the accumulation pore volume distribution curve of n the relative fine pore of measuring point.) expression the Sn maximum value greater than 0.7.Its reason is as follows,
The intensity of ceramic honeycomb structure not only depends on the porosity and average pore size, also depends on pore-size distribution.Even particularly because the pore-size distribution rapid change (by improving the uniformity of pore size), the porosity more than 60% and average pore size more than 15 μ m, still can obtain high-intensity ceramic honeycomb structure.
The gradient Sn of the porosity of ceramic honeycomb structure, average pore size and accumulation pore volume distribution curve adopts Micromeritics system autopour (オ-ト Port ア) III9410, is measured by mercury penetration method.When adopting mercury penetration method, in the mensuration groove of earlier sample being packed into, after the decompression, importing mercury and pressurization are tried to achieve fine pore and the relation of accumulating pore volume from pressure and the mercury volume that is pressed into the sample pore in groove.If pressure strengthens, mercury then can immerse in the finer pore, measures the volume of the fine pore suitable with pressurization.Therefore, can draw determination data by order from hole, big thin footpath to little fine pore.
From the fine pore Dn-1 that measures (n-1) the individual measuring point that begins and fine pore Dn that accumulates pore volume Vn-1 and (n) individual measuring point and accumulation pore volume Vn, utilize following formula (1) to try to achieve the gradient Sn of n measuring point.At Fig. 4 is a middle example having represented the measurement result of Sn.In Fig. 4, some a is the fine pore D by the 1st and the 2nd measuring point
1, D
2With accumulation pore volume V
1, V
2The gradient S1[(V that tries to achieve
1-V
2)/(logD
1-logD
2)], some b is the fine pore D by the 2nd and the 3rd measuring point
2, D
3With accumulation pore volume V
2, V
3The gradient S2[(V that tries to achieve
2-V
3)/(logD
2-logD
3)].The distribution of the gradient Sn of accumulation pore volume distribution curve as shown in Figure 4 as can be known, if the maximum value less than 0.7 of Sn, then pore size distribution range is wider, if the maximum value of Sn greater than 0.7, then pore size distribution range is very narrow.
If pore size distribution range is wider, thick pore increases can cause the intensity reduction, and in addition, particulate stops up pore becomes the increasing proportion that pressure drop increases the fine pore of reason.Therefore, be difficult to make low pressure loss and high strength simultaneously and deposit.To this,,,, make low pressure loss and the high strength while and deposit so can reduce the ratio of thick pore and fine pore because pore-size distribution is very narrow and small if the maximum value of Sn is greater than 0.7.This point can be learnt from Fig. 5 of relation of intensity relative value is contracted in the maximum value of the gradient Sn of expression accumulation pore volume distribution curve and A axial compression.As shown in Figure 5, when the maximum value of Sn greater than 0.7 the time, the A axial compression intensity level that contracts is more than 1.5 times of existing product intensity level (as the maximum value of Sn 0.6 when following).That is, when the maximum value of Sn as can be known greater than 0.7 the time, the mechanical strength of ceramic honeycomb structure significantly improves.For obtaining low pressure loss and high strength simultaneously, the maximum value of Sn is more preferably greater than 0.9.
The porosity of ceramic honeycomb structure is in the 60-75%.The porosity is lower than at 60% o'clock, and the pressure drop meeting of filter is too high, surpasses at 75% o'clock, and not only the intensity of filter can reduce, and the collecting efficiency of particulate also will decrease simultaneously.The pressure drop of filter was lower when the porosity 65% was above.In addition, when the porosity 70% when following, can further reduce the intensity and the particulate collecting efficient of filter.Therefore, the optimum range of the porosity should be 60-75%.
The pore average pore size that exists at ceramic honeycomb structure is 15-25 μ m.During average pore size less than 15 μ m, it is too high that filter can pressure drop occur, and when surpassing 25 μ m, not only the intensity of filter can reduce, simultaneously owing to collect less than atomic little particle, so particulate collecting efficient also reduces.For obtaining this reciprocal property of low pressure loss and high strength simultaneously, the optimum range of average pore size should be 18-22 μ m.
