representusp32 616 BULK DENSITY AND TAPPED DENSITY 堆密度和振实密度 ——中英对照

616

BULK DENSITY AND TAPPED DENSITY

松密度和紧密度

The bulk density of a solid is often very difficult to measure since the slightest

disturbance of the bed may result in a new bulk density. Moreover, it is clear

that the bulking properties of a powder are dependent on the “history” of the

powder (e.g., how it was handled), and that it can be packed to have a range of

bulk densities. Thus, it is essential in reporting bulk density to specify how the

determination was made.

固体的松密度的测量很困难，测量时，轻微的震动就会导致松 密度的不同。

因此，

可以知道

粉末的松 散性取决于粉末的来历。

而且压紧之后，

会有一个密度范围。< /p>

因此，

报告松密度时，

必须说明结果是如 何得到的。

Because the interparticulate interactions that influence the bulking properties

of a powder are also the interactions that interfere with powder flow, a

comparison of the bulk and tapped densities can give a measure of the relative

importance of these interactions in a given powder. Such a comparison is often

used as an index of the ability of the powder to flow. The bulk density often is

the bulk density of the powder “as poured” or as passively filled into a

measuring vessel. The tapped density is a limiting density attained after

“tapping down,” usually in a device that l

ifts and drops a volumetric measuring

cylinder containing the powder a fixed distance.

微粒的相互作用不仅影响粉末的 松散性，

而且影响粉末的流速。

粉末的松密度和紧密度的比

较，

可以看出微粒的相互作用的相对重要性的量度标准。

力的一个指标。

粉末的松密度的测量就是直接将粉末倾入一个量器。

紧密度是被叩后的极限

密度，通常使用一个设备，将一个装有固定高度粉末的量筒举起，落下。

BULK DENSITY

Bulk density is determined by measuring the volume of a known mass of

powder sample that has been passed through a screen into a graduated

cylinder (

Method I

) or through a volume-measuring apparatus into a cup

(

Method II

).

松密度的测量是将已知质量的样品的粉末过筛进入一 个量筒

（方法Ⅰ）

或通过一个体积测量

器进入一个容器（方法Ⅱ）

。

Method I

—

Measurement in a Graduated Cylinder

方法Ⅰ

:

用量筒测量

Procedure

—

Unless otherwise specified, pass a quantity of material sufficient

to complete the test through a 1.00-mm (No. 18) screen to break up

agglomerates that may have formed during storage. Into a dry 250-mL cylinder

introduce, without compacting, approximately 100 g of test sample,

M

,

weighed with 0.1% accuracy. If it is not possible to use 100 g, the amount of

the test sample and the volume of the cylinder may be modified and the test

conditions specified with the results. Select a sample mass having an

untapped apparent volume of 150 to 250 mL. A 100-mL cylinder is used for

apparent volumes between 50 mL and 100 mL. Carefully level the powder

without compacting, if necessary, and read the unsettled apparent volume,

V

o

,

to the nearest graduated unit. Calculate the bulk density, in g per mL

1

, by the

formula:

步骤： 除非有特殊说明，先将足够量的样品过筛（

1.00-mm

编 号

18

）去除存储时可能形

成的大块。 称取约

100g

（精确至

0.1%

）的样品置

250-mL

的量筒，不要压实 。如果不

可能用

100g

样品，

样品量和量筒大小可以改变。

报告结果时说明测试条件。

样品的质量的

选择为不叩实外观体积为

150

至

250mL.

一个

100-mL

的量筒可用于的外观体积为

50mL

和

100mL

之间。小心地夷平样品粉末不要压实， 如果需要，读取未处理的外观上的体积，

V0

至最接近的刻度。 计算松密度，

g/mL ,

用下列公式：

(

M

) / (

V

o

).

Generally replicate determinations are desirable for the determination of this

property.

一般需重复测量。

Method II

—

Measurement in a Volumeter

方法Ⅱ：用体积计测量

The apparatus (

Fig. 1

),

装置如图一：

Fig. 1. Scott Volumeter.

conforming to the dimensions in ASTM B 329-90 (Scott Volumeter)

2

, consists

of a top funnel fitted with a 1.00-mm (No. 18) screen or the screen opening

specified in the individual monograph. The funnel is mounted over a baffle box

containing four glass baffle plates over which the powder slides and bounces

as it passes. At the bottom of the baffle box is a funnel that collects the powder

and allows it to pour into a cup of specified capacity mounted directly below it.

The cup may be cylindrical (25.00 ±

0.05 mL volume with an inside diameter of

30.00 ±

2.00 mm) or a square (16.39 ±

0.05 mL volume with inside dimensions

of 25.4 ±

0.076 mm).

符合美国材料实验协会

B 329-90

的尺寸（斯科特体积计）

，顶部有一个漏斗，上面放一个

合适 的

1.00mm

的筛子（除非有特殊说明，编号

18

）

,

漏斗装在一个由

4

个玻璃挡板组成

的导料槽上，粉末顺着玻 璃挡板滑行和反跳。在导料槽的底部是一个用来聚拢粉末的漏斗，

在漏斗的正下方放置一 个指定容量的样品收集容器。此容器可以是圆柱的（体积

25.00±

< br>0.05mL

，内径

30.00±

2.00mm

）或正方的（体积

16.39±

0.05mL

，内径

25.4±

0.076mm

）

.

Procedure

—

Allow an excess of powder to flow through the apparatus into the

sample receiving cup until it overflows, using a minimum of 25 cm

3

of powder

with the square cup and 35 cm

3

of powder with the cylindrical cup. Carefully

scrape excess powder from the top of the cup by smoothly moving the edge of

the blade of a spatula perpendicular to and in contact with the top surface of

the cup, taking care to keep the spatula perpendicular to prevent packing or

removal of powder from the cup. Remove any material from the sides of the

cup, and determine the weight,

M,

of the powder to the nearest 0.1%.

Calculate the bulk density, in g per mL, by the formula:

步骤：将样品粉末倒入设备，直至样品收集容器的粉末溢出。用至少

25m3

的粉末洒在正

方形状的样品收集容器上或用至少< /p>

35m3

的粉末洒在圆柱状的样品收集容器上，垂直方向