JPH0812132B2 - Sludge sampling method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sludge sampling method used for automatic moisture measurement of dehydrated sludge in a sewage treatment plant or the like.

(Prior art) When measuring the water content of dehydrated sludge, manually sample the sludge from the conveyor line, put it in a tabletop water content measuring device such as an infrared moisture meter, and dry it. It is common practice to measure the reduction. For this reason, a method of automatically sampling sludge from the conveyor line has heretofore been unknown. However, recently, in order to automate the sludge dewatering process, there is an increasing demand for detecting the water content of the sludge online and controlling the preceding and subsequent processes so that the operating conditions are optimal.

As described above, in order to control the front and rear processes online, it is required that the accuracy of the moisture measurement value be on the order of% or less, and the error at the time of sampling must be minimized in addition to the measurement technique. For example, a sludge transfer conveyor is generally washed with water in a belt cycle, and in most cases, water adheres to the belt surface. As one of the means for reducing the influence of the attached moisture, it is possible to carry out sampling at a position where a large amount of sludge is loaded. Therefore, an apparatus for sampling sludge from the central portion of the conveyor by a sampling head provided at the tip of the swing arm has begun to be commercially available from some companies. However, since this device has a structure that always samples the sludge in the central part of the conveyor, if the sludge loading state is deviated from the center of the belt, it is not possible to sample a sufficient amount, and the conveyor If there is a water distribution of sludge in the width direction of the sludge, there was a problem that the sampling as a representative water sample of the whole sludge could not be performed.

(Problems to be Solved by the Invention) The present invention solves the conventional problems as described above, and when the sludge loading state is deviated from the center of the belt, or the water content of the sludge is unevenly distributed in the width direction. Even if you are
It was completed for the purpose of a sludge sampling method that can always perform accurate sampling.

(Means for Solving the Problems) The present invention made to solve the above problems is to install a guide rail extending in the width direction above a conveyor that conveys dewatered sludge, and to move on the guide rail. A hollow cylindrical sampling head is attached to the lower surface of the table, and the sampling head is quickly lowered toward the dehydrated sludge at a plurality of sampling positions in the width direction of the conveyor, and the dehydrated sludge at each sampling position is sequentially tamped inside. It is characterized in that it is collected in a closed state.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example. (1) is a belt type conveyor that conveys dewatered sludge, and the conveyor (1) is located above the conveyor (1). Thus, the guide rail (2) extending in the width direction of the conveyor (1) is installed. (3) is a platform that can move on the guide rail (2), and can perform sampling while gradually moving from one end to the other end of the conveyor (1) according to a preset program. However, in addition to this, it is also possible to detect the position of the dehydrated sludge on the conveyor (1) by a sensor and move the table (3) to an appropriate position. On the lower surface of this stand (3), a sampling head (6) which can be quickly moved up and down by a cylinder (4) and a guide rod (5).
Is installed. The sampling head (6) is provided with a hollow cylindrical body having an open lower surface at its tip, and the sampling head (6) is provided from the upper surface of the dehydrated sludge on the conveyor (1) to a position close to the belt surface. By lowering it, the dehydrated sludge can be collected in a state of being tamped inside. However, in order to prevent the conveyor (1) from being damaged, its lowest position is slightly above the belt surface so as to avoid direct contact. In addition, (7) is a moisture measuring device main body having a function of controlling the entire operation.

To sample dewatered sludge with the above device,
While the platform (3) is intermittently moved along the guide rail (2) extending in the width direction of the conveyor (1), the platform (3) is stopped at a plurality of sampling positions in the width direction of the conveyor (1), and the cylinders are provided at the respective stop positions. By (4), the sampling head (6) is quickly lowered to a position close to the belt surface, and the dehydrated sludge is tamped inside the hollow cylindrical sampling head (6) for sampling. At this time, the stop position of the table (3) can be freely determined by the program set in the main body of the moisture measuring device (7), and is detected by the sludge sensor attached to the table (3) as described above. The proper position can be set depending on the sludge load distribution. For example, in FIG. 2, eight sampling positions are shown by double circles, and thus dehydrated sludge can be sampled from many points. The sampled dehydrated sludge sequentially becomes clogged inside the hollow cylindrical sampling head (6), and then the sampling head (6) moves up by the action of the cylinder (4) and moves to the right to move to the moisture measuring instrument. Dewatered sludge is taken out at the take-out part of the main body (7). Various modifications can be made to the elevating mechanism and the like of the sampling head (6).

(Effects of the Invention) As described above, the present invention performs sampling of dehydrated sludge at a plurality of sampling positions in the width direction of the conveyor, and sequentially projects the dehydrated sludge at each sampling position into the hollow cylindrical sampling head. Since it can be collected in a solidified state, unlike the conventional one where the sample was collected from a fixed position on the conveyor,
Even when the sludge loading state is biased from the sensor or when the water content of the sludge is unbalanced in the width direction, a sample representing the entire sludge can be correctly sampled. Therefore, according to the present invention, the water content of the dehydrated sludge can be accurately measured, and there is an advantage that the control in the post-process becomes easy. Therefore, the present invention is extremely large in that it contributes to the industrial development as a sludge sampling method that eliminates the conventional problems.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, and FIG. 2 is a plan view thereof. (1): conveyor, (2): guide rail, (3):
Table, (6): Sampling head

Claims (1)

[Claims] 1. A guide rail extending in the width direction is installed above a conveyor that conveys dewatered sludge, and a hollow cylindrical sampling head is attached to the lower surface of a table that moves on the guide rail. A sludge sampling method characterized in that a plurality of sampling positions in the width direction of a conveyor are quickly lowered toward the dehydrated sludge, and the dehydrated sludge at each sampling position is sequentially compacted inside and collected.