The main chemical of porous ceramic that constitutes ceramic honeycomb structure is in fact by the SiO of 42-56 quality %
2, 30-45 quality % Al
2O
3And the compositions such as MgO of 12-16 quality %, the Main Ingredients and Appearance of crystallised phase preferably adopts steinheilite.Ceramic honeycomb filter of the present invention utilizes the owned low thermal expansion characteristics of steinheilite, also is difficult to produce and breaks even apply thermal shock.But the present invention is not limited to use steinheilite, also can use other to have stable on heating pottery, as materials such as mullite, alumina, silicon nitride, silicon carbide, aluminium nitride, lithium alumina silicate, aluminium titanates, zirconium oxides.
When filter regeneration, be the efficient combustion particulate, (a) length that begins from sealing material filter end face with near the two ends of the runner sealing material sealing filter outer wall, (b) is less than 8.2% of filter total length, and the length setting that (c) makes sealed at both ends runner is advisable in the radial direction length range of maximum 5x next door spacing from the outer wall to the center.Its reason is, because waste gas can not flow into sealed at both ends runner, therefore can make the runner of sealing play the effect of heat insulation air layer, suppress from of the thermal radiation of filter outer wall to metal shell, thus can the collected particulate of efficient burning.In addition,, can suppress the pressure drop of filter to greatest extent, prevent that engine performance from descending by sealed at both ends runner is set.
The length that begins by filter end face from sealing runner sealed at both ends material the filter total length 8.2% in, can suppress the ignition heat of particulate with the degree that can ignore by sealing material dispersing to metal shell.The length that begins from the filter end face when sealing material surpass the filter total length 8.2% the time, can not ignore particle burning heat to the dispersing of metal shell, the particle burning of collection is not thorough, will cause the reduction of filter regeneration rate.
Because the flow channel length of two end part sealings is set in from the outer wall to the center in the radial direction length range of maximum 5x next door spacing, so can be to greatest extent the pressure drop of filter be suppressed at minimum degree.If but the flow channel length of two end part sealing surpasses the radial direction length range of maximum 5x next door spacing from the outer wall to the center, will reduce the ratio in the next door with filter function relatively, thereby cause the pressure drop of filter to be risen.
The length that begins near the filter end face of the runner two end part sealing material the sealing filter outer wall is preferably less than 3.3% of filter length overall.Thus, near the runner the filter outer wall plays the effect of heat insulation air layer can be bigger, and the heat that diffuses to metal shell from the filter outer wall can further reduce, the collected particulate that can burn more efficiently, and the regeneration rate of filter will further improve.
Near the flow channel length sealed at both ends outer wall is controlled at from the outer wall to the center in the radial direction length range of maximum 3x next door spacing, can further reduces the pressure drop of filter thus.As a result, can reduce the back pressure of motor, thereby further improve the performance of motor.
Ceramic honeycomb structure of the present invention can be by following technology manufacturing.At first, in ceramic material powder, add the pore-creating material of the porosity in the 60-75% scope behind the sintering, the Mean particle diameter of described pore-creating material more than 20 μ m, particularly in the 40-80 mu m range and particle diameter 20-100 μ m account for more than 50%.As required, shaping aids such as Bond, oiling agent are blended in this mixture, add water and make the quantitative mixture of plasticization.With described quantitative mixture extrusion molding, form the formed body of honeycombed structure, after the oven dry, the pore-creating material is removed in burning.Secondly, sintered moulded body is to obtain to have in the next door the intrinsic fine pore of pottery and by removing the ceramic honeycomb structure of the pore that the pore-creating material forms.Like this, ceramic products by original fine pore with (Mean particle diameter is more than 20 μ m, and particle diameter 20-100 μ m accounts for more than 50% by making the consistent pore-creating material of particle diameter.) combination of formed pore, the average fine pore in next door can be controlled in the 15-25 mu m range, simultaneously, the maximum value of the Sn of expression pore-size distribution inclined degree can be controlled at more than 0.7.Particularly for cordierite ceramic owing to itself just have the fine pore of 1-20 μ m, so with Mean particle diameter be more than the 20 μ m and the pore-creating material that accounts for more than 50% of particle diameter 20-100 μ m combined, its effect is best.
The pore-creating material is graphite, wheat flour, toner etc., preferably carry out classification with form Mean particle diameter more than 20 μ m, particle diameter 20-100 μ m accounts for the size distribution more than 50%.In addition, when using toner, create conditions by adjusting it, preferably also reach Mean particle diameter more than 20 μ m, particle diameter 20-100 μ m accounts for the size distribution more than 50%.
