What are domestic and economic sewage?
Household, home, single -family pumping stations, or how else he would call them, however, pumping stations with a small amount of pressed sewage and a small frequency of switching on. An example of a family of four generates from 500 to 600 liters of sewage per day (according to 150 l/person per day). We include water from washing, washing, bathing and toilets. Various biological and chemical content, but still a very high level of hydration. Lack of severe chemistry and low fat content of e.g. washing dishes and pots after meals. Some liquids for dishes, soap, washing powder, shampoos or shower gels, sometimes some cleaning agents for the kitchen, bathrooms, toilet bowls or light cosmetic chemistry. This is the sewage from houses, commonly known as living and economic. At the same time, we divide them into gray water, flowing from all washbasins, bidet and showers, and into black water containing solid fractions with faeces.
Type of pumps for home pumping stations
Assuming that only the content of our digestive system plus toilet paper goes to the toilets, it is a highly hydrated and soft material with which no sewage pump, regardless of type and type, should have the slightest problem. So why is it different and we use so many types of pumps?
We divide the pumps for home pumping stations into two main groups: with and without a crushing system. We divide each of these groups into smaller target subgroups. And so, the pumps without crushers with the so -called free flight are basically divided into the range of solid particles, which can fly under the rotor without clogging it. E.g. 10, 20, 30, 40 and 50 mm or intermediate values of the type 25mm, 35mm, etc. Here the matter is simple, the greater the free flight, the greater the fraction may be embossed and the less chance of clogging and damage to the pump. Pumps with a crushing system can divide into types of cutting and melting systems and due to the structure of the hydraulic system: centrifugal and displacement rotor.
Advantages of pumps with a free flight and VORTEX type rotor
Free ball flight with a diameter of "x" is a very popular hydraulic system in network and municipal pumping stations, why it is so reluctant to be used in home pumping stations. This is due to the need to use larger diameters of the discharge pipelines, usually a minimum of 50 mm inside, i.e. PE63 pipes. The larger diameter of the discharge pipe is a larger volume of sewage in the pipeline and with a constant volume of sewage slower transport to the sewage treatment plant, but the larger diameter of the pipe is also a greater cost of the investment. The advantage, however, is the greater bandwidth of the pipe and faster pumping more sewage, lower pressing resistance and a much lower risk of clogging. With short discharge pipelines, it is definitely better to use pumps with a free flight.
Advantages of pumps with a shredder
The grinder, cutting knife, disk, cutter or cutting rotor are just some of the names of many types of fancy crushing systems. All of them are designed to cut or torn solid fractions and thicker sewage content, so that they can crush them with narrow pipelines. The advantages are obvious, narrow pipelines are a small volume in pipes, low investment cost, and crushed sewage fractions do not clog the infrastructure. Also, pumps with shredders, thanks to their small channels in the hydraulic system of the pump, produce much larger pressure than pumps with free flights, and thus allow you to press with long, narrow pipelines over long distances, overcoming great resistance on the pipeline and significant exceeds in the field.
Disadvantages of pumps with VORTEX rotors
As I mentioned earlier, a large flight under the rotor is high pressure losses produced by the pump. Therefore, the lifting height must be compensated by increased pump power. The cost of the investment is higher due to the larger infrastructure diameters (pipes, valves, valves, connections), especially at long distances. When geometric (level difference in the field) and the pipeline resistance (losses resulting from the friction of sewage with a pipeline) exceeding a total of 20 m, the use of free flights in home pumping stations lose its sense economically, because it would require the purchase and use of larger power and more expensive pumps, which time Working a day would be counted in one minutes.
Disadvantages of shredding pumps
If the sewage contained only gray and black water with faeces and toilet paper, which is soluble in water, the crushing system would not be needed at all, and the rotor itself would easily cope with mint of sewage - the exception are, for example, fanatics of eating cherry with seeds in whole. Unfortunately, the carefree users of toilet and all sewage drains mean that advanced cutting systems and grinding permanent bodies carried with sewage are necessary. Even the best, the most sophisticated and most expensive in the performance and purchase of crushing systems lose the fight against human thoughtlessness. According to producers, knives, disks, cutters, etc. They cut almost everything: rags, gloves, mops, films, pieces of wires, shoes, sticks, sometimes even beer cans and plastic packaging. So what's the problem? Well, that sewage contain a lot of sand, gravel, sometimes pebbles, wires and other garbage that should not be in sewage. At a cut speed of several to tens of thousands of cuts per minute, it is quickly concentrated and cutting sharp cutting edges. As a result, rags and strings begin to wrap on knives or a rotor, wires and sticks clog the input and, as a result, the pump stops, the engine warms and burns the insulation of engine windings as a result of overheating. Renovation in most cases is then unprofitable, and the cost of replacement with a new one is lower than the cost of renovation, so we generate another costly electro -sovertice.
Use this shredder or not?
As an engineer designing pump systems for over seventeen years, I would like to say unequivocally - not to use. Unfortunately, it is not that simple. Each system has its pros and cons, which I will try to sum up:
| Pumps with a shredder | Pumps with a free flight |
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In my opinion, wherever I can use I would use pumps with a free flight, because the operating costs of shredders may exceed investment costs in the future. We will not gain anything at low pump power if it works for a long time because it is clogged or has low performance. For single -family households, where there is one owner and a small number of random users, I would allow the use of a shredder, because in the case of clogging it is not difficult to find guilty and social losses are small. In cases of collective investments, several houses, tenement houses or housing estates, the use of shredders should only be forced by terrain and distance from the treatment plant. And the used shredder should be made of high quality alloys, e.g. chrome cast iron or hardened stainless steel, the use of cheap cast iron crusters or cutting rotors is a simple way to trouble.