If because the pore-creating material is spherical for being similar to, then formed pore also will be circular in the next door, so can reduce the stress of pore is concentrated, and produced honeycomb molded body with superior mechanical intensity.In addition, if the pore-creating material is a hollow body, then is easy to burning and removes the pore-creating material.Therefore, when the pore-creating material is removed in burning, the problem that the next door can not occur chapping, and can improve the rate that manufactures a finished product.
This paper will introduce the present invention in detail by following specific embodiment, but the present invention should not be limited to this.
For manufacturing has SiO by quality 49-51%
2, quality 35-37% Al
2O
3And the steinheilite of the MgO of quality 13-15% formation Main Ingredients and Appearance, need in white clay powder, calcined kaolin powder, alumina powder, aluminium-hydroxide powder, silica powder and talcum powder, distinguish and quantitatively mix the spherical resin powder that adds Bond, oiling agent and be used as pore creating material.In the mixture of gained, add water, make the quantitative mixture of plasticization.With the cellular and oven dry of this quantitative mixture compacting cylindrical shape.
In Figure 16, represented particle size distribution as the spherical resin powder of pore creating material.In addition, the particle diameter ratio of the Mean particle diameter of spherical resin powder and 20-100 μ m sees the following form.
| Pore creating material | Mean particle diameter (μ m) | The particle diameter ratio (quality %) of 20-100 μ m |
| |
64 | 75 |
| |
62 | 62 |
| |
52 | 48 |
With 1350-1440 ℃ temperature sintering gained formed body, as shown in Figure 1, produce the various cordierite material honeycomb molded bodies 10 that constitute by porous ceramic next door 3 and through hole 2.The diameter of the honeycomb molded body 10 of gained is 143mm, and length is 152mm, and the wall thickness in next door is 0.3mm, every 1cm
2The quantity of runner is 46.
The particle diameter of particle diameter by adjusting ceramic material powder and proportioning, pore-creating material and adding quantity, molding condition, sintering condition etc. have been made embodiment 1 and 2 and the honeycomb molded body of reference example 1.Adopt Micromeritics system autopour III9410, measure the fine pore of various ceramic honeycomb structures by mercury penetration method.The accumulation pore volume of gained and the relation between the mercury pressure setting value are as shown in figure 10.The relation of fine pore and setting pressure is as follows: (in the formula: α is the surface tension of mercury to fine pore=-4 α cos θ/P; θ is the wrapping angle of mercury and solid, and P is a setting pressure.)。Because 4 α cos θ are constant, so fine pore and setting pressure are inverse relation.In addition, the accumulation pore volume is the weight that is pressed into the volume/sample of mercury.As shown in Figure 10, between the about 100 μ m of about 10 μ m-, the gradient of the accumulation pore volume distribution curve in embodiment's 1 sample tilts very much, the gradient of the accumulation pore volume distribution curve of embodiment's 2 samples also tilts very much, but the gradient of the accumulation pore volume distribution curve of sample is then milder in the reference example 1.
With described identical, obtain the porosity, the average pore size of each sample and the maximum value of accumulating the gradient Sn of pore volume distribution curve.In addition, originally can try to achieve smoothed curve, and can obtain the gradient Sn of accumulation pore volume distribution curve according to the difference of slight gap place accumulation pore volume identical on its curve with fine pore according to the chart of determination data.But from as shown in Figure 10, because curve is very level and smooth, and in fact the logarithm of the fine pore that relates to of measuring point have uniformly-spaced, therefore, even if utilize the fine pore data of n measuring point and (n-1) individual measuring point to ask for gradient Sn, also almost do not have error.Its gained result is referring to table 1.In addition, the relation between the gradient Sn of the fine pore of each honeycomb molded body median septum and accumulation pore volume distribution curve as shown in Figure 6.
As Fig. 2 (a), (b) shown in, seal the two ends runner opening portion of each honeycomb molded body by adopting sealing material 12a, 12b, can obtain porous cordierite honeycomb filter 11.The pressure drop of various each filter 11 of expression and the evaluation result of breakage resistance in table 1.
On the pressure drop test stand, measure pressure drop by making gasometry flow into honeycomb filter, and evaluate with following standard.
Zero: pressure drop is (qualified) below the admissible value of practicality.
*: pressure drop surpasses practical admissible value (defective).
About breakage resistance, the A axial compression that the specification M505-87 that can draft according to civic organization's automotive engineering " exhausted gases purification catalyzer with the test method of ceramic integral (セ ラ ミ Star Network モ ノ リ ス) carrier " measures each filter intensity that contracts is by the contract relative value (with the horizontal index of existing product as 1.0) of intensity of following standard rating A axial compression.
◎: the A axial compression intensity that contracts is (qualified) more than 2.0.
Zero: the A axial compression strength deficiency 2.0 that contracts, (qualified) more than 1.5.
*: the A axial compression strength deficiency 1.5 (defective) that contracts.
Based on pressure drop and breakage resistance, carry out overall merit by following standard.
◎: pressure drop is o, when breakage resistance is ◎.
Zero: pressure drop and breakage resistance are at 1 o'clock.
*: there is one to be when defective in pressure drop and the breakage resistance.
Table 1
Annotate: the gradient of (1) accumulation pore volume distribution curve
As shown in Table 1, in embodiment 1 and 2, because of the maximum value of Sn more than 0.7, so even the porosity surpasses 60%, average pore size is 15-25 μ m, the pressure drop of filter is also less, it is qualified that breakage resistant luer also belongs to, overall merit is respectively ◎ and zero.
In addition, because the ceramic honeycomb filter of reference example 1, the maximum value less than 0.7 of Sn, so though pressure drop is qualified, breakage resistance defective (*), overall merit is *.
Embodiment 3-7
Make the plasticization quantitative mixture identical, and press the extrusion molding method, make the cylindrical shape honeycomb molded body by quantitative mixture with embodiment 1.For obtaining various next doors thickness and every 1cm
2Runner quantity, adjusted the size of forming die.With 1350-1440 ℃ of each formed body of temperature sintering, make the cordierite honeycomb molded body of the embodiment 3-7 with various porous matter next doors and through hole.The diameter of each honeycomb molded body be 143mm, length be 152mm, and next door thickness be 0.15-0.33mm, every 1cm
2Runner quantity be 39-62.In addition, the porosity of each honeycomb molded body is 65%, and average pore size is 20.8%, and the maximum value of the gradient Sn of accumulation pore volume distribution curve is 1.12.
Adopt the two ends of the method sealing filter identical, making cordierite honeycomb filter with embodiment 1.Similarly to Example 1, the pressure drop and the breakage resistance of each filter have been measured.The results are shown in Table 2.As shown in Table 2, the overall merit of the cordierite honeycomb filter of embodiment 3-7 is ◎ and zero.
Table 2
Embodiment 8 and embodiment 9, reference example 2
As the stupalith of surface area at high proportion, be that active oxidation aluminium powder and the oxidation aluminium glue of 5 μ m sneaked in the water with medium particle diameter, obtain activating aluminum paste.With embodiment 1 and 2 and reference example 1 identical, this powder slurry is coated on the ceramic honeycomb structure.After removing unnecessary powder slurry, coating repeatedly, the activation aluminium of 60g/L is coated on the honeycomb molded body the most at last.With 120 ℃ of oven dry honeycomb molded bodies, then with 800 ℃ of sintering.In addition, again honeycomb molded body is immersed in the platinum chloride hydrogen-oxygen solution, carry out drying with 120 ℃ after, with 800 ℃ of sintering.Make the ceramic honeycomb filter that has about 2g/L platinum catalyst thus.
Adopt the method mensuration identical to have the pressure drop of the ceramic honeycomb filter of platinum catalyst with embodiment 1.Have the pressure drop of the ceramic honeycomb filter of platinum catalyst according to embodiment's 1 identical standard rating.In addition, on the pressure drop test stand, make the quantitative gas of carbonaceous powder flow through honeycomb filter, make filter collect carbon dust.Measure carbon dust and collect the pressure drop of front and back, ask for pressure drop difference Δ P (pressure drop before the pressure drop carbon dust after carbon dust is collected is collected), and adopt following standard to evaluate.It the results are shown in Table shown in 3.
O: pressure drop is (qualified) below the admissible value of practicality.
*: pressure drop surpasses practical admissible value (defective).
Table 3
| Example NO | Have the pressure drop of catalyzer | Pressure drop difference Δ P |
| Embodiment 8 | ○ | ○ |
| Embodiment 9 | ○ | ○ |
| Reference example 2 | × | × |
Embodiment 8 and embodiment's 9 ceramic honeycomb filter pressure drop is not risen to some extent because of having catalyzer, and the evaluation that has catalyst pressure drop is qualified (zero).On the other hand, the ceramic honeycomb filter pressure drop of reference example 2 is significantly risen because of having catalyzer, so the evaluation of pressure drop is defective (*).
Embodiment 8 and embodiment's 9 ceramic honeycomb filter, the pressure drop difference Δ P before and after its carbon dust is collected belongs to qualified (zero) in the allowed band of practicality.And the pressure drop difference Δ P of the carbon dust of reference example 2 before and after collecting exceeds practical allowed band and belongs to defective (*).
By as can be known described, the gradient Sn maximum value of accumulation pore volume distribution curve is in the ceramic honeycomb filter more than 0.7 (embodiment 8 and embodiment 9), even after having catalyzer, the pressure drop ascensional range is also less, and because the pressure drop ascensional range is also less when collecting by carbon dust, so filter capability is good.
Implement 10-14, reference example 3-7
To have with the material powder of the steinheilite of embodiment's 1 identical composition and mix, after adopting the extrusion molding method to make formed honeycomb structure, with 1400 ℃ of temperature sintering, making external diameter is that 267mm, length are that 305mm, next door thickness are that 0.3mm, next door spacing are that 1.47mm, periphery wall thickness are the honeycomb molded body of the steinheilite manufacturing of 1.5mm.
For when alternately sealing cordierite honeycomb structure runner end, in order to seal near the two ends of the runner outer wall, the sealing powder slurry of being made by the steinheilite raw material should be filled into after the runner end of cordierite honeycomb structure, dry and sintering, make the cordierite honeycomb filter of total length 305mm.For regulating the scope (to represent to radius centered direction length from periphery wall) that the length that begins near the filter end face of the sealed at both ends material of the runner sealing periphery wall and sealing both ends runner exist, and adjusted the filling condition of sealing powder slurry in the end.
Make the cordierite honeycomb filter of the waste gas of the diesel engine that contains particulate by gained, behind the collection particulate, combustion particle makes filter regeneration.The measurement result of regeneration rate and pressure drop is shown in Table 4.In the table 4, the relative length of sealed at both ends runner is [(length that begins near the filter end face of the sealed at both ends material of the runner sealing periphery wall)/(filter total length)] x 100.In addition, on the so-called end face scope of sealed at both ends runner to represent that to the length of radius centered direction there is scope in the sealing both ends runner from outer wall.
Regeneration rate is [(particulate loading of the collection-residual particulate loading in regeneration back)/(collected particulate loading)] x100 (%).Adopt following standard rating regeneration rate.
◎: regeneration rate is 90% when above (qualified).
Zero: regeneration rate is 80% when above (qualified).
*: during regeneration rate less than 80% (defective).
Use 7.5Nm
3The flow eudiometry pressure drop of/min, and by following standard it is evaluated.
◎: pressure drop is (qualified) when 200mmAq is following.
Zero: when pressure drop is 200mmAq-250mmAq (qualified).
*: when pressure drop exceeds 250mmAq (defective).
Overall merit is undertaken by following standard.
◎: when regeneration rate and pressure drop are ◎.
Zero: regeneration rate and pressure drop are when qualified.
*: even have one in regeneration rate and the pressure drop just when defective.
As shown in Table 4, in embodiment 10-14, the length that begins near the filter end face of the sealed at both ends material of the runner sealing periphery wall is at below 8.2% of filter total length, because runner is from the periphery wall to the center near the outer wall of sealing both ends, in the scope of maximum 5x next door spacing, so regeneration rate and pressure drop be zero or ◎ qualified, Comprehensive Assessment is also all qualified.Particularly among the embodiment 13, because the length that begins near the filter end face of the sealed at both ends material of the runner sealing periphery wall is in the condition of filter total length below 3.3%, and the scope necessary condition of the maximum 3x next door spacing of runner from the outer wall to the center all is met near the outer wall of sealing both ends, so regeneration rate, pressure drop and Comprehensive Assessment are ◎.
In reference example 3-7, the length that begins near the filter end face of the sealed at both ends material of the runner sealing periphery wall surpasses 8.2% of filter total length, so during particle burning, disperse more by the sealing material ignition heat, regeneration rate defective (*), overall merit also be *.
Particularly in reference example 6, near the periphery wall of sealing both ends runner from outer wall outside the scope of maximum 5x next door, center spacing.Therefore, though the runner effect of heat insulation at two ends is bigger near the sealing outer wall, regeneration rate is ◎, has reduced the runner quantity that plays filtering function in fact, thus pressure drop defective (*), Comprehensive Assessment also defective (*).
In the filter of reference example 7, owing near outer wall, there is not the runner of sealing both ends, do not play effect of heat insulation by periphery wall, thus regeneration rate defective (*), Comprehensive Assessment also defective (*).
Embodiment 15,16
Adopt the method identical with embodiment 10, the material powder of mixing steinheilite is made honeycomb molded body with the extrusion molding method.Behind the regulation runner of sealing honeycomb molded body two end part,, make the cordierite honeycomb formed bodies with 1400 ℃ of temperature sintering.At the outer circumferential face of removing the sintering body at edge by machining, the steinheilite congeries (Mean particle diameter 15 μ m) that is coated with 100 Quality Mgmt Dept reaches the powder slurry that adds Bond and water gained in the colloidal silica of 10 Quality Mgmt Dept, forms periphery wall., periphery wall dried and sintering, make the cordierite honeycomb filter of following size thereafter.
External diameter: 267mm;
Total length: 305mm;
Next door thickness: 0.3mm;
Next door spacing: 1.47mm; And
Periphery wall thickness: 1.5mm.
According to the method identical, evaluate the regeneration rate and the pressure drop of each honeycomb filter with embodiment 4.The results are shown in Table shown in 4.In any embodiment of embodiment 15 and 16, the length that begins near the filter end face of the sealed at both ends material of the runner sealing periphery wall is in the condition of filter total length 8.2% below, and near the range of condition of the maximum 5x next door spacing of runner from the outer wall to the center of the periphery wall of sealing both ends all is met.As a result, regeneration rate, the pressure drop of embodiment 15 and 16 filter all be zero or ◎ qualified, overall merit is also all qualified.
Table 4
Annotate: Pp is the next door spacing.
Sealing material
Fig. 7 represents other example of ceramic honeycomb filter of the present invention.Fig. 8 is the A-A sectional drawing of Fig. 7.Dotted line 30 expressions are from the radial direction length range of outer wall 11a to central direction 2x next door spacing, and the two ends that are present in the runner in the scope between dotted line 30 and the periphery wall 11a are sealed.As near outer wall 11a, have the example of the filter 11 of sealing both ends runner, except that example shown in Fig. 7 and 8, Fig. 9 (a)-(d) has exemplified other example.
Though the invention has been described with reference to accompanying drawing, the section shape of ceramic honeycomb tectosome is not limited to circle, also can adopt ellipse to wait other shape.
Make in the body at ceramic honeycomb knot of the present invention, because the gradient Sn maximum value of next door pore accumulation pore volume distribution curve is more than 0.7, even therefore adopt the macro porosity of 60-75%, and the big average pore size ratio of 15-25 μ m, when using, also can satisfy the reciprocal property of so-called low pressure loss and high collecting efficiency as diesel particulate filter.And mechanical fasteners power when thermal stress that produces during use and thermal shock stress, assembling and the mechanical stress that produces because of vibration can not damaged ceramic honeycomb filter of the present invention, and have favorable durability.In addition, the possible time of ceramic honeycomb filter collection particulate of the present invention is longer, can high efficiency remove particulate during filter regeneration.
Claims (7)
1, a kind of ceramic honeycomb filter, it is made of the ceramic honeycomb tectosome with porous matter next door of dividing many runners, utilize the particulate of waste gas by containing in the described porous matter next door filtering waste gas, it is characterized in that, the main component of the crystallizing layer of described ceramic honeycomb filter is a steinheilite, mullite, alumina, silicon nitride, silicon carbide, aluminium nitride, the lithium alumina silicate, aluminium titanates or zirconium oxide, seal the end of regulation runner in the described runner, and near the runner the periphery wall seals with sealing material at two end part, the length that described sealing material begins from the filter end face is at below 8.2% of filter total length, and the described runner of sealing both ends be present in from outside in the radial direction length range of maximum 5x next door, thoughtful center spacing.
2, ceramic honeycomb filter according to claim 1 is characterized in that, the length that begins from the end face of the sealing material that seals near the runner the described periphery wall at two end part is at below 3.3% of ceramic honeycomb filter length overall.
3, ceramic honeycomb filter according to claim 1, it is characterized in that, near the runner the sealed periphery wall in described two ends be from the periphery wall of honeycomb filter end face towards the center of honeycomb filter end face, be present in the runner of the length range of maximum 3x next door spacing.
According to any one described ceramic honeycomb filter of claim 1 to 3, it is characterized in that 4, the periphery wall of described ceramic honeycomb filter is by the steinheilite particle and the colloidal silica that exists betwixt constitutes.
5, a kind of manufacture method of ceramic honeycomb filter, its can plasticization pottery quantitatively the mixture extrusion molding be cellular and fire, and become ceramic honeycomb structure, and the two end part of the runner of described ceramic honeycomb structure are alternately sealed, it is characterized in that, the main component of the crystallizing layer of described ceramic honeycomb filter is a steinheilite, mullite, alumina, silicon nitride, silicon carbide, aluminium nitride, the lithium alumina silicate, aluminium titanates or zirconium oxide, and from outside circumferential center, the two end part of the runner of existence seal from the length below 8.2% of filter end face with the filter total length in the scope of the radial direction length of maximum 5 * next door spacing.
6, the manufacture method of ceramic honeycomb filter according to claim 5 is characterized in that, seals from the length below 3.3% of filter end face with the filter total length.
7, the manufacture method of ceramic honeycomb filter according to claim 5 is characterized in that, from outside circumferential center, the two end part of the runner of existence seal in the scope of the radial direction length of maximum 3 * next door spacing.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001278691 | 2001-09-13 | ||
| JP278691/01 | 2001-09-13 | ||
| JP307098/01 | 2001-10-03 | ||
| JP331421/01 | 2001-10-29 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB021545553A Division CN1272529C (en) | 2001-09-13 | 2002-09-13 | Honeycomb ceramic filter |
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| CN1900493A CN1900493A (en) | 2007-01-24 |
| CN100523446C true CN100523446C (en) | 2009-08-05 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2006101054269A Expired - Fee Related CN100458109C (en) | 2001-09-13 | 2002-09-13 | Ceramic honeycomb filter |
| CNB2006101054254A Expired - Fee Related CN100523446C (en) | 2001-09-13 | 2002-09-13 | Ceramic honeycomb filter |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2006101054269A Expired - Fee Related CN100458109C (en) | 2001-09-13 | 2002-09-13 | Ceramic honeycomb filter |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2009017642A1 (en) * | 2007-07-31 | 2009-02-05 | Corning Incorporated | Compositions for applying to ceramic honeycomb bodies |
| KR101770660B1 (en) | 2009-09-04 | 2017-08-23 | 히타치 긴조쿠 가부시키가이샤 | Ceramic honeycomb structure and its production method |
| US9649587B2 (en) * | 2013-09-24 | 2017-05-16 | Hitachi Metals, Ltd. | Ceramic honeycomb structure and its production method |
| KR102441764B1 (en) * | 2015-03-24 | 2022-09-07 | 히타치 긴조쿠 가부시키가이샤 | Ceramic Honeycomb Structure |
| JP7097327B2 (en) * | 2019-04-26 | 2022-07-07 | 株式会社Soken | Exhaust gas purification filter |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61136412A (en) * | 1984-12-07 | 1986-06-24 | Matsushita Electric Ind Co Ltd | Exhaust gas filter |
| JPH0669534B2 (en) * | 1987-02-12 | 1994-09-07 | 日本碍子株式会社 | Cordierite honeycomb structure |
| JP2578176B2 (en) * | 1988-08-12 | 1997-02-05 | 日本碍子株式会社 | Porous ceramic honeycomb filter and method for producing the same |
| US5223318A (en) * | 1990-08-06 | 1993-06-29 | Corning Incorporated | Titania substrates and fabrication |
| EP0677498A3 (en) * | 1994-04-12 | 1996-09-04 | Corning Inc | Method of plugging selected open ends of a ceramic honeycomb structure. |
| JPH1099626A (en) * | 1996-09-30 | 1998-04-21 | Ibiden Co Ltd | Honeycomb filter and its manufacture |
| US6261982B1 (en) * | 1998-11-12 | 2001-07-17 | Asahi Glass Company Ltd. | Cordierite ceramic filter |
-
2002
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| CN100458109C (en) | 2009-02-04 |
| CN1900493A (en) | 2007-01-24 |